* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2014 */
+/* Copyright (c) University of Cambridge 1995 - 2019 */
+/* Copyright (c) The Exim Maintainers 2020 - 2021 */
/* See the file NOTICE for conditions of use and distribution. */
/* Portions Copyright (c) The OpenSSL Project 1999 */
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
+#ifndef OPENSSL_NO_ECDH
+# include <openssl/ec.h>
+#endif
#ifndef DISABLE_OCSP
# include <openssl/ocsp.h>
#endif
-#ifdef EXPERIMENTAL_DANE
-# include <danessl.h>
+#ifdef SUPPORT_DANE
+# include "danessl.h"
#endif
#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
# define EXIM_HAVE_OPENSSL_TLSEXT
#endif
-#if OPENSSL_VERSION_NUMBER >= 0x010100000L
-# define EXIM_HAVE_OPENSSL_CHECKHOST
+#if OPENSSL_VERSION_NUMBER >= 0x00908000L
+# define EXIM_HAVE_RSA_GENKEY_EX
+#endif
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+# define EXIM_HAVE_OCSP_RESP_COUNT
+# define OPENSSL_AUTO_SHA256
+#else
+# define EXIM_HAVE_EPHEM_RSA_KEX
+# define EXIM_HAVE_RAND_PSEUDO
+#endif
+#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
+# define EXIM_HAVE_SHA256
#endif
-#if OPENSSL_VERSION_NUMBER >= 0x010000000L \
+
+/* X509_check_host provides sane certificate hostname checking, but was added
+to OpenSSL late, after other projects forked off the code-base. So in
+addition to guarding against the base version number, beware that LibreSSL
+does not (at this time) support this function.
+
+If LibreSSL gains a different API, perhaps via libtls, then we'll probably
+opt to disentangle and ask a LibreSSL user to provide glue for a third
+crypto provider for libtls instead of continuing to tie the OpenSSL glue
+into even twistier knots. If LibreSSL gains the same API, we can just
+change this guard and punt the issue for a while longer. */
+
+#ifndef LIBRESSL_VERSION_NUMBER
+# if OPENSSL_VERSION_NUMBER >= 0x010100000L
+# define EXIM_HAVE_OPENSSL_CHECKHOST
+# define EXIM_HAVE_OPENSSL_DH_BITS
+# define EXIM_HAVE_OPENSSL_TLS_METHOD
+# define EXIM_HAVE_OPENSSL_KEYLOG
+# define EXIM_HAVE_OPENSSL_CIPHER_GET_ID
+# define EXIM_HAVE_SESSION_TICKET
+# define EXIM_HAVE_OPESSL_TRACE
+# define EXIM_HAVE_OPESSL_GET0_SERIAL
+# ifndef DISABLE_OCSP
+# define EXIM_HAVE_OCSP
+# endif
+# define EXIM_HAVE_ALPN /* fail ret from hshake-cb is ignored by LibreSSL */
+# else
+# define EXIM_NEED_OPENSSL_INIT
+# endif
+# if OPENSSL_VERSION_NUMBER >= 0x010000000L \
&& (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L
-# define EXIM_HAVE_OPENSSL_CHECKHOST
+# define EXIM_HAVE_OPENSSL_CHECKHOST
+# endif
+#endif
+
+#if LIBRESSL_VERSION_NUMBER >= 0x3040000fL
+# define EXIM_HAVE_OPENSSL_CIPHER_GET_ID
+#endif
+
+#if !defined(LIBRESSL_VERSION_NUMBER) \
+ || LIBRESSL_VERSION_NUMBER >= 0x20010000L
+# if !defined(OPENSSL_NO_ECDH)
+# if OPENSSL_VERSION_NUMBER >= 0x0090800fL
+# define EXIM_HAVE_ECDH
+# endif
+# if OPENSSL_VERSION_NUMBER >= 0x10002000L
+# define EXIM_HAVE_OPENSSL_EC_NIST2NID
+# endif
+# endif
+#endif
+
+#ifndef LIBRESSL_VERSION_NUMBER
+# if OPENSSL_VERSION_NUMBER >= 0x010101000L
+# define OPENSSL_HAVE_KEYLOG_CB
+# define OPENSSL_HAVE_NUM_TICKETS
+# define EXIM_HAVE_OPENSSL_CIPHER_STD_NAME
+# else
+# define OPENSSL_BAD_SRVR_OURCERT
+# endif
#endif
#if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP)
# define DISABLE_OCSP
#endif
+#ifndef DISABLE_TLS_RESUME
+# if OPENSSL_VERSION_NUMBER < 0x0101010L
+# error OpenSSL version too old for session-resumption
+# endif
+#endif
+
+#ifdef EXIM_HAVE_OPENSSL_CHECKHOST
+# include <openssl/x509v3.h>
+#endif
+
+#ifndef EXIM_HAVE_OPENSSL_CIPHER_STD_NAME
+# ifndef EXIM_HAVE_OPENSSL_CIPHER_GET_ID
+# define SSL_CIPHER_get_id(c) (c->id)
+# endif
+# ifndef MACRO_PREDEF
+# include "tls-cipher-stdname.c"
+# endif
+#endif
+
+/*************************************************
+* OpenSSL option parse *
+*************************************************/
+
+typedef struct exim_openssl_option {
+ uschar *name;
+ long value;
+} exim_openssl_option;
+/* We could use a macro to expand, but we need the ifdef and not all the
+options document which version they were introduced in. Policylet: include
+all options unless explicitly for DTLS, let the administrator choose which
+to apply.
+
+This list is current as of:
+ ==> 1.1.1c <==
+
+XXX could we autobuild this list, as with predefined-macros?
+Seems just parsing ssl.h for SSL_OP_.* would be enough (except to exclude DTLS).
+Also allow a numeric literal?
+*/
+static exim_openssl_option exim_openssl_options[] = {
+/* KEEP SORTED ALPHABETICALLY! */
+#ifdef SSL_OP_ALL
+ { US"all", (long) SSL_OP_ALL },
+#endif
+#ifdef SSL_OP_ALLOW_NO_DHE_KEX
+ { US"allow_no_dhe_kex", SSL_OP_ALLOW_NO_DHE_KEX },
+#endif
+#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
+ { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION },
+#endif
+#ifdef SSL_OP_CIPHER_SERVER_PREFERENCE
+ { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE },
+#endif
+#ifdef SSL_OP_CRYPTOPRO_TLSEXT_BUG
+ { US"cryptopro_tlsext_bug", SSL_OP_CRYPTOPRO_TLSEXT_BUG },
+#endif
+#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
+ { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS },
+#endif
+#ifdef SSL_OP_ENABLE_MIDDLEBOX_COMPAT
+ { US"enable_middlebox_compat", SSL_OP_ENABLE_MIDDLEBOX_COMPAT },
+#endif
+#ifdef SSL_OP_EPHEMERAL_RSA
+ { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA },
+#endif
+#ifdef SSL_OP_LEGACY_SERVER_CONNECT
+ { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT },
+#endif
+#ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
+ { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER },
+#endif
+#ifdef SSL_OP_MICROSOFT_SESS_ID_BUG
+ { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG },
+#endif
+#ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING
+ { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING },
+#endif
+#ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG
+ { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG },
+#endif
+#ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
+ { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG },
+#endif
+#ifdef SSL_OP_NO_ANTI_REPLAY
+ { US"no_anti_replay", SSL_OP_NO_ANTI_REPLAY },
+#endif
+#ifdef SSL_OP_NO_COMPRESSION
+ { US"no_compression", SSL_OP_NO_COMPRESSION },
+#endif
+#ifdef SSL_OP_NO_ENCRYPT_THEN_MAC
+ { US"no_encrypt_then_mac", SSL_OP_NO_ENCRYPT_THEN_MAC },
+#endif
+#ifdef SSL_OP_NO_RENEGOTIATION
+ { US"no_renegotiation", SSL_OP_NO_RENEGOTIATION },
+#endif
+#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
+ { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION },
+#endif
+#ifdef SSL_OP_NO_SSLv2
+ { US"no_sslv2", SSL_OP_NO_SSLv2 },
+#endif
+#ifdef SSL_OP_NO_SSLv3
+ { US"no_sslv3", SSL_OP_NO_SSLv3 },
+#endif
+#ifdef SSL_OP_NO_TICKET
+ { US"no_ticket", SSL_OP_NO_TICKET },
+#endif
+#ifdef SSL_OP_NO_TLSv1
+ { US"no_tlsv1", SSL_OP_NO_TLSv1 },
+#endif
+#ifdef SSL_OP_NO_TLSv1_1
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+# if SSL_OP_NO_TLSv1_1 == 0x00000400L
+ /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */
+# warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring
+# define NO_SSL_OP_NO_TLSv1_1
+# endif
+# endif
+# ifndef NO_SSL_OP_NO_TLSv1_1
+ { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 },
+# endif
+#endif
+#ifdef SSL_OP_NO_TLSv1_2
+ { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 },
+#endif
+#ifdef SSL_OP_NO_TLSv1_3
+ { US"no_tlsv1_3", SSL_OP_NO_TLSv1_3 },
+#endif
+#ifdef SSL_OP_PRIORITIZE_CHACHA
+ { US"prioritize_chacha", SSL_OP_PRIORITIZE_CHACHA },
+#endif
+#ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG
+ { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG },
+#endif
+#ifdef SSL_OP_SINGLE_DH_USE
+ { US"single_dh_use", SSL_OP_SINGLE_DH_USE },
+#endif
+#ifdef SSL_OP_SINGLE_ECDH_USE
+ { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE },
+#endif
+#ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG
+ { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG },
+#endif
+#ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
+ { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG },
+#endif
+#ifdef SSL_OP_TLS_BLOCK_PADDING_BUG
+ { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG },
+#endif
+#ifdef SSL_OP_TLS_D5_BUG
+ { US"tls_d5_bug", SSL_OP_TLS_D5_BUG },
+#endif
+#ifdef SSL_OP_TLS_ROLLBACK_BUG
+ { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG },
+#endif
+#ifdef SSL_OP_TLSEXT_PADDING
+ { US"tlsext_padding", SSL_OP_TLSEXT_PADDING },
+#endif
+};
+
+#ifndef MACRO_PREDEF
+static int exim_openssl_options_size = nelem(exim_openssl_options);
+static long init_options = 0;
+#endif
+
+#ifdef MACRO_PREDEF
+void
+options_tls(void)
+{
+uschar buf[64];
+
+for (struct exim_openssl_option * o = exim_openssl_options;
+ o < exim_openssl_options + nelem(exim_openssl_options); o++)
+ {
+ /* Trailing X is workaround for problem with _OPT_OPENSSL_NO_TLSV1
+ being a ".ifdef _OPT_OPENSSL_NO_TLSV1_3" match */
+
+ spf(buf, sizeof(buf), US"_OPT_OPENSSL_%T_X", o->name);
+ builtin_macro_create(buf);
+ }
+
+# ifndef DISABLE_TLS_RESUME
+builtin_macro_create_var(US"_RESUME_DECODE", RESUME_DECODE_STRING );
+# endif
+# ifdef SSL_OP_NO_TLSv1_3
+builtin_macro_create(US"_HAVE_TLS1_3");
+# endif
+# ifdef OPENSSL_BAD_SRVR_OURCERT
+builtin_macro_create(US"_TLS_BAD_MULTICERT_IN_OURCERT");
+# endif
+# ifdef EXIM_HAVE_OCSP
+builtin_macro_create(US"_HAVE_TLS_OCSP");
+builtin_macro_create(US"_HAVE_TLS_OCSP_LIST");
+# endif
+# ifdef EXIM_HAVE_ALPN
+builtin_macro_create(US"_HAVE_TLS_ALPN");
+# endif
+}
+#else
+
+/******************************************************************************/
+
/* Structure for collecting random data for seeding. */
typedef struct randstuff {
Simple case: client, `client_ctx`
As a client, we can be doing a callout or cut-through delivery while receiving
a message. So we have a client context, which should have options initialised
- from the SMTP Transport.
+ from the SMTP Transport. We may also concurrently want to make TLS connections
+ to utility daemons, so client-contexts are allocated and passed around in call
+ args rather than using a gobal.
Server:
There are two cases: with and without ServerNameIndication from the client.
configuration.
*/
-static SSL_CTX *client_ctx = NULL;
-static SSL_CTX *server_ctx = NULL;
-static SSL *client_ssl = NULL;
-static SSL *server_ssl = NULL;
+typedef struct {
+ SSL_CTX * ctx;
+ SSL * ssl;
+ gstring * corked;
+} exim_openssl_client_tls_ctx;
+
+
+/* static SSL_CTX *server_ctx = NULL; */
+/* static SSL *server_ssl = NULL; */
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
static SSL_CTX *server_sni = NULL;
#endif
+#ifdef EXIM_HAVE_ALPN
+static BOOL server_seen_alpn = FALSE;
+#endif
static char ssl_errstring[256];
-static int ssl_session_timeout = 200;
+static int ssl_session_timeout = 7200; /* Two hours */
static BOOL client_verify_optional = FALSE;
static BOOL server_verify_optional = FALSE;
static BOOL reexpand_tls_files_for_sni = FALSE;
-typedef struct tls_ext_ctx_cb {
- uschar *certificate;
- uschar *privatekey;
+typedef struct ocsp_resp {
+ struct ocsp_resp * next;
+ OCSP_RESPONSE * resp;
+} ocsp_resplist;
+
+typedef struct exim_openssl_state {
+ exim_tlslib_state lib_state;
+#define lib_ctx libdata0
+#define lib_ssl libdata1
+
+ tls_support * tlsp;
+ uschar * certificate;
+ uschar * privatekey;
+ BOOL is_server;
#ifndef DISABLE_OCSP
- BOOL is_server;
+ STACK_OF(X509) *verify_stack; /* chain for verifying the proof */
union {
struct {
uschar *file;
- uschar *file_expanded;
- OCSP_RESPONSE *response;
+ const uschar *file_expanded;
+ ocsp_resplist *olist;
} server;
struct {
X509_STORE *verify_store; /* non-null if status requested */
} client;
} u_ocsp;
#endif
- uschar *dhparam;
+ uschar * dhparam;
/* these are cached from first expand */
- uschar *server_cipher_list;
+ uschar * server_cipher_list;
/* only passed down to tls_error: */
- host_item *host;
-
-#ifdef EXPERIMENTAL_CERTNAMES
- uschar * verify_cert_hostnames;
+ host_item * host;
+ const uschar * verify_cert_hostnames;
+#ifndef DISABLE_EVENT
+ uschar * event_action;
#endif
-#ifdef EXPERIMENTAL_EVENT
- uschar * event_action;
-#endif
-} tls_ext_ctx_cb;
+} exim_openssl_state_st;
/* should figure out a cleanup of API to handle state preserved per
implementation, for various reasons, which can be void * in the APIs.
For now, we hack around it. */
-tls_ext_ctx_cb *client_static_cbinfo = NULL;
-tls_ext_ctx_cb *server_static_cbinfo = NULL;
+exim_openssl_state_st *client_static_state = NULL; /*XXX should not use static; multiple concurrent clients! */
+exim_openssl_state_st state_server = {.is_server = TRUE};
static int
-setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
- int (*cert_vfy_cb)(int, X509_STORE_CTX *) );
+setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host,
+ uschar ** errstr );
/* Callbacks */
-#ifdef EXIM_HAVE_OPENSSL_TLSEXT
-static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg);
-#endif
#ifndef DISABLE_OCSP
static int tls_server_stapling_cb(SSL *s, void *arg);
#endif
+
+/* Daemon-called, before every connection, key create/rotate */
+#ifndef DISABLE_TLS_RESUME
+static void tk_init(void);
+static int tls_exdata_idx = -1;
+#endif
+
+static void
+tls_per_lib_daemon_tick(void)
+{
+#ifndef DISABLE_TLS_RESUME
+tk_init();
+#endif
+}
+
+/* Called once at daemon startup */
+
+static void
+tls_per_lib_daemon_init(void)
+{
+tls_daemon_creds_reload();
+}
+
+
/*************************************************
* Handle TLS error *
*************************************************/
host NULL if setting up a server;
the connected host if setting up a client
msg error message or NULL if we should ask OpenSSL
+ errstr pointer to output error message
Returns: OK/DEFER/FAIL
*/
static int
-tls_error(uschar * prefix, const host_item * host, uschar * msg)
+tls_error(uschar * prefix, const host_item * host, uschar * msg, uschar ** errstr)
{
if (!msg)
{
- ERR_error_string(ERR_get_error(), ssl_errstring);
- msg = (uschar *)ssl_errstring;
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ msg = US ssl_errstring;
}
-if (host)
- {
- log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection (%s): %s",
- host->name, host->address, prefix, msg);
- return FAIL;
- }
-else
- {
- uschar *conn_info = smtp_get_connection_info();
- if (Ustrncmp(conn_info, US"SMTP ", 5) == 0)
- conn_info += 5;
- /* I'd like to get separated H= here, but too hard for now */
- log_write(0, LOG_MAIN, "TLS error on %s (%s): %s",
- conn_info, prefix, msg);
- return DEFER;
- }
+msg = string_sprintf("(%s): %s", prefix, msg);
+DEBUG(D_tls) debug_printf("TLS error '%s'\n", msg);
+if (errstr) *errstr = msg;
+return host ? FAIL : DEFER;
}
-/*************************************************
-* Callback to generate RSA key *
-*************************************************/
+/**************************************************
+* General library initalisation *
+**************************************************/
-/*
-Arguments:
- s SSL connection
- export not used
- keylength keylength
+static BOOL
+lib_rand_init(void * addr)
+{
+randstuff r;
+if (!RAND_status()) return TRUE;
-Returns: pointer to generated key
-*/
+gettimeofday(&r.tv, NULL);
+r.p = getpid();
+RAND_seed(US (&r), sizeof(r));
+RAND_seed(US big_buffer, big_buffer_size);
+if (addr) RAND_seed(US addr, sizeof(addr));
-static RSA *
-rsa_callback(SSL *s, int export, int keylength)
-{
-RSA *rsa_key;
-export = export; /* Shut picky compilers up */
-DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength);
-rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL);
-if (rsa_key == NULL)
- {
- ERR_error_string(ERR_get_error(), ssl_errstring);
- log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s",
- ssl_errstring);
- return NULL;
- }
-return rsa_key;
+return RAND_status();
}
-
-/* Extreme debug
-#ifndef DISABLE_OCSP
-void
-x509_store_dump_cert_s_names(X509_STORE * store)
+static void
+tls_openssl_init(void)
{
-STACK_OF(X509_OBJECT) * roots= store->objs;
-int i;
-static uschar name[256];
+static BOOL once = FALSE;
+if (once) return;
+once = TRUE;
-for(i= 0; i<sk_X509_OBJECT_num(roots); i++)
- {
- X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i);
- if(tmp_obj->type == X509_LU_X509)
- {
- X509 * current_cert= tmp_obj->data.x509;
- X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name));
- debug_printf(" %s\n", name);
- }
- }
-}
+#ifdef EXIM_NEED_OPENSSL_INIT
+SSL_load_error_strings(); /* basic set up */
+OpenSSL_add_ssl_algorithms();
#endif
-*/
+#if defined(EXIM_HAVE_SHA256) && !defined(OPENSSL_AUTO_SHA256)
+/* SHA256 is becoming ever more popular. This makes sure it gets added to the
+list of available digests. */
+EVP_add_digest(EVP_sha256());
+#endif
-/*************************************************
-* Callback for verification *
-*************************************************/
+(void) lib_rand_init(NULL);
+(void) tls_openssl_options_parse(openssl_options, &init_options);
+}
-/* The SSL library does certificate verification if set up to do so. This
-callback has the current yes/no state is in "state". If verification succeeded,
-we set up the tls_peerdn string. If verification failed, what happens depends
-on whether the client is required to present a verifiable certificate or not.
-If verification is optional, we change the state to yes, but still log the
-verification error. For some reason (it really would help to have proper
-documentation of OpenSSL), this callback function then gets called again, this
-time with state = 1. In fact, that's useful, because we can set up the peerdn
-value, but we must take care not to set the private verified flag on the second
-time through.
-Note: this function is not called if the client fails to present a certificate
-when asked. We get here only if a certificate has been received. Handling of
-optional verification for this case is done when requesting SSL to verify, by
-setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case.
+/*************************************************
+* Initialize for DH *
+*************************************************/
-May be called multiple times for different issues with a certificate, even
-for a given "depth" in the certificate chain.
+/* If dhparam is set, expand it, and load up the parameters for DH encryption.
+Server only.
Arguments:
- state current yes/no state as 1/0
- x509ctx certificate information.
- client TRUE for client startup, FALSE for server startup
+ sctx The current SSL CTX (inbound or outbound)
+ dhparam DH parameter file or fixed parameter identity string
+ errstr error string pointer
-Returns: 1 if verified, 0 if not
+Returns: TRUE if OK (nothing to set up, or setup worked)
*/
-static int
-verify_callback(int state, X509_STORE_CTX *x509ctx,
- tls_support *tlsp, BOOL *calledp, BOOL *optionalp)
+static BOOL
+init_dh(SSL_CTX * sctx, uschar * dhparam, uschar ** errstr)
+{
+BIO * bio;
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+DH * dh;
+#else
+EVP_PKEY * pkey;
+#endif
+uschar * dhexpanded;
+const char * pem;
+int dh_bitsize;
+
+if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded, errstr))
+ return FALSE;
+
+if (!dhexpanded || !*dhexpanded)
+ bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1);
+else if (dhexpanded[0] == '/')
+ {
+ if (!(bio = BIO_new_file(CS dhexpanded, "r")))
+ {
+ tls_error(string_sprintf("could not read dhparams file %s", dhexpanded),
+ NULL, US strerror(errno), errstr);
+ return FALSE;
+ }
+ }
+else
+ {
+ if (Ustrcmp(dhexpanded, "none") == 0)
+ {
+ DEBUG(D_tls) debug_printf("Requested no DH parameters.\n");
+ return TRUE;
+ }
+
+ if (!(pem = std_dh_prime_named(dhexpanded)))
+ {
+ tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded),
+ NULL, US strerror(errno), errstr);
+ return FALSE;
+ }
+ bio = BIO_new_mem_buf(CS pem, -1);
+ }
+
+if (!(
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+ dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL)
+#else
+ pkey = PEM_read_bio_Parameters_ex(bio, NULL, NULL, NULL)
+#endif
+ ) )
+ {
+ BIO_free(bio);
+ tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded),
+ NULL, NULL, errstr);
+ return FALSE;
+ }
+
+/* note: our default limit of 2236 is not a multiple of 8; the limit comes from
+an NSS limit, and the GnuTLS APIs handle bit-sizes fine, so we went with 2236.
