* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
/* See the file NOTICE for conditions of use and distribution. */
/* Copyright (c) Phil Pennock 2012 */
The code herein is a revamp of GnuTLS integration using the current APIs; the
original tls-gnu.c was based on a patch which was contributed by Nikos
-Mavroyanopoulos. The revamp is partially a rewrite, partially cut&paste as
+Mavrogiannopoulos. The revamp is partially a rewrite, partially cut&paste as
appropriate.
APIs current as of GnuTLS 2.12.18; note that the GnuTLS manual is for GnuTLS 3,
/* man-page is incorrect, gnutls_rnd() is not in gnutls.h: */
#include <gnutls/crypto.h>
+/* needed to disable PKCS11 autoload unless requested */
+#if GNUTLS_VERSION_NUMBER >= 0x020c00
+# include <gnutls/pkcs11.h>
+# define SUPPORT_PARAM_TO_PK_BITS
+#endif
+#if GNUTLS_VERSION_NUMBER < 0x030103 && !defined(DISABLE_OCSP)
+# warning "GnuTLS library version too old; define DISABLE_OCSP in Makefile"
+# define DISABLE_OCSP
+#endif
+#if GNUTLS_VERSION_NUMBER < 0x020a00 && !defined(DISABLE_EVENT)
+# warning "GnuTLS library version too old; tls:cert event unsupported"
+# define DISABLE_EVENT
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030000
+# define SUPPORT_SELFSIGN /* Uncertain what version is first usable but 2.12.23 is not */
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030306
+# define SUPPORT_CA_DIR
+#else
+# undef SUPPORT_CA_DIR
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030014
+# define SUPPORT_SYSDEFAULT_CABUNDLE
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030104
+# define GNUTLS_CERT_VFY_STATUS_PRINT
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030109
+# define SUPPORT_CORK
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x03010a
+# define SUPPORT_GNUTLS_SESS_DESC
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030300
+# define GNUTLS_AUTO_GLOBAL_INIT
+# define GNUTLS_AUTO_PKCS11_MANUAL
+#endif
+#if (GNUTLS_VERSION_NUMBER >= 0x030404) \
+ || (GNUTLS_VERSION_NUMBER >= 0x030311) && (GNUTLS_VERSION_NUMBER & 0xffff00 == 0x030300)
+# ifndef DISABLE_OCSP
+# define EXIM_HAVE_OCSP
+# endif
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030500
+# define SUPPORT_GNUTLS_KEYLOG
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030506 && !defined(DISABLE_OCSP)
+# define SUPPORT_SRV_OCSP_STACK
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030600
+# define GNUTLS_AUTO_DHPARAMS
+#endif
+#if GNUTLS_VERSION_NUMBER >= 0x030603
+# define EXIM_HAVE_TLS1_3
+# define SUPPORT_GNUTLS_EXT_RAW_PARSE
+# define GNUTLS_OCSP_STATUS_REQUEST_GET2
+#endif
+
+#ifdef SUPPORT_DANE
+# if GNUTLS_VERSION_NUMBER >= 0x030000
+# define DANESSL_USAGE_DANE_TA 2
+# define DANESSL_USAGE_DANE_EE 3
+# else
+# error GnuTLS version too early for DANE
+# endif
+# if GNUTLS_VERSION_NUMBER < 0x999999
+# define GNUTLS_BROKEN_DANE_VALIDATION
+# endif
+#endif
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+# if GNUTLS_VERSION_NUMBER < 0x030603
+# error GNUTLS version too early for session-resumption
+# endif
+#endif
+
+#ifndef DISABLE_OCSP
+# include <gnutls/ocsp.h>
+#endif
+#ifdef SUPPORT_DANE
+# include <gnutls/dane.h>
+#endif
+
+#include "tls-cipher-stdname.c"
+
+
+#ifdef MACRO_PREDEF
+void
+options_tls(void)
+{
+# ifdef EXPERIMENTAL_TLS_RESUME
+builtin_macro_create_var(US"_RESUME_DECODE", RESUME_DECODE_STRING );
+# endif
+# ifdef EXIM_HAVE_TLS1_3
+builtin_macro_create(US"_HAVE_TLS1_3");
+# endif
+# ifdef EXIM_HAVE_OCSP
+builtin_macro_create(US"_HAVE_TLS_OCSP");
+# endif
+# ifdef SUPPORT_SRV_OCSP_STACK
+builtin_macro_create(US"_HAVE_TLS_OCSP_LIST");
+# endif
+}
+#else
+
+
/* GnuTLS 2 vs 3
GnuTLS 3 only:
/* Values for verify_requirement */
-enum peer_verify_requirement { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED };
+enum peer_verify_requirement
+ { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED, VERIFY_DANE };
/* This holds most state for server or client; with this, we can set up an
outbound TLS-enabled connection in an ACL callout, while not stomping all
be set to point to content in one of these instances, as appropriate for
the stage of the process lifetime.
-Not handled here: globals tls_active, tls_bits, tls_cipher, tls_peerdn,
-tls_certificate_verified, tls_channelbinding_b64, tls_sni.
+Not handled here: global tlsp->tls_channelbinding.
*/
typedef struct exim_gnutls_state {
- gnutls_session_t session;
+ gnutls_session_t session;
gnutls_certificate_credentials_t x509_cred;
- gnutls_priority_t priority_cache;
+ gnutls_priority_t priority_cache;
enum peer_verify_requirement verify_requirement;
- int fd_in;
- int fd_out;
- BOOL peer_cert_verified;
- BOOL trigger_sni_changes;
- BOOL have_set_peerdn;
- const struct host_item *host;
- uschar *peerdn;
- uschar *ciphersuite;
- uschar *received_sni;
+ int fd_in;
+ int fd_out;
+
+ BOOL peer_cert_verified:1;
+ BOOL peer_dane_verified:1;
+ BOOL trigger_sni_changes:1;
+ BOOL have_set_peerdn:1;
+ BOOL xfer_eof:1; /*XXX never gets set! */
+ BOOL xfer_error:1;
+#ifdef SUPPORT_CORK
+ BOOL corked:1;
+#endif
+
+ const struct host_item *host; /* NULL if server */
+ gnutls_x509_crt_t peercert;
+ uschar *peerdn;
+ uschar *ciphersuite;
+ uschar *received_sni;
const uschar *tls_certificate;
const uschar *tls_privatekey;
const uschar *tls_verify_certificates;
const uschar *tls_crl;
const uschar *tls_require_ciphers;
+
uschar *exp_tls_certificate;
uschar *exp_tls_privatekey;
- uschar *exp_tls_sni;
uschar *exp_tls_verify_certificates;
uschar *exp_tls_crl;
uschar *exp_tls_require_ciphers;
+ const uschar *exp_tls_verify_cert_hostnames;
+#ifndef DISABLE_EVENT
+ uschar *event_action;
+#endif
+#ifdef SUPPORT_DANE
+ char * const * dane_data;
+ const int * dane_data_len;
+#endif
+
+ tls_support *tlsp; /* set in tls_init() */
uschar *xfer_buffer;
int xfer_buffer_lwm;
int xfer_buffer_hwm;
- int xfer_eof;
- int xfer_error;
} exim_gnutls_state_st;
static const exim_gnutls_state_st exim_gnutls_state_init = {
- NULL, NULL, NULL, VERIFY_NONE, -1, -1, FALSE, FALSE, FALSE,
- NULL, NULL, NULL, NULL,
- NULL, NULL, NULL, NULL, NULL, NULL,
- NULL, NULL, NULL, NULL, NULL, NULL,
- NULL, 0, 0, 0, 0,
+ /* all elements not explicitly intialised here get 0/NULL/FALSE */
+ .fd_in = -1,
+ .fd_out = -1,
};
/* Not only do we have our own APIs which don't pass around state, assuming
single-threaded to keep from processing data on an inbound TLS connection while
talking to another TLS connection for an outbound check. This does mean that
there's no way for heart-beats to be responded to, for the duration of the
-second connection. */
+second connection.
+XXX But see gnutls_session_get_ptr()
+*/
-static exim_gnutls_state_st state_server, state_client;
-static exim_gnutls_state_st *current_global_tls_state;
+static exim_gnutls_state_st state_server;
+#ifndef GNUTLS_AUTO_DHPARAMS
/* dh_params are initialised once within the lifetime of a process using TLS;
if we used TLS in a long-lived daemon, we'd have to reconsider this. But we
don't want to repeat this. */
static gnutls_dh_params_t dh_server_params = NULL;
+#endif
-/* No idea how this value was chosen; preserving it. Default is 3600. */
-
-static const int ssl_session_timeout = 200;
+static int ssl_session_timeout = 7200; /* Two hours */
-static const char * const exim_default_gnutls_priority = "NORMAL";
+static const uschar * const exim_default_gnutls_priority = US"NORMAL";
/* Guard library core initialisation */
static BOOL exim_gnutls_base_init_done = FALSE;
+#ifndef DISABLE_OCSP
+static BOOL gnutls_buggy_ocsp = FALSE;
+static BOOL exim_testharness_disable_ocsp_validity_check = FALSE;
+#endif
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+static gnutls_datum_t server_sessticket_key;
+#endif
/* ------------------------------------------------------------------------ */
/* macros */
/* Set this to control gnutls_global_set_log_level(); values 0 to 9 will setup
the library logging; a value less than 0 disables the calls to set up logging
-callbacks. */
+callbacks. GNuTLS also looks for an environment variable - except not for
+setuid binaries, making it useless - "GNUTLS_DEBUG_LEVEL".