+But older OpenSSL can only report in bytes (octets), not bits. If someone wants
+to dance at the edge, then they can raise the limit or use current libraries. */
+
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+# ifdef EXIM_HAVE_OPENSSL_DH_BITS
+/* Added in commit 26c79d5641d; `git describe --contains` says OpenSSL_1_1_0-pre1~1022
+This predates OpenSSL_1_1_0 (before a, b, ...) so is in all 1.1.0 */
+dh_bitsize = DH_bits(dh);
+# else
+dh_bitsize = 8 * DH_size(dh);
+# endif
+#else /* 3.0.0 + */
+dh_bitsize = EVP_PKEY_get_bits(pkey);
+#endif
+
+/* Even if it is larger, we silently return success rather than cause things to
+fail out, so that a too-large DH will not knock out all TLS; it's a debatable
+choice. Likewise for a failing attempt to set one. */
+
+if (dh_bitsize <= tls_dh_max_bits)
+ {
+ if (
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+ SSL_CTX_set_tmp_dh(sctx, dh)
+#else
+ SSL_CTX_set0_tmp_dh_pkey(sctx, pkey)
+#endif
+ == 0)
+ {
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (D-H param setting '%s'): %s",
+ dhexpanded ? dhexpanded : US"default", ssl_errstring);
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+ /* EVP_PKEY_free(pkey); crashes */
+#endif
+ }
+ else
+ DEBUG(D_tls)
+ debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n",
+ dhexpanded ? dhexpanded : US"default", dh_bitsize);
+ }
+else
+ DEBUG(D_tls)
+ debug_printf("dhparams '%s' %d bits, is > tls_dh_max_bits limit of %d\n",
+ dhexpanded ? dhexpanded : US"default", dh_bitsize, tls_dh_max_bits);
+
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+DH_free(dh);
+#endif
+/* The EVP_PKEY ownership stays with the ctx; do not free it */
+
+BIO_free(bio);
+return TRUE;
+}
+
+
+
+
+/*************************************************
+* Initialize for ECDH *
+*************************************************/
+
+/* Load parameters for ECDH encryption. Server only.
+
+For now, we stick to NIST P-256 because: it's simple and easy to configure;
+it avoids any patent issues that might bite redistributors; despite events in
+the news and concerns over curve choices, we're not cryptographers, we're not
+pretending to be, and this is "good enough" to be better than no support,
+protecting against most adversaries. Given another year or two, there might
+be sufficient clarity about a "right" way forward to let us make an informed
+decision, instead of a knee-jerk reaction.
+
+Longer-term, we should look at supporting both various named curves and
+external files generated with "openssl ecparam", much as we do for init_dh().
+We should also support "none" as a value, to explicitly avoid initialisation.
+
+Patches welcome.
+
+Arguments:
+ sctx The current SSL CTX (inbound or outbound)
+ errstr error string pointer
+
+Returns: TRUE if OK (nothing to set up, or setup worked)
+*/
+
+static BOOL
+init_ecdh(SSL_CTX * sctx, uschar ** errstr)
+{
+#ifdef OPENSSL_NO_ECDH
+return TRUE;
+#else
+
+uschar * exp_curve;
+int nid;
+BOOL rv;
+
+# ifndef EXIM_HAVE_ECDH
+DEBUG(D_tls)
+ debug_printf("No OpenSSL API to define ECDH parameters, skipping\n");
+return TRUE;
+# else
+
+if (!expand_check(tls_eccurve, US"tls_eccurve", &exp_curve, errstr))
+ return FALSE;
+if (!exp_curve || !*exp_curve)
+ return TRUE;
+
+/* "auto" needs to be handled carefully.
+ * OpenSSL < 1.0.2: we do not select anything, but fallback to prime256v1
+ * OpenSSL < 1.1.0: we have to call SSL_CTX_set_ecdh_auto
+ * (openssl/ssl.h defines SSL_CTRL_SET_ECDH_AUTO)
+ * OpenSSL >= 1.1.0: we do not set anything, the libray does autoselection
+ * https://github.com/openssl/openssl/commit/fe6ef2472db933f01b59cad82aa925736935984b
+ */
+if (Ustrcmp(exp_curve, "auto") == 0)
+ {
+#if OPENSSL_VERSION_NUMBER < 0x10002000L
+ DEBUG(D_tls) debug_printf(
+ "ECDH OpenSSL < 1.0.2: temp key parameter settings: overriding \"auto\" with \"prime256v1\"\n");
+ exp_curve = US"prime256v1";
+#else
+# if defined SSL_CTRL_SET_ECDH_AUTO
+ DEBUG(D_tls) debug_printf(
+ "ECDH OpenSSL 1.0.2+: temp key parameter settings: autoselection\n");
+ SSL_CTX_set_ecdh_auto(sctx, 1);
+ return TRUE;
+# else
+ DEBUG(D_tls) debug_printf(
+ "ECDH OpenSSL 1.1.0+: temp key parameter settings: default selection\n");
+ return TRUE;
+# endif
+#endif
+ }
+
+DEBUG(D_tls) debug_printf("ECDH: curve '%s'\n", exp_curve);
+if ( (nid = OBJ_sn2nid (CCS exp_curve)) == NID_undef
+# ifdef EXIM_HAVE_OPENSSL_EC_NIST2NID
+ && (nid = EC_curve_nist2nid(CCS exp_curve)) == NID_undef
+# endif
+ )
+ {
+ tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", exp_curve),
+ NULL, NULL, errstr);
+ return FALSE;
+ }
+
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ {
+ EC_KEY * ecdh;
+ if (!(ecdh = EC_KEY_new_by_curve_name(nid)))
+ {
+ tls_error(US"Unable to create ec curve", NULL, NULL, errstr);
+ return FALSE;
+ }
+
+ /* The "tmp" in the name here refers to setting a temporary key
+ not to the stability of the interface. */
+
+ if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0))
+ tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), NULL, NULL, errstr);
+ else
+ DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve);
+ EC_KEY_free(ecdh);
+ }
+
+#else /* v 3.0.0 + */
+
+if ((rv = SSL_CTX_set1_groups(sctx, &nid, 1)) == 0)
+ tls_error(string_sprintf("Error enabling '%s' group", exp_curve), NULL, NULL, errstr);
+else
+ DEBUG(D_tls) debug_printf("ECDH: enabled '%s' group\n", exp_curve);
+
+#endif
+
+return !rv;
+
+# endif /*EXIM_HAVE_ECDH*/
+#endif /*OPENSSL_NO_ECDH*/
+}
+
+
+
+/*************************************************
+* Expand key and cert file specs *
+*************************************************/
+
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+/*
+Arguments:
+ s SSL connection (not used)
+ export not used
+ keylength keylength
+
+Returns: pointer to generated key
+*/
+
+static RSA *
+rsa_callback(SSL *s, int export, int keylength)
+{
+RSA *rsa_key;
+#ifdef EXIM_HAVE_RSA_GENKEY_EX
+BIGNUM *bn = BN_new();
+#endif
+
+DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength);
+
+# ifdef EXIM_HAVE_RSA_GENKEY_EX
+if ( !BN_set_word(bn, (unsigned long)RSA_F4)
+ || !(rsa_key = RSA_new())
+ || !RSA_generate_key_ex(rsa_key, keylength, bn, NULL)
+ )
+# else
+if (!(rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL)))
+# endif
+
+ {
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s",
+ ssl_errstring);
+ return NULL;
+ }
+return rsa_key;
+}
+#endif /* pre-3.0.0 */
+
+
+
+/* Create and install a selfsigned certificate, for use in server mode */
+/*XXX we could arrange to call this during prelo for a null tls_certificate option.
+The normal cache inval + relo will suffice.
+Just need a timer for inval. */
+
+static int
+tls_install_selfsign(SSL_CTX * sctx, uschar ** errstr)
+{
+X509 * x509 = NULL;
+EVP_PKEY * pkey;
+X509_NAME * name;
+uschar * where;
+
+DEBUG(D_tls) debug_printf("TLS: generating selfsigned server cert\n");
+where = US"allocating pkey";
+if (!(pkey = EVP_PKEY_new()))
+ goto err;
+
+where = US"allocating cert";
+if (!(x509 = X509_new()))
+ goto err;
+
+where = US"generating pkey";
+#if OPENSSL_VERSION_NUMBER < 0x30000000L
+ {
+ RSA * rsa;
+ if (!(rsa = rsa_callback(NULL, 0, 2048)))
+ goto err;
+
+ where = US"assigning pkey";
+ if (!EVP_PKEY_assign_RSA(pkey, rsa))
+ goto err;
+ }
+#else
+pkey = EVP_RSA_gen(2048);
+#endif
+
+X509_set_version(x509, 2); /* N+1 - version 3 */
+ASN1_INTEGER_set(X509_get_serialNumber(x509), 1);
+X509_gmtime_adj(X509_get_notBefore(x509), 0);
+X509_gmtime_adj(X509_get_notAfter(x509), (long)2 * 60 * 60); /* 2 hour */
+X509_set_pubkey(x509, pkey);
+
+name = X509_get_subject_name(x509);
+X509_NAME_add_entry_by_txt(name, "C",
+ MBSTRING_ASC, CUS "UK", -1, -1, 0);
+X509_NAME_add_entry_by_txt(name, "O",
+ MBSTRING_ASC, CUS "Exim Developers", -1, -1, 0);
+X509_NAME_add_entry_by_txt(name, "CN",
+ MBSTRING_ASC, CUS smtp_active_hostname, -1, -1, 0);
+X509_set_issuer_name(x509, name);
+
+where = US"signing cert";
+if (!X509_sign(x509, pkey, EVP_md5()))
+ goto err;
+
+where = US"installing selfsign cert";
+if (!SSL_CTX_use_certificate(sctx, x509))
+ goto err;
+
+where = US"installing selfsign key";
+if (!SSL_CTX_use_PrivateKey(sctx, pkey))
+ goto err;
+
+return OK;
+
+err:
+ (void) tls_error(where, NULL, NULL, errstr);
+ if (x509) X509_free(x509);
+ if (pkey) EVP_PKEY_free(pkey);
+ return DEFER;
+}
+
+
+
+
+
+
+
+/*************************************************
+* Information callback *
+*************************************************/
+
+/* The SSL library functions call this from time to time to indicate what they
+are doing. We copy the string to the debugging output when TLS debugging has
+been requested.
+
+Arguments:
+ s the SSL connection
+ where
+ ret
+
+Returns: nothing
+*/
+
+static void
+info_callback(SSL *s, int where, int ret)
+{
+DEBUG(D_tls)
+ {
+ const uschar * str;
+
+ if (where & SSL_ST_CONNECT)
+ str = US"SSL_connect";
+ else if (where & SSL_ST_ACCEPT)
+ str = US"SSL_accept";
+ else
+ str = US"SSL info (undefined)";
+
+ if (where & SSL_CB_LOOP)
+ debug_printf("%s: %s\n", str, SSL_state_string_long(s));
+ else if (where & SSL_CB_ALERT)
+ debug_printf("SSL3 alert %s:%s:%s\n",
+ str = where & SSL_CB_READ ? US"read" : US"write",
+ SSL_alert_type_string_long(ret), SSL_alert_desc_string_long(ret));
+ else if (where & SSL_CB_EXIT)
+ {
+ if (ret == 0)
+ debug_printf("%s: failed in %s\n", str, SSL_state_string_long(s));
+ else if (ret < 0)
+ debug_printf("%s: error in %s\n", str, SSL_state_string_long(s));
+ }
+ else if (where & SSL_CB_HANDSHAKE_START)
+ debug_printf("%s: hshake start: %s\n", str, SSL_state_string_long(s));
+ else if (where & SSL_CB_HANDSHAKE_DONE)
+ debug_printf("%s: hshake done: %s\n", str, SSL_state_string_long(s));
+ }
+}
+
+#ifdef OPENSSL_HAVE_KEYLOG_CB
+static void
+keylog_callback(const SSL *ssl, const char *line)
+{
+char * filename;
+FILE * fp;
+DEBUG(D_tls) debug_printf("%.200s\n", line);
+if (!(filename = getenv("SSLKEYLOGFILE"))) return;
+if (!(fp = fopen(filename, "a"))) return;
+fprintf(fp, "%s\n", line);
+fclose(fp);
+}
+#endif
+
+
+
+
+
+#ifndef DISABLE_EVENT
+static int
+verify_event(tls_support * tlsp, X509 * cert, int depth, const uschar * dn,
+ BOOL *calledp, const BOOL *optionalp, const uschar * what)
{
-X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
-int depth = X509_STORE_CTX_get_error_depth(x509ctx);
-static uschar txt[256];
-#ifdef EXPERIMENTAL_EVENT
uschar * ev;
uschar * yield;
+X509 * old_cert;
+
+ev = tlsp == &tls_out ? client_static_state->event_action : event_action;
+if (ev)
+ {
+ DEBUG(D_tls) debug_printf("verify_event: %s %d\n", what, depth);
+ old_cert = tlsp->peercert;
+ tlsp->peercert = X509_dup(cert);
+ /* NB we do not bother setting peerdn */
+ if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth), &errno)))
+ {
+ log_write(0, LOG_MAIN, "[%s] %s verify denied by event-action: "
+ "depth=%d cert=%s: %s",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ what, depth, dn, yield);
+ *calledp = TRUE;
+ if (!*optionalp)
+ {
+ if (old_cert) tlsp->peercert = old_cert; /* restore 1st failing cert */
+ return 1; /* reject (leaving peercert set) */
+ }
+ DEBUG(D_tls) debug_printf("Event-action verify failure overridden "
+ "(host in tls_try_verify_hosts)\n");
+ tlsp->verify_override = TRUE;
+ }
+ X509_free(tlsp->peercert);
+ tlsp->peercert = old_cert;
+ }
+return 0;
+}
+#endif
+
+/*************************************************
+* Callback for verification *
+*************************************************/
+
+/* The SSL library does certificate verification if set up to do so. This
+callback has the current yes/no state is in "state". If verification succeeded,
+we set the certificate-verified flag. If verification failed, what happens
+depends on whether the client is required to present a verifiable certificate
+or not.
+
+If verification is optional, we change the state to yes, but still log the
+verification error. For some reason (it really would help to have proper
+documentation of OpenSSL), this callback function then gets called again, this
+time with state = 1. We must take care not to set the private verified flag on
+the second time through.
+
+Note: this function is not called if the client fails to present a certificate
+when asked. We get here only if a certificate has been received. Handling of
+optional verification for this case is done when requesting SSL to verify, by
+setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case.
+
+May be called multiple times for different issues with a certificate, even
+for a given "depth" in the certificate chain.
+
+Arguments:
+ preverify_ok current yes/no state as 1/0
+ x509ctx certificate information.
+ tlsp per-direction (client vs. server) support data
+ calledp has-been-called flag
+ optionalp verification-is-optional flag
+
+Returns: 0 if verification should fail, otherwise 1
+*/
+
+static int
+verify_callback(int preverify_ok, X509_STORE_CTX * x509ctx,
+ tls_support * tlsp, BOOL * calledp, BOOL * optionalp)
+{
+X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+uschar dn[256];
+
+if (!X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)))
+ {
+ DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n");
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address);
+ return 0;
+ }
+dn[sizeof(dn)-1] = '\0';
+
+tlsp->verify_override = FALSE;
+if (preverify_ok == 0)
+ {
+ uschar * extra = verify_mode ? string_sprintf(" (during %c-verify for [%s])",
+ *verify_mode, sender_host_address)
+ : US"";
+ log_write(0, LOG_MAIN, "[%s] SSL verify error%s: depth=%d error=%s cert=%s",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ extra, depth,
+ X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), dn);
+ *calledp = TRUE;
+ if (!*optionalp)
+ {
+ if (!tlsp->peercert)
+ tlsp->peercert = X509_dup(cert); /* record failing cert */
+ return 0; /* reject */
+ }
+ DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
+ "tls_try_verify_hosts)\n");
+ tlsp->verify_override = TRUE;
+ }
+
+else if (depth != 0)
+ {
+ DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, dn);
+#ifndef DISABLE_OCSP
+ if (tlsp == &tls_out && client_static_state->u_ocsp.client.verify_store)
+ { /* client, wanting stapling */
+ /* Add the server cert's signing chain as the one
+ for the verification of the OCSP stapled information. */
+
+ if (!X509_STORE_add_cert(client_static_state->u_ocsp.client.verify_store,
+ cert))
+ ERR_clear_error();
+ sk_X509_push(client_static_state->verify_stack, cert);
+ }
+#endif
+#ifndef DISABLE_EVENT
+ if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL"))
+ return 0; /* reject, with peercert set */
#endif
+ }
+else
+ {
+ const uschar * verify_cert_hostnames;
+
+ if ( tlsp == &tls_out
+ && ((verify_cert_hostnames = client_static_state->verify_cert_hostnames)))
+ /* client, wanting hostname check */
+ {
+
+#ifdef EXIM_HAVE_OPENSSL_CHECKHOST
+# ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
+# define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0
+# endif
+# ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS
+# define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0
+# endif
+ int sep = 0;
+ const uschar * list = verify_cert_hostnames;
+ uschar * name;
+ int rc;
+ while ((name = string_nextinlist(&list, &sep, NULL, 0)))
+ if ((rc = X509_check_host(cert, CCS name, 0,
+ X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
+ | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS,
+ NULL)))
+ {
+ if (rc < 0)
+ {
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address);
+ name = NULL;
+ }
+ break;
+ }
+ if (!name)
+#else
+ if (!tls_is_name_for_cert(verify_cert_hostnames, cert))
+#endif
+ {
+ uschar * extra = verify_mode
+ ? string_sprintf(" (during %c-verify for [%s])",
+ *verify_mode, sender_host_address)
+ : US"";
+ log_write(0, LOG_MAIN,
+ "[%s] SSL verify error%s: certificate name mismatch: DN=\"%s\" H=\"%s\"",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ extra, dn, verify_cert_hostnames);
+ *calledp = TRUE;
+ if (!*optionalp)
+ {
+ if (!tlsp->peercert)
+ tlsp->peercert = X509_dup(cert); /* record failing cert */
+ return 0; /* reject */
+ }
+ DEBUG(D_tls) debug_printf("SSL verify name failure overridden (host in "
+ "tls_try_verify_hosts)\n");
+ tlsp->verify_override = TRUE;
+ }
+ }
+
+#ifndef DISABLE_EVENT
+ if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL"))
+ return 0; /* reject, with peercert set */
+#endif
+
+ DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n",
+ *calledp ? "" : " authenticated", dn);
+ *calledp = TRUE;
+ }
+
+return 1; /* accept, at least for this level */
+}
+
+static int
+verify_callback_client(int preverify_ok, X509_STORE_CTX *x509ctx)
+{
+return verify_callback(preverify_ok, x509ctx, &tls_out,
+ &client_verify_callback_called, &client_verify_optional);
+}
+
+static int
+verify_callback_server(int preverify_ok, X509_STORE_CTX *x509ctx)
+{
+return verify_callback(preverify_ok, x509ctx, &tls_in,
+ &server_verify_callback_called, &server_verify_optional);
+}
+
+
+#ifdef SUPPORT_DANE
+
+/* This gets called *by* the dane library verify callback, which interposes
+itself.
+*/
+static int
+verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx)
+{
+X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
+uschar dn[256];
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+#ifndef DISABLE_EVENT
+BOOL dummy_called, optional = FALSE;
+#endif
+
+if (!X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)))
+ {
+ DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n");
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error",
+ deliver_host_address);
+ return 0;
+ }
+dn[sizeof(dn)-1] = '\0';
+
+DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n",
+ preverify_ok ? "ok":"BAD", depth, dn);
+
+#ifndef DISABLE_EVENT
+ if (verify_event(&tls_out, cert, depth, dn,
+ &dummy_called, &optional, US"DANE"))
+ return 0; /* reject, with peercert set */
+#endif
+
+if (preverify_ok == 1)
+ {
+ tls_out.dane_verified = TRUE;
+#ifndef DISABLE_OCSP
+ if (client_static_state->u_ocsp.client.verify_store)
+ { /* client, wanting stapling */
+ /* Add the server cert's signing chain as the one
+ for the verification of the OCSP stapled information. */
+
+ if (!X509_STORE_add_cert(client_static_state->u_ocsp.client.verify_store,
+ cert))
+ ERR_clear_error();
+ sk_X509_push(client_static_state->verify_stack, cert);
+ }
+#endif
+ }
+else
+ {
+ int err = X509_STORE_CTX_get_error(x509ctx);
+ DEBUG(D_tls)
+ debug_printf(" - err %d '%s'\n", err, X509_verify_cert_error_string(err));
+ if (err == X509_V_ERR_APPLICATION_VERIFICATION)
+ preverify_ok = 1;
+ }
+return preverify_ok;
+}
+
+#endif /*SUPPORT_DANE*/
+
+
+#ifndef DISABLE_OCSP
+/*************************************************
+* Load OCSP information into state *
+*************************************************/
+/* Called to load the server OCSP response from the given file into memory, once
+caller has determined this is needed. Checks validity. Debugs a message
+if invalid.
+
+ASSUMES: single response, for single cert.
+
+Arguments:
+ state various parts of session state
+ filename the filename putatively holding an OCSP response
+ is_pem file is PEM format; otherwise is DER
+*/
+
+static void
+ocsp_load_response(exim_openssl_state_st * state, const uschar * filename,
+ BOOL is_pem)
+{
+BIO * bio;
+OCSP_RESPONSE * resp;
+OCSP_BASICRESP * basic_response;
+OCSP_SINGLERESP * single_response;
+ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd;
+STACK_OF(X509) * sk;
+unsigned long verify_flags;
+int status, reason, i;
-X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt));
+DEBUG(D_tls)
+ debug_printf("tls_ocsp_file (%s) '%s'\n", is_pem ? "PEM" : "DER", filename);
+
+if (!filename || !*filename) return;
-if (state == 0)
+ERR_clear_error();
+if (!(bio = BIO_new_file(CS filename, "rb")))
{
- log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s",
- depth,
- X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)),
- txt);
- *calledp = TRUE;
- if (!*optionalp)
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "Failed to open OCSP response file \"%s\": %.100s",
+ filename, ERR_reason_error_string(ERR_get_error()));
+ return;
+ }
+
+if (is_pem)
+ {
+ uschar * data, * freep;
+ char * dummy;
+ long len;
+ if (!PEM_read_bio(bio, &dummy, &dummy, &data, &len))
{
- tlsp->peercert = X509_dup(cert);
- return 0; /* reject */
+ log_write(0, LOG_MAIN|LOG_PANIC, "Failed to read PEM file \"%s\": %.100s",
+ filename, ERR_reason_error_string(ERR_get_error()));
+ return;
}
- DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
- "tls_try_verify_hosts)\n");
+ freep = data;
+ resp = d2i_OCSP_RESPONSE(NULL, CUSS &data, len);
+ OPENSSL_free(freep);
}
+else
+ resp = d2i_OCSP_RESPONSE_bio(bio, NULL);
+BIO_free(bio);
-else if (depth != 0)
+if (!resp)
{
- DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, txt);
-#ifndef DISABLE_OCSP
- if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store)
- { /* client, wanting stapling */
- /* Add the server cert's signing chain as the one
- for the verification of the OCSP stapled information. */
-
- if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store,
- cert))
- ERR_clear_error();
- }
+ log_write(0, LOG_MAIN|LOG_PANIC, "Error reading OCSP response from \"%s\": %s",
+ filename, ERR_reason_error_string(ERR_get_error()));
+ return;
+ }
+
+if ((status = OCSP_response_status(resp)) != OCSP_RESPONSE_STATUS_SUCCESSFUL)
+ {
+ DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n",
+ OCSP_response_status_str(status), status);
+ goto bad;
+ }
+
+#ifdef notdef
+ {
+ BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
+ OCSP_RESPONSE_print(bp, resp, 0); /* extreme debug: stapling content */
+ BIO_free(bp);
+ }
#endif
-#ifdef EXPERIMENTAL_EVENT
- ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action;
- if (ev)
+
+if (!(basic_response = OCSP_response_get1_basic(resp)))
+ {
+ DEBUG(D_tls)
+ debug_printf("OCSP response parse error: unable to extract basic response.\n");
+ goto bad;
+ }
+
+sk = state->verify_stack;
+verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */
+
+/* May need to expose ability to adjust those flags?
+OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT
+OCSP_TRUSTOTHER OCSP_NOINTERN */
+
+/* This does a full verify on the OCSP proof before we load it for serving
+up; possibly overkill - just date-checks might be nice enough.
+
+OCSP_basic_verify takes a "store" arg, but does not
+use it for the chain verification, which is all we do
+when OCSP_NOVERIFY is set. The content from the wire
+"basic_response" and a cert-stack "sk" are all that is used.
+
+We have a stack, loaded in setup_certs() if tls_verify_certificates
+was a file (not a directory, or "system"). It is unfortunate we
+cannot used the connection context store, as that would neatly
+handle the "system" case too, but there seems to be no library
+function for getting a stack from a store.
+[ In OpenSSL 1.1 - ? X509_STORE_CTX_get0_chain(ctx) ? ]
+We do not free the stack since it could be needed a second time for
+SNI handling.
+
+Separately we might try to replace using OCSP_basic_verify() - which seems to not
+be a public interface into the OpenSSL library (there's no manual entry) -
+But what with? We also use OCSP_basic_verify in the client stapling callback.
+And there we NEED it; we must verify that status... unless the
+library does it for us anyway? */
+
+if ((i = OCSP_basic_verify(basic_response, sk, NULL, verify_flags)) < 0)
+ {
+ DEBUG(D_tls)
{
- tlsp->peercert = X509_dup(cert);
- if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth))))
- {
- log_write(0, LOG_MAIN, "SSL verify denied by event-action: "
- "depth=%d cert=%s: %s", depth, txt, yield);
- *calledp = TRUE;
- if (!*optionalp)
- return 0; /* reject */
- DEBUG(D_tls) debug_printf("Event-action verify failure overridden "
- "(host in tls_try_verify_hosts)\n");
- }
- X509_free(tlsp->peercert);
- tlsp->peercert = NULL;
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ debug_printf("OCSP response verify failure: %s\n", US ssl_errstring);
}
-#endif
+ goto bad;
}
-else
+
+/* Here's the simplifying assumption: there's only one response, for the
+one certificate we use, and nothing for anything else in a chain. If this
+proves false, we need to extract a cert id from our issued cert
+(tls_certificate) and use that for OCSP_resp_find_status() (which finds the
+right cert in the stack and then calls OCSP_single_get0_status()).
+
+I'm hoping to avoid reworking a bunch more of how we handle state here.
+
+XXX that will change when we add support for (TLS1.3) whole-chain stapling
+*/
+
+if (!(single_response = OCSP_resp_get0(basic_response, 0)))
{
-#ifdef EXPERIMENTAL_CERTNAMES
- uschar * verify_cert_hostnames;
-#endif
+ DEBUG(D_tls)
+ debug_printf("Unable to get first response from OCSP basic response.\n");
+ goto bad;
+ }
- tlsp->peerdn = txt;
- tlsp->peercert = X509_dup(cert);
+status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd);
+if (status != V_OCSP_CERTSTATUS_GOOD)
+ {
+ DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n",
+ OCSP_cert_status_str(status), status,
+ OCSP_crl_reason_str(reason), reason);
+ goto bad;
+ }
-#ifdef EXPERIMENTAL_CERTNAMES
- if ( tlsp == &tls_out
- && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames)))
- /* client, wanting hostname check */
+if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
+ {
+ DEBUG(D_tls) debug_printf("OCSP status invalid times.\n");
+ goto bad;
+ }
-# if EXIM_HAVE_OPENSSL_CHECKHOST
-# ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
-# define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0
-# endif
-# ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS
-# define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0
-# endif
+supply_response:
+ /* Add the resp to the list used by tls_server_stapling_cb() */
+ {
+ ocsp_resplist ** op = &state->u_ocsp.server.olist, * oentry;
+ while (oentry = *op)
+ op = &oentry->next;
+ *op = oentry = store_get(sizeof(ocsp_resplist), FALSE);
+ oentry->next = NULL;
+ oentry->resp = resp;
+ }
+return;
+
+bad:
+ if (f.running_in_test_harness)
{
- int sep = 0;
- uschar * list = verify_cert_hostnames;
- uschar * name;
- int rc;
- while ((name = string_nextinlist(&list, &sep, NULL, 0)))
- if ((rc = X509_check_host(cert, name, 0,
- X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
- | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS)))
+ extern char ** environ;
+ if (environ) for (uschar ** p = USS environ; *p; p++)
+ if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0)
{
- if (rc < 0)
- {
- log_write(0, LOG_MAIN, "SSL verify error: internal error\n");
- name = NULL;
- }
- break;
+ DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n");
+ goto supply_response;
}
- if (!name)
- {
- log_write(0, LOG_MAIN,
- "SSL verify error: certificate name mismatch: \"%s\"\n", txt);
- *calledp = TRUE;
- if (!*optionalp)
- return 0; /* reject */
- DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
- "tls_try_verify_hosts)\n");
- }
}
-# else
- if (!tls_is_name_for_cert(verify_cert_hostnames, cert))
+return;
+}
+
+
+static void
+ocsp_free_response_list(exim_openssl_state_st * cbinfo)
+{
+for (ocsp_resplist * olist = cbinfo->u_ocsp.server.olist; olist;
+ olist = olist->next)
+ OCSP_RESPONSE_free(olist->resp);
+cbinfo->u_ocsp.server.olist = NULL;
+}
+#endif /*!DISABLE_OCSP*/
+
+
+
+
+
+static int
+tls_add_certfile(SSL_CTX * sctx, exim_openssl_state_st * cbinfo, uschar * file,
+ uschar ** errstr)
+{
+DEBUG(D_tls) debug_printf("tls_certificate file '%s'\n", file);
+if (!SSL_CTX_use_certificate_chain_file(sctx, CS file))
+ return tls_error(string_sprintf(
+ "SSL_CTX_use_certificate_chain_file file=%s", file),
+ cbinfo->host, NULL, errstr);
+return 0;
+}
+
+static int
+tls_add_pkeyfile(SSL_CTX * sctx, exim_openssl_state_st * cbinfo, uschar * file,
+ uschar ** errstr)
+{
+DEBUG(D_tls) debug_printf("tls_privatekey file '%s'\n", file);
+if (!SSL_CTX_use_PrivateKey_file(sctx, CS file, SSL_FILETYPE_PEM))
+ return tls_error(string_sprintf(
+ "SSL_CTX_use_PrivateKey_file file=%s", file), cbinfo->host, NULL, errstr);
+return 0;
+}
+
+
+
+
+/* Called once during tls_init and possibly again during TLS setup, for a
+new context, if Server Name Indication was used and tls_sni was seen in
+the certificate string.
+
+Arguments:
+ sctx the SSL_CTX* to update
+ state various parts of session state
+ errstr error string pointer
+
+Returns: OK/DEFER/FAIL
+*/
+
+static int
+tls_expand_session_files(SSL_CTX * sctx, exim_openssl_state_st * state,
+ uschar ** errstr)
+{
+uschar * expanded;
+
+if (!state->certificate)
+ {
+ if (!state->is_server) /* client */
+ return OK;
+ /* server */
+ if (tls_install_selfsign(sctx, errstr) != OK)
+ return DEFER;
+ }
+else
+ {
+ int err;
+
+ if ( !reexpand_tls_files_for_sni
+ && ( Ustrstr(state->certificate, US"tls_sni")
+ || Ustrstr(state->certificate, US"tls_in_sni")
+ || Ustrstr(state->certificate, US"tls_out_sni")
+ ) )
+ reexpand_tls_files_for_sni = TRUE;
+
+ if (!expand_check(state->certificate, US"tls_certificate", &expanded, errstr))
+ return DEFER;
+
+ if (expanded)
+ if (state->is_server)
{
- log_write(0, LOG_MAIN,
- "SSL verify error: certificate name mismatch: \"%s\"\n", txt);
- *calledp = TRUE;
- if (!*optionalp)
- return 0; /* reject */
- DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
- "tls_try_verify_hosts)\n");
+ const uschar * file_list = expanded;
+ int sep = 0;
+ uschar * file;
+#ifndef DISABLE_OCSP
+ const uschar * olist = state->u_ocsp.server.file;
+ int osep = 0;
+ uschar * ofile;
+ BOOL fmt_pem = FALSE;
+
+ if (olist)
+ if (!expand_check(olist, US"tls_ocsp_file", USS &olist, errstr))
+ return DEFER;
+ if (olist && !*olist)
+ olist = NULL;
+
+ if ( state->u_ocsp.server.file_expanded && olist
+ && (Ustrcmp(olist, state->u_ocsp.server.file_expanded) == 0))
+ {
+ DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n");
+ olist = NULL;
+ }
+ else
+ {
+ ocsp_free_response_list(state);
+ state->u_ocsp.server.file_expanded = olist;
+ }
+#endif
+
+ while (file = string_nextinlist(&file_list, &sep, NULL, 0))
+ {
+ if ((err = tls_add_certfile(sctx, state, file, errstr)))
+ return err;
+
+#ifndef DISABLE_OCSP
+ if (olist)
+ if ((ofile = string_nextinlist(&olist, &osep, NULL, 0)))
+ {
+ if (Ustrncmp(ofile, US"PEM ", 4) == 0)
+ {
+ fmt_pem = TRUE;
+ ofile += 4;
+ }
+ else if (Ustrncmp(ofile, US"DER ", 4) == 0)
+ {
+ fmt_pem = FALSE;
+ ofile += 4;
+ }
+ ocsp_load_response(state, ofile, fmt_pem);
+ }
+ else
+ DEBUG(D_tls) debug_printf("ran out of ocsp file list\n");
+#endif
+ }
}
-# endif
-#endif /*EXPERIMENTAL_CERTNAMES*/
+ else /* would there ever be a need for multiple client certs? */
+ if ((err = tls_add_certfile(sctx, state, expanded, errstr)))
+ return err;
-#ifdef EXPERIMENTAL_EVENT
- ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action;
- if (ev)
- if ((yield = event_raise(ev, US"tls:cert", US"0")))
+ if ( state->privatekey
+ && !expand_check(state->privatekey, US"tls_privatekey", &expanded, errstr))
+ return DEFER;
+
+ /* If expansion was forced to fail, key_expanded will be NULL. If the result
+ of the expansion is an empty string, ignore it also, and assume the private
+ key is in the same file as the certificate. */
+
+ if (expanded && *expanded)
+ if (state->is_server)
{
- log_write(0, LOG_MAIN, "SSL verify denied by event-action: "
- "depth=0 cert=%s: %s", txt, yield);
- *calledp = TRUE;
- if (!*optionalp)
- return 0; /* reject */
- DEBUG(D_tls) debug_printf("Event-action verify failure overridden "
- "(host in tls_try_verify_hosts)\n");
- }
-#endif
+ const uschar * file_list = expanded;
+ int sep = 0;
+ uschar * file;
- DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n",
- *calledp ? "" : " authenticated", txt);
- if (!*calledp) tlsp->certificate_verified = TRUE;
- *calledp = TRUE;
+ while (file = string_nextinlist(&file_list, &sep, NULL, 0))
+ if ((err = tls_add_pkeyfile(sctx, state, file, errstr)))
+ return err;
+ }
+ else /* would there ever be a need for multiple client certs? */
+ if ((err = tls_add_pkeyfile(sctx, state, expanded, errstr)))
+ return err;
}
-return 1; /* accept, at least for this level */
+return OK;
}
-static int
-verify_callback_client(int state, X509_STORE_CTX *x509ctx)
+
+
+
+/**************************************************
+* One-time init credentials for server and client *
+**************************************************/
+
+static void
+normalise_ciphers(uschar ** ciphers, const uschar * pre_expansion_ciphers)
{
-return verify_callback(state, x509ctx, &tls_out, &client_verify_callback_called, &client_verify_optional);
+uschar * s = *ciphers;
+
+if (!s || !Ustrchr(s, '_')) return; /* no change needed */
+
+if (s == pre_expansion_ciphers)
+ s = string_copy(s); /* get writable copy */
+
+for (uschar * t = s; *t; t++) if (*t == '_') *t = '-';
+*ciphers = s;
}
static int
-verify_callback_server(int state, X509_STORE_CTX *x509ctx)
+server_load_ciphers(SSL_CTX * ctx, exim_openssl_state_st * state,
+ uschar * ciphers, uschar ** errstr)
{
-return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, &server_verify_optional);
+DEBUG(D_tls) debug_printf("required ciphers: %s\n", ciphers);
+if (!SSL_CTX_set_cipher_list(ctx, CS ciphers))
+ return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL, errstr);
+state->server_cipher_list = ciphers;
+return OK;
}
-#ifdef EXPERIMENTAL_DANE
-/* This gets called *by* the dane library verify callback, which interposes
-itself.
-*/
static int
-verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx)
+lib_ctx_new(SSL_CTX ** ctxp, host_item * host, uschar ** errstr)
{
-X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
-static uschar txt[256];
-#ifdef EXPERIMENTAL_EVENT
-int depth = X509_STORE_CTX_get_error_depth(x509ctx);
-uschar * yield;
+SSL_CTX * ctx;
+#ifdef EXIM_HAVE_OPENSSL_TLS_METHOD
+if (!(ctx = SSL_CTX_new(host ? TLS_client_method() : TLS_server_method())))
+#else
+if (!(ctx = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method())))
+#endif
+ return tls_error(US"SSL_CTX_new", host, NULL, errstr);
+
+/* Set up the information callback, which outputs if debugging is at a suitable
+level. */
+
+DEBUG(D_tls)
+ {
+ SSL_CTX_set_info_callback(ctx, (void (*)())info_callback);
+#if defined(EXIM_HAVE_OPESSL_TRACE) && !defined(OPENSSL_NO_SSL_TRACE)
+ /* this needs a debug build of OpenSSL */
+ SSL_CTX_set_msg_callback(ctx, (void (*)())SSL_trace);
#endif
+#ifdef OPENSSL_HAVE_KEYLOG_CB
+ SSL_CTX_set_keylog_callback(ctx, (void (*)())keylog_callback);
+#endif
+ }
+
+/* Automatically re-try reads/writes after renegotiation. */
+(void) SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY);
+*ctxp = ctx;
+return OK;
+}
+
+
+static unsigned
+tls_server_creds_init(void)
+{
+SSL_CTX * ctx;
+uschar * dummy_errstr;
+unsigned lifetime = 0;
+
+tls_openssl_init();
+
+state_server.lib_state = null_tls_preload;
+
+if (lib_ctx_new(&ctx, NULL, &dummy_errstr) != OK)
+ return 0;
+state_server.lib_state.lib_ctx = ctx;
+
+/* Preload DH params and EC curve */
+
+if (opt_unset_or_noexpand(tls_dhparam))
+ {
+ DEBUG(D_tls) debug_printf("TLS: preloading DH params for server\n");
+ if (init_dh(ctx, tls_dhparam, &dummy_errstr))
+ state_server.lib_state.dh = TRUE;
+ }
+else
+ DEBUG(D_tls) debug_printf("TLS: not preloading DH params for server\n");
+if (opt_unset_or_noexpand(tls_eccurve))
+ {
+ DEBUG(D_tls) debug_printf("TLS: preloading ECDH curve for server\n");
+ if (init_ecdh(ctx, &dummy_errstr))
+ state_server.lib_state.ecdh = TRUE;
+ }
+else
+ DEBUG(D_tls) debug_printf("TLS: not preloading ECDH curve for server\n");
-X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt));
+#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)
+/* If we can, preload the server-side cert, key and ocsp */
-DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s\n", txt);
-tls_out.peerdn = txt;
-tls_out.peercert = X509_dup(cert);
+if ( opt_set_and_noexpand(tls_certificate)
+# ifndef DISABLE_OCSP
+ && opt_unset_or_noexpand(tls_ocsp_file)
+#endif
+ && opt_unset_or_noexpand(tls_privatekey))
+ {
+ /* Set watches on the filenames. The implementation does de-duplication
+ so we can just blindly do them all. */
-#ifdef EXPERIMENTAL_EVENT
- if (client_static_cbinfo->event_action)
+ if ( tls_set_watch(tls_certificate, TRUE)
+# ifndef DISABLE_OCSP
+ && tls_set_watch(tls_ocsp_file, TRUE)
+#endif
+ && tls_set_watch(tls_privatekey, TRUE))
{
- if ((yield = event_raise(client_static_cbinfo->event_action,
- US"tls:cert", string_sprintf("%d", depth))))
- {
- log_write(0, LOG_MAIN, "DANE verify denied by event-action: "
- "depth=%d cert=%s: %s", depth, txt, yield);
- tls_out.certificate_verified = FALSE;
- return 0; /* reject */
- }
- if (depth != 0)
- {
- X509_free(tls_out.peercert);
- tls_out.peercert = NULL;
- }
+ state_server.certificate = tls_certificate;
+ state_server.privatekey = tls_privatekey;
+#ifndef DISABLE_OCSP
+ state_server.u_ocsp.server.file = tls_ocsp_file;
+#endif
+
+ DEBUG(D_tls) debug_printf("TLS: preloading server certs\n");
+ if (tls_expand_session_files(ctx, &state_server, &dummy_errstr) == OK)
+ state_server.lib_state.conn_certs = TRUE;
}
+ }
+else if ( !tls_certificate && !tls_privatekey
+# ifndef DISABLE_OCSP
+ && !tls_ocsp_file
#endif
+ )
+ { /* Generate & preload a selfsigned cert. No files to watch. */
+ if (tls_expand_session_files(ctx, &state_server, &dummy_errstr) == OK)
+ {
+ state_server.lib_state.conn_certs = TRUE;
+ lifetime = f.running_in_test_harness ? 2 : 60 * 60; /* 1 hour */
+ }
+ }
+else
+ DEBUG(D_tls) debug_printf("TLS: not preloading server certs\n");
-if (state == 1)
- tls_out.dane_verified =
- tls_out.certificate_verified = TRUE;
-return 1;
-}
-#endif /*EXPERIMENTAL_DANE*/
+/* If we can, preload the Authorities for checking client certs against.
+Actual choice to do verify is made (tls_{,try_}verify_hosts)
+at TLS conn startup */
+if ( opt_set_and_noexpand(tls_verify_certificates)
+ && opt_unset_or_noexpand(tls_crl))
+ {
+ /* Watch the default dir also as they are always included */
-/*************************************************
-* Information callback *
-*************************************************/
+ if ( tls_set_watch(CUS X509_get_default_cert_file(), FALSE)
+ && tls_set_watch(tls_verify_certificates, FALSE)
+ && tls_set_watch(tls_crl, FALSE))
+ {
+ DEBUG(D_tls) debug_printf("TLS: preloading CA bundle for server\n");
-/* The SSL library functions call this from time to time to indicate what they
-are doing. We copy the string to the debugging output when TLS debugging has
-been requested.
+ if (setup_certs(ctx, tls_verify_certificates, tls_crl, NULL, &dummy_errstr)
+ == OK)
+ state_server.lib_state.cabundle = TRUE;
+ }
+ }
+else
+ DEBUG(D_tls) debug_printf("TLS: not preloading CA bundle for server\n");
+#endif /* EXIM_HAVE_INOTIFY */
-Arguments:
- s the SSL connection
- where
- ret
-Returns: nothing
-*/
+/* If we can, preload the ciphers control string */
-static void
-info_callback(SSL *s, int where, int ret)
-{
-where = where;
-ret = ret;
-DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s));
+if (opt_set_and_noexpand(tls_require_ciphers))
+ {
+ DEBUG(D_tls) debug_printf("TLS: preloading cipher list for server\n");
+ normalise_ciphers(&tls_require_ciphers, tls_require_ciphers);
+ if (server_load_ciphers(ctx, &state_server, tls_require_ciphers,
+ &dummy_errstr) == OK)
+ state_server.lib_state.pri_string = TRUE;
+ }
+else
+ DEBUG(D_tls) debug_printf("TLS: not preloading cipher list for server\n");
+return lifetime;
}
-/*************************************************
-* Initialize for DH *
-*************************************************/
-/* If dhparam is set, expand it, and load up the parameters for DH encryption.
+/* Preload whatever creds are static, onto a transport. The client can then
+just copy the pointer as it starts up.
+Called from the daemon after a cache-invalidate with watch set; called from
+a queue-run startup with watch clear. */
-Arguments:
- dhparam DH parameter file or fixed parameter identity string
- host connected host, if client; NULL if server
+static void
+tls_client_creds_init(transport_instance * t, BOOL watch)
+{
+smtp_transport_options_block * ob = t->options_block;
+exim_openssl_state_st tpt_dummy_state;
+host_item * dummy_host = (host_item *)1;
+uschar * dummy_errstr;
+SSL_CTX * ctx;
-Returns: TRUE if OK (nothing to set up, or setup worked)
-*/
+tls_openssl_init();
-static BOOL
-init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host)
-{
-BIO *bio;
-DH *dh;
-uschar *dhexpanded;
-const char *pem;
+ob->tls_preload = null_tls_preload;
+if (lib_ctx_new(&ctx, dummy_host, &dummy_errstr) != OK)
+ return;
+ob->tls_preload.lib_ctx = ctx;
-if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded))
- return FALSE;
+tpt_dummy_state.lib_state = ob->tls_preload;
-if (!dhexpanded || !*dhexpanded)
- bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1);
-else if (dhexpanded[0] == '/')
+#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)
+if ( opt_set_and_noexpand(ob->tls_certificate)
+ && opt_unset_or_noexpand(ob->tls_privatekey))
{
- if (!(bio = BIO_new_file(CS dhexpanded, "r")))
+ if ( !watch
+ || ( tls_set_watch(ob->tls_certificate, FALSE)
+ && tls_set_watch(ob->tls_privatekey, FALSE)
+ ) )
{
- tls_error(string_sprintf("could not read dhparams file %s", dhexpanded),
- host, US strerror(errno));
- return FALSE;
+ uschar * pkey = ob->tls_privatekey;
+
+ DEBUG(D_tls)
+ debug_printf("TLS: preloading client certs for transport '%s'\n",t->name);
+
+ if ( tls_add_certfile(ctx, &tpt_dummy_state, ob->tls_certificate,
+ &dummy_errstr) == 0
+ && tls_add_pkeyfile(ctx, &tpt_dummy_state,
+ pkey ? pkey : ob->tls_certificate,
+ &dummy_errstr) == 0
+ )
+ ob->tls_preload.conn_certs = TRUE;
}
}
else
- {
- if (Ustrcmp(dhexpanded, "none") == 0)
- {
- DEBUG(D_tls) debug_printf("Requested no DH parameters.\n");
- return TRUE;
- }
+ DEBUG(D_tls)
+ debug_printf("TLS: not preloading client certs, for transport '%s'\n", t->name);
- if (!(pem = std_dh_prime_named(dhexpanded)))
- {
- tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded),
- host, US strerror(errno));
- return FALSE;
- }
- bio = BIO_new_mem_buf(CS pem, -1);
- }
-if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL)))
+if ( opt_set_and_noexpand(ob->tls_verify_certificates)
+ && opt_unset_or_noexpand(ob->tls_crl))
{
- BIO_free(bio);
- tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded),
- host, NULL);
- return FALSE;
- }
+ if ( !watch
+ || tls_set_watch(CUS X509_get_default_cert_file(), FALSE)
+ && tls_set_watch(ob->tls_verify_certificates, FALSE)
+ && tls_set_watch(ob->tls_crl, FALSE)
+ )
+ {
+ DEBUG(D_tls)
+ debug_printf("TLS: preloading CA bundle for transport '%s'\n", t->name);
-/* Even if it is larger, we silently return success rather than cause things
- * to fail out, so that a too-large DH will not knock out all TLS; it's a
- * debatable choice. */
-if ((8*DH_size(dh)) > tls_dh_max_bits)
- {
- DEBUG(D_tls)
- debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d",
- 8*DH_size(dh), tls_dh_max_bits);
+ if (setup_certs(ctx, ob->tls_verify_certificates,
+ ob->tls_crl, dummy_host, &dummy_errstr) == OK)
+ ob->tls_preload.cabundle = TRUE;
+ }
}
else
- {
- SSL_CTX_set_tmp_dh(sctx, dh);
DEBUG(D_tls)
- debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n",
- dhexpanded ? dhexpanded : US"default", 8*DH_size(dh));
- }
-
-DH_free(dh);
-BIO_free(bio);
+ debug_printf("TLS: not preloading CA bundle, for transport '%s'\n", t->name);
-return TRUE;
+#endif /*EXIM_HAVE_INOTIFY*/
}
+#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)
+/* Invalidate the creds cached, by dropping the current ones.