+Allegedly the testscript line "GNUTLS_DEBUG_LEVEL=9 sudo exim ..." would work,
+but the env var must be added to /etc/sudoers too. */
#ifndef EXIM_GNUTLS_LIBRARY_LOG_LEVEL
-#define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1
+# define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1
#endif
#ifndef EXIM_CLIENT_DH_MIN_BITS
-#define EXIM_CLIENT_DH_MIN_BITS 1024
+# define EXIM_CLIENT_DH_MIN_BITS 1024
#endif
/* With GnuTLS 2.12.x+ we have gnutls_sec_param_to_pk_bits() with which we
can ask for a bit-strength. Without that, we stick to the constant we had
before, for now. */
#ifndef EXIM_SERVER_DH_BITS_PRE2_12
-#define EXIM_SERVER_DH_BITS_PRE2_12 1024
+# define EXIM_SERVER_DH_BITS_PRE2_12 1024
#endif
-#define exim_gnutls_err_check(Label) do { \
- if (rc != GNUTLS_E_SUCCESS) { return tls_error((Label), gnutls_strerror(rc), host); } } while (0)
-
-#define expand_check_tlsvar(Varname) expand_check(state->Varname, US #Varname, &state->exp_##Varname)
+#define expand_check_tlsvar(Varname, errstr) \
+ expand_check(state->Varname, US #Varname, &state->exp_##Varname, errstr)
#if GNUTLS_VERSION_NUMBER >= 0x020c00
-#define HAVE_GNUTLS_SESSION_CHANNEL_BINDING
-#define HAVE_GNUTLS_SEC_PARAM_CONSTANTS
-#define HAVE_GNUTLS_RND
+# define HAVE_GNUTLS_SESSION_CHANNEL_BINDING
+# define HAVE_GNUTLS_SEC_PARAM_CONSTANTS
+# define HAVE_GNUTLS_RND
+/* The security fix we provide with the gnutls_allow_auto_pkcs11 option
+ * (4.82 PP/09) introduces a compatibility regression. The symbol simply
+ * isn't available sometimes, so this needs to become a conditional
+ * compilation; the sanest way to deal with this being a problem on
+ * older OSes is to block it in the Local/Makefile with this compiler
+ * definition */
+# ifndef AVOID_GNUTLS_PKCS11
+# define HAVE_GNUTLS_PKCS11
+# endif /* AVOID_GNUTLS_PKCS11 */
#endif
static int exim_sni_handling_cb(gnutls_session_t session);
+#ifdef EXPERIMENTAL_TLS_RESUME
+static int
+tls_server_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when,
+ unsigned incoming, const gnutls_datum_t * msg);
+#endif
+/* Daemon one-time initialisation */
+void
+tls_daemon_init(void)
+{
+#ifdef EXPERIMENTAL_TLS_RESUME
+/* We are dependent on the GnuTLS implementation of the Session Ticket
+encryption; both the strength and the key rotation period. We hope that
+the strength at least matches that of the ciphersuite (but GnuTLS does not
+document this). */
+
+static BOOL once = FALSE;
+if (once) return;
+once = TRUE;
+gnutls_session_ticket_key_generate(&server_sessticket_key); /* >= 2.10.0 */
+if (f.running_in_test_harness) ssl_session_timeout = 6;
+#endif
+}
/* ------------------------------------------------------------------------ */
/* Static functions */
usually obtained from gnutls_strerror()
host NULL if setting up a server;
the connected host if setting up a client
+ errstr pointer to returned error string
Returns: OK/DEFER/FAIL
*/
static int
-tls_error(const uschar *prefix, const char *msg, const host_item *host)
+tls_error(const uschar *prefix, const uschar *msg, const host_item *host,
+ uschar ** errstr)
{
-if (host)
- {
- log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s)%s%s",
- host->name, host->address, prefix, msg ? ": " : "", msg ? msg : "");
- return FAIL;
- }
-else
- {
- uschar *conn_info = smtp_get_connection_info();
- if (Ustrncmp(conn_info, US"SMTP ", 5) == 0)
- conn_info += 5;
- log_write(0, LOG_MAIN, "TLS error on %s (%s)%s%s",
- conn_info, prefix, msg ? ": " : "", msg ? msg : "");
- return DEFER;
- }
+if (errstr)
+ *errstr = string_sprintf("(%s)%s%s", prefix, msg ? ": " : "", msg ? msg : US"");
+return host ? FAIL : DEFER;
}
+static int
+tls_error_gnu(const uschar *prefix, int err, const host_item *host,
+ uschar ** errstr)
+{
+return tls_error(prefix, US gnutls_strerror(err), host, errstr);
+}
+
+static int
+tls_error_sys(const uschar *prefix, int err, const host_item *host,
+ uschar ** errstr)
+{
+return tls_error(prefix, US strerror(err), host, errstr);
+}
/*************************************************
state the current GnuTLS exim state container
rc the GnuTLS error code, or 0 if it's a local error
when text identifying read or write
- text local error text when ec is 0
+ text local error text when rc is 0
Returns: nothing
*/
static void
record_io_error(exim_gnutls_state_st *state, int rc, uschar *when, uschar *text)
{
-const char *msg;
+const uschar * msg;
+uschar * errstr;
if (rc == GNUTLS_E_FATAL_ALERT_RECEIVED)
- msg = CS string_sprintf("%s: %s", US gnutls_strerror(rc),
+ msg = string_sprintf("A TLS fatal alert has been received: %s",
US gnutls_alert_get_name(gnutls_alert_get(state->session)));
else
- msg = gnutls_strerror(rc);
+ msg = US gnutls_strerror(rc);
+
+(void) tls_error(when, msg, state->host, &errstr);
-tls_error(when, msg, state->host);
+if (state->host)
+ log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection %s",
+ state->host->name, state->host->address, errstr);
+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", conn_info, errstr);
+ }
}
* Set various Exim expansion vars *
*************************************************/
+#define exim_gnutls_cert_err(Label) \
+ do \
+ { \
+ if (rc != GNUTLS_E_SUCCESS) \
+ { \
+ DEBUG(D_tls) debug_printf("TLS: cert problem: %s: %s\n", \
+ (Label), gnutls_strerror(rc)); \
+ return rc; \
+ } \
+ } while (0)
+
+static int
+import_cert(const gnutls_datum_t * cert, gnutls_x509_crt_t * crtp)
+{
+int rc;
+
+rc = gnutls_x509_crt_init(crtp);
+exim_gnutls_cert_err(US"gnutls_x509_crt_init (crt)");
+
+rc = gnutls_x509_crt_import(*crtp, cert, GNUTLS_X509_FMT_DER);
+exim_gnutls_cert_err(US"failed to import certificate [gnutls_x509_crt_import(cert)]");
+
+return rc;
+}
+
+#undef exim_gnutls_cert_err
+
+
/* We set various Exim global variables from the state, once a session has
been established. With TLS callouts, may need to change this to stack
variables, or just re-call it with the server state after client callout
has finished.
-Make sure anything set here is inset in tls_getc().
+Make sure anything set here is unset in tls_getc().
Sets:
tls_active fd
tls_bits strength indicator
tls_certificate_verified bool indicator
- tls_channelbinding_b64 for some SASL mechanisms
+ tls_channelbinding for some SASL mechanisms
+ tls_ver a string
tls_cipher a string
+ tls_peercert pointer to library internal
tls_peerdn a string
tls_sni a (UTF-8) string
-Also:
- current_global_tls_state for API limitations
+ tls_ourcert pointer to library internal
Argument:
state the relevant exim_gnutls_state_st *
*/
static void
-extract_exim_vars_from_tls_state(exim_gnutls_state_st *state)
+extract_exim_vars_from_tls_state(exim_gnutls_state_st * state)
{
-gnutls_cipher_algorithm_t cipher;
#ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING
int old_pool;
int rc;
gnutls_datum_t channel;
#endif
+tls_support * tlsp = state->tlsp;
-current_global_tls_state = state;
-
-tls_active = state->fd_out;
+tlsp->active.sock = state->fd_out;
+tlsp->active.tls_ctx = state;
-cipher = gnutls_cipher_get(state->session);
-/* returns size in "bytes" */
-tls_bits = gnutls_cipher_get_key_size(cipher) * 8;
+DEBUG(D_tls) debug_printf("cipher: %s\n", state->ciphersuite);
-tls_cipher = state->ciphersuite;
-
-DEBUG(D_tls) debug_printf("cipher: %s\n", tls_cipher);
-
-tls_certificate_verified = state->peer_cert_verified;
+tlsp->certificate_verified = state->peer_cert_verified;
+#ifdef SUPPORT_DANE
+tlsp->dane_verified = state->peer_dane_verified;
+#endif
-/* note that tls_channelbinding_b64 is not saved to the spool file, since it's
+/* note that tls_channelbinding is not saved to the spool file, since it's
only available for use for authenticators while this TLS session is running. */
-tls_channelbinding_b64 = NULL;
+tlsp->channelbinding = NULL;
#ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING
channel.data = NULL;
channel.size = 0;
-rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel);
-if (rc) {
- DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc));
-} else {
+if ((rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel)))
+ { DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc)); }
+else
+ {
+ /* Declare the taintedness of the binding info. On server, untainted; on
+ client, tainted - being the Finish msg from the server. */
+
old_pool = store_pool;
store_pool = POOL_PERM;
- tls_channelbinding_b64 = auth_b64encode(channel.data, (int)channel.size);
+ tlsp->channelbinding = b64encode_taint(CUS channel.data, (int)channel.size,
+ !!state->host);
store_pool = old_pool;
- DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage.\n");
-}
+ DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage\n");
+ }
#endif
-tls_peerdn = state->peerdn;
+/* peercert is set in peer_status() */
+tlsp->peerdn = state->peerdn;
+tlsp->sni = state->received_sni;
-tls_sni = state->received_sni;
+/* record our certificate */
+ {
+ const gnutls_datum_t * cert = gnutls_certificate_get_ours(state->session);
+ gnutls_x509_crt_t crt;
+
+ tlsp->ourcert = cert && import_cert(cert, &crt)==0 ? crt : NULL;
+ }
}
+#ifndef GNUTLS_AUTO_DHPARAMS
/*************************************************
* Setup up DH parameters *
*************************************************/
*/
static int
-init_server_dh(void)
+init_server_dh(uschar ** errstr)
{
int fd, rc;
unsigned int dh_bits;
-gnutls_datum m;
+gnutls_datum_t m = {.data = NULL, .size = 0};
uschar filename_buf[PATH_MAX];
uschar *filename = NULL;
size_t sz;
uschar *exp_tls_dhparam;
BOOL use_file_in_spool = FALSE;
-BOOL use_fixed_file = FALSE;
host_item *host = NULL; /* dummy for macros */
DEBUG(D_tls) debug_printf("Initialising GnuTLS server params.\n");
-rc = gnutls_dh_params_init(&dh_server_params);
-exim_gnutls_err_check(US"gnutls_dh_params_init");
-
-m.data = NULL;
-m.size = 0;
+if ((rc = gnutls_dh_params_init(&dh_server_params)))
+ return tls_error_gnu(US"gnutls_dh_params_init", rc, host, errstr);
-if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam))
+if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam, errstr))
return DEFER;
if (!exp_tls_dhparam)
}
else if (exp_tls_dhparam[0] != '/')
{
- m.data = US std_dh_prime_named(exp_tls_dhparam);
- if (m.data == NULL)
- return tls_error(US"No standard prime named", CS exp_tls_dhparam, NULL);
+ if (!(m.data = US std_dh_prime_named(exp_tls_dhparam)))
+ return tls_error(US"No standard prime named", exp_tls_dhparam, NULL, errstr);
m.size = Ustrlen(m.data);
}
else
- {
- use_fixed_file = TRUE;
filename = exp_tls_dhparam;
- }
if (m.data)
{
- rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM);
- exim_gnutls_err_check(US"gnutls_dh_params_import_pkcs3");
+ if ((rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM)))
+ return tls_error_gnu(US"gnutls_dh_params_import_pkcs3", rc, host, errstr);
DEBUG(D_tls) debug_printf("Loaded fixed standard D-H parameters\n");
return OK;
}
#ifdef HAVE_GNUTLS_SEC_PARAM_CONSTANTS
/* If you change this constant, also change dh_param_fn_ext so that we can use a
different filename and ensure we have sufficient bits. */
-dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL);
-if (!dh_bits)
- return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL);
+
+if (!(dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL)))
+ return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL, errstr);
DEBUG(D_tls)
debug_printf("GnuTLS tells us that for D-H PK, NORMAL is %d bits.\n",
dh_bits);
{
if (!string_format(filename_buf, sizeof(filename_buf),
"%s/gnutls-params-%d", spool_directory, dh_bits))
- return tls_error(US"overlong filename", NULL, NULL);
+ return tls_error(US"overlong filename", NULL, NULL, errstr);
filename = filename_buf;
}
/* Open the cache file for reading and if successful, read it and set up the
parameters. */
-fd = Uopen(filename, O_RDONLY, 0);
-if (fd >= 0)
+if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0)
{
struct stat statbuf;
FILE *fp;
{
saved_errno = errno;
(void)close(fd);
- return tls_error(US"TLS cache stat failed", strerror(saved_errno), NULL);
+ return tls_error_sys(US"TLS cache stat failed", saved_errno, NULL, errstr);
}
if (!S_ISREG(statbuf.st_mode))
{
(void)close(fd);
- return tls_error(US"TLS cache not a file", NULL, NULL);
+ return tls_error(US"TLS cache not a file", NULL, NULL, errstr);
}
- fp = fdopen(fd, "rb");
- if (!fp)
+ if (!(fp = fdopen(fd, "rb")))
{
saved_errno = errno;
(void)close(fd);
- return tls_error(US"fdopen(TLS cache stat fd) failed",
- strerror(saved_errno), NULL);
+ return tls_error_sys(US"fdopen(TLS cache stat fd) failed",
+ saved_errno, NULL, errstr);
}
m.size = statbuf.st_size;
- m.data = malloc(m.size);
- if (m.data == NULL)
+ if (!(m.data = store_malloc(m.size)))
{
fclose(fp);
- return tls_error(US"malloc failed", strerror(errno), NULL);
+ return tls_error_sys(US"malloc failed", errno, NULL, errstr);
}
- sz = fread(m.data, m.size, 1, fp);
- if (!sz)
+ if (!(sz = fread(m.data, m.size, 1, fp)))
{
saved_errno = errno;
fclose(fp);
- free(m.data);
- return tls_error(US"fread failed", strerror(saved_errno), NULL);
+ store_free(m.data);
+ return tls_error_sys(US"fread failed", saved_errno, NULL, errstr);
}
fclose(fp);
rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM);
- free(m.data);
- exim_gnutls_err_check(US"gnutls_dh_params_import_pkcs3");
+ store_free(m.data);
+ if (rc)
+ return tls_error_gnu(US"gnutls_dh_params_import_pkcs3", rc, host, errstr);
DEBUG(D_tls) debug_printf("read D-H parameters from file \"%s\"\n", filename);
}
}
else
return tls_error(string_open_failed(errno, "\"%s\" for reading", filename),
- NULL, NULL);
+ NULL, NULL, errstr);
/* If ret < 0, either the cache file does not exist, or the data it contains
is not useful. One particular case of this is when upgrading from an older
if ((PATH_MAX - Ustrlen(filename)) < 10)
return tls_error(US"Filename too long to generate replacement",
- CS filename, NULL);
-
- temp_fn = string_copy(US "%s.XXXXXXX");
- fd = mkstemp(CS temp_fn); /* modifies temp_fn */
- if (fd < 0)
- return tls_error(US"Unable to open temp file", strerror(errno), NULL);
- (void)fchown(fd, exim_uid, exim_gid); /* Probably not necessary */
-
- /* GnuTLS overshoots!
- * If we ask for 2236, we might get 2237 or more.
- * But there's no way to ask GnuTLS how many bits there really are.
- * We can ask how many bits were used in a TLS session, but that's it!
- * The prime itself is hidden behind too much abstraction.
- * So we ask for less, and proceed on a wing and a prayer.
- * First attempt, subtracted 3 for 2233 and got 2240.
- */
+ filename, NULL, errstr);
+
+ temp_fn = string_copy(US"%s.XXXXXXX");
+ if ((fd = mkstemp(CS temp_fn)) < 0) /* modifies temp_fn */
+ return tls_error_sys(US"Unable to open temp file", errno, NULL, errstr);
+ (void)exim_chown(temp_fn, exim_uid, exim_gid); /* Probably not necessary */
+
+ /* GnuTLS overshoots! If we ask for 2236, we might get 2237 or more. But
+ there's no way to ask GnuTLS how many bits there really are. We can ask
+ how many bits were used in a TLS session, but that's it! The prime itself
+ is hidden behind too much abstraction. So we ask for less, and proceed on
+ a wing and a prayer. First attempt, subtracted 3 for 2233 and got 2240. */
+
if (dh_bits >= EXIM_CLIENT_DH_MIN_BITS + 10)
{
dh_bits_gen = dh_bits - 10;
DEBUG(D_tls)
debug_printf("requesting generation of %d bit Diffie-Hellman prime ...\n",
dh_bits_gen);
- rc = gnutls_dh_params_generate2(dh_server_params, dh_bits_gen);
- exim_gnutls_err_check(US"gnutls_dh_params_generate2");
+ if ((rc = gnutls_dh_params_generate2(dh_server_params, dh_bits_gen)))
+ return tls_error_gnu(US"gnutls_dh_params_generate2", rc, host, errstr);
/* gnutls_dh_params_export_pkcs3() will tell us the exact size, every time,
and I confirmed that a NULL call to get the size first is how the GnuTLS
sz = 0;
m.data = NULL;
- rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM,
- m.data, &sz);
- if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER)
- exim_gnutls_err_check(US"gnutls_dh_params_export_pkcs3(NULL) sizing");
+ if ( (rc = gnutls_dh_params_export_pkcs3(dh_server_params,
+ GNUTLS_X509_FMT_PEM, m.data, &sz))
+ && rc != GNUTLS_E_SHORT_MEMORY_BUFFER)
+ return tls_error_gnu(US"gnutls_dh_params_export_pkcs3(NULL) sizing",
+ rc, host, errstr);
m.size = sz;
- m.data = malloc(m.size);
- if (m.data == NULL)
- return tls_error(US"memory allocation failed", strerror(errno), NULL);
+ if (!(m.data = store_malloc(m.size)))
+ return tls_error_sys(US"memory allocation failed", errno, NULL, errstr);
+
/* this will return a size 1 less than the allocation size above */
- rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM,
- m.data, &sz);
- if (rc != GNUTLS_E_SUCCESS)
+ if ((rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM,
+ m.data, &sz)))
{
- free(m.data);
- exim_gnutls_err_check(US"gnutls_dh_params_export_pkcs3() real");
+ store_free(m.data);
+ return tls_error_gnu(US"gnutls_dh_params_export_pkcs3() real", rc, host, errstr);
}
m.size = sz; /* shrink by 1, probably */
- sz = write_to_fd_buf(fd, m.data, (size_t) m.size);
- if (sz != m.size)
+ if ((sz = write_to_fd_buf(fd, m.data, (size_t) m.size)) != m.size)
{
- free(m.data);
- return tls_error(US"TLS cache write D-H params failed",
- strerror(errno), NULL);
+ store_free(m.data);
+ return tls_error_sys(US"TLS cache write D-H params failed",
+ errno, NULL, errstr);
}
- free(m.data);
- sz = write_to_fd_buf(fd, US"\n", 1);
- if (sz != 1)
- return tls_error(US"TLS cache write D-H params final newline failed",
- strerror(errno), NULL);
+ store_free(m.data);
+ if ((sz = write_to_fd_buf(fd, US"\n", 1)) != 1)
+ return tls_error_sys(US"TLS cache write D-H params final newline failed",
+ errno, NULL, errstr);
- rc = close(fd);
- if (rc)
- return tls_error(US"TLS cache write close() failed",
- strerror(errno), NULL);
+ if ((rc = close(fd)))
+ return tls_error_sys(US"TLS cache write close() failed", errno, NULL, errstr);
if (Urename(temp_fn, filename) < 0)
- return tls_error(string_sprintf("failed to rename \"%s\" as \"%s\"",
- temp_fn, filename), strerror(errno), NULL);
+ return tls_error_sys(string_sprintf("failed to rename \"%s\" as \"%s\"",
+ temp_fn, filename), errno, NULL, errstr);
DEBUG(D_tls) debug_printf("wrote D-H parameters to file \"%s\"\n", filename);
}
DEBUG(D_tls) debug_printf("initialized server D-H parameters\n");
return OK;
}
+#endif
+
+
+
+
+/* Create and install a selfsigned certificate, for use in server mode */
+
+static int
+tls_install_selfsign(exim_gnutls_state_st * state, uschar ** errstr)
+{
+gnutls_x509_crt_t cert = NULL;
+time_t now;
+gnutls_x509_privkey_t pkey = NULL;
+const uschar * where;
+int rc;
+
+#ifndef SUPPORT_SELFSIGN
+where = US"library too old";
+rc = GNUTLS_E_NO_CERTIFICATE_FOUND;
+if (TRUE) goto err;
+#endif
+
+where = US"initialising pkey";
+if ((rc = gnutls_x509_privkey_init(&pkey))) goto err;
+
+where = US"initialising cert";
+if ((rc = gnutls_x509_crt_init(&cert))) goto err;
+
+where = US"generating pkey"; /* Hangs on 2.12.23 */
+if ((rc = gnutls_x509_privkey_generate(pkey, GNUTLS_PK_RSA,
+#ifdef SUPPORT_PARAM_TO_PK_BITS
+# ifndef GNUTLS_SEC_PARAM_MEDIUM
+# define GNUTLS_SEC_PARAM_MEDIUM GNUTLS_SEC_PARAM_HIGH
+# endif
+ gnutls_sec_param_to_pk_bits(GNUTLS_PK_RSA, GNUTLS_SEC_PARAM_MEDIUM),
+#else
+ 2048,
+#endif
+ 0)))
+ goto err;
+
+where = US"configuring cert";
+now = 1;
+if ( (rc = gnutls_x509_crt_set_version(cert, 3))
+ || (rc = gnutls_x509_crt_set_serial(cert, &now, sizeof(now)))
+ || (rc = gnutls_x509_crt_set_activation_time(cert, now = time(NULL)))
+ || (rc = gnutls_x509_crt_set_expiration_time(cert, now + 60 * 60)) /* 1 hr */
+ || (rc = gnutls_x509_crt_set_key(cert, pkey))
+
+ || (rc = gnutls_x509_crt_set_dn_by_oid(cert,
+ GNUTLS_OID_X520_COUNTRY_NAME, 0, "UK", 2))
+ || (rc = gnutls_x509_crt_set_dn_by_oid(cert,
+ GNUTLS_OID_X520_ORGANIZATION_NAME, 0, "Exim Developers", 15))
+ || (rc = gnutls_x509_crt_set_dn_by_oid(cert,
+ GNUTLS_OID_X520_COMMON_NAME, 0,
+ smtp_active_hostname, Ustrlen(smtp_active_hostname)))
+ )
+ goto err;
+
+where = US"signing cert";
+if ((rc = gnutls_x509_crt_sign(cert, cert, pkey))) goto err;
+
+where = US"installing selfsign cert";
+ /* Since: 2.4.0 */
+if ((rc = gnutls_certificate_set_x509_key(state->x509_cred, &cert, 1, pkey)))
+ goto err;
+
+rc = OK;
+
+out:
+ if (cert) gnutls_x509_crt_deinit(cert);
+ if (pkey) gnutls_x509_privkey_deinit(pkey);
+ return rc;
+
+err:
+ rc = tls_error_gnu(where, rc, NULL, errstr);
+ goto out;
+}
+
+
+
+
+/* Add certificate and key, from files.