+Call when we notice one of the source files has changed. */
+
+static void
+tls_server_creds_invalidate(void)
+{
+SSL_CTX_free(state_server.lib_state.lib_ctx);
+state_server.lib_state = null_tls_preload;
+}
-#ifndef DISABLE_OCSP
-/*************************************************
-* Load OCSP information into state *
-*************************************************/
-
-/* Called to load the server OCSP response from the given file into memory, once
-caller has determined this is needed. Checks validity. Debugs a message
-if invalid.
-
-ASSUMES: single response, for single cert.
+static void
+tls_client_creds_invalidate(transport_instance * t)
+{
+smtp_transport_options_block * ob = t->options_block;
+SSL_CTX_free(ob->tls_preload.lib_ctx);
+ob->tls_preload = null_tls_preload;
+}
-Arguments:
- sctx the SSL_CTX* to update
- cbinfo various parts of session state
- expanded the filename putatively holding an OCSP response
+#else
-*/
+static void
+tls_server_creds_invalidate(void)
+{ return; }
static void
-ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded)
-{
-BIO *bio;
-OCSP_RESPONSE *resp;
-OCSP_BASICRESP *basic_response;
-OCSP_SINGLERESP *single_response;
-ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
-X509_STORE *store;
-unsigned long verify_flags;
-int status, reason, i;
+tls_client_creds_invalidate(transport_instance * t)
+{ return; }
-cbinfo->u_ocsp.server.file_expanded = string_copy(expanded);
-if (cbinfo->u_ocsp.server.response)
- {
- OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response);
- cbinfo->u_ocsp.server.response = NULL;
- }
+#endif /*EXIM_HAVE_INOTIFY*/
-bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb");
-if (!bio)
- {
- DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n",
- cbinfo->u_ocsp.server.file_expanded);
- return;
- }
-resp = d2i_OCSP_RESPONSE_bio(bio, NULL);
-BIO_free(bio);
-if (!resp)
- {
- DEBUG(D_tls) debug_printf("Error reading OCSP response.\n");
- return;
- }
+/* Extreme debug
+#ifndef DISABLE_OCSP
+void
+x509_store_dump_cert_s_names(X509_STORE * store)
+{
+STACK_OF(X509_OBJECT) * roots= store->objs;
+static uschar name[256];
-status = OCSP_response_status(resp);
-if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL)
+for (int i= 0; i < sk_X509_OBJECT_num(roots); i++)
{
- DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n",
- OCSP_response_status_str(status), status);
- goto bad;
+ X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i);
+ if(tmp_obj->type == X509_LU_X509)
+ {
+ X509_NAME * sn = X509_get_subject_name(tmp_obj->data.x509);
+ if (X509_NAME_oneline(sn, CS name, sizeof(name)))
+ {
+ name[sizeof(name)-1] = '\0';
+ debug_printf(" %s\n", name);
+ }
+ }
}
+}
+#endif
+*/
-basic_response = OCSP_response_get1_basic(resp);
-if (!basic_response)
- {
- DEBUG(D_tls)
- debug_printf("OCSP response parse error: unable to extract basic response.\n");
- goto bad;
- }
-store = SSL_CTX_get_cert_store(sctx);
-verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */
+#ifndef DISABLE_TLS_RESUME
+/* Manage the keysets used for encrypting the session tickets, on the server. */
-/* May need to expose ability to adjust those flags?
-OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT
-OCSP_TRUSTOTHER OCSP_NOINTERN */
+typedef struct { /* Session ticket encryption key */
+ uschar name[16];
-i = OCSP_basic_verify(basic_response, NULL, store, verify_flags);
-if (i <= 0)
- {
- DEBUG(D_tls) {
- ERR_error_string(ERR_get_error(), ssl_errstring);
- debug_printf("OCSP response verify failure: %s\n", US ssl_errstring);
- }
- goto bad;
- }
+ const EVP_CIPHER * aes_cipher;
+ uschar aes_key[32]; /* size needed depends on cipher. aes_128 implies 128/8 = 16? */
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ const EVP_MD * hmac_hash;
+# else
+ const uschar * hmac_hashname;
+# endif
+ uschar hmac_key[16];
+ time_t renew;
+ time_t expire;
+} exim_stek;
-/* Here's the simplifying assumption: there's only one response, for the
-one certificate we use, and nothing for anything else in a chain. If this
-proves false, we need to extract a cert id from our issued cert
-(tls_certificate) and use that for OCSP_resp_find_status() (which finds the
-right cert in the stack and then calls OCSP_single_get0_status()).
+static exim_stek exim_tk; /* current key */
+static exim_stek exim_tk_old; /* previous key */
-I'm hoping to avoid reworking a bunch more of how we handle state here. */
-single_response = OCSP_resp_get0(basic_response, 0);
-if (!single_response)
- {
- DEBUG(D_tls)
- debug_printf("Unable to get first response from OCSP basic response.\n");
- goto bad;
- }
+static void
+tk_init(void)
+{
+time_t t = time(NULL);
-status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd);
-if (status != V_OCSP_CERTSTATUS_GOOD)
+if (exim_tk.name[0])
{
- DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n",
- OCSP_cert_status_str(status), status,
- OCSP_crl_reason_str(reason), reason);
- goto bad;
+ if (exim_tk.renew >= t) return;
+ exim_tk_old = exim_tk;
}
-if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
- {
- DEBUG(D_tls) debug_printf("OCSP status invalid times.\n");
- goto bad;
- }
+if (f.running_in_test_harness) ssl_session_timeout = 6;
-supply_response:
- cbinfo->u_ocsp.server.response = resp;
-return;
+DEBUG(D_tls) debug_printf("OpenSSL: %s STEK\n", exim_tk.name[0] ? "rotating" : "creating");
+if (RAND_bytes(exim_tk.aes_key, sizeof(exim_tk.aes_key)) <= 0) return;
+if (RAND_bytes(exim_tk.hmac_key, sizeof(exim_tk.hmac_key)) <= 0) return;
+if (RAND_bytes(exim_tk.name+1, sizeof(exim_tk.name)-1) <= 0) return;
-bad:
- if (running_in_test_harness)
- {
- extern char ** environ;
- uschar ** p;
- for (p = USS environ; *p != NULL; p++)
- if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0)
- {
- DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n");
- goto supply_response;
- }
- }
-return;
+exim_tk.name[0] = 'E';
+exim_tk.aes_cipher = EVP_aes_256_cbc();
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+exim_tk.hmac_hash = EVP_sha256();
+# else
+exim_tk.hmac_hashname = US "sha256";
+# endif
+exim_tk.expire = t + ssl_session_timeout;
+exim_tk.renew = t + ssl_session_timeout/2;
}
-#endif /*!DISABLE_OCSP*/
-
+static exim_stek *
+tk_current(void)
+{
+if (!exim_tk.name[0]) return NULL;
+return &exim_tk;
+}
+static exim_stek *
+tk_find(const uschar * name)
+{
+return memcmp(name, exim_tk.name, sizeof(exim_tk.name)) == 0 ? &exim_tk
+ : memcmp(name, exim_tk_old.name, sizeof(exim_tk_old.name)) == 0 ? &exim_tk_old
+ : NULL;
+}
-/*************************************************
-* Expand key and cert file specs *
-*************************************************/
-
-/* Called once during tls_init and possibly again during TLS setup, for a
-new context, if Server Name Indication was used and tls_sni was seen in
-the certificate string.
-
-Arguments:
- sctx the SSL_CTX* to update
- cbinfo various parts of session state
-
-Returns: OK/DEFER/FAIL
-*/
static int
-tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo)
+tk_hmac_init(
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ HMAC_CTX * hctx,
+#else
+ EVP_MAC_CTX * hctx,
+#endif
+ exim_stek * key
+ )
{
-uschar *expanded;
-
-if (cbinfo->certificate == NULL)
- return OK;
-
-if (Ustrstr(cbinfo->certificate, US"tls_sni") ||
- Ustrstr(cbinfo->certificate, US"tls_in_sni") ||
- Ustrstr(cbinfo->certificate, US"tls_out_sni")
- )
- reexpand_tls_files_for_sni = TRUE;
+/*XXX will want these dependent on the ssl session strength */
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key),
+ key->hmac_hash, NULL);
+#else
+ {
+ OSSL_PARAM params[3];
+ uschar * hk = string_copy(key->hmac_hashname); /* need nonconst */
+ params[0] = OSSL_PARAM_construct_octet_string("key", key->hmac_key, sizeof(key->hmac_key));
+ params[1] = OSSL_PARAM_construct_utf8_string("digest", CS hk, 0);
+ params[2] = OSSL_PARAM_construct_end();
+ if (EVP_MAC_CTX_set_params(hctx, params) == 0)
+ {
+ DEBUG(D_tls) debug_printf("EVP_MAC_CTX_set_params: %s\n",
+ ERR_reason_error_string(ERR_get_error()));
+ return 0; /* error in mac initialisation */
+ }
+}
+#endif
+return 1;
+}
-if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded))
- return DEFER;
+/* Callback for session tickets, on server */
+static int
+ticket_key_callback(SSL * ssl, uschar key_name[16],
+ uschar * iv, EVP_CIPHER_CTX * c_ctx,
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+ HMAC_CTX * hctx,
+#else
+ EVP_MAC_CTX * hctx,
+#endif
+ int enc)
+{
+tls_support * tlsp = state_server.tlsp;
+exim_stek * key;
-if (expanded != NULL)
+if (enc)
{
- DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded);
- if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded))
- return tls_error(string_sprintf(
- "SSL_CTX_use_certificate_chain_file file=%s", expanded),
- cbinfo->host, NULL);
- }
+ DEBUG(D_tls) debug_printf("ticket_key_callback: create new session\n");
+ tlsp->resumption |= RESUME_CLIENT_REQUESTED;
-if (cbinfo->privatekey != NULL &&
- !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded))
- return DEFER;
+ if (RAND_bytes(iv, EVP_MAX_IV_LENGTH) <= 0)
+ return -1; /* insufficient random */
-/* If expansion was forced to fail, key_expanded will be NULL. If the result
-of the expansion is an empty string, ignore it also, and assume the private
-key is in the same file as the certificate. */
+ if (!(key = tk_current())) /* current key doesn't exist or isn't valid */
+ return 0; /* key couldn't be created */
+ memcpy(key_name, key->name, 16);
+ DEBUG(D_tls) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - time(NULL));
-if (expanded != NULL && *expanded != 0)
- {
- DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded);
- if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM))
- return tls_error(string_sprintf(
- "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL);
- }
+ if (tk_hmac_init(hctx, key) == 0) return 0;
+ EVP_EncryptInit_ex(c_ctx, key->aes_cipher, NULL, key->aes_key, iv);
-#ifndef DISABLE_OCSP
-if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL)
+ DEBUG(D_tls) debug_printf("ticket created\n");
+ return 1;
+ }
+else
{
- if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded))
- return DEFER;
+ time_t now = time(NULL);
+
+ DEBUG(D_tls) debug_printf("ticket_key_callback: retrieve session\n");
+ tlsp->resumption |= RESUME_CLIENT_SUGGESTED;
- if (expanded != NULL && *expanded != 0)
+ if (!(key = tk_find(key_name)) || key->expire < now)
{
- DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded);
- if (cbinfo->u_ocsp.server.file_expanded &&
- (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0))
+ DEBUG(D_tls)
{
- DEBUG(D_tls)
- debug_printf("tls_ocsp_file value unchanged, using existing values.\n");
- } else {
- ocsp_load_response(sctx, cbinfo, expanded);
+ debug_printf("ticket not usable (%s)\n", key ? "expired" : "not found");
+ if (key) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - now);
}
+ return 0;
}
- }
-#endif
-return OK;
+ if (tk_hmac_init(hctx, key) == 0) return 0;
+ EVP_DecryptInit_ex(c_ctx, key->aes_cipher, NULL, key->aes_key, iv);
+
+ DEBUG(D_tls) debug_printf("ticket usable, STEK expire " TIME_T_FMT "\n", key->expire - now);
+
+ /* The ticket lifetime and renewal are the same as the STEK lifetime and
+ renewal, which is overenthusiastic. A factor of, say, 3x longer STEK would
+ be better. To do that we'd have to encode ticket lifetime in the name as
+ we don't yet see the restored session. Could check posthandshake for TLS1.3
+ and trigger a new ticket then, but cannot do that for TLS1.2 */
+ return key->renew < now ? 2 : 1;
+ }
}
+#endif /* !DISABLE_TLS_RESUME */
+
+static void
+setup_cert_verify(SSL_CTX * ctx, BOOL optional,
+ int (*cert_vfy_cb)(int, X509_STORE_CTX *))
+{
+/* If verification is optional, don't fail if no certificate */
+
+SSL_CTX_set_verify(ctx,
+ SSL_VERIFY_PEER | (optional ? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT),
+ cert_vfy_cb);
+}
/*************************************************
arg Callback of "our" registered data
Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK}
+
+XXX might need to change to using ClientHello callback,
+per https://www.openssl.org/docs/manmaster/man3/SSL_client_hello_cb_fn.html
*/
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg)
{
const char *servername = SSL_get_servername(s, TLSEXT_NAMETYPE_host_name);
-tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
+exim_openssl_state_st *state = (exim_openssl_state_st *) arg;
int rc;
int old_pool = store_pool;
+uschar * dummy_errstr;
if (!servername)
return SSL_TLSEXT_ERR_OK;
/* Make the extension value available for expansion */
store_pool = POOL_PERM;
-tls_in.sni = string_copy(US servername);
+tls_in.sni = string_copy_taint(US servername, TRUE);
store_pool = old_pool;
if (!reexpand_tls_files_for_sni)
not confident that memcpy wouldn't break some internal reference counting.
Especially since there's a references struct member, which would be off. */
-if (!(server_sni = SSL_CTX_new(SSLv23_server_method())))
- {
- ERR_error_string(ERR_get_error(), ssl_errstring);
- DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring);
- return SSL_TLSEXT_ERR_NOACK;
- }
+if (lib_ctx_new(&server_sni, NULL, &dummy_errstr) != OK)
+ goto bad;
/* Not sure how many of these are actually needed, since SSL object
already exists. Might even need this selfsame callback, for reneg? */
-SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(server_ctx));
-SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(server_ctx));
-SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx));
-SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx));
-SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb);
-SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo);
-if (cbinfo->server_cipher_list)
- SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list);
+ {
+ SSL_CTX * ctx = state_server.lib_state.lib_ctx;
+ SSL_CTX_set_info_callback(server_sni, SSL_CTX_get_info_callback(ctx));
+ SSL_CTX_set_mode(server_sni, SSL_CTX_get_mode(ctx));
+ SSL_CTX_set_options(server_sni, SSL_CTX_get_options(ctx));
+ SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(ctx));
+ SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb);
+ SSL_CTX_set_tlsext_servername_arg(server_sni, state);
+ }
+
+if ( !init_dh(server_sni, state->dhparam, &dummy_errstr)
+ || !init_ecdh(server_sni, &dummy_errstr)
+ )
+ goto bad;
+
+if ( state->server_cipher_list
+ && !SSL_CTX_set_cipher_list(server_sni, CS state->server_cipher_list))
+ goto bad;
+
#ifndef DISABLE_OCSP
-if (cbinfo->u_ocsp.server.file)
+if (state->u_ocsp.server.file)
{
SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb);
- SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo);
+ SSL_CTX_set_tlsext_status_arg(server_sni, state);
}
#endif
-rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server);
-if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
+ {
+ uschar * expcerts;
+ if ( !expand_check(tls_verify_certificates, US"tls_verify_certificates",
+ &expcerts, &dummy_errstr)
+ || (rc = setup_certs(server_sni, expcerts, tls_crl, NULL,
+ &dummy_errstr)) != OK)
+ goto bad;
+
+ if (expcerts && *expcerts)
+ setup_cert_verify(server_sni, FALSE, verify_callback_server);
+ }
/* do this after setup_certs, because this can require the certs for verifying
OCSP information. */
-rc = tls_expand_session_files(server_sni, cbinfo);
-if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
-
-if (!init_dh(server_sni, cbinfo->dhparam, NULL))
- return SSL_TLSEXT_ERR_NOACK;
+if ((rc = tls_expand_session_files(server_sni, state, &dummy_errstr)) != OK)
+ goto bad;
DEBUG(D_tls) debug_printf("Switching SSL context.\n");
SSL_set_SSL_CTX(s, server_sni);
-
return SSL_TLSEXT_ERR_OK;
+
+bad: return SSL_TLSEXT_ERR_ALERT_FATAL;
}
#endif /* EXIM_HAVE_OPENSSL_TLSEXT */
+#ifdef EXIM_HAVE_ALPN
+/*************************************************
+* Callback to handle ALPN *
+*************************************************/
+
+/* Called on server if tls_alpn nonblank after expansion,
+when client offers ALPN, after the SNI callback.
+If set and not matching the list then we dump the connection */
+
+static int
+tls_server_alpn_cb(SSL *ssl, const uschar ** out, uschar * outlen,
+ const uschar * in, unsigned int inlen, void * arg)
+{
+server_seen_alpn = TRUE;
+DEBUG(D_tls)
+ {
+ debug_printf("Received TLS ALPN offer:");
+ for (int pos = 0, siz; pos < inlen; pos += siz+1)
+ {
+ siz = in[pos];
+ if (pos + 1 + siz > inlen) siz = inlen - pos - 1;
+ debug_printf(" '%.*s'", siz, in + pos + 1);
+ }
+ debug_printf(". Our list: '%s'\n", tls_alpn);
+ }
+
+/* Look for an acceptable ALPN */
+
+if ( inlen > 1 /* at least one name */
+ && in[0]+1 == inlen /* filling the vector, so exactly one name */
+ )
+ {
+ const uschar * list = tls_alpn;
+ int sep = 0;
+ for (uschar * name; name = string_nextinlist(&list, &sep, NULL, 0); )
+ if (Ustrncmp(in+1, name, in[0]) == 0)
+ {
+ *out = in+1; /* we checked for exactly one, so can just point to it */
+ *outlen = inlen;
+ return SSL_TLSEXT_ERR_OK; /* use ALPN */
+ }
+ }
+
+/* More than one name from clilent, or name did not match our list. */
+
+/* This will be fatal to the TLS conn; would be nice to kill TCP also.
+Maybe as an option in future; for now leave control to the config (must-tls). */
+
+DEBUG(D_tls) debug_printf("TLS ALPN rejected\n");
+return SSL_TLSEXT_ERR_ALERT_FATAL;
+}
+#endif /* EXIM_HAVE_ALPN */
+
+
+
#ifndef DISABLE_OCSP
/*************************************************
static int
tls_server_stapling_cb(SSL *s, void *arg)
{
-const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
-uschar *response_der;
+const exim_openssl_state_st * state = arg;
+ocsp_resplist * olist = state->u_ocsp.server.olist;
+uschar * response_der; /*XXX blob */
int response_der_len;
DEBUG(D_tls)
- debug_printf("Received TLS status request (OCSP stapling); %s response.",
- cbinfo->u_ocsp.server.response ? "have" : "lack");
+ debug_printf("Received TLS status request (OCSP stapling); %s response list\n",
+ olist ? "have" : "lack");
tls_in.ocsp = OCSP_NOT_RESP;
-if (!cbinfo->u_ocsp.server.response)
+if (!olist)
+ return SSL_TLSEXT_ERR_NOACK;
+
+#ifdef EXIM_HAVE_OPESSL_GET0_SERIAL
+ {
+ const X509 * cert_sent = SSL_get_certificate(s);
+ const ASN1_INTEGER * cert_serial = X509_get0_serialNumber(cert_sent);
+ const BIGNUM * cert_bn = ASN1_INTEGER_to_BN(cert_serial, NULL);
+
+ for (; olist; olist = olist->next)
+ {
+ OCSP_BASICRESP * bs = OCSP_response_get1_basic(olist->resp);
+ const OCSP_SINGLERESP * single = OCSP_resp_get0(bs, 0);
+ const OCSP_CERTID * cid = OCSP_SINGLERESP_get0_id(single);
+ ASN1_INTEGER * res_cert_serial;
+ const BIGNUM * resp_bn;
+ ASN1_OCTET_STRING * res_cert_iNameHash;
+
+
+ (void) OCSP_id_get0_info(&res_cert_iNameHash, NULL, NULL, &res_cert_serial,
+ (OCSP_CERTID *) cid);
+ resp_bn = ASN1_INTEGER_to_BN(res_cert_serial, NULL);
+
+ DEBUG(D_tls)
+ {
+ debug_printf("cert serial: %s\n", BN_bn2hex(cert_bn));
+ debug_printf("resp serial: %s\n", BN_bn2hex(resp_bn));
+ }
+
+ if (BN_cmp(cert_bn, resp_bn) == 0)
+ {
+ DEBUG(D_tls) debug_printf("matched serial for ocsp\n");
+
+ /*XXX TODO: check the rest of the list for duplicate matches.
+ If any, need to also check the Issuer Name hash.