+
+Return:
+ Zero or negative: good. Negate value for certificate index if < 0.
+ Greater than zero: FAIL or DEFER code.
+*/
+
+static int
+tls_add_certfile(exim_gnutls_state_st * state, const host_item * host,
+ uschar * certfile, uschar * keyfile, uschar ** errstr)
+{
+int rc = gnutls_certificate_set_x509_key_file(state->x509_cred,
+ CS certfile, CS keyfile, GNUTLS_X509_FMT_PEM);
+if (rc < 0)
+ return tls_error_gnu(
+ string_sprintf("cert/key setup: cert=%s key=%s", certfile, keyfile),
+ rc, host, errstr);
+return -rc;
+}
+
+
+#if !defined(DISABLE_OCSP) && !defined(SUPPORT_GNUTLS_EXT_RAW_PARSE)
+/* Load an OCSP proof from file for sending by the server. Called
+on getting a status-request handshake message, for earlier versions
+of GnuTLS. */
+
+static int
+server_ocsp_stapling_cb(gnutls_session_t session, void * ptr,
+ gnutls_datum_t * ocsp_response)
+{
+int ret;
+DEBUG(D_tls) debug_printf("OCSP stapling callback: %s\n", US ptr);
+
+if ((ret = gnutls_load_file(ptr, ocsp_response)) < 0)
+ {
+ DEBUG(D_tls) debug_printf("Failed to load ocsp stapling file %s\n",
+ CS ptr);
+ tls_in.ocsp = OCSP_NOT_RESP;
+ return GNUTLS_E_NO_CERTIFICATE_STATUS;
+ }
+
+tls_in.ocsp = OCSP_VFY_NOT_TRIED;
+return 0;
+}
+#endif
+
+
+#ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE
+/* Make a note that we saw a status-request */
+static int
+tls_server_clienthello_ext(void * ctx, unsigned tls_id,
+ const unsigned char *data, unsigned size)
+{
+/* https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */
+if (tls_id == 5) /* status_request */
+ {
+ DEBUG(D_tls) debug_printf("Seen status_request extension from client\n");
+ tls_in.ocsp = OCSP_NOT_RESP;
+ }
+return 0;
+}
+
+/* Callback for client-hello, on server, if we think we might serve stapled-OCSP */
+static int
+tls_server_clienthello_cb(gnutls_session_t session, unsigned int htype,
+ unsigned when, unsigned int incoming, const gnutls_datum_t * msg)
+{
+/* Call fn for each extension seen. 3.6.3 onwards */
+return gnutls_ext_raw_parse(NULL, tls_server_clienthello_ext, msg,
+ GNUTLS_EXT_RAW_FLAG_TLS_CLIENT_HELLO);
+}
+
+
+/* Make a note that we saw a status-response */
+static int
+tls_server_servercerts_ext(void * ctx, unsigned tls_id,
+ const unsigned char *data, unsigned size)
+{
+/* debug_printf("%s %u\n", __FUNCTION__, tls_id); */
+/* https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */
+if (FALSE && tls_id == 5) /* status_request */
+ {
+ DEBUG(D_tls) debug_printf("Seen status_request extension\n");
+ tls_in.ocsp = exim_testharness_disable_ocsp_validity_check
+ ? OCSP_VFY_NOT_TRIED : OCSP_VFIED; /* We know that GnuTLS verifies responses */
+ }
+return 0;
+}
+
+/* Callback for certificates packet, on server, if we think we might serve stapled-OCSP */
+static int
+tls_server_servercerts_cb(gnutls_session_t session, unsigned int htype,
+ unsigned when, unsigned int incoming, const gnutls_datum_t * msg)
+{
+/* Call fn for each extension seen. 3.6.3 onwards */
+#ifdef notdef
+/*XXX crashes */
+return gnutls_ext_raw_parse(NULL, tls_server_servercerts_ext, msg, 0);
+#endif
+}
+#endif
+
+/*XXX in tls1.3 the cert-status travel as an extension next to the cert, in the
+ "Handshake Protocol: Certificate" record.
+So we need to spot the Certificate handshake message, parse it and spot any status_request extension(s)
+
+This is different to tls1.2 - where it is a separate record (wireshake term) / handshake message (gnutls term).
+*/
+
+#if defined(EXPERIMENTAL_TLS_RESUME) || defined(SUPPORT_GNUTLS_EXT_RAW_PARSE)
+/* Callback for certificate-status, on server. We sent stapled OCSP. */
+static int
+tls_server_certstatus_cb(gnutls_session_t session, unsigned int htype,
+ unsigned when, unsigned int incoming, const gnutls_datum_t * msg)
+{
+DEBUG(D_tls) debug_printf("Sending certificate-status\n"); /*XXX we get this for tls1.2 but not for 1.3 */
+#ifdef SUPPORT_SRV_OCSP_STACK
+tls_in.ocsp = exim_testharness_disable_ocsp_validity_check
+ ? OCSP_VFY_NOT_TRIED : OCSP_VFIED; /* We know that GnuTLS verifies responses */
+#else
+tls_in.ocsp = OCSP_VFY_NOT_TRIED;
+#endif
+return 0;
+}
+/* Callback for handshake messages, on server */
+static int
+tls_server_hook_cb(gnutls_session_t sess, u_int htype, unsigned when,
+ unsigned incoming, const gnutls_datum_t * msg)
+{
+/* debug_printf("%s: htype %u\n", __FUNCTION__, htype); */
+switch (htype)
+ {
+# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE
+ case GNUTLS_HANDSHAKE_CLIENT_HELLO:
+ return tls_server_clienthello_cb(sess, htype, when, incoming, msg);
+ case GNUTLS_HANDSHAKE_CERTIFICATE_PKT:
+ return tls_server_servercerts_cb(sess, htype, when, incoming, msg);
+# endif
+ case GNUTLS_HANDSHAKE_CERTIFICATE_STATUS:
+ return tls_server_certstatus_cb(sess, htype, when, incoming, msg);
+# ifdef EXPERIMENTAL_TLS_RESUME
+ case GNUTLS_HANDSHAKE_NEW_SESSION_TICKET:
+ return tls_server_ticket_cb(sess, htype, when, incoming, msg);
+# endif
+ default:
+ return 0;
+ }
+}
+#endif
+#if !defined(DISABLE_OCSP) && defined(SUPPORT_GNUTLS_EXT_RAW_PARSE)
+static void
+tls_server_testharness_ocsp_fiddle(void)
+{
+extern char ** environ;
+if (environ) for (uschar ** p = USS environ; *p; p++)
+ if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0)
+ {
+ DEBUG(D_tls) debug_printf("Permitting known bad OCSP response\n");
+ exim_testharness_disable_ocsp_validity_check = TRUE;
+ }
+}
+#endif
/*************************************************
* Variables re-expanded post-SNI *
Arguments:
state exim_gnutls_state_st *
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
-tls_expand_session_files(exim_gnutls_state_st *state)
+tls_expand_session_files(exim_gnutls_state_st * state, uschar ** errstr)
{
struct stat statbuf;
int rc;
int cert_count;
/* We check for tls_sni *before* expansion. */
-if (!state->host)
- {
+if (!host) /* server */
if (!state->received_sni)
{
- if (state->tls_certificate && Ustrstr(state->tls_certificate, US"tls_sni"))
+ if ( state->tls_certificate
+ && ( Ustrstr(state->tls_certificate, US"tls_sni")
+ || Ustrstr(state->tls_certificate, US"tls_in_sni")
+ || Ustrstr(state->tls_certificate, US"tls_out_sni")
+ ) )
{
DEBUG(D_tls) debug_printf("We will re-expand TLS session files if we receive SNI.\n");
state->trigger_sni_changes = TRUE;
saved_tls_verify_certificates = state->exp_tls_verify_certificates;
saved_tls_crl = state->exp_tls_crl;
}
- }
-rc = gnutls_certificate_allocate_credentials(&state->x509_cred);
-exim_gnutls_err_check(US"gnutls_certificate_allocate_credentials");
+if ((rc = gnutls_certificate_allocate_credentials(&state->x509_cred)))
+ return tls_error_gnu(US"gnutls_certificate_allocate_credentials",
+ rc, host, errstr);
+
+#ifdef SUPPORT_SRV_OCSP_STACK
+gnutls_certificate_set_flags(state->x509_cred, GNUTLS_CERTIFICATE_API_V2);
+
+# if !defined(DISABLE_OCSP) && defined(SUPPORT_GNUTLS_EXT_RAW_PARSE)
+if (!host && tls_ocsp_file)
+ {
+ if (f.running_in_test_harness)
+ tls_server_testharness_ocsp_fiddle();
+
+ if (exim_testharness_disable_ocsp_validity_check)
+ gnutls_certificate_set_flags(state->x509_cred,
+ GNUTLS_CERTIFICATE_API_V2 | GNUTLS_CERTIFICATE_SKIP_OCSP_RESPONSE_CHECK);
+ }
+# endif
+#endif
/* remember: expand_check_tlsvar() is expand_check() but fiddling with
state members, assuming consistent naming; and expand_check() returns
/* check if we at least have a certificate, before doing expensive
D-H generation. */
-if (!expand_check_tlsvar(tls_certificate))
+if (!expand_check_tlsvar(tls_certificate, errstr))
return DEFER;
/* certificate is mandatory in server, optional in client */
-if ((state->exp_tls_certificate == NULL) ||
- (*state->exp_tls_certificate == '\0'))
- {
- if (state->host == NULL)
- return tls_error(US"no TLS server certificate is specified", NULL, NULL);
+if ( !state->exp_tls_certificate
+ || !*state->exp_tls_certificate
+ )
+ if (!host)
+ return tls_install_selfsign(state, errstr);
else
DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n");
- }
-if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey))
+if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey, errstr))
return DEFER;
/* tls_privatekey is optional, defaulting to same file as certificate */
-if (state->tls_privatekey == NULL || *state->tls_privatekey == '\0')
+if (!state->tls_privatekey || !*state->tls_privatekey)
{
state->tls_privatekey = state->tls_certificate;
state->exp_tls_privatekey = state->exp_tls_certificate;
state->exp_tls_certificate, state->exp_tls_privatekey);
if (state->received_sni)
- {
- if ((Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0) &&
- (Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0))
+ if ( Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0
+ && Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0
+ )
{
DEBUG(D_tls) debug_printf("TLS SNI: cert and key unchanged\n");
}
{
DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair.\n");
}
+
+ if (!host) /* server */
+ {
+ const uschar * clist = state->exp_tls_certificate;
+ const uschar * klist = state->exp_tls_privatekey;
+ const uschar * olist;
+ int csep = 0, ksep = 0, osep = 0, cnt = 0;
+ uschar * cfile, * kfile, * ofile;
+#ifndef DISABLE_OCSP
+# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE
+ gnutls_x509_crt_fmt_t ocsp_fmt = GNUTLS_X509_FMT_DER;
+# endif
+
+ if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", &ofile, errstr))
+ return DEFER;
+ olist = ofile;
+#endif
+
+ while (cfile = string_nextinlist(&clist, &csep, NULL, 0))
+
+ if (!(kfile = string_nextinlist(&klist, &ksep, NULL, 0)))
+ return tls_error(US"cert/key setup: out of keys", NULL, host, errstr);
+ else if (0 < (rc = tls_add_certfile(state, host, cfile, kfile, errstr)))
+ return rc;
+ else
+ {
+ int gnutls_cert_index = -rc;
+ DEBUG(D_tls) debug_printf("TLS: cert/key %d %s registered\n",
+ gnutls_cert_index, cfile);
+
+#ifndef DISABLE_OCSP
+ if (tls_ocsp_file)
+ {
+ /* Set the OCSP stapling server info */
+ if (gnutls_buggy_ocsp)
+ {
+ DEBUG(D_tls)
+ debug_printf("GnuTLS library is buggy for OCSP; avoiding\n");
+ }
+ else if ((ofile = string_nextinlist(&olist, &osep, NULL, 0)))
+ {
+ DEBUG(D_tls) debug_printf("OCSP response file %d = %s\n",
+ gnutls_cert_index, ofile);
+# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE
+ if (Ustrncmp(ofile, US"PEM ", 4) == 0)
+ {
+ ocsp_fmt = GNUTLS_X509_FMT_PEM;
+ ofile += 4;
+ }
+ else if (Ustrncmp(ofile, US"DER ", 4) == 0)
+ {
+ ocsp_fmt = GNUTLS_X509_FMT_DER;
+ ofile += 4;
+ }
+
+ if ((rc = gnutls_certificate_set_ocsp_status_request_file2(
+ state->x509_cred, CCS ofile, gnutls_cert_index,
+ ocsp_fmt)) < 0)
+ return tls_error_gnu(
+ US"gnutls_certificate_set_ocsp_status_request_file2",
+ rc, host, errstr);
+ DEBUG(D_tls)
+ debug_printf(" %d response%s loaded\n", rc, rc>1 ? "s":"");
+
+ /* Arrange callbacks for OCSP request observability */
+
+ gnutls_handshake_set_hook_function(state->session,
+ GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb);
+
+# else
+# if defined(SUPPORT_SRV_OCSP_STACK)
+ if ((rc = gnutls_certificate_set_ocsp_status_request_function2(
+ state->x509_cred, gnutls_cert_index,
+ server_ocsp_stapling_cb, ofile)))
+ return tls_error_gnu(
+ US"gnutls_certificate_set_ocsp_status_request_function2",
+ rc, host, errstr);
+ else
+# endif
+ {
+ if (cnt++ > 0)
+ {
+ DEBUG(D_tls)
+ debug_printf("oops; multiple OCSP files not supported\n");
+ break;
+ }
+ gnutls_certificate_set_ocsp_status_request_function(
+ state->x509_cred, server_ocsp_stapling_cb, ofile);
+ }
+# endif /* SUPPORT_GNUTLS_EXT_RAW_PARSE */
+ }
+ else
+ DEBUG(D_tls) debug_printf("ran out of OCSP response files in list\n");
+ }
+#endif /* DISABLE_OCSP */
+ }
+ }
+ else /* client */
+ {
+ if (0 < (rc = tls_add_certfile(state, host,
+ state->exp_tls_certificate, state->exp_tls_privatekey, errstr)))
+ return rc;
+ DEBUG(D_tls) debug_printf("TLS: cert/key registered\n");
}
- rc = gnutls_certificate_set_x509_key_file(state->x509_cred,
- CS state->exp_tls_certificate, CS state->exp_tls_privatekey,
- GNUTLS_X509_FMT_PEM);
- exim_gnutls_err_check(
- string_sprintf("cert/key setup: cert=%s key=%s",
- state->exp_tls_certificate, state->exp_tls_privatekey));
- DEBUG(D_tls) debug_printf("TLS: cert/key registered\n");
} /* tls_certificate */
+
/* Set the trusted CAs file if one is provided, and then add the CRL if one is
provided. Experiment shows that, if the certificate file is empty, an unhelpful
error message is provided. However, if we just refrain from setting anything up
if (state->tls_verify_certificates && *state->tls_verify_certificates)
{
- if (!expand_check_tlsvar(tls_verify_certificates))
+ if (!expand_check_tlsvar(tls_verify_certificates, errstr))
return DEFER;
+#ifndef SUPPORT_SYSDEFAULT_CABUNDLE
+ if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0)
+ state->exp_tls_verify_certificates = NULL;
+#endif
if (state->tls_crl && *state->tls_crl)
- if (!expand_check_tlsvar(tls_crl))
+ if (!expand_check_tlsvar(tls_crl, errstr))
return DEFER;
if (!(state->exp_tls_verify_certificates &&
return OK;
}
-if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0)
+#ifdef SUPPORT_SYSDEFAULT_CABUNDLE
+if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0)
+ cert_count = gnutls_certificate_set_x509_system_trust(state->x509_cred);
+else
+#endif
{
- log_write(0, LOG_MAIN|LOG_PANIC, "could not stat %s "
- "(tls_verify_certificates): %s", state->exp_tls_verify_certificates,
- strerror(errno));
- return DEFER;
- }
+ if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "could not stat '%s' "
+ "(tls_verify_certificates): %s", state->exp_tls_verify_certificates,
+ strerror(errno));
+ return DEFER;
+ }
-/* The test suite passes in /dev/null; we could check for that path explicitly,
-but who knows if someone has some weird FIFO which always dumps some certs, or
-other weirdness. The thing we really want to check is that it's not a
-directory, since while OpenSSL supports that, GnuTLS does not.
-So s/!S_ISREG/S_ISDIR/ and change some messsaging ... */
-if (S_ISDIR(statbuf.st_mode))
- {
- DEBUG(D_tls)
- debug_printf("verify certificates path is a dir: \"%s\"\n",
- state->exp_tls_verify_certificates);
- log_write(0, LOG_MAIN|LOG_PANIC,
- "tls_verify_certificates \"%s\" is a directory",
- state->exp_tls_verify_certificates);
- return DEFER;
- }
+#ifndef SUPPORT_CA_DIR
+ /* The test suite passes in /dev/null; we could check for that path explicitly,
+ but who knows if someone has some weird FIFO which always dumps some certs, or
+ other weirdness. The thing we really want to check is that it's not a
+ directory, since while OpenSSL supports that, GnuTLS does not.
+ So s/!S_ISREG/S_ISDIR/ and change some messaging ... */
+ if (S_ISDIR(statbuf.st_mode))
+ {
+ DEBUG(D_tls)
+ debug_printf("verify certificates path is a dir: \"%s\"\n",
+ state->exp_tls_verify_certificates);
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "tls_verify_certificates \"%s\" is a directory",
+ state->exp_tls_verify_certificates);
+ return DEFER;
+ }
+#endif
-DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n",
- state->exp_tls_verify_certificates, statbuf.st_size);
+ DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n",
+ state->exp_tls_verify_certificates, statbuf.st_size);
-if (statbuf.st_size == 0)
- {
- DEBUG(D_tls)
- debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n");
- return OK;
+ if (statbuf.st_size == 0)
+ {
+ DEBUG(D_tls)
+ debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n");
+ return OK;
+ }
+
+ cert_count =
+
+#ifdef SUPPORT_CA_DIR
+ (statbuf.st_mode & S_IFMT) == S_IFDIR
+ ?