+ Without this, we will provide the wrong status in the case of
+ duplicate id. */
+
+ break;
+ }
+ DEBUG(D_tls) debug_printf("not match serial for ocsp\n");
+ }
+ if (!olist)
+ {
+ DEBUG(D_tls) debug_printf("failed to find match for ocsp\n");
+ return SSL_TLSEXT_ERR_NOACK;
+ }
+ }
+#else
+if (olist->next)
+ {
+ DEBUG(D_tls) debug_printf("OpenSSL version too early to support multi-leaf OCSP\n");
return SSL_TLSEXT_ERR_NOACK;
+ }
+#endif
+/*XXX could we do the i2d earlier, rather than during the callback? */
response_der = NULL;
-response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response,
- &response_der);
+response_der_len = i2d_OCSP_RESPONSE(olist->resp, &response_der);
if (response_der_len <= 0)
return SSL_TLSEXT_ERR_NOACK;
-SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len);
+SSL_set_tlsext_status_ocsp_resp(state_server.lib_state.lib_ssl,
+ response_der, response_der_len);
tls_in.ocsp = OCSP_VFIED;
return SSL_TLSEXT_ERR_OK;
}
static int
tls_client_stapling_cb(SSL *s, void *arg)
{
-tls_ext_ctx_cb * cbinfo = arg;
+exim_openssl_state_st * cbinfo = arg;
const unsigned char * p;
int len;
OCSP_RESPONSE * rsp;
OCSP_BASICRESP * bs;
int i;
-DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):");
+DEBUG(D_tls) debug_printf("Received TLS status callback (OCSP stapling):\n");
len = SSL_get_tlsext_status_ocsp_resp(s, &p);
if(!p)
{
/* Expect this when we requested ocsp but got none */
- if ( cbinfo->u_ocsp.client.verify_required
- && log_extra_selector & LX_tls_cipher)
- log_write(0, LOG_MAIN, "Received TLS status callback, null content");
+ if (cbinfo->u_ocsp.client.verify_required && LOGGING(tls_cipher))
+ log_write(0, LOG_MAIN, "Required TLS certificate status not received");
else
DEBUG(D_tls) debug_printf(" null\n");
return cbinfo->u_ocsp.client.verify_required ? 0 : 1;
}
-if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
- {
- tls_out.ocsp = OCSP_FAILED;
- if (log_extra_selector & LX_tls_cipher)
+if (!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
+ {
+ tls_out.ocsp = OCSP_FAILED; /*XXX should use tlsp-> to permit concurrent outbound */
+ if (LOGGING(tls_cipher))
log_write(0, LOG_MAIN, "Received TLS cert status response, parse error");
else
DEBUG(D_tls) debug_printf(" parse error\n");
return 0;
- }
+ }
-if(!(bs = OCSP_response_get1_basic(rsp)))
+if (!(bs = OCSP_response_get1_basic(rsp)))
{
tls_out.ocsp = OCSP_FAILED;
- if (log_extra_selector & LX_tls_cipher)
+ if (LOGGING(tls_cipher))
log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response");
else
DEBUG(D_tls) debug_printf(" error parsing response\n");
*/
{
BIO * bp = NULL;
- int status, reason;
- ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
+#ifndef EXIM_HAVE_OCSP_RESP_COUNT
+ STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses;
+#endif
- DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE);
+ DEBUG(D_tls) bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
/*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */
/* Use the chain that verified the server cert to verify the stapled info */
/* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */
- if ((i = OCSP_basic_verify(bs, NULL,
- cbinfo->u_ocsp.client.verify_store, 0)) <= 0)
- {
- tls_out.ocsp = OCSP_FAILED;
- if (log_extra_selector & LX_tls_cipher)
- log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable");
- BIO_printf(bp, "OCSP response verify failure\n");
- ERR_print_errors(bp);
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
- goto out;
- }
+ if ((i = OCSP_basic_verify(bs, cbinfo->verify_stack,
+ cbinfo->u_ocsp.client.verify_store, OCSP_NOEXPLICIT)) <= 0)
+ if (ERR_peek_error())
+ {
+ tls_out.ocsp = OCSP_FAILED;
+ if (LOGGING(tls_cipher)) log_write(0, LOG_MAIN,
+ "Received TLS cert status response, itself unverifiable: %s",
+ ERR_reason_error_string(ERR_peek_error()));
+ BIO_printf(bp, "OCSP response verify failure\n");
+ ERR_print_errors(bp);
+ OCSP_RESPONSE_print(bp, rsp, 0);
+ goto failed;
+ }
+ else
+ DEBUG(D_tls) debug_printf("no explicit trust for OCSP signing"
+ " in the root CA certificate; ignoring\n");
+
+ DEBUG(D_tls) debug_printf("OCSP response well-formed and signed OK\n");
+
+ /*XXX So we have a good stapled OCSP status. How do we know
+ it is for the cert of interest? OpenSSL 1.1.0 has a routine
+ OCSP_resp_find_status() which matches on a cert id, which presumably
+ we should use. Making an id needs OCSP_cert_id_new(), which takes
+ issuerName, issuerKey, serialNumber. Are they all in the cert?
- BIO_printf(bp, "OCSP response well-formed and signed OK\n");
+ For now, carry on blindly accepting the resp. */
+ for (int idx =
+#ifdef EXIM_HAVE_OCSP_RESP_COUNT
+ OCSP_resp_count(bs) - 1;
+#else
+ sk_OCSP_SINGLERESP_num(sresp) - 1;
+#endif
+ idx >= 0; idx--)
{
- STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses;
- OCSP_SINGLERESP * single;
+ OCSP_SINGLERESP * single = OCSP_resp_get0(bs, idx);
+ int status, reason;
+ ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd;
- if (sk_OCSP_SINGLERESP_num(sresp) != 1)
- {
- tls_out.ocsp = OCSP_FAILED;
- log_write(0, LOG_MAIN, "OCSP stapling "
- "with multiple responses not handled");
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
- goto out;
- }
- single = OCSP_resp_get0(bs, 0);
+ /*XXX so I can see putting a loop in here to handle a rsp with >1 singleresp
+ - but what happens with a GnuTLS-style input?
+
+ we could do with a debug label for each singleresp
+ - it has a certID with a serialNumber, but I see no API to get that
+ */
status = OCSP_single_get0_status(single, &reason, &rev,
&thisupd, &nextupd);
- }
- DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd);
- DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd);
- if (!OCSP_check_validity(thisupd, nextupd,
- EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
- {
- tls_out.ocsp = OCSP_FAILED;
- DEBUG(D_tls) ERR_print_errors(bp);
- log_write(0, LOG_MAIN, "Server OSCP dates invalid");
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
- }
- else
- {
+ DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd);
+ DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd);
+ if (!OCSP_check_validity(thisupd, nextupd,
+ EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
+ {
+ tls_out.ocsp = OCSP_FAILED;
+ DEBUG(D_tls) ERR_print_errors(bp);
+ log_write(0, LOG_MAIN, "OCSP dates invalid");
+ goto failed;
+ }
+
DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n",
OCSP_cert_status_str(status));
switch(status)
{
case V_OCSP_CERTSTATUS_GOOD:
- tls_out.ocsp = OCSP_VFIED;
- i = 1;
- break;
+ continue; /* the idx loop */
case V_OCSP_CERTSTATUS_REVOKED:
- tls_out.ocsp = OCSP_FAILED;
log_write(0, LOG_MAIN, "Server certificate revoked%s%s",
reason != -1 ? "; reason: " : "",
reason != -1 ? OCSP_crl_reason_str(reason) : "");
DEBUG(D_tls) time_print(bp, "Revocation Time", rev);
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
break;
default:
- tls_out.ocsp = OCSP_FAILED;
log_write(0, LOG_MAIN,
"Server certificate status unknown, in OCSP stapling");
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
break;
}
+
+ goto failed;
}
- out:
+
+ i = 1;
+ tls_out.ocsp = OCSP_VFIED;
+ goto good;
+
+ failed:
+ tls_out.ocsp = OCSP_FAILED;
+ i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
+ good:
BIO_free(bp);
}
/*************************************************
* Initialize for TLS *
*************************************************/
-
/* Called from both server and client code, to do preliminary initialization
of the library. We allocate and return a context structure.
Arguments:
- ctxp returned SSL context
host connected host, if client; NULL if server
- dhparam DH parameter file
- certificate certificate file
- privatekey private key
+ ob transport options block, if client; NULL if server
ocsp_file file of stapling info (server); flag for require ocsp (client)
addr address if client; NULL if server (for some randomness)
- cbp place to put allocated callback context
+ caller_state place to put pointer to allocated state-struct
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
-tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate,
- uschar *privatekey,
+tls_init(host_item * host, smtp_transport_options_block * ob,
#ifndef DISABLE_OCSP
uschar *ocsp_file,
#endif
- address_item *addr, tls_ext_ctx_cb ** cbp)
+ address_item *addr, exim_openssl_state_st ** caller_state,
+ tls_support * tlsp,
+ uschar ** errstr)
{
-long init_options;
+SSL_CTX * ctx;
+exim_openssl_state_st * state;
int rc;
-BOOL okay;
-tls_ext_ctx_cb * cbinfo;
-cbinfo = store_malloc(sizeof(tls_ext_ctx_cb));
-cbinfo->certificate = certificate;
-cbinfo->privatekey = privatekey;
-#ifndef DISABLE_OCSP
-if ((cbinfo->is_server = host==NULL))
+if (host) /* client */
{
- cbinfo->u_ocsp.server.file = ocsp_file;
- cbinfo->u_ocsp.server.file_expanded = NULL;
- cbinfo->u_ocsp.server.response = NULL;
+ state = store_malloc(sizeof(exim_openssl_state_st));
+ memset(state, 0, sizeof(*state));
+ state->certificate = ob->tls_certificate;
+ state->privatekey = ob->tls_privatekey;
+ state->is_server = FALSE;
+ state->dhparam = NULL;
+ state->lib_state = ob->tls_preload;
+ }
+else /* server */
+ {
+ state = &state_server;
+ state->certificate = tls_certificate;
+ state->privatekey = tls_privatekey;
+ state->is_server = TRUE;
+ state->dhparam = tls_dhparam;
+ state->lib_state = state_server.lib_state;
}
-else
- cbinfo->u_ocsp.client.verify_store = NULL;
-#endif
-cbinfo->dhparam = dhparam;
-cbinfo->server_cipher_list = NULL;
-cbinfo->host = host;
-#ifdef EXPERIMENTAL_EVENT
-cbinfo->event_action = NULL;
-#endif
-
-SSL_load_error_strings(); /* basic set up */
-OpenSSL_add_ssl_algorithms();
-#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
-/* SHA256 is becoming ever more popular. This makes sure it gets added to the
-list of available digests. */
-EVP_add_digest(EVP_sha256());
-#endif
+state->tlsp = tlsp;
+state->host = host;
-/* Create a context.
-The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant
-negotiation in the different methods; as far as I can tell, the only
-*_{server,client}_method which allows negotiation is SSLv23, which exists even
-when OpenSSL is built without SSLv2 support.
-By disabling with openssl_options, we can let admins re-enable with the
-existing knob. */
+if (!state->lib_state.pri_string)
+ state->server_cipher_list = NULL;
-*ctxp = SSL_CTX_new((host == NULL)?
- SSLv23_server_method() : SSLv23_client_method());
+#ifndef DISABLE_EVENT
+state->event_action = NULL;
+#endif
-if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL);
+tls_openssl_init();
/* It turns out that we need to seed the random number generator this early in
order to get the full complement of ciphers to work. It took me roughly a day
On systems that have /dev/urandom, SSL may automatically seed itself from
there. Otherwise, we have to make something up as best we can. Double check
-afterwards. */
-
-if (!RAND_status())
- {
- randstuff r;
- gettimeofday(&r.tv, NULL);
- r.p = getpid();
+afterwards.
- RAND_seed((uschar *)(&r), sizeof(r));
- RAND_seed((uschar *)big_buffer, big_buffer_size);
- if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr));
+Although we likely called this before, at daemon startup, this is a chance
+to mix in further variable info (time, pid) if needed. */
- if (!RAND_status())
- return tls_error(US"RAND_status", host,
- US"unable to seed random number generator");
- }
-
-/* Set up the information callback, which outputs if debugging is at a suitable
-level. */
-
-SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback);
-
-/* Automatically re-try reads/writes after renegotiation. */
-(void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY);
+if (!lib_rand_init(addr))
+ return tls_error(US"RAND_status", host,
+ US"unable to seed random number generator", errstr);
/* Apply administrator-supplied work-arounds.
Historically we applied just one requested option,
No OpenSSL version number checks: the options we accept depend upon the
availability of the option value macros from OpenSSL. */
-okay = tls_openssl_options_parse(openssl_options, &init_options);
-if (!okay)
- return tls_error(US"openssl_options parsing failed", host, NULL);
+if (!init_options)
+ if (!tls_openssl_options_parse(openssl_options, &init_options))
+ return tls_error(US"openssl_options parsing failed", host, NULL, errstr);
+
+/* Create a context.
+The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant
+negotiation in the different methods; as far as I can tell, the only
+*_{server,client}_method which allows negotiation is SSLv23, which exists even
+when OpenSSL is built without SSLv2 support.
+By disabling with openssl_options, we can let admins re-enable with the
+existing knob. */
+
+if (!(ctx = state->lib_state.lib_ctx))
+ {
+ if ((rc = lib_ctx_new(&ctx, host, errstr)) != OK)
+ return rc;
+ state->lib_state.lib_ctx = ctx;
+ }
+#ifndef DISABLE_TLS_RESUME
+tlsp->resumption = RESUME_SUPPORTED;
+#endif
if (init_options)
{
+#ifndef DISABLE_TLS_RESUME
+ /* Should the server offer session resumption? */
+ if (!host && verify_check_host(&tls_resumption_hosts) == OK)
+ {
+ DEBUG(D_tls) debug_printf("tls_resumption_hosts overrides openssl_options\n");
+ init_options &= ~SSL_OP_NO_TICKET;
+ tlsp->resumption |= RESUME_SERVER_TICKET; /* server will give ticket on request */
+ tlsp->host_resumable = TRUE;
+ }
+#endif
+
DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options);
- if (!(SSL_CTX_set_options(*ctxp, init_options)))
+ if (!(SSL_CTX_set_options(ctx, init_options)))
return tls_error(string_sprintf(
- "SSL_CTX_set_option(%#lx)", init_options), host, NULL);
+ "SSL_CTX_set_option(%#lx)", init_options), host, NULL, errstr);
}
else
DEBUG(D_tls) debug_printf("no SSL CTX options to set\n");
+/* We'd like to disable session cache unconditionally, but foolish Outlook
+Express clients then give up the first TLS connection and make a second one
+(which works). Only when there is an IMAP service on the same machine.
+Presumably OE is trying to use the cache for A on B. Leave it enabled for
+now, until we work out a decent way of presenting control to the config. It
+will never be used because we use a new context every time. */
+#ifdef notdef
+(void) SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
+#endif
+
/* Initialize with DH parameters if supplied */
+/* Initialize ECDH temp key parameter selection */
+
+if (!host)
+ {
+ if (state->lib_state.dh)
+ { DEBUG(D_tls) debug_printf("TLS: DH params were preloaded\n"); }
+ else
+ if (!init_dh(ctx, state->dhparam, errstr)) return DEFER;
-if (!init_dh(*ctxp, dhparam, host)) return DEFER;
+ if (state->lib_state.ecdh)
+ { DEBUG(D_tls) debug_printf("TLS: ECDH curve was preloaded\n"); }
+ else
+ if (!init_ecdh(ctx, errstr)) return DEFER;
+ }
/* Set up certificate and key (and perhaps OCSP info) */
-rc = tls_expand_session_files(*ctxp, cbinfo);
-if (rc != OK) return rc;
+if (state->lib_state.conn_certs)
+ {
+ DEBUG(D_tls)
+ debug_printf("TLS: %s certs were preloaded\n", host ? "client":"server");
+ }
+else
+ {
+#ifndef DISABLE_OCSP
+ if (!host)
+ {
+ state->u_ocsp.server.file = ocsp_file;
+ state->u_ocsp.server.file_expanded = NULL;
+ state->u_ocsp.server.olist = NULL;
+ }
+#endif
+ if ((rc = tls_expand_session_files(ctx, state, errstr)) != OK) return rc;
+ }
+
+/* If we need to handle SNI or OCSP, do so */
-/* If we need to handle SNI, do so */
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
-if (host == NULL) /* server */
+# ifndef DISABLE_OCSP
+ if (!(state->verify_stack = sk_X509_new_null()))
+ {
+ DEBUG(D_tls) debug_printf("failed to create stack for stapling verify\n");
+ return FAIL;
+ }
+# endif
+
+if (!host) /* server */
{
# ifndef DISABLE_OCSP
- /* We check u_ocsp.server.file, not server.response, because we care about if
+ /* We check u_ocsp.server.file, not server.olist, because we care about if
the option exists, not what the current expansion might be, as SNI might
change the certificate and OCSP file in use between now and the time the
callback is invoked. */
- if (cbinfo->u_ocsp.server.file)
+ if (state->u_ocsp.server.file)
{
- SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb);
- SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo);
+ SSL_CTX_set_tlsext_status_cb(ctx, tls_server_stapling_cb);
+ SSL_CTX_set_tlsext_status_arg(ctx, state);
}
# endif
/* We always do this, so that $tls_sni is available even if not used in
tls_certificate */
- SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb);
- SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo);
+ SSL_CTX_set_tlsext_servername_callback(ctx, tls_servername_cb);
+ SSL_CTX_set_tlsext_servername_arg(ctx, state);
+
+# ifdef EXIM_HAVE_ALPN
+ if (tls_alpn && *tls_alpn)
+ {
+ uschar * exp_alpn;
+ if ( expand_check(tls_alpn, US"tls_alpn", &exp_alpn, errstr)
+ && *exp_alpn && !isblank(*exp_alpn))
+ {
+ tls_alpn = exp_alpn; /* subprocess so ok to overwrite */
+ SSL_CTX_set_alpn_select_cb(ctx, tls_server_alpn_cb, state);
+ }
+ else
+ tls_alpn = NULL;
+ }
+# endif
}
# ifndef DISABLE_OCSP
else /* client */
if(ocsp_file) /* wanting stapling */
{
- if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new()))
+ if (!(state->u_ocsp.client.verify_store = X509_STORE_new()))
{
DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n");
return FAIL;
}
- SSL_CTX_set_tlsext_status_cb(*ctxp, tls_client_stapling_cb);
- SSL_CTX_set_tlsext_status_arg(*ctxp, cbinfo);
+ SSL_CTX_set_tlsext_status_cb(ctx, tls_client_stapling_cb);
+ SSL_CTX_set_tlsext_status_arg(ctx, state);
}
# endif
#endif
-#ifdef EXPERIMENTAL_CERTNAMES
-cbinfo->verify_cert_hostnames = NULL;
-#endif
+state->verify_cert_hostnames = NULL;
+#ifdef EXIM_HAVE_EPHEM_RSA_KEX
/* Set up the RSA callback */
+SSL_CTX_set_tmp_rsa_callback(ctx, rsa_callback);
+#endif
-SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback);
-
-/* Finally, set the timeout, and we are done */
+/* Finally, set the session cache timeout, and we are done.
+The period appears to be also used for (server-generated) session tickets */
-SSL_CTX_set_timeout(*ctxp, ssl_session_timeout);
+SSL_CTX_set_timeout(ctx, ssl_session_timeout);
DEBUG(D_tls) debug_printf("Initialized TLS\n");
-*cbp = cbinfo;
+*caller_state = state;
return OK;
}
/*
Argument: pointer to an SSL structure for the connection
- buffer to use for answer
- size of buffer
pointer to number of bits for cipher
-Returns: nothing
+Returns: pointer to allocated string in perm-pool
*/
-static void
-construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits)
+static uschar *
+construct_cipher_name(SSL * ssl, const uschar * ver, int * bits)
{
-/* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't
+int pool = store_pool;
+/* With OpenSSL 1.0.0a, 'c' needs to be const but the documentation doesn't
yet reflect that. It should be a safe change anyway, even 0.9.8 versions have
the accessor functions use const in the prototype. */
-const SSL_CIPHER *c;
-const uschar *ver;
-ver = (const uschar *)SSL_get_version(ssl);
+const SSL_CIPHER * c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl);
+uschar * s;
-c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl);
SSL_CIPHER_get_bits(c, bits);
-string_format(cipherbuf, bsize, "%s:%s:%u", ver,
- SSL_CIPHER_get_name(c), *bits);
+store_pool = POOL_PERM;
+s = string_sprintf("%s:%s:%u", ver, SSL_CIPHER_get_name(c), *bits);
+store_pool = pool;
+DEBUG(D_tls) debug_printf("Cipher: %s\n", s);
+return s;
+}
+
+
+/* Get IETF-standard name for ciphersuite.
+Argument: pointer to an SSL structure for the connection
+Returns: pointer to string
+*/
+
+static const uschar *
+cipher_stdname_ssl(SSL * ssl)
+{
+#ifdef EXIM_HAVE_OPENSSL_CIPHER_STD_NAME
+return CUS SSL_CIPHER_standard_name(SSL_get_current_cipher(ssl));
+#else
+ushort id = 0xffff & SSL_CIPHER_get_id(SSL_get_current_cipher(ssl));
+return cipher_stdname(id >> 8, id & 0xff);
+#endif
+}
+
+
+static const uschar *
+tlsver_name(SSL * ssl)
+{
+uschar * s, * p;
+int pool = store_pool;
+
+store_pool = POOL_PERM;
+s = string_copy(US SSL_get_version(ssl));
+store_pool = pool;
+if ((p = Ustrchr(s, 'v'))) /* TLSv1.2 -> TLS1.2 */
+ for (;; p++) if (!(*p = p[1])) break;
+return CUS s;
+}
+
+
+static void
+peer_cert(SSL * ssl, tls_support * tlsp, uschar * peerdn, unsigned siz)
+{
+/*XXX we might consider a list-of-certs variable for the cert chain.
+SSL_get_peer_cert_chain(SSL*). We'd need a new variable type and support
+in list-handling functions, also consider the difference between the entire
+chain and the elements sent by the peer. */
-DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf);
+tlsp->peerdn = NULL;
+
+/* Will have already noted peercert on a verify fail; possibly not the leaf */
+if (!tlsp->peercert)
+ tlsp->peercert = SSL_get_peer_certificate(ssl);
+/* Beware anonymous ciphers which lead to server_cert being NULL */
+if (tlsp->peercert)
+ if (!X509_NAME_oneline(X509_get_subject_name(tlsp->peercert), CS peerdn, siz))
+ { DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); }
+ else
+ {
+ int oldpool = store_pool;
+
+ peerdn[siz-1] = '\0'; /* paranoia */
+ store_pool = POOL_PERM;
+ tlsp->peerdn = string_copy(peerdn);
+ store_pool = oldpool;
+
+ /* We used to set CV in the cert-verify callbacks (either plain or dane)
+ but they don't get called on session-resumption. So use the official
+ interface, which uses the resumed value. Unfortunately this claims verified
+ when it actually failed but we're in try-verify mode, due to us wanting the
+ knowlege that it failed so needing to have the callback and forcing a
+ permissive return. If we don't force it, the TLS startup is failed.
+ The extra bit of information is set in verify_override in the cb, stashed
+ for resumption next to the TLS session, and used here. */
+
+ if (!tlsp->verify_override)
+ tlsp->certificate_verified =
+#ifdef SUPPORT_DANE
+ tlsp->dane_verified ||
+#endif
+ SSL_get_verify_result(ssl) == X509_V_OK;
+ }
}
* Set up for verifying certificates *
*************************************************/
-/* Called by both client and server startup
+#ifndef DISABLE_OCSP
+/* Load certs from file, return TRUE on success */
+
+static BOOL
+chain_from_pem_file(const uschar * file, STACK_OF(X509) ** vp)
+{
+BIO * bp;
+STACK_OF(X509) * verify_stack = *vp;
+
+if (verify_stack)
+ while (sk_X509_num(verify_stack) > 0)
+ X509_free(sk_X509_pop(verify_stack));
+else
+ verify_stack = sk_X509_new_null();
+
+if (!(bp = BIO_new_file(CS file, "r"))) return FALSE;
+for (X509 * x; x = PEM_read_bio_X509(bp, NULL, 0, NULL); )
+ sk_X509_push(verify_stack, x);
+BIO_free(bp);
+*vp = verify_stack;
+return TRUE;
+}
+#endif
+
+
+
+/* Called by both client and server startup; on the server possibly
+repeated after a Server Name Indication.