+ gnutls_certificate_set_x509_trust_dir(state->x509_cred,
+ CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM)
+ :
+#endif
+ gnutls_certificate_set_x509_trust_file(state->x509_cred,
+ CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM);
+
+#ifdef SUPPORT_CA_DIR
+ /* Mimic the behaviour with OpenSSL of not advertising a usable-cert list
+ when using the directory-of-certs config model. */
+
+ if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
+ gnutls_certificate_send_x509_rdn_sequence(state->session, 1);
+#endif
}
-cert_count = gnutls_certificate_set_x509_trust_file(state->x509_cred,
- CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM);
if (cert_count < 0)
- {
- rc = cert_count;
- exim_gnutls_err_check(US"gnutls_certificate_set_x509_trust_file");
- }
-DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", cert_count);
+ return tls_error_gnu(US"setting certificate trust", cert_count, host, errstr);
+DEBUG(D_tls)
+ debug_printf("Added %d certificate authorities.\n", cert_count);
if (state->tls_crl && *state->tls_crl &&
state->exp_tls_crl && *state->exp_tls_crl)
{
DEBUG(D_tls) debug_printf("loading CRL file = %s\n", state->exp_tls_crl);
- cert_count = gnutls_certificate_set_x509_crl_file(state->x509_cred,
- CS state->exp_tls_crl, GNUTLS_X509_FMT_PEM);
- if (cert_count < 0)
- {
- rc = cert_count;
- exim_gnutls_err_check(US"gnutls_certificate_set_x509_crl_file");
- }
+ if ((cert_count = gnutls_certificate_set_x509_crl_file(state->x509_cred,
+ CS state->exp_tls_crl, GNUTLS_X509_FMT_PEM)) < 0)
+ return tls_error_gnu(US"gnutls_certificate_set_x509_crl_file",
+ cert_count, host, errstr);
+
DEBUG(D_tls) debug_printf("Processed %d CRLs.\n", cert_count);
}
Arguments:
state exim_gnutls_state_st *
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
-tls_set_remaining_x509(exim_gnutls_state_st *state)
+tls_set_remaining_x509(exim_gnutls_state_st *state, uschar ** errstr)
{
int rc;
const host_item *host = state->host; /* macro should be reconsidered? */
+#ifndef GNUTLS_AUTO_DHPARAMS
/* Create D-H parameters, or read them from the cache file. This function does
its own SMTP error messaging. This only happens for the server, TLS D-H ignores
client-side params. */
if (!state->host)
{
if (!dh_server_params)
- {
- rc = init_server_dh();
- if (rc != OK) return rc;
- }
+ if ((rc = init_server_dh(errstr)) != OK) return rc;
+
+ /* Unnecessary & discouraged with 3.6.0 or later */
gnutls_certificate_set_dh_params(state->x509_cred, dh_server_params);
}
+#endif
/* Link the credentials to the session. */
-rc = gnutls_credentials_set(state->session, GNUTLS_CRD_CERTIFICATE, state->x509_cred);
-exim_gnutls_err_check(US"gnutls_credentials_set");
+if ((rc = gnutls_credentials_set(state->session,
+ GNUTLS_CRD_CERTIFICATE, state->x509_cred)))
+ return tls_error_gnu(US"gnutls_credentials_set", rc, host, errstr);
return OK;
}
* Initialize for GnuTLS *
*************************************************/
-/* Called from both server and client code. In the case of a server, errors
+
+#ifndef DISABLE_OCSP
+
+static BOOL
+tls_is_buggy_ocsp(void)
+{
+const uschar * s;
+uschar maj, mid, mic;
+
+s = CUS gnutls_check_version(NULL);
+maj = atoi(CCS s);
+if (maj == 3)
+ {
+ while (*s && *s != '.') s++;
+ mid = atoi(CCS ++s);
+ if (mid <= 2)
+ return TRUE;
+ else if (mid >= 5)
+ return FALSE;
+ else
+ {
+ while (*s && *s != '.') s++;
+ mic = atoi(CCS ++s);
+ return mic <= (mid == 3 ? 16 : 3);
+ }
+ }
+return FALSE;
+}
+
+#endif
+
+
+/* Called from both server and client code. In the case of a server, errors
before actual TLS negotiation return DEFER.
Arguments:
cas CA certs file
crl CRL file
require_ciphers tls_require_ciphers setting
+ caller_state returned state-info structure
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
const uschar *cas,
const uschar *crl,
const uschar *require_ciphers,
- exim_gnutls_state_st **caller_state)
+ exim_gnutls_state_st **caller_state,
+ tls_support * tlsp,
+ uschar ** errstr)
{
-exim_gnutls_state_st *state;
+exim_gnutls_state_st * state;
int rc;
size_t sz;
-const char *errpos;
-uschar *p;
-BOOL want_default_priorities;
+const char * errpos;
+const uschar * p;
if (!exim_gnutls_base_init_done)
{
DEBUG(D_tls) debug_printf("GnuTLS global init required.\n");
- rc = gnutls_global_init();
- exim_gnutls_err_check(US"gnutls_global_init");
+#if defined(HAVE_GNUTLS_PKCS11) && !defined(GNUTLS_AUTO_PKCS11_MANUAL)
+ /* By default, gnutls_global_init will init PKCS11 support in auto mode,
+ which loads modules from a config file, which sounds good and may be wanted
+ by some sysadmin, but also means in common configurations that GNOME keyring
+ environment variables are used and so breaks for users calling mailq.
+ To prevent this, we init PKCS11 first, which is the documented approach. */
+ if (!gnutls_allow_auto_pkcs11)
+ if ((rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL)))
+ return tls_error_gnu(US"gnutls_pkcs11_init", rc, host, errstr);
+#endif
+
+#ifndef GNUTLS_AUTO_GLOBAL_INIT
+ if ((rc = gnutls_global_init()))
+ return tls_error_gnu(US"gnutls_global_init", rc, host, errstr);
+#endif
#if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0
DEBUG(D_tls)
{
gnutls_global_set_log_function(exim_gnutls_logger_cb);
- /* arbitrarily chosen level; bump upto 9 for more */
+ /* arbitrarily chosen level; bump up to 9 for more */
gnutls_global_set_log_level(EXIM_GNUTLS_LIBRARY_LOG_LEVEL);
}
#endif
+#ifndef DISABLE_OCSP
+ if (tls_ocsp_file && (gnutls_buggy_ocsp = tls_is_buggy_ocsp()))
+ log_write(0, LOG_MAIN, "OCSP unusable with this GnuTLS library version");
+#endif
+
exim_gnutls_base_init_done = TRUE;
}
if (host)
{
- state = &state_client;
+ /* For client-side sessions we allocate a context. This lets us run
+ several in parallel. */
+ int old_pool = store_pool;
+ store_pool = POOL_PERM;
+ state = store_get(sizeof(exim_gnutls_state_st), FALSE);
+ store_pool = old_pool;
+
memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init));
+ state->tlsp = tlsp;
DEBUG(D_tls) debug_printf("initialising GnuTLS client session\n");
rc = gnutls_init(&state->session, GNUTLS_CLIENT);
}
{
state = &state_server;
memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init));
+ state->tlsp = tlsp;
DEBUG(D_tls) debug_printf("initialising GnuTLS server session\n");
rc = gnutls_init(&state->session, GNUTLS_SERVER);
}
-exim_gnutls_err_check(US"gnutls_init");
+if (rc)
+ return tls_error_gnu(US"gnutls_init", rc, host, errstr);
state->host = host;
DEBUG(D_tls)
debug_printf("Expanding various TLS configuration options for session credentials.\n");
-rc = tls_expand_session_files(state);
-if (rc != OK) return rc;
+if ((rc = tls_expand_session_files(state, errstr)) != OK) return rc;
/* These are all other parts of the x509_cred handling, since SNI in GnuTLS
requires a new structure afterwards. */
-rc = tls_set_remaining_x509(state);
-if (rc != OK) return rc;
+if ((rc = tls_set_remaining_x509(state, errstr)) != OK) return rc;
/* set SNI in client, only */
if (host)
{
- if (!expand_check_tlsvar(tls_sni))
+ if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni, errstr))
return DEFER;
- if (state->exp_tls_sni && *state->exp_tls_sni)
+ if (state->tlsp->sni && *state->tlsp->sni)
{
DEBUG(D_tls)
- debug_printf("Setting TLS client SNI to \"%s\"\n", state->exp_tls_sni);
- sz = Ustrlen(state->exp_tls_sni);
- rc = gnutls_server_name_set(state->session,
- GNUTLS_NAME_DNS, state->exp_tls_sni, sz);
- exim_gnutls_err_check(US"gnutls_server_name_set");
+ debug_printf("Setting TLS client SNI to \"%s\"\n", state->tlsp->sni);
+ sz = Ustrlen(state->tlsp->sni);
+ if ((rc = gnutls_server_name_set(state->session,
+ GNUTLS_NAME_DNS, state->tlsp->sni, sz)))
+ return tls_error_gnu(US"gnutls_server_name_set", rc, host, errstr);
}
}
else if (state->tls_sni)
DEBUG(D_tls) debug_printf("*** PROBABLY A BUG *** " \
- "have an SNI set for a client [%s]\n", state->tls_sni);
+ "have an SNI set for a server [%s]\n", state->tls_sni);
/* This is the priority string support,
-http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
+http://www.gnutls.org/manual/html_node/Priority-Strings.html
and replaces gnutls_require_kx, gnutls_require_mac & gnutls_require_protocols.
This was backwards incompatible, but means Exim no longer needs to track
all algorithms and provide string forms for them. */
-want_default_priorities = TRUE;
-
+p = NULL;
if (state->tls_require_ciphers && *state->tls_require_ciphers)
{
- if (!expand_check_tlsvar(tls_require_ciphers))
+ if (!expand_check_tlsvar(tls_require_ciphers, errstr))
return DEFER;
if (state->exp_tls_require_ciphers && *state->exp_tls_require_ciphers)
{
- DEBUG(D_tls) debug_printf("GnuTLS session cipher/priority \"%s\"\n",
- state->exp_tls_require_ciphers);
-
- rc = gnutls_priority_init(&state->priority_cache,
- CS state->exp_tls_require_ciphers, &errpos);
- want_default_priorities = FALSE;
p = state->exp_tls_require_ciphers;
+ DEBUG(D_tls) debug_printf("GnuTLS session cipher/priority \"%s\"\n", p);
}
}
-if (want_default_priorities)
+if (!p)
{
+ p = exim_default_gnutls_priority;
DEBUG(D_tls)
- debug_printf("GnuTLS using default session cipher/priority \"%s\"\n",
- exim_default_gnutls_priority);
- rc = gnutls_priority_init(&state->priority_cache,
- exim_default_gnutls_priority, &errpos);
- p = US exim_default_gnutls_priority;
+ debug_printf("GnuTLS using default session cipher/priority \"%s\"\n", p);
}
-exim_gnutls_err_check(string_sprintf(
- "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"",
- p, errpos - CS p, errpos));
+if ((rc = gnutls_priority_init(&state->priority_cache, CCS p, &errpos)))
+ return tls_error_gnu(string_sprintf(
+ "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"",
+ p, errpos - CS p, errpos),
+ rc, host, errstr);
-rc = gnutls_priority_set(state->session, state->priority_cache);
-exim_gnutls_err_check(US"gnutls_priority_set");
+if ((rc = gnutls_priority_set(state->session, state->priority_cache)))
+ return tls_error_gnu(US"gnutls_priority_set", rc, host, errstr);
+
+/* This also sets the server ticket expiration time to the same, and
+the STEK rotation time to 3x. */
gnutls_db_set_cache_expiration(state->session, ssl_session_timeout);
}
*caller_state = state;
-/* needs to happen before callbacks during handshake */
-current_global_tls_state = state;
return OK;
}
-
/*************************************************
* Extract peer information *
*************************************************/
+static const uschar *
+cipher_stdname_kcm(gnutls_kx_algorithm_t kx, gnutls_cipher_algorithm_t cipher,
+ gnutls_mac_algorithm_t mac)
+{
+uschar cs_id[2];
+gnutls_kx_algorithm_t kx_i;
+gnutls_cipher_algorithm_t cipher_i;
+gnutls_mac_algorithm_t mac_i;
+
+for (size_t i = 0;
+ gnutls_cipher_suite_info(i, cs_id, &kx_i, &cipher_i, &mac_i, NULL);
+ i++)
+ if (kx_i == kx && cipher_i == cipher && mac_i == mac)
+ return cipher_stdname(cs_id[0], cs_id[1]);
+return NULL;
+}
+
+
+
/* Called from both server and client code.
Only this is allowed to set state->peerdn and state->have_set_peerdn
and we use that to detect double-calls.
Arguments:
state exim_gnutls_state_st *
+ errstr pointer to error string
Returns: OK/DEFER/FAIL
*/
static int
-peer_status(exim_gnutls_state_st *state)
+peer_status(exim_gnutls_state_st * state, uschar ** errstr)
{
-uschar cipherbuf[256];
-const gnutls_datum *cert_list;
+gnutls_session_t session = state->session;
+const gnutls_datum_t * cert_list;
int old_pool, rc;
unsigned int cert_list_size = 0;
gnutls_protocol_t protocol;
gnutls_mac_algorithm_t mac;
gnutls_certificate_type_t ct;
gnutls_x509_crt_t crt;
-uschar *p, *dn_buf;
+uschar * dn_buf;
size_t sz;
if (state->have_set_peerdn)
state->peerdn = NULL;
/* tls_cipher */
-cipher = gnutls_cipher_get(state->session);
-protocol = gnutls_protocol_get_version(state->session);
-mac = gnutls_mac_get(state->session);
-kx = gnutls_kx_get(state->session);
-
-string_format(cipherbuf, sizeof(cipherbuf),
- "%s:%s:%d",
- gnutls_protocol_get_name(protocol),
- gnutls_cipher_suite_get_name(kx, cipher, mac),
- (int) gnutls_cipher_get_key_size(cipher) * 8);
-
-/* I don't see a way that spaces could occur, in the current GnuTLS
-code base, but it was a concern in the old code and perhaps older GnuTLS
-releases did return "TLS 1.0"; play it safe, just in case. */
-for (p = cipherbuf; *p != '\0'; ++p)
- if (isspace(*p))
- *p = '-';
+cipher = gnutls_cipher_get(session);
+protocol = gnutls_protocol_get_version(session);
+mac = gnutls_mac_get(session);
+kx =
+#ifdef GNUTLS_TLS1_3
+ protocol >= GNUTLS_TLS1_3 ? 0 :
+#endif
+ gnutls_kx_get(session);
+
old_pool = store_pool;
-store_pool = POOL_PERM;
-state->ciphersuite = string_copy(cipherbuf);
+ {
+ tls_support * tlsp = state->tlsp;
+ store_pool = POOL_PERM;
+
+#ifdef SUPPORT_GNUTLS_SESS_DESC
+ {
+ gstring * g = NULL;
+ uschar * s = US gnutls_session_get_desc(session), c;
+
+ /* Nikos M suggests we use this by preference. It returns like:
+ (TLS1.3)-(ECDHE-SECP256R1)-(RSA-PSS-RSAE-SHA256)-(AES-256-GCM)
+
+ For partial back-compat, put a colon after the TLS version, replace the
+ )-( grouping with __, replace in-group - with _ and append the :keysize. */
+
+ /* debug_printf("peer_status: gnutls_session_get_desc %s\n", s); */
+
+ for (s++; (c = *s) && c != ')'; s++) g = string_catn(g, s, 1);
+
+ tlsp->ver = string_copyn(g->s, g->ptr);
+ for (uschar * p = US tlsp->ver; *p; p++)
+ if (*p == '-') { *p = '\0'; break; } /* TLS1.0-PKIX -> TLS1.0 */
+
+ g = string_catn(g, US":", 1);
+ if (*s) s++; /* now on _ between groups */
+ while ((c = *s))
+ {
+ for (*++s && ++s; (c = *s) && c != ')'; s++)
+ g = string_catn(g, c == '-' ? US"_" : s, 1);
+ /* now on ) closing group */
+ if ((c = *s) && *++s == '-') g = string_catn(g, US"__", 2);
+ /* now on _ between groups */
+ }
+ g = string_catn(g, US":", 1);
+ g = string_cat(g, string_sprintf("%d", (int) gnutls_cipher_get_key_size(cipher) * 8));
+ state->ciphersuite = string_from_gstring(g);
+ }
+#else
+ state->ciphersuite = string_sprintf("%s:%s:%d",
+ gnutls_protocol_get_name(protocol),
+ gnutls_cipher_suite_get_name(kx, cipher, mac),
+ (int) gnutls_cipher_get_key_size(cipher) * 8);
+
+ /* I don't see a way that spaces could occur, in the current GnuTLS
+ code base, but it was a concern in the old code and perhaps older GnuTLS
+ releases did return "TLS 1.0"; play it safe, just in case. */
+
+ for (uschar * p = state->ciphersuite; *p; p++) if (isspace(*p)) *p = '-';
+ tlsp->ver = string_copyn(state->ciphersuite,
+ Ustrchr(state->ciphersuite, ':') - state->ciphersuite);
+#endif
+
+/* debug_printf("peer_status: ciphersuite %s\n", state->ciphersuite); */
+
+ tlsp->cipher = state->ciphersuite;
+ tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8;
+
+ tlsp->cipher_stdname = cipher_stdname_kcm(kx, cipher, mac);
+ }
store_pool = old_pool;
-tls_cipher = state->ciphersuite;
/* tls_peerdn */
-cert_list = gnutls_certificate_get_peers(state->session, &cert_list_size);
+cert_list = gnutls_certificate_get_peers(session, &cert_list_size);
-if (cert_list == NULL || cert_list_size == 0)
+if (!cert_list || cert_list_size == 0)
{
DEBUG(D_tls) debug_printf("TLS: no certificate from peer (%p & %d)\n",
cert_list, cert_list_size);
- if (state->verify_requirement == VERIFY_REQUIRED)
+ if (state->verify_requirement >= VERIFY_REQUIRED)
return tls_error(US"certificate verification failed",
- "no certificate received from peer", state->host);
+ US"no certificate received from peer", state->host, errstr);
return OK;
}
-ct = gnutls_certificate_type_get(state->session);
-if (ct != GNUTLS_CRT_X509)
+if ((ct = gnutls_certificate_type_get(session)) != GNUTLS_CRT_X509)
{
- const char *ctn = gnutls_certificate_type_get_name(ct);
+ const uschar * ctn = US gnutls_certificate_type_get_name(ct);
DEBUG(D_tls)
debug_printf("TLS: peer cert not X.509 but instead \"%s\"\n", ctn);
- if (state->verify_requirement == VERIFY_REQUIRED)
+ if (state->verify_requirement >= VERIFY_REQUIRED)
return tls_error(US"certificate verification not possible, unhandled type",
- ctn, state->host);
+ ctn, state->host, errstr);
return OK;
}
-#define exim_gnutls_peer_err(Label) do { \
- if (rc != GNUTLS_E_SUCCESS) { \
- DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", (Label), gnutls_strerror(rc)); \
- if (state->verify_requirement == VERIFY_REQUIRED) { return tls_error((Label), gnutls_strerror(rc), state->host); } \
- return OK; } } while (0)
+#define exim_gnutls_peer_err(Label) \
+ do { \
+ if (rc != GNUTLS_E_SUCCESS) \
+ { \
+ DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", \
+ (Label), gnutls_strerror(rc)); \
+ if (state->verify_requirement >= VERIFY_REQUIRED) \
+ return tls_error_gnu((Label), rc, state->host, errstr); \
+ return OK; \
+ } \
+ } while (0)
-rc = gnutls_x509_crt_init(&crt);
-exim_gnutls_peer_err(US"gnutls_x509_crt_init (crt)");
+rc = import_cert(&cert_list[0], &crt);
+exim_gnutls_peer_err(US"cert 0");
+
+state->tlsp->peercert = state->peercert = crt;
-rc = gnutls_x509_crt_import(crt, &cert_list[0], GNUTLS_X509_FMT_DER);
-exim_gnutls_peer_err(US"failed to import certificate [gnutls_x509_crt_import(cert 0)]");
sz = 0;
rc = gnutls_x509_crt_get_dn(crt, NULL, &sz);
if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER)
exim_gnutls_peer_err(US"getting size for cert DN failed");
return FAIL; /* should not happen */
}
-dn_buf = store_get_perm(sz);
+dn_buf = store_get_perm(sz, TRUE); /* tainted */
rc = gnutls_x509_crt_get_dn(crt, CS dn_buf, &sz);
exim_gnutls_peer_err(US"failed to extract certificate DN [gnutls_x509_crt_get_dn(cert 0)]");
+
state->peerdn = dn_buf;
return OK;
the peer information, but that's too new for some OSes.