Arguments:
sctx SSL_CTX* to initialise
- certs certs file or NULL
+ certs certs file, expanded
crl CRL file or NULL
host NULL in a server; the remote host in a client
- optional TRUE if called from a server for a host in tls_try_verify_hosts;
- otherwise passed as FALSE
- cert_vfy_cb Callback function for certificate verification
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
-setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
- int (*cert_vfy_cb)(int, X509_STORE_CTX *) )
+setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host,
+ uschar ** errstr)
{
uschar *expcerts, *expcrl;
-if (!expand_check(certs, US"tls_verify_certificates", &expcerts))
+if (!expand_check(certs, US"tls_verify_certificates", &expcerts, errstr))
return DEFER;
+DEBUG(D_tls) debug_printf("tls_verify_certificates: %s\n", expcerts);
-if (expcerts != NULL && *expcerts != '\0')
+if (expcerts && *expcerts)
{
- struct stat statbuf;
+ /* Tell the library to use its compiled-in location for the system default
+ CA bundle. Then add the ones specified in the config, if any. */
+
if (!SSL_CTX_set_default_verify_paths(sctx))
- return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL);
+ return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL, errstr);
- if (Ustat(expcerts, &statbuf) < 0)
- {
- log_write(0, LOG_MAIN|LOG_PANIC,
- "failed to stat %s for certificates", expcerts);
- return DEFER;
- }
- else
+ if (Ustrcmp(expcerts, "system") != 0 && Ustrncmp(expcerts, "system,", 7) != 0)
{
- uschar *file, *dir;
- if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
- { file = NULL; dir = expcerts; }
+ struct stat statbuf;
+
+ if (Ustat(expcerts, &statbuf) < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failed to stat %s for certificates", expcerts);
+ return DEFER;
+ }
else
- { file = expcerts; dir = NULL; }
-
- /* If a certificate file is empty, the next function fails with an
- unhelpful error message. If we skip it, we get the correct behaviour (no
- certificates are recognized, but the error message is still misleading (it
- says no certificate was supplied.) But this is better. */
-
- if ((file == NULL || statbuf.st_size > 0) &&
- !SSL_CTX_load_verify_locations(sctx, CS file, CS dir))
- return tls_error(US"SSL_CTX_load_verify_locations", host, NULL);
-
- /* Load the list of CAs for which we will accept certs, for sending
- to the client. This is only for the one-file tls_verify_certificates
- variant.
- If a list isn't loaded into the server, but
- some verify locations are set, the server end appears to make
- a wildcard reqest for client certs.
- Meanwhile, the client library as deafult behaviour *ignores* the list
- we send over the wire - see man SSL_CTX_set_client_cert_cb.
- Because of this, and that the dir variant is likely only used for
- the public-CA bundle (not for a private CA), not worth fixing.
- */
- if (file != NULL)
{
- STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file);
-DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n",
- sk_X509_NAME_num(names));
- SSL_CTX_set_client_CA_list(sctx, names);
+ uschar *file, *dir;
+ if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
+ { file = NULL; dir = expcerts; }
+ else
+ {
+ STACK_OF(X509) * verify_stack =
+#ifndef DISABLE_OCSP
+ !host ? state_server.verify_stack :
+#endif
+ NULL;
+ STACK_OF(X509) ** vp = &verify_stack;
+
+ file = expcerts; dir = NULL;
+#ifndef DISABLE_OCSP
+ /* In the server if we will be offering an OCSP proof, load chain from
+ file for verifying the OCSP proof at load time. */
+
+/*XXX Glitch! The file here is tls_verify_certs: the chain for verifying the client cert.
+This is inconsistent with the need to verify the OCSP proof of the server cert.
+*/
+ if ( !host
+ && statbuf.st_size > 0
+ && state_server.u_ocsp.server.file
+ && !chain_from_pem_file(file, vp)
+ )
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failed to load cert chain from %s", file);
+ return DEFER;
+ }
+#endif
+ }
+
+ /* If a certificate file is empty, the load function fails with an
+ unhelpful error message. If we skip it, we get the correct behaviour (no
+ certificates are recognized, but the error message is still misleading (it
+ says no certificate was supplied). But this is better. */
+
+ if ( (!file || statbuf.st_size > 0)
+ && !SSL_CTX_load_verify_locations(sctx, CS file, CS dir))
+ return tls_error(US"SSL_CTX_load_verify_locations",
+ host, NULL, errstr);
+
+ /* On the server load the list of CAs for which we will accept certs, for
+ sending to the client. This is only for the one-file
+ tls_verify_certificates variant.
+ If a list isn't loaded into the server, but some verify locations are set,
+ the server end appears to make a wildcard request for client certs.
+ Meanwhile, the client library as default behaviour *ignores* the list
+ we send over the wire - see man SSL_CTX_set_client_cert_cb.
+ Because of this, and that the dir variant is likely only used for
+ the public-CA bundle (not for a private CA), not worth fixing. */
+
+ if (file)
+ {
+ STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file);
+ int i = sk_X509_NAME_num(names);
+
+ if (!host) SSL_CTX_set_client_CA_list(sctx, names);
+ DEBUG(D_tls) debug_printf("Added %d additional certificate authorit%s\n",
+ i, i>1 ? "ies":"y");
+ }
+ else
+ DEBUG(D_tls)
+ debug_printf("Added dir for additional certificate authorities\n");
}
}
/* Handle a certificate revocation list. */
- #if OPENSSL_VERSION_NUMBER > 0x00907000L
+#if OPENSSL_VERSION_NUMBER > 0x00907000L
/* This bit of code is now the version supplied by Lars Mainka. (I have
- * merely reformatted it into the Exim code style.)
+ merely reformatted it into the Exim code style.)
- * "From here I changed the code to add support for multiple crl's
- * in pem format in one file or to support hashed directory entries in
- * pem format instead of a file. This method now uses the library function
- * X509_STORE_load_locations to add the CRL location to the SSL context.
- * OpenSSL will then handle the verify against CA certs and CRLs by
- * itself in the verify callback." */
+ "From here I changed the code to add support for multiple crl's
+ in pem format in one file or to support hashed directory entries in
+ pem format instead of a file. This method now uses the library function
+ X509_STORE_load_locations to add the CRL location to the SSL context.
+ OpenSSL will then handle the verify against CA certs and CRLs by
+ itself in the verify callback." */
- if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER;
- if (expcrl != NULL && *expcrl != 0)
+ if (!expand_check(crl, US"tls_crl", &expcrl, errstr)) return DEFER;
+ if (expcrl && *expcrl)
{
struct stat statbufcrl;
if (Ustat(expcrl, &statbufcrl) < 0)
DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file);
}
if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0)
- return tls_error(US"X509_STORE_load_locations", host, NULL);
+ return tls_error(US"X509_STORE_load_locations", host, NULL, errstr);
/* setting the flags to check against the complete crl chain */
}
}
- #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
-
- /* If verification is optional, don't fail if no certificate */
-
- SSL_CTX_set_verify(sctx,
- SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT),
- cert_vfy_cb);
+#endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
}
return OK;
/*************************************************
* Start a TLS session in a server *
*************************************************/
-
/* This is called when Exim is running as a server, after having received
the STARTTLS command. It must respond to that command, and then negotiate
a TLS session.
Arguments:
- require_ciphers allowed ciphers
+ errstr pointer to error message
Returns: OK on success
DEFER for errors before the start of the negotiation
- FAIL for errors during the negotation; the server can't
+ FAIL for errors during the negotiation; the server can't
continue running.
*/
int
-tls_server_start(const uschar *require_ciphers)
+tls_server_start(uschar ** errstr)
{
int rc;
-uschar *expciphers;
-tls_ext_ctx_cb *cbinfo;
-static uschar cipherbuf[256];
+uschar * expciphers;
+exim_openssl_state_st * dummy_statep;
+SSL_CTX * ctx;
+SSL * ssl;
+static uschar peerdn[256];
/* Check for previous activation */
-if (tls_in.active >= 0)
+if (tls_in.active.sock >= 0)
{
- tls_error(US"STARTTLS received after TLS started", NULL, US"");
- smtp_printf("554 Already in TLS\r\n");
+ tls_error(US"STARTTLS received after TLS started", NULL, US"", errstr);
+ smtp_printf("554 Already in TLS\r\n", FALSE);
return FAIL;
}
/* Initialize the SSL library. If it fails, it will already have logged
the error. */
-rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey,
+rc = tls_init(NULL, NULL,
#ifndef DISABLE_OCSP
tls_ocsp_file,
#endif
- NULL, &server_static_cbinfo);
+ NULL, &dummy_statep, &tls_in, errstr);
if (rc != OK) return rc;
-cbinfo = server_static_cbinfo;
-
-if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers))
- return FAIL;
+ctx = state_server.lib_state.lib_ctx;
/* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
were historically separated by underscores. So that I can use either form in my
tests, and also for general convenience, we turn underscores into hyphens here.
+
+XXX SSL_CTX_set_cipher_list() is replaced by SSL_CTX_set_ciphersuites()
+for TLS 1.3 . Since we do not call it at present we get the default list:
+TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256
*/
-if (expciphers != NULL)
+if (state_server.lib_state.pri_string)
+ { DEBUG(D_tls) debug_printf("TLS: cipher list was preloaded\n"); }
+else
{
- uschar *s = expciphers;
- while (*s != 0) { if (*s == '_') *s = '-'; s++; }
- DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers);
- if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers))
- return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL);
- cbinfo->server_cipher_list = expciphers;
+ if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers, errstr))
+ return FAIL;
+
+ if (expciphers)
+ {
+ normalise_ciphers(&expciphers, tls_require_ciphers);
+ if ((rc = server_load_ciphers(ctx, &state_server, expciphers, errstr)) != OK)
+ return rc;
+ }
}
/* If this is a host for which certificate verification is mandatory or
optional, set up appropriately. */
tls_in.certificate_verified = FALSE;
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
tls_in.dane_verified = FALSE;
#endif
server_verify_callback_called = FALSE;
if (verify_check_host(&tls_verify_hosts) == OK)
- {
- rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL,
- FALSE, verify_callback_server);
- if (rc != OK) return rc;
server_verify_optional = FALSE;
- }
else if (verify_check_host(&tls_try_verify_hosts) == OK)
- {
- rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL,
- TRUE, verify_callback_server);
- if (rc != OK) return rc;
server_verify_optional = TRUE;
- }
+else
+ goto skip_certs;
+
+ {
+ uschar * expcerts;
+ if (!expand_check(tls_verify_certificates, US"tls_verify_certificates",
+ &expcerts, errstr))
+ return DEFER;
+ DEBUG(D_tls) debug_printf("tls_verify_certificates: %s\n", expcerts);
+
+ if (state_server.lib_state.cabundle)
+ { DEBUG(D_tls) debug_printf("TLS: CA bundle for server was preloaded\n"); }
+ else
+ if ((rc = setup_certs(ctx, expcerts, tls_crl, NULL, errstr)) != OK)
+ return rc;
+
+ if (expcerts && *expcerts)
+ setup_cert_verify(ctx, server_verify_optional, verify_callback_server);
+ }
+skip_certs: ;
+
+#ifndef DISABLE_TLS_RESUME
+# if OPENSSL_VERSION_NUMBER < 0x30000000L
+SSL_CTX_set_tlsext_ticket_key_cb(ctx, ticket_key_callback);
+/* despite working, appears to always return failure, so ignoring */
+# else
+SSL_CTX_set_tlsext_ticket_key_evp_cb(ctx, ticket_key_callback);
+/* despite working, appears to always return failure, so ignoring */
+# endif
+#endif
+
+#ifdef OPENSSL_HAVE_NUM_TICKETS
+# ifndef DISABLE_TLS_RESUME
+SSL_CTX_set_num_tickets(ctx, tls_in.host_resumable ? 1 : 0);
+# else
+SSL_CTX_set_num_tickets(ctx, 0); /* send no TLS1.3 stateful-tickets */
+# endif
+#endif
+
/* Prepare for new connection */
-if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL);
+if (!(ssl = SSL_new(ctx)))
+ return tls_error(US"SSL_new", NULL, NULL, errstr);
+state_server.lib_state.lib_ssl = ssl;
/* Warning: we used to SSL_clear(ssl) here, it was removed.
*
the response. Other smtp_printf() calls do not need it, because in non-TLS
mode, the fflush() happens when smtp_getc() is called. */
-SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx));
+SSL_set_session_id_context(ssl, sid_ctx, Ustrlen(sid_ctx));
if (!tls_in.on_connect)
{
- smtp_printf("220 TLS go ahead\r\n");
+ smtp_printf("220 TLS go ahead\r\n", FALSE);
fflush(smtp_out);
}
/* Now negotiate the TLS session. We put our own timer on it, since it seems
that the OpenSSL library doesn't. */
-SSL_set_wfd(server_ssl, fileno(smtp_out));
-SSL_set_rfd(server_ssl, fileno(smtp_in));
-SSL_set_accept_state(server_ssl);
+SSL_set_wfd(ssl, fileno(smtp_out));
+SSL_set_rfd(ssl, fileno(smtp_in));
+SSL_set_accept_state(ssl);
DEBUG(D_tls) debug_printf("Calling SSL_accept\n");
+ERR_clear_error();
sigalrm_seen = FALSE;
-if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
-rc = SSL_accept(server_ssl);
-alarm(0);
+if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout);
+rc = SSL_accept(ssl);
+ALARM_CLR(0);
if (rc <= 0)
{
- tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL);
- if (ERR_get_error() == 0)
- log_write(0, LOG_MAIN,
- "TLS client disconnected cleanly (rejected our certificate?)");
- return FAIL;
+ int error = SSL_get_error(ssl, rc);
+ switch(error)
+ {
+ case SSL_ERROR_NONE:
+ break;
+
+ case SSL_ERROR_ZERO_RETURN:
+ DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
+ (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr);
+ (void) event_raise(event_action, US"tls:fail:connect", *errstr, NULL);
+
+ if (SSL_get_shutdown(ssl) == SSL_RECEIVED_SHUTDOWN)
+ SSL_shutdown(ssl);
+
+ tls_close(NULL, TLS_NO_SHUTDOWN);
+ return FAIL;
+
+ /* Handle genuine errors */
+ case SSL_ERROR_SSL:
+ {
+ uschar * s = NULL;
+ int r = ERR_GET_REASON(ERR_peek_error());
+ if ( r == SSL_R_WRONG_VERSION_NUMBER
+#ifdef SSL_R_VERSION_TOO_LOW
+ || r == SSL_R_VERSION_TOO_LOW
+#endif
+ || r == SSL_R_UNKNOWN_PROTOCOL || r == SSL_R_UNSUPPORTED_PROTOCOL)
+ s = string_sprintf("(%s)", SSL_get_version(ssl));
+ (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : s, errstr);
+ (void) event_raise(event_action, US"tls:fail:connect", *errstr, NULL);
+ return FAIL;
+ }
+
+ default:
+ DEBUG(D_tls) debug_printf("Got SSL error %d\n", error);
+ if (error == SSL_ERROR_SYSCALL)
+ {
+ if (!errno)
+ {
+ *errstr = US"SSL_accept: TCP connection closed by peer";
+ (void) event_raise(event_action, US"tls:fail:connect", *errstr, NULL);
+ return FAIL;
+ }
+ DEBUG(D_tls) debug_printf(" - syscall %s\n", strerror(errno));
+ }
+ (void) tls_error(US"SSL_accept", NULL,
+ sigalrm_seen ? US"timed out"
+ : ERR_peek_error() ? NULL : string_sprintf("ret %d", error),
+ errstr);
+ (void) event_raise(event_action, US"tls:fail:connect", *errstr, NULL);
+ return FAIL;
+ }
}
DEBUG(D_tls) debug_printf("SSL_accept was successful\n");
+ERR_clear_error(); /* Even success can leave errors in the stack. Seen with
+ anon-authentication ciphersuite negotiated. */
+
+#ifndef DISABLE_TLS_RESUME
+if (SSL_session_reused(ssl))
+ {
+ tls_in.resumption |= RESUME_USED;
+ DEBUG(D_tls) debug_printf("Session reused\n");
+ }
+#endif
+
+#ifdef EXIM_HAVE_ALPN
+/* If require-alpn, check server_seen_alpn here. Else abort TLS */
+if (!tls_alpn || !*tls_alpn)
+ { DEBUG(D_tls) debug_printf("TLS: was not watching for ALPN\n"); }
+else if (!server_seen_alpn)
+ if (verify_check_host(&hosts_require_alpn) == OK)
+ {
+ /* We'd like to send a definitive Alert but OpenSSL provides no facility */
+ SSL_shutdown(ssl);
+ tls_error(US"handshake", NULL, US"ALPN required but not negotiated", errstr);
+ return FAIL;
+ }
+ else
+ { DEBUG(D_tls) debug_printf("TLS: no ALPN presented in handshake\n"); }
+else DEBUG(D_tls)
+ {
+ const uschar * name;
+ unsigned len;
+ SSL_get0_alpn_selected(ssl, &name, &len);
+ if (len && name)
+ debug_printf("ALPN negotiated: '%.*s'\n", (int)*name, name+1);
+ else
+ debug_printf("ALPN: no protocol negotiated\n");
+ }
+#endif
+
+
+/* TLS has been set up. Record data for the connection,
+adjust the input functions to read via TLS, and initialize things. */
-/* TLS has been set up. Adjust the input functions to read via TLS,
-and initialize things. */
+#ifdef SSL_get_extms_support
+tls_in.ext_master_secret = SSL_get_extms_support(ssl) == 1;
+#endif
+peer_cert(ssl, &tls_in, peerdn, sizeof(peerdn));
-construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits);
-tls_in.cipher = cipherbuf;
+tls_in.ver = tlsver_name(ssl);
+tls_in.cipher = construct_cipher_name(ssl, tls_in.ver, &tls_in.bits);
+tls_in.cipher_stdname = cipher_stdname_ssl(ssl);
DEBUG(D_tls)
{
uschar buf[2048];
- if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL)
+ if (SSL_get_shared_ciphers(ssl, CS buf, sizeof(buf)))
debug_printf("Shared ciphers: %s\n", buf);
+
+#ifdef EXIM_HAVE_OPENSSL_KEYLOG
+ {
+ BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
+ SSL_SESSION_print_keylog(bp, SSL_get_session(ssl));
+ BIO_free(bp);
+ }
+#endif
+
+#ifdef EXIM_HAVE_SESSION_TICKET
+ {
+ SSL_SESSION * ss = SSL_get_session(ssl);
+ if (SSL_SESSION_has_ticket(ss)) /* 1.1.0 */
+ debug_printf("The session has a ticket, life %lu seconds\n",
+ SSL_SESSION_get_ticket_lifetime_hint(ss));
+ }
+#endif
}
/* Record the certificate we presented */
{
- X509 * crt = SSL_get_certificate(server_ssl);
+ X509 * crt = SSL_get_certificate(ssl);
tls_in.ourcert = crt ? X509_dup(crt) : NULL;
}
+/* Channel-binding info for authenticators
+See description in https://paquier.xyz/postgresql-2/channel-binding-openssl/ */
+ {
+ uschar c, * s;
+ size_t len = SSL_get_peer_finished(ssl, &c, 0);
+ int old_pool = store_pool;
+
+ SSL_get_peer_finished(ssl, s = store_get((int)len, FALSE), len);
+ store_pool = POOL_PERM;
+ tls_in.channelbinding = b64encode_taint(CUS s, (int)len, FALSE);
+ store_pool = old_pool;
+ DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage %p\n", tls_in.channelbinding);
+ }
+
/* Only used by the server-side tls (tls_in), including tls_getc.
Client-side (tls_out) reads (seem to?) go via
smtp_read_response()/ip_recv().
Hence no need to duplicate for _in and _out.
*/
-ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size);
+if (!ssl_xfer_buffer) ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size);
ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0;
-ssl_xfer_eof = ssl_xfer_error = 0;
+ssl_xfer_eof = ssl_xfer_error = FALSE;
receive_getc = tls_getc;
+receive_getbuf = tls_getbuf;
+receive_get_cache = tls_get_cache;
+receive_hasc = tls_hasc;
receive_ungetc = tls_ungetc;
receive_feof = tls_feof;
receive_ferror = tls_ferror;
-receive_smtp_buffered = tls_smtp_buffered;
-tls_in.active = fileno(smtp_out);
+tls_in.active.sock = fileno(smtp_out);
+tls_in.active.tls_ctx = NULL; /* not using explicit ctx for server-side */
return OK;
}
static int
tls_client_basic_ctx_init(SSL_CTX * ctx,
- host_item * host, smtp_transport_options_block * ob
-#ifdef EXPERIMENTAL_CERTNAMES
- , tls_ext_ctx_cb * cbinfo
-#endif
- )
+ host_item * host, smtp_transport_options_block * ob, exim_openssl_state_st * state,
+ uschar ** errstr)
{
int rc;
-/* stick to the old behaviour for compatibility if tls_verify_certificates is
- set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only
- the specified host patterns if one of them is defined */
-if ( (!ob->tls_verify_hosts && !ob->tls_try_verify_hosts)
- || (verify_check_this_host(&ob->tls_verify_hosts, NULL,
- host->name, host->address, NULL) == OK)
+/* Back-compatible old behaviour if tls_verify_certificates is set but both
+tls_verify_hosts and tls_try_verify_hosts are not set. Check only the specified
+host patterns if one of them is set with content. */
+
+if ( ( ( !ob->tls_verify_hosts || !ob->tls_verify_hosts
+ || Ustrcmp(ob->tls_try_verify_hosts, ":") == 0
+ )
+ && ( !ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts
+ || Ustrcmp(ob->tls_try_verify_hosts, ":") == 0
+ )
+ )
+ || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK
)
client_verify_optional = FALSE;
-else if (verify_check_this_host(&ob->tls_try_verify_hosts, NULL,
- host->name, host->address, NULL) == OK)
+else if (verify_check_given_host(CUSS &ob->tls_try_verify_hosts, host) == OK)
client_verify_optional = TRUE;
else
return OK;
-if ((rc = setup_certs(ctx, ob->tls_verify_certificates,
- ob->tls_crl, host, client_verify_optional, verify_callback_client)) != OK)
- return rc;
+ {
+ uschar * expcerts;
+ if (!expand_check(ob->tls_verify_certificates, US"tls_verify_certificates",
+ &expcerts, errstr))
+ return DEFER;
+ DEBUG(D_tls) debug_printf("tls_verify_certificates: %s\n", expcerts);
+
+ if (state->lib_state.cabundle)
+ { DEBUG(D_tls) debug_printf("TLS: CA bundle was preloaded\n"); }
+ else
+ if ((rc = setup_certs(ctx, expcerts, ob->tls_crl, host, errstr)) != OK)
+ return rc;
+
+ if (expcerts && *expcerts)
+ setup_cert_verify(ctx, client_verify_optional, verify_callback_client);
+ }
-#ifdef EXPERIMENTAL_CERTNAMES
-if (verify_check_this_host(&ob->tls_verify_cert_hostnames, NULL,
- host->name, host->address, NULL) == OK)
+if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK)
{
- cbinfo->verify_cert_hostnames = host->name;
+ state->verify_cert_hostnames =
+#ifdef SUPPORT_I18N
+ string_domain_utf8_to_alabel(host->certname, NULL);
+#else
+ host->certname;
+#endif
DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n",
- cbinfo->verify_cert_hostnames);
+ state->verify_cert_hostnames);
}
-#endif
return OK;
}
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
static int
-dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa)
+dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa, uschar ** errstr)
{
-dns_record * rr;
dns_scan dnss;
const char * hostnames[2] = { CS host->name, NULL };
int found = 0;
if (DANESSL_init(ssl, NULL, hostnames) != 1)
- return tls_error(US"hostnames load", host, NULL);
+ return tls_error(US"hostnames load", host, NULL, errstr);
-for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
- rr;
+for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
- ) if (rr->type == T_TLSA)
+ ) if (rr->type == T_TLSA && rr->size > 3)
{
- uschar * p = rr->data;
+ const uschar * p = rr->data;
uint8_t usage, selector, mtype;
const char * mdname;
switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3))
{
default:
+ return tls_error(US"tlsa load", host, NULL, errstr);
case 0: /* action not taken */
- return tls_error(US"tlsa load", host, NULL);
case 1: break;
}
return OK;
log_write(0, LOG_MAIN, "DANE error: No usable TLSA records");
-return FAIL;
+return DEFER;
+}
+#endif /*SUPPORT_DANE*/
+
+
+
+#ifndef DISABLE_TLS_RESUME
+/* On the client, get any stashed session for the given IP from hints db
+and apply it to the ssl-connection for attempted resumption. */
+
+static void
+tls_retrieve_session(tls_support * tlsp, SSL * ssl, const uschar * key)
+{
+tlsp->resumption |= RESUME_SUPPORTED;
+if (tlsp->host_resumable)
+ {
+ dbdata_tls_session * dt;
+ int len;
+ open_db dbblock, * dbm_file;
+
+ tlsp->resumption |= RESUME_CLIENT_REQUESTED;
+ DEBUG(D_tls) debug_printf("checking for resumable session for %s\n", key);
+ if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE)))
+ {
+ /* key for the db is the IP */
+ if ((dt = dbfn_read_with_length(dbm_file, key, &len)))
+ {
+ SSL_SESSION * ss = NULL;
+ const uschar * sess_asn1 = dt->session;
+
+ len -= sizeof(dbdata_tls_session);
+ if (!(d2i_SSL_SESSION(&ss, &sess_asn1, (long)len)))
+ {
+ DEBUG(D_tls)
+ {
+ ERR_error_string_n(ERR_get_error(),
+ ssl_errstring, sizeof(ssl_errstring));
+ debug_printf("decoding session: %s\n", ssl_errstring);
+ }
+ }
+ else
+ {
+ unsigned long lifetime =
+#ifdef EXIM_HAVE_SESSION_TICKET
+ SSL_SESSION_get_ticket_lifetime_hint(ss);
+#else /* Use, fairly arbitrilarily, what we as server would */
+ f.running_in_test_harness ? 6 : ssl_session_timeout;
+#endif
+ if (lifetime + dt->time_stamp < time(NULL))
+ {
+ DEBUG(D_tls) debug_printf("session expired\n");
+ dbfn_delete(dbm_file, key);
+ }
+ else if (!SSL_set_session(ssl, ss))
+ {
+ DEBUG(D_tls)
+ {
+ ERR_error_string_n(ERR_get_error(),
+ ssl_errstring, sizeof(ssl_errstring));
+ debug_printf("applying session to ssl: %s\n", ssl_errstring);
+ }
+ }
+ else
+ {
+ DEBUG(D_tls) debug_printf("good session\n");
+ tlsp->resumption |= RESUME_CLIENT_SUGGESTED;
+ tlsp->verify_override = dt->verify_override;
+ tlsp->ocsp = dt->ocsp;
+ }
+ }
+ }
+ else
+ DEBUG(D_tls) debug_printf("no session record\n");
+ dbfn_close(dbm_file);
+ }
+ }
+}
+
+
+/* On the client, save the session for later resumption */
+
+static int
+tls_save_session_cb(SSL * ssl, SSL_SESSION * ss)
+{
+exim_openssl_state_st * cbinfo = SSL_get_ex_data(ssl, tls_exdata_idx);
+tls_support * tlsp;
+
+DEBUG(D_tls) debug_printf("tls_save_session_cb\n");
+
+if (!cbinfo || !(tlsp = cbinfo->tlsp)->host_resumable) return 0;
+
+# ifdef OPENSSL_HAVE_NUM_TICKETS
+if (SSL_SESSION_is_resumable(ss)) /* 1.1.1 */
+# endif
+ {
+ int len = i2d_SSL_SESSION(ss, NULL);
+ int dlen = sizeof(dbdata_tls_session) + len;
+ dbdata_tls_session * dt = store_get(dlen, TRUE);
+ uschar * s = dt->session;
+ open_db dbblock, * dbm_file;
+
+ DEBUG(D_tls) debug_printf("session is resumable\n");
+ tlsp->resumption |= RESUME_SERVER_TICKET; /* server gave us a ticket */
+
+ dt->verify_override = tlsp->verify_override;
+ dt->ocsp = tlsp->ocsp;
+ (void) i2d_SSL_SESSION(ss, &s); /* s gets bumped to end */
+
+ if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE)))
+ {
+ const uschar * key = cbinfo->host->address;
+ dbfn_delete(dbm_file, key);
+ dbfn_write(dbm_file, key, dt, dlen);
+ dbfn_close(dbm_file);
+ DEBUG(D_tls) debug_printf("wrote session (len %u) to db\n",
+ (unsigned)dlen);
+ }
+ }
+return 1;
+}
+
+
+static void
+tls_client_ctx_resume_prehandshake(
+ exim_openssl_client_tls_ctx * exim_client_ctx, tls_support * tlsp,
+ smtp_transport_options_block * ob, host_item * host)
+{
+/* Should the client request a session resumption ticket? */
+if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, host) == OK)
+ {
+ tlsp->host_resumable = TRUE;
+
+ SSL_CTX_set_session_cache_mode(exim_client_ctx->ctx,
+ SSL_SESS_CACHE_CLIENT
+ | SSL_SESS_CACHE_NO_INTERNAL | SSL_SESS_CACHE_NO_AUTO_CLEAR);
+ SSL_CTX_sess_set_new_cb(exim_client_ctx->ctx, tls_save_session_cb);
+ }
+}
+
+static BOOL
+tls_client_ssl_resume_prehandshake(SSL * ssl, tls_support * tlsp,
+ host_item * host, uschar ** errstr)
+{
+if (tlsp->host_resumable)
+ {
+ DEBUG(D_tls)
+ debug_printf("tls_resumption_hosts overrides openssl_options, enabling tickets\n");
+ SSL_clear_options(ssl, SSL_OP_NO_TICKET);
+
+ tls_exdata_idx = SSL_get_ex_new_index(0, 0, 0, 0, 0);
+ if (!SSL_set_ex_data(ssl, tls_exdata_idx, client_static_state))
+ {
+ tls_error(US"set ex_data", host, NULL, errstr);
+ return FALSE;
+ }
+ debug_printf("tls_exdata_idx %d cbinfo %p\n", tls_exdata_idx, client_static_state);
+ }
+
+tlsp->resumption = RESUME_SUPPORTED;
+/* Pick up a previous session, saved on an old ticket */
+tls_retrieve_session(tlsp, ssl, host->address);
+return TRUE;
+}
+
+static void
+tls_client_resume_posthandshake(exim_openssl_client_tls_ctx * exim_client_ctx,
+ tls_support * tlsp)
+{
+if (SSL_session_reused(exim_client_ctx->ssl))
+ {
+ DEBUG(D_tls) debug_printf("The session was reused\n");
+ tlsp->resumption |= RESUME_USED;
+ }
}
-#endif /*EXPERIMENTAL_DANE*/
+#endif /* !DISABLE_TLS_RESUME */
+
+
+#ifdef EXIM_HAVE_ALPN
+/* Expand and convert an Exim list to an ALPN list. False return for fail.
+NULL plist return for silent no-ALPN.
+*/
+
+static BOOL
+tls_alpn_plist(const uschar * tls_alpn, const uschar ** plist, unsigned * plen,
+ uschar ** errstr)
+{
+uschar * exp_alpn;
+
+if (!expand_check(tls_alpn, US"tls_alpn", &exp_alpn, errstr))
+ return FALSE;
+
+if (!exp_alpn)
+ {
+ DEBUG(D_tls) debug_printf("Setting TLS ALPN forced to fail, not sending\n");
+ *plist = NULL;
+ }
+else
+ {
+ /* The server implementation only accepts exactly one protocol name
+ but it's little extra code complexity in the client. */
+ const uschar * list = exp_alpn;
+ uschar * p = store_get(Ustrlen(exp_alpn), is_tainted(exp_alpn)), * s, * t;
+ int sep = 0;
+ uschar len;
+
+ for (t = p; s = string_nextinlist(&list, &sep, NULL, 0); t += len)
+ {
+ *t++ = len = (uschar) Ustrlen(s);
+ memcpy(t, s, len);
+ }
+ *plist = (*plen = t - p) ? p : NULL;
+ }
+return TRUE;
+}
+#endif /* EXIM_HAVE_ALPN */
/*************************************************
/* Called from the smtp transport after STARTTLS has been accepted.
-Argument:
- fd the fd of the connection
- host connected host (for messages)
- addr the first address
- tb transport (always smtp)
- tlsa_dnsa tlsa lookup, if DANE, else null
-
-Returns: OK on success
- FAIL otherwise - note that tls_error() will not give DEFER
- because this is not a server
+Arguments:
+ cctx connection context
+ conn_args connection details
+ cookie datum for randomness; can be NULL
+ tlsp record details of TLS channel configuration here; must be non-NULL
+ errstr error string pointer
+
+Returns: TRUE for success with TLS session context set in connection context,
+ FALSE on error
*/
-int
-tls_client_start(int fd, host_item *host, address_item *addr,
- transport_instance *tb
-#ifdef EXPERIMENTAL_DANE
- , dns_answer * tlsa_dnsa
-#endif
- )
+BOOL
+tls_client_start(client_conn_ctx * cctx, smtp_connect_args * conn_args,
+ void * cookie, tls_support * tlsp, uschar ** errstr)
{
-smtp_transport_options_block * ob =
- (smtp_transport_options_block *)tb->options_block;
-static uschar txt[256];
+host_item * host = conn_args->host; /* for msgs and option-tests */
+transport_instance * tb = conn_args->tblock; /* always smtp or NULL */
+smtp_transport_options_block * ob = tb
+ ? (smtp_transport_options_block *)tb->options_block
+ : &smtp_transport_option_defaults;
+exim_openssl_client_tls_ctx * exim_client_ctx;
uschar * expciphers;
-X509 * server_cert;
int rc;
-static uschar cipherbuf[256];
+static uschar peerdn[256];
#ifndef DISABLE_OCSP
BOOL request_ocsp = FALSE;
BOOL require_ocsp = FALSE;
#endif
-#ifdef EXPERIMENTAL_DANE
-tls_out.tlsa_usage = 0;
+rc = store_pool;
+store_pool = POOL_PERM;
+exim_client_ctx = store_get(sizeof(exim_openssl_client_tls_ctx), FALSE);
+exim_client_ctx->corked = NULL;
+store_pool = rc;
+
+#ifdef SUPPORT_DANE
+tlsp->tlsa_usage = 0;
#endif
#ifndef DISABLE_OCSP
{
-# ifdef EXPERIMENTAL_DANE
- if ( tlsa_dnsa
+# ifdef SUPPORT_DANE
+ /*XXX this should be moved to caller, to be common across gnutls/openssl */
+ if ( conn_args->dane
&& ob->hosts_request_ocsp[0] == '*'
&& ob->hosts_request_ocsp[1] == '\0'
)
}
# endif
- if ((require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp,
- NULL, host->name, host->address, NULL) == OK))
+ if ((require_ocsp =
+ verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK))
request_ocsp = TRUE;
else
-# ifdef EXPERIMENTAL_DANE
+# ifdef SUPPORT_DANE
if (!request_ocsp)
# endif
- request_ocsp = verify_check_this_host(&ob->hosts_request_ocsp,
- NULL, host->name, host->address, NULL) == OK;
+ request_ocsp =
+ verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK;
}
#endif
-rc = tls_init(&client_ctx, host, NULL,
- ob->tls_certificate, ob->tls_privatekey,
+rc = tls_init(host, ob,
#ifndef DISABLE_OCSP
(void *)(long)request_ocsp,
#endif
- addr, &client_static_cbinfo);
-if (rc != OK) return rc;
+ cookie, &client_static_state, tlsp, errstr);
+if (rc != OK) return FALSE;
+
+exim_client_ctx->ctx = client_static_state->lib_state.lib_ctx;
-tls_out.certificate_verified = FALSE;
+tlsp->certificate_verified = FALSE;
client_verify_callback_called = FALSE;
-if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers",
- &expciphers))
- return FAIL;
+expciphers = NULL;
+#ifdef SUPPORT_DANE
+if (conn_args->dane)
+ {
+ /* We fall back to tls_require_ciphers if unset, empty or forced failure, but
+ other failures should be treated as problems. */
+ if (ob->dane_require_tls_ciphers &&
+ !expand_check(ob->dane_require_tls_ciphers, US"dane_require_tls_ciphers",
+ &expciphers, errstr))
+ return FALSE;
+ if (expciphers && *expciphers == '\0')
+ expciphers = NULL;
-/* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
-are separated by underscores. So that I can use either form in my tests, and
-also for general convenience, we turn underscores into hyphens here. */
+ normalise_ciphers(&expciphers, ob->dane_require_tls_ciphers);
+ }
+#endif
+if (!expciphers)
+ {
+ if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers",
+ &expciphers, errstr))
+ return FALSE;
+
+ /* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
+ are separated by underscores. So that I can use either form in my tests, and
+ also for general convenience, we turn underscores into hyphens here. */
+
+ normalise_ciphers(&expciphers, ob->tls_require_ciphers);
+ }
-if (expciphers != NULL)
+if (expciphers)
{
- uschar *s = expciphers;
- while (*s != 0) { if (*s == '_') *s = '-'; s++; }
DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers);
- if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers))
- return tls_error(US"SSL_CTX_set_cipher_list", host, NULL);
+ if (!SSL_CTX_set_cipher_list(exim_client_ctx->ctx, CS expciphers))
+ {
+ tls_error(US"SSL_CTX_set_cipher_list", host, NULL, errstr);
+ return FALSE;
+ }
}
-#ifdef EXPERIMENTAL_DANE
-if (tlsa_dnsa)
+#ifdef SUPPORT_DANE
+if (conn_args->dane)
{
- SSL_CTX_set_verify(client_ctx,
+ SSL_CTX_set_verify(exim_client_ctx->ctx,
SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
verify_callback_client_dane);
if (!DANESSL_library_init())
- return tls_error(US"library init", host, NULL);
- if (DANESSL_CTX_init(client_ctx) <= 0)
- return tls_error(US"context init", host, NULL);
+ {
+ tls_error(US"library init", host, NULL, errstr);
+ return FALSE;
+ }
+ if (DANESSL_CTX_init(exim_client_ctx->ctx) <= 0)
+ {
+ tls_error(US"context init", host, NULL, errstr);
+ return FALSE;
+ }
}
else
#endif
- if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob
-#ifdef EXPERIMENTAL_CERTNAMES
- , client_static_cbinfo
+if (tls_client_basic_ctx_init(exim_client_ctx->ctx, host, ob,
+ client_static_state, errstr) != OK)
+ return FALSE;
+
+#ifndef DISABLE_TLS_RESUME
+tls_client_ctx_resume_prehandshake(exim_client_ctx, tlsp, ob, host);
#endif
- )) != OK)
- return rc;
-if ((client_ssl = SSL_new(client_ctx)) == NULL)
- return tls_error(US"SSL_new", host, NULL);
-SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx));
-SSL_set_fd(client_ssl, fd);
-SSL_set_connect_state(client_ssl);
+
+if (!(exim_client_ctx->ssl = SSL_new(exim_client_ctx->ctx)))
+ {
+ tls_error(US"SSL_new", host, NULL, errstr);
+ return FALSE;
+ }
+SSL_set_session_id_context(exim_client_ctx->ssl, sid_ctx, Ustrlen(sid_ctx));
+
+SSL_set_fd(exim_client_ctx->ssl, cctx->sock);
+SSL_set_connect_state(exim_client_ctx->ssl);
if (ob->tls_sni)
{
- if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni))
- return FAIL;
- if (tls_out.sni == NULL)
+ if (!expand_check(ob->tls_sni, US"tls_sni", &tlsp->sni, errstr))
+ return FALSE;
+ if (!tlsp->sni)
{
DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n");
}
- else if (!Ustrlen(tls_out.sni))
- tls_out.sni = NULL;
+ else if (!Ustrlen(tlsp->sni))
+ tlsp->sni = NULL;
else
{
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
- DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni);
- SSL_set_tlsext_host_name(client_ssl, tls_out.sni);
+ DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tlsp->sni);
+ SSL_set_tlsext_host_name(exim_client_ctx->ssl, tlsp->sni);
#else
- DEBUG(D_tls)
- debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n",
- tls_out.sni);
+ log_write(0, LOG_MAIN, "SNI unusable with this OpenSSL library version; ignoring \"%s\"\n",
+ tlsp->sni);
#endif
}
}
-#ifdef EXPERIMENTAL_DANE
-if (tlsa_dnsa)
- if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa)) != OK)
- return rc;
+if (ob->tls_alpn)
+#ifdef EXIM_HAVE_ALPN
+ {
+ const uschar * plist;
+ unsigned plen;
+
+ if (!tls_alpn_plist(ob->tls_alpn, &plist, &plen, errstr))
+ return FALSE;
+ if (plist)
+ if (SSL_set_alpn_protos(exim_client_ctx->ssl, plist, plen) != 0)
+ {
+ tls_error(US"alpn init", host, NULL, errstr);
+ return FALSE;
+ }
+ else
+ DEBUG(D_tls) debug_printf("Setting TLS ALPN '%s'\n", ob->tls_alpn);
+ }
+#else
+ log_write(0, LOG_MAIN, "ALPN unusable with this OpenSSL library version; ignoring \"%s\"\n",
+ ob->tls_alpn);
+#endif
+
+#ifdef SUPPORT_DANE
+if (conn_args->dane)
+ if (dane_tlsa_load(exim_client_ctx->ssl, host, &conn_args->tlsa_dnsa, errstr) != OK)
+ return FALSE;
#endif
#ifndef DISABLE_OCSP
/* Request certificate status at connection-time. If the server
does OCSP stapling we will get the callback (set in tls_init()) */
-# ifdef EXPERIMENTAL_DANE
+# ifdef SUPPORT_DANE
if (request_ocsp)
{
const uschar * s;
{ /* Re-eval now $tls_out_tlsa_usage is populated. If
this means we avoid the OCSP request, we wasted the setup
cost in tls_init(). */
- require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp,
- NULL, host->name, host->address, NULL) == OK;
- request_ocsp = require_ocsp ? TRUE
- : verify_check_this_host(&ob->hosts_request_ocsp,
- NULL, host->name, host->address, NULL) == OK;
+ require_ocsp = verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK;
+ request_ocsp = require_ocsp
+ || verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK;
}
}
-# endif
+# endif
+
+if (request_ocsp)
+ {
+ SSL_set_tlsext_status_type(exim_client_ctx->ssl, TLSEXT_STATUSTYPE_ocsp);
+ client_static_state->u_ocsp.client.verify_required = require_ocsp;
+ tlsp->ocsp = OCSP_NOT_RESP;
+ }
+#endif
+
+#ifndef DISABLE_TLS_RESUME
+if (!tls_client_ssl_resume_prehandshake(exim_client_ctx->ssl, tlsp, host,
+ errstr))
+ return FALSE;
+#endif
+
+#ifndef DISABLE_EVENT
+client_static_state->event_action = tb ? tb->event_action : NULL;
+#endif
+
+/* There doesn't seem to be a built-in timeout on connection. */
+
+DEBUG(D_tls) debug_printf("Calling SSL_connect\n");
+sigalrm_seen = FALSE;
+ALARM(ob->command_timeout);
+rc = SSL_connect(exim_client_ctx->ssl);
+ALARM_CLR(0);
+
+#ifdef SUPPORT_DANE
+if (conn_args->dane)
+ DANESSL_cleanup(exim_client_ctx->ssl);
+#endif
+
+if (rc <= 0)
+ {
+ tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL, errstr);
+ return FALSE;
+ }
-if (request_ocsp)
+DEBUG(D_tls)
+ {
+ debug_printf("SSL_connect succeeded\n");
+#ifdef EXIM_HAVE_OPENSSL_KEYLOG
{
- SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp);
- client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp;
- tls_out.ocsp = OCSP_NOT_RESP;
+ BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
+ SSL_SESSION_print_keylog(bp, SSL_get_session(exim_client_ctx->ssl));
+ BIO_free(bp);
}
#endif
+ }
-#ifdef EXPERIMENTAL_EVENT
-client_static_cbinfo->event_action = tb->event_action;
+#ifndef DISABLE_TLS_RESUME
+tls_client_resume_posthandshake(exim_client_ctx, tlsp);
#endif
-/* There doesn't seem to be a built-in timeout on connection. */
-
-DEBUG(D_tls) debug_printf("Calling SSL_connect\n");
-sigalrm_seen = FALSE;
-alarm(ob->command_timeout);
-rc = SSL_connect(client_ssl);
-alarm(0);
+#ifdef EXIM_HAVE_ALPN
+if (ob->tls_alpn) /* We requested. See what was negotiated. */
+ {
+ const uschar * name;
+ unsigned len;
-#ifdef EXPERIMENTAL_DANE
-if (tlsa_dnsa)
- DANESSL_cleanup(client_ssl);
+ SSL_get0_alpn_selected(exim_client_ctx->ssl, &name, &len);
+ if (len > 0)
+ { DEBUG(D_tls) debug_printf("ALPN negotiated %u: '%.*s'\n", len, (int)*name, name+1); }
+ else if (verify_check_given_host(CUSS &ob->hosts_require_alpn, host) == OK)
+ {
+ /* Would like to send a relevant fatal Alert, but OpenSSL has no API */
+ tls_error(US"handshake", host, US"ALPN required but not negotiated", errstr);
+ return FALSE;
+ }
+ }
#endif
-if (rc <= 0)
- return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL);
+#ifdef SSL_get_extms_support
+tlsp->ext_master_secret = SSL_get_extms_support(exim_client_ctx->ssl) == 1;
+#endif
+peer_cert(exim_client_ctx->ssl, tlsp, peerdn, sizeof(peerdn));
-DEBUG(D_tls) debug_printf("SSL_connect succeeded\n");
+tlsp->ver = tlsver_name(exim_client_ctx->ssl);
+tlsp->cipher = construct_cipher_name(exim_client_ctx->ssl, tlsp->ver, &tlsp->bits);
+tlsp->cipher_stdname = cipher_stdname_ssl(exim_client_ctx->ssl);
-/* Beware anonymous ciphers which lead to server_cert being NULL */
-/*XXX server_cert is never freed... use X509_free() */
-server_cert = SSL_get_peer_certificate (client_ssl);
-if (server_cert)
+/* Record the certificate we presented */
{
- tls_out.peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert),
- CS txt, sizeof(txt));
- tls_out.peerdn = txt; /*XXX a static buffer... */
+ X509 * crt = SSL_get_certificate(exim_client_ctx->ssl);
+ tlsp->ourcert = crt ? X509_dup(crt) : NULL;
}
-else
- tls_out.peerdn = NULL;
-
-construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits);
-tls_out.cipher = cipherbuf;
-/* Record the certificate we presented */
+/*XXX will this work with continued-TLS? */
+/* Channel-binding info for authenticators */
{
- X509 * crt = SSL_get_certificate(client_ssl);
- tls_out.ourcert = crt ? X509_dup(crt) : NULL;
+ uschar c, * s;
+ size_t len = SSL_get_finished(exim_client_ctx->ssl, &c, 0);
+ int old_pool = store_pool;
+
+ SSL_get_finished(exim_client_ctx->ssl, s = store_get((int)len, TRUE), len);
+ store_pool = POOL_PERM;
+ tlsp->channelbinding = b64encode_taint(CUS s, (int)len, TRUE);
+ store_pool = old_pool;
+ DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage %p %p\n", tlsp->channelbinding, tlsp);
}
-tls_out.active = fd;
-return OK;
+tlsp->active.sock = cctx->sock;
+tlsp->active.tls_ctx = exim_client_ctx;
+cctx->tls_ctx = exim_client_ctx;
+return TRUE;
}
+static BOOL
+tls_refill(unsigned lim)
+{
+SSL * ssl = state_server.lib_state.lib_ssl;
+int error;
+int inbytes;
+
+DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl,
+ ssl_xfer_buffer, ssl_xfer_buffer_size);
+
+ERR_clear_error();
+if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout);
+inbytes = SSL_read(ssl, CS ssl_xfer_buffer,
+ MIN(ssl_xfer_buffer_size, lim));
+error = SSL_get_error(ssl, inbytes);
+if (smtp_receive_timeout > 0) ALARM_CLR(0);
+
+if (had_command_timeout) /* set by signal handler */
+ smtp_command_timeout_exit(); /* does not return */
+if (had_command_sigterm)
+ smtp_command_sigterm_exit();
+if (had_data_timeout)
+ smtp_data_timeout_exit();
+if (had_data_sigint)
+ smtp_data_sigint_exit();
+
+/* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been
+closed down, not that the socket itself has been closed down. Revert to
+non-SSL handling. */
+
+switch(error)
+ {
+ case SSL_ERROR_NONE:
+ break;
+
+ case SSL_ERROR_ZERO_RETURN:
+ DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
+
+ if (SSL_get_shutdown(ssl) == SSL_RECEIVED_SHUTDOWN)
+ SSL_shutdown(ssl);
+
+ tls_close(NULL, TLS_NO_SHUTDOWN);
+ return FALSE;
+
+ /* Handle genuine errors */
+ case SSL_ERROR_SSL:
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring);
+ ssl_xfer_error = TRUE;
+ return FALSE;
+
+ default:
+ DEBUG(D_tls) debug_printf("Got SSL error %d\n", error);
+ DEBUG(D_tls) if (error == SSL_ERROR_SYSCALL)
+ debug_printf(" - syscall %s\n", strerror(errno));
+ ssl_xfer_error = TRUE;
+ return FALSE;
+ }
+
+#ifndef DISABLE_DKIM
+dkim_exim_verify_feed(ssl_xfer_buffer, inbytes);
+#endif
+ssl_xfer_buffer_hwm = inbytes;
+ssl_xfer_buffer_lwm = 0;
+return TRUE;
+}
+
+
/*************************************************
* TLS version of getc *
*************************************************/
/* This gets the next byte from the TLS input buffer. If the buffer is empty,
it refills the buffer via the SSL reading function.
-Arguments: none
+Arguments: lim Maximum amount to read/buffer
Returns: the next character or EOF
Only used by the server-side TLS.
*/
int
-tls_getc(void)
+tls_getc(unsigned lim)
{
if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm)
- {
- int error;
- int inbytes;
-
- DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl,
- ssl_xfer_buffer, ssl_xfer_buffer_size);
-
- if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
- inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size);
- error = SSL_get_error(server_ssl, inbytes);
- alarm(0);
+ if (!tls_refill(lim))
+ return ssl_xfer_error ? EOF : smtp_getc(lim);
- /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been
- closed down, not that the socket itself has been closed down. Revert to
- non-SSL handling. */
+/* Something in the buffer; return next uschar */
- if (error == SSL_ERROR_ZERO_RETURN)
- {
- DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
+return ssl_xfer_buffer[ssl_xfer_buffer_lwm++];
+}
- receive_getc = smtp_getc;
- receive_ungetc = smtp_ungetc;
- receive_feof = smtp_feof;
- receive_ferror = smtp_ferror;
- receive_smtp_buffered = smtp_buffered;
-
- SSL_free(server_ssl);
- server_ssl = NULL;
- tls_in.active = -1;
- tls_in.bits = 0;
- tls_in.cipher = NULL;
- tls_in.peerdn = NULL;
- tls_in.sni = NULL;
-
- return smtp_getc();
- }
+BOOL
+tls_hasc(void)
+{
+return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm;
+}
- /* Handle genuine errors */
+uschar *
+tls_getbuf(unsigned * len)
+{
+unsigned size;
+uschar * buf;
- else if (error == SSL_ERROR_SSL)
+if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm)
+ if (!tls_refill(*len))
{
- ERR_error_string(ERR_get_error(), ssl_errstring);
- log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring);
- ssl_xfer_error = 1;
- return EOF;
+ if (!ssl_xfer_error) return smtp_getbuf(len);
+ *len = 0;
+ return NULL;
}
- else if (error != SSL_ERROR_NONE)
- {
- DEBUG(D_tls) debug_printf("Got SSL error %d\n", error);
- ssl_xfer_error = 1;
- return EOF;
- }
+if ((size = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm) > *len)
+ size = *len;
+buf = &ssl_xfer_buffer[ssl_xfer_buffer_lwm];
+ssl_xfer_buffer_lwm += size;
+*len = size;
+return buf;
+}
+
+void
+tls_get_cache(unsigned lim)
+{
#ifndef DISABLE_DKIM
- dkim_exim_verify_feed(ssl_xfer_buffer, inbytes);
+int n = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm;
+debug_printf("tls_get_cache\n");
+if (n > lim)
+ n = lim;
+if (n > 0)
+ dkim_exim_verify_feed(ssl_xfer_buffer+ssl_xfer_buffer_lwm, n);
#endif
- ssl_xfer_buffer_hwm = inbytes;
- ssl_xfer_buffer_lwm = 0;
- }
+}
-/* Something in the buffer; return next uschar */
-return ssl_xfer_buffer[ssl_xfer_buffer_lwm++];
+BOOL
+tls_could_getc(void)
+{
+return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm
+ || SSL_pending(state_server.lib_state.lib_ssl) > 0;
}
-
/*************************************************
* Read bytes from TLS channel *
*************************************************/
/*
Arguments:
+ ct_ctx client context pointer, or NULL for the one global server context
buff buffer of data
len size of buffer
Returns: the number of bytes read
- -1 after a failed read
+ -1 after a failed read, including EOF
Only used by the client-side TLS.
*/
int
-tls_read(BOOL is_server, uschar *buff, size_t len)
+tls_read(void * ct_ctx, uschar *buff, size_t len)
{
-SSL *ssl = is_server ? server_ssl : client_ssl;
+SSL * ssl = ct_ctx ? ((exim_openssl_client_tls_ctx *)ct_ctx)->ssl
+ : state_server.lib_state.lib_ssl;
int inbytes;
int error;
DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", ssl,
buff, (unsigned int)len);
+ERR_clear_error();
inbytes = SSL_read(ssl, CS buff, len);
error = SSL_get_error(ssl, inbytes);
return -1;
}
else if (error != SSL_ERROR_NONE)
- {
return -1;
- }
return inbytes;
}
/*
Arguments:
- is_server channel specifier
+ ct_ctx client context pointer, or NULL for the one global server context
buff buffer of data
len number of bytes
+ more further data expected soon
Returns: the number of bytes after a successful write,
-1 after a failed write
-Used by both server-side and client-side TLS.
+Used by both server-side and client-side TLS. Calling with len zero and more unset
+will flush buffered writes; buff can be null for this case.
*/
int
-tls_write(BOOL is_server, const uschar *buff, size_t len)
+tls_write(void * ct_ctx, const uschar * buff, size_t len, BOOL more)
{
-int outbytes;
-int error;
-int left = len;
-SSL *ssl = is_server ? server_ssl : client_ssl;
+size_t olen = len;
+int outbytes, error;
+SSL * ssl = ct_ctx
+ ? ((exim_openssl_client_tls_ctx *)ct_ctx)->ssl
+ : state_server.lib_state.lib_ssl;
+static gstring * server_corked = NULL;
+gstring ** corkedp = ct_ctx
+ ? &((exim_openssl_client_tls_ctx *)ct_ctx)->corked : &server_corked;
+gstring * corked = *corkedp;
+
+DEBUG(D_tls) debug_printf("%s(%p, %lu%s)\n", __FUNCTION__,
+ buff, (unsigned long)len, more ? ", more" : "");
+
+/* Lacking a CORK or MSG_MORE facility (such as GnuTLS has) we copy data when
+"more" is notified. This hack is only ok if small amounts are involved AND only
+one stream does it, in one context (i.e. no store reset). Currently it is used
+for the responses to the received SMTP MAIL , RCPT, DATA sequence, only.
+We support callouts done by the server process by using a separate client
+context for the stashed information. */
+/* + if PIPE_COMMAND, banner & ehlo-resp for smmtp-on-connect. Suspect there's
+a store reset there, so use POOL_PERM. */
+/* + if CHUNKING, cmds EHLO,MAIL,RCPT(s),BDAT */
+
+if (more || corked)
+ {
+ if (!len) buff = US &error; /* dummy just so that string_catn is ok */
+
+ int save_pool = store_pool;
+ store_pool = POOL_PERM;
+
+ corked = string_catn(corked, buff, len);
+
+ store_pool = save_pool;
+
+ if (more)
+ {
+ *corkedp = corked;
+ return len;
+ }
+ buff = CUS corked->s;
+ len = corked->ptr;
+ *corkedp = NULL;
+ }
-DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left);
-while (left > 0)
+for (int left = len; left > 0;)
{
- DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left);
+ DEBUG(D_tls) debug_printf("SSL_write(%p, %p, %d)\n", ssl, buff, left);
+ ERR_clear_error();
outbytes = SSL_write(ssl, CS buff, left);
error = SSL_get_error(ssl, outbytes);
DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error);
switch (error)
{
- case SSL_ERROR_SSL:
- ERR_error_string(ERR_get_error(), ssl_errstring);
- log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring);
- return -1;
+ case SSL_ERROR_NONE: /* the usual case */
+ left -= outbytes;
+ buff += outbytes;
+ break;
- case SSL_ERROR_NONE:
- left -= outbytes;
- buff += outbytes;
- break;
+ case SSL_ERROR_SSL:
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring);
+ return -1;
case SSL_ERROR_ZERO_RETURN:
- log_write(0, LOG_MAIN, "SSL channel closed on write");
- return -1;
+ log_write(0, LOG_MAIN, "SSL channel closed on write");
+ return -1;
case SSL_ERROR_SYSCALL:
- log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s",
- sender_fullhost ? sender_fullhost : US"<unknown>",
- strerror(errno));
+ if (ct_ctx || errno != ECONNRESET || !f.smtp_in_quit)
+ log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s",
+ sender_fullhost ? sender_fullhost : US"<unknown>",
+ strerror(errno));
+ else if (LOGGING(protocol_detail))
+ log_write(0, LOG_MAIN, "[%s] after QUIT, client reset TCP before"
+ " SMTP response and TLS close\n", sender_host_address);
+ else
+ DEBUG(D_tls) debug_printf("[%s] SSL_write: after QUIT,"
+ " client reset TCP before TLS close\n", sender_host_address);
+ return -1;
default:
- log_write(0, LOG_MAIN, "SSL_write error %d", error);
- return -1;
+ log_write(0, LOG_MAIN, "SSL_write error %d", error);
+ return -1;
}
}
-return len;
+return olen;
}
+/*
+Arguments:
+ ct_ctx client TLS context pointer, or NULL for the one global server context
+*/
+
+void
+tls_shutdown_wr(void * ct_ctx)
+{
+exim_openssl_client_tls_ctx * o_ctx = ct_ctx;
+SSL ** sslp = o_ctx ? &o_ctx->ssl : (SSL **) &state_server.lib_state.lib_ssl;
+int * fdp = o_ctx ? &tls_out.active.sock : &tls_in.active.sock;
+int rc;
+
+if (*fdp < 0) return; /* TLS was not active */
+
+tls_write(ct_ctx, NULL, 0, FALSE); /* flush write buffer */
+
+HDEBUG(D_transport|D_tls|D_acl|D_v) debug_printf_indent(" SMTP(TLS shutdown)>>\n");
+rc = SSL_shutdown(*sslp);
+if (rc < 0) DEBUG(D_tls)
+ {
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ debug_printf("SSL_shutdown: %s\n", ssl_errstring);
+ }
+}
+
/*************************************************
* Close down a TLS session *
*************************************************/
daemon, to shut down the TLS library, without actually doing a shutdown (which
would tamper with the SSL session in the parent process).
-Arguments: TRUE if SSL_shutdown is to be called
+Arguments:
+ ct_ctx client TLS context pointer, or NULL for the one global server context
+ do_shutdown 0 no data-flush or TLS close-alert
+ 1 if TLS close-alert is to be sent,
+ 2 if also response to be waited for
+
Returns: nothing
Used by both server-side and client-side TLS.
*/
void
-tls_close(BOOL is_server, BOOL shutdown)
+tls_close(void * ct_ctx, int do_shutdown)
{
-SSL **sslp = is_server ? &server_ssl : &client_ssl;
-int *fdp = is_server ? &tls_in.active : &tls_out.active;
+exim_openssl_client_tls_ctx * o_ctx = ct_ctx;
+SSL ** sslp = o_ctx ? &o_ctx->ssl : (SSL **) &state_server.lib_state.lib_ssl;
+int * fdp = o_ctx ? &tls_out.active.sock : &tls_in.active.sock;
if (*fdp < 0) return; /* TLS was not active */
-if (shutdown)
+if (do_shutdown)
+ {
+ int rc;
+ DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n",
+ do_shutdown > 1 ? " (with response-wait)" : "");
+
+ tls_write(ct_ctx, NULL, 0, FALSE); /* flush write buffer */
+
+ if ( (rc = SSL_shutdown(*sslp)) == 0 /* send "close notify" alert */
+ && do_shutdown > 1)
+ {
+ ALARM(2);
+ rc = SSL_shutdown(*sslp); /* wait for response */
+ ALARM_CLR(0);
+ }
+
+ if (rc < 0) DEBUG(D_tls)
+ {
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ debug_printf("SSL_shutdown: %s\n", ssl_errstring);
+ }
+ }
+
+if (!o_ctx) /* server side */
{
- DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n");
- SSL_shutdown(*sslp);
+#ifndef DISABLE_OCSP
+ sk_X509_pop_free(state_server.verify_stack, X509_free);
+ state_server.verify_stack = NULL;
+#endif
+
+ receive_getc = smtp_getc;
+ receive_getbuf = smtp_getbuf;
+ receive_get_cache = smtp_get_cache;
+ receive_hasc = smtp_hasc;
+ receive_ungetc = smtp_ungetc;
+ receive_feof = smtp_feof;
+ receive_ferror = smtp_ferror;
+ tls_in.active.tls_ctx = NULL;
+ tls_in.sni = NULL;
+ /* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */
}
SSL_free(*sslp);
*sslp = NULL;
-
*fdp = -1;
}
SSL_CTX *ctx;
uschar *s, *expciphers, *err;
-/* this duplicates from tls_init(), we need a better "init just global
-state, for no specific purpose" singleton function of our own */
-
-SSL_load_error_strings();
-OpenSSL_add_ssl_algorithms();
-#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
-/* SHA256 is becoming ever more popular. This makes sure it gets added to the
-list of available digests. */
-EVP_add_digest(EVP_sha256());
-#endif
+tls_openssl_init();
if (!(tls_require_ciphers && *tls_require_ciphers))
return NULL;
-if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers,
+ &err))
return US"failed to expand tls_require_ciphers";
if (!(expciphers && *expciphers))
return NULL;
-/* normalisation ripped from above */
-s = expciphers;
-while (*s != 0) { if (*s == '_') *s = '-'; s++; }
+normalise_ciphers(&expciphers, tls_require_ciphers);
err = NULL;
-
-ctx = SSL_CTX_new(SSLv23_server_method());
-if (!ctx)
+if (lib_ctx_new(&ctx, NULL, &err) == OK)
{
- ERR_error_string(ERR_get_error(), ssl_errstring);
- return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring);
- }
+ DEBUG(D_tls)
+ debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers);
-DEBUG(D_tls)
- debug_printf("tls_require_ciphers expands to \"%s\"\n", expciphers);
+ if (!SSL_CTX_set_cipher_list(ctx, CS expciphers))
+ {
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed: %s",
+ expciphers, ssl_errstring);
+ }
-if (!SSL_CTX_set_cipher_list(ctx, CS expciphers))
- {
- ERR_error_string(ERR_get_error(), ssl_errstring);
- err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers);
+ SSL_CTX_free(ctx);
}
-
-SSL_CTX_free(ctx);
-
return err;
}
int i, needed_len;
static pid_t pidlast = 0;
pid_t pidnow;
-uschar *p;
uschar smallbuf[sizeof(r)];
if (max <= 1)
gettimeofday(&r.tv, NULL);
r.p = getpid();
- RAND_seed((uschar *)(&r), sizeof(r));
+ RAND_seed(US (&r), sizeof(r));
}
/* We're after pseudo-random, not random; if we still don't have enough data
in the internal PRNG then our options are limited. We could sleep and hope
if (i < needed_len)
needed_len = i;
+#ifdef EXIM_HAVE_RAND_PSEUDO
/* We do not care if crypto-strong */
i = RAND_pseudo_bytes(smallbuf, needed_len);
+#else
+i = RAND_bytes(smallbuf, needed_len);
+#endif
+
if (i < 0)
{
DEBUG(D_all)
}
r = 0;
-for (p = smallbuf; needed_len; --needed_len, ++p)
- {
- r *= 256;
- r += *p;
- }
+for (uschar * p = smallbuf; needed_len; --needed_len, ++p)
+ r = 256 * r + *p;
/* We don't particularly care about weighted results; if someone wants
smooth distribution and cares enough then they should submit a patch then. */
Returns success or failure in parsing
*/
-struct exim_openssl_option {
- uschar *name;
- long value;
-};
-/* We could use a macro to expand, but we need the ifdef and not all the
-options document which version they were introduced in. Policylet: include
-all options unless explicitly for DTLS, let the administrator choose which
-to apply.
-
-This list is current as of:
- ==> 1.0.1b <==
-Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev
-*/
-static struct exim_openssl_option exim_openssl_options[] = {
-/* KEEP SORTED ALPHABETICALLY! */
-#ifdef SSL_OP_ALL
- { US"all", SSL_OP_ALL },
-#endif
-#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
- { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION },
-#endif
-#ifdef SSL_OP_CIPHER_SERVER_PREFERENCE
- { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE },
-#endif
-#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
- { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS },
-#endif
-#ifdef SSL_OP_EPHEMERAL_RSA
- { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA },
-#endif
-#ifdef SSL_OP_LEGACY_SERVER_CONNECT
- { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT },
-#endif
-#ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
- { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER },
-#endif
-#ifdef SSL_OP_MICROSOFT_SESS_ID_BUG
- { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG },
-#endif
-#ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING
- { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING },
-#endif
-#ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG
- { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG },
-#endif
-#ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
- { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG },
-#endif
-#ifdef SSL_OP_NO_COMPRESSION
- { US"no_compression", SSL_OP_NO_COMPRESSION },
-#endif
-#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
- { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION },
-#endif
-#ifdef SSL_OP_NO_SSLv2
- { US"no_sslv2", SSL_OP_NO_SSLv2 },
-#endif
-#ifdef SSL_OP_NO_SSLv3
- { US"no_sslv3", SSL_OP_NO_SSLv3 },
-#endif
-#ifdef SSL_OP_NO_TICKET
- { US"no_ticket", SSL_OP_NO_TICKET },
-#endif
-#ifdef SSL_OP_NO_TLSv1
- { US"no_tlsv1", SSL_OP_NO_TLSv1 },
-#endif
-#ifdef SSL_OP_NO_TLSv1_1
-#if SSL_OP_NO_TLSv1_1 == 0x00000400L
- /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */
-#warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring
-#else
- { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 },
-#endif
-#endif
-#ifdef SSL_OP_NO_TLSv1_2
- { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 },
-#endif
-#ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG
- { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG },
-#endif
-#ifdef SSL_OP_SINGLE_DH_USE
- { US"single_dh_use", SSL_OP_SINGLE_DH_USE },
-#endif
-#ifdef SSL_OP_SINGLE_ECDH_USE
- { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE },
-#endif
-#ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG
- { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG },
-#endif
-#ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
- { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG },
-#endif
-#ifdef SSL_OP_TLS_BLOCK_PADDING_BUG
- { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG },
-#endif
-#ifdef SSL_OP_TLS_D5_BUG
- { US"tls_d5_bug", SSL_OP_TLS_D5_BUG },
-#endif
-#ifdef SSL_OP_TLS_ROLLBACK_BUG
- { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG },
-#endif
-};
-static int exim_openssl_options_size =
- sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option);
static BOOL
tls_openssl_options_parse(uschar *option_spec, long *results)
{
long result, item;
-uschar *s, *end;
-uschar keep_c;
+uschar * exp, * end;
BOOL adding, item_parsed;
-result = 0L;
+/* Server: send no (<= TLS1.2) session tickets */
+result = SSL_OP_NO_TICKET;
+
/* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed
- * from default because it increases BEAST susceptibility. */
+from default because it increases BEAST susceptibility. */
#ifdef SSL_OP_NO_SSLv2
result |= SSL_OP_NO_SSLv2;
#endif
+#ifdef SSL_OP_NO_SSLv3
+result |= SSL_OP_NO_SSLv3;
+#endif
+#ifdef SSL_OP_SINGLE_DH_USE
+result |= SSL_OP_SINGLE_DH_USE;
+#endif
+#ifdef SSL_OP_NO_RENEGOTIATION
+result |= SSL_OP_NO_RENEGOTIATION;
+#endif
-if (option_spec == NULL)
+if (!option_spec)
{
*results = result;
return TRUE;
}
-for (s=option_spec; *s != '\0'; /**/)
+if (!expand_check(option_spec, US"openssl_options", &exp, &end))
+ return FALSE;
+
+for (uschar * s = exp; *s; /**/)
{
while (isspace(*s)) ++s;
if (*s == '\0')
return FALSE;
}
adding = *s++ == '+';
- for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ;
- keep_c = *end;
- *end = '\0';
- item_parsed = tls_openssl_one_option_parse(s, &item);
+ for (end = s; *end && !isspace(*end); ) end++;
+ item_parsed = tls_openssl_one_option_parse(string_copyn(s, end-s), &item);
if (!item_parsed)
{
DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s);
return FALSE;
}
- DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n",
- adding ? "adding" : "removing", result, item, s);
+ DEBUG(D_tls) debug_printf("openssl option, %s %08lx: %08lx (%s)\n",
+ adding ? "adding to " : "removing from", result, item, s);
if (adding)
result |= item;
else
result &= ~item;
- *end = keep_c;
s = end;
}
return TRUE;
}
+#endif /*!MACRO_PREDEF*/
/* vi: aw ai sw=2
*/
/* End of tls-openssl.c */
git://git.exim.org / exim.git / blobdiff