Arguments:
- state exim_gnutls_state_st *
- error where to put an error message
+ state exim_gnutls_state_st *
+ errstr where to put an error message
Returns:
FALSE if the session should be rejected
*/
static BOOL
-verify_certificate(exim_gnutls_state_st *state, const char **error)
+verify_certificate(exim_gnutls_state_st * state, uschar ** errstr)
{
int rc;
-unsigned int verify;
+uint verify;
+
+DEBUG(D_tls) debug_printf("TLS: checking peer certificate\n");
+*errstr = NULL;
+rc = peer_status(state, errstr);
-*error = NULL;
+if (state->verify_requirement == VERIFY_NONE)
+ return TRUE;
-rc = peer_status(state);
-if (rc != OK)
+if (rc != OK || !state->peerdn)
{
verify = GNUTLS_CERT_INVALID;
- *error = "not supplied";
+ *errstr = US"certificate not supplied";
}
else
+
{
+#ifdef SUPPORT_DANE
+ if (state->verify_requirement == VERIFY_DANE && state->host)
+ {
+ /* Using dane_verify_session_crt() would be easy, as it does it all for us
+ including talking to a DNS resolver. But we want to do that bit ourselves
+ as the testsuite intercepts and fakes its own DNS environment. */
+
+ dane_state_t s;
+ dane_query_t r;
+ uint lsize;
+ const gnutls_datum_t * certlist =
+ gnutls_certificate_get_peers(state->session, &lsize);
+ int usage = tls_out.tlsa_usage;
+
+# ifdef GNUTLS_BROKEN_DANE_VALIDATION
+ /* Split the TLSA records into two sets, TA and EE selectors. Run the
+ dane-verification separately so that we know which selector verified;
+ then we know whether to do name-verification (needed for TA but not EE). */
+
+ if (usage == ((1<<DANESSL_USAGE_DANE_TA) | (1<<DANESSL_USAGE_DANE_EE)))
+ { /* a mixed-usage bundle */
+ int i, j, nrec;
+ const char ** dd;
+ int * ddl;
+
+ for (nrec = 0; state->dane_data_len[nrec]; ) nrec++;
+ nrec++;
+
+ dd = store_get(nrec * sizeof(uschar *), FALSE);
+ ddl = store_get(nrec * sizeof(int), FALSE);
+ nrec--;
+
+ if ((rc = dane_state_init(&s, 0)))
+ goto tlsa_prob;
+
+ for (usage = DANESSL_USAGE_DANE_EE;
+ usage >= DANESSL_USAGE_DANE_TA; usage--)
+ { /* take records with this usage */
+ for (j = i = 0; i < nrec; i++)
+ if (state->dane_data[i][0] == usage)
+ {
+ dd[j] = state->dane_data[i];
+ ddl[j++] = state->dane_data_len[i];
+ }
+ if (j)
+ {
+ dd[j] = NULL;
+ ddl[j] = 0;
+
+ if ((rc = dane_raw_tlsa(s, &r, (char * const *)dd, ddl, 1, 0)))
+ goto tlsa_prob;
+
+ if ((rc = dane_verify_crt_raw(s, certlist, lsize,
+ gnutls_certificate_type_get(state->session),
+ r, 0,
+ usage == DANESSL_USAGE_DANE_EE
+ ? DANE_VFLAG_ONLY_CHECK_EE_USAGE : 0,
+ &verify)))
+ {
+ DEBUG(D_tls)
+ debug_printf("TLSA record problem: %s\n", dane_strerror(rc));
+ }
+ else if (verify == 0) /* verification passed */
+ {
+ usage = 1 << usage;
+ break;
+ }
+ }
+ }
+
+ if (rc) goto tlsa_prob;
+ }
+ else
+# endif
+ {
+ if ( (rc = dane_state_init(&s, 0))
+ || (rc = dane_raw_tlsa(s, &r, state->dane_data, state->dane_data_len,
+ 1, 0))
+ || (rc = dane_verify_crt_raw(s, certlist, lsize,
+ gnutls_certificate_type_get(state->session),
+ r, 0,
+# ifdef GNUTLS_BROKEN_DANE_VALIDATION
+ usage == (1 << DANESSL_USAGE_DANE_EE)
+ ? DANE_VFLAG_ONLY_CHECK_EE_USAGE : 0,
+# else
+ 0,
+# endif
+ &verify))
+ )
+ goto tlsa_prob;
+ }
+
+ if (verify != 0) /* verification failed */
+ {
+ gnutls_datum_t str;
+ (void) dane_verification_status_print(verify, &str, 0);
+ *errstr = US str.data; /* don't bother to free */
+ goto badcert;
+ }
+
+# ifdef GNUTLS_BROKEN_DANE_VALIDATION
+ /* If a TA-mode TLSA record was used for verification we must additionally
+ verify the cert name (but not the CA chain). For EE-mode, skip it. */
+
+ if (usage & (1 << DANESSL_USAGE_DANE_EE))
+# endif
+ {
+ state->peer_dane_verified = state->peer_cert_verified = TRUE;
+ goto goodcert;
+ }
+# ifdef GNUTLS_BROKEN_DANE_VALIDATION
+ /* Assume that the name on the A-record is the one that should be matching
+ the cert. An alternate view is that the domain part of the email address
+ is also permissible. */
+
+ if (gnutls_x509_crt_check_hostname(state->tlsp->peercert,
+ CS state->host->name))
+ {
+ state->peer_dane_verified = state->peer_cert_verified = TRUE;
+ goto goodcert;
+ }
+# endif
+ }
+#endif /*SUPPORT_DANE*/
+
rc = gnutls_certificate_verify_peers2(state->session, &verify);
}
-/* Handle the result of verification. INVALID seems to be set as well
-as REVOKED, but leave the test for both. */
+/* Handle the result of verification. INVALID is set if any others are. */
-if ((rc < 0) || (verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED)) != 0)
+if (rc < 0 || verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED))
{
state->peer_cert_verified = FALSE;
- if (*error == NULL)
- *error = ((verify & GNUTLS_CERT_REVOKED) != 0) ? "revoked" : "invalid";
+ if (!*errstr)
+ {
+#ifdef GNUTLS_CERT_VFY_STATUS_PRINT
+ DEBUG(D_tls)
+ {
+ gnutls_datum_t txt;
+
+ if (gnutls_certificate_verification_status_print(verify,
+ gnutls_certificate_type_get(state->session), &txt, 0)
+ == GNUTLS_E_SUCCESS)
+ {
+ debug_printf("%s\n", txt.data);
+ gnutls_free(txt.data);
+ }
+ }
+#endif
+ *errstr = verify & GNUTLS_CERT_REVOKED
+ ? US"certificate revoked" : US"certificate invalid";
+ }
DEBUG(D_tls)
- debug_printf("TLS certificate verification failed (%s): peerdn=%s\n",
- *error, state->peerdn ? state->peerdn : US"<unset>");
+ debug_printf("TLS certificate verification failed (%s): peerdn=\"%s\"\n",
+ *errstr, state->peerdn ? state->peerdn : US"<unset>");
- if (state->verify_requirement == VERIFY_REQUIRED)
- {
- gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE);
- return FALSE;
- }
+ if (state->verify_requirement >= VERIFY_REQUIRED)
+ goto badcert;
DEBUG(D_tls)
debug_printf("TLS verify failure overridden (host in tls_try_verify_hosts)\n");
}
+
else
{
+ /* Client side, check the server's certificate name versus the name on the
+ A-record for the connection we made. What to do for server side - what name
+ to use for client? We document that there is no such checking for server
+ side. */
+
+ if ( state->exp_tls_verify_cert_hostnames
+ && !gnutls_x509_crt_check_hostname(state->tlsp->peercert,
+ CS state->exp_tls_verify_cert_hostnames)
+ )
+ {
+ DEBUG(D_tls)
+ debug_printf("TLS certificate verification failed: cert name mismatch\n");
+ if (state->verify_requirement >= VERIFY_REQUIRED)
+ goto badcert;
+ return TRUE;
+ }
+
state->peer_cert_verified = TRUE;
- DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=%s\n",
+ DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=\"%s\"\n",
state->peerdn ? state->peerdn : US"<unset>");
}
-tls_peerdn = state->peerdn;
+goodcert:
+ state->tlsp->peerdn = state->peerdn;
+ return TRUE;
-return TRUE;
+#ifdef SUPPORT_DANE
+tlsa_prob:
+ *errstr = string_sprintf("TLSA record problem: %s",
+ rc == DANE_E_REQUESTED_DATA_NOT_AVAILABLE ? "none usable" : dane_strerror(rc));
+#endif
+
+badcert:
+ gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE);
+ return FALSE;
}
For inability to get SNI information, we return 0.
We only return non-zero if re-setup failed.
+Only used for server-side TLS.
*/
static int
{
char sni_name[MAX_HOST_LEN];
size_t data_len = MAX_HOST_LEN;
-exim_gnutls_state_st *state = current_global_tls_state;
+exim_gnutls_state_st *state = &state_server;
unsigned int sni_type;
int rc, old_pool;
+uschar * dummy_errstr;
rc = gnutls_server_name_get(session, sni_name, &data_len, &sni_type, 0);
if (rc != GNUTLS_E_SUCCESS)
{
- DEBUG(D_tls) {
+ DEBUG(D_tls)
if (rc == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
debug_printf("TLS: no SNI presented in handshake.\n");
else
debug_printf("TLS failure: gnutls_server_name_get(): %s [%d]\n",
gnutls_strerror(rc), rc);
- };
return 0;
}
/* We now have a UTF-8 string in sni_name */
old_pool = store_pool;
store_pool = POOL_PERM;
-state->received_sni = string_copyn(US sni_name, data_len);
+state->received_sni = string_copy_taint(US sni_name, TRUE);
store_pool = old_pool;
/* We set this one now so that variable expansions below will work */
-tls_sni = state->received_sni;
+state->tlsp->sni = state->received_sni;
DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", sni_name,
state->trigger_sni_changes ? "" : " (unused for certificate selection)");
if (!state->trigger_sni_changes)
return 0;
-rc = tls_expand_session_files(state);
-if (rc != OK)
+if ((rc = tls_expand_session_files(state, &dummy_errstr)) != OK)
{
/* If the setup of certs/etc failed before handshake, TLS would not have
been offered. The best we can do now is abort. */
return GNUTLS_E_APPLICATION_ERROR_MIN;
}
-rc = tls_set_remaining_x509(state);
+rc = tls_set_remaining_x509(state, &dummy_errstr);
if (rc != OK) return GNUTLS_E_APPLICATION_ERROR_MIN;
return 0;
+#ifndef DISABLE_EVENT
+/*
+We use this callback to get observability and detail-level control
+for an exim TLS connection (either direction), raising a tls:cert event
+for each cert in the chain presented by the peer. Any event
+can deny verification.
+
+Return 0 for the handshake to continue or non-zero to terminate.
+*/
+
+static int
+verify_cb(gnutls_session_t session)
+{
+const gnutls_datum_t * cert_list;
+unsigned int cert_list_size = 0;
+gnutls_x509_crt_t crt;
+int rc;
+uschar * yield;
+exim_gnutls_state_st * state = gnutls_session_get_ptr(session);
+if ((cert_list = gnutls_certificate_get_peers(session, &cert_list_size)))
+ while (cert_list_size--)
+ {
+ if ((rc = import_cert(&cert_list[cert_list_size], &crt)) != GNUTLS_E_SUCCESS)
+ {
+ DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n",
+ cert_list_size, gnutls_strerror(rc));
+ break;
+ }
+
+ state->tlsp->peercert = crt;
+ if ((yield = event_raise(state->event_action,
+ US"tls:cert", string_sprintf("%d", cert_list_size))))
+ {
+ log_write(0, LOG_MAIN,
+ "SSL verify denied by event-action: depth=%d: %s",
+ cert_list_size, yield);
+ return 1; /* reject */
+ }
+ state->tlsp->peercert = NULL;
+ }
+
+return 0;
+}
+
+#endif
+
+
+static gstring *
+ddump(gnutls_datum_t * d)
+{
+gstring * g = string_get((d->size+1) * 2);
+uschar * s = d->data;
+for (unsigned i = d->size; i > 0; i--, s++)
+ {
+ g = string_catn(g, US "0123456789abcdef" + (*s >> 4), 1);
+ g = string_catn(g, US "0123456789abcdef" + (*s & 0xf), 1);
+ }
+return g;
+}
+
+static void
+post_handshake_debug(exim_gnutls_state_st * state)
+{
+#ifdef SUPPORT_GNUTLS_SESS_DESC
+debug_printf("%s\n", gnutls_session_get_desc(state->session));
+#endif
+
+#ifdef SUPPORT_GNUTLS_KEYLOG
+# ifdef EXIM_HAVE_TLS1_3
+if (gnutls_protocol_get_version(state->session) < GNUTLS_TLS1_3)
+# else
+if (TRUE)
+# endif
+ {
+ gnutls_datum_t c, s;
+ gstring * gc, * gs;
+ /* For TLS1.2 we only want the client random and the master secret */
+ gnutls_session_get_random(state->session, &c, &s);
+ gnutls_session_get_master_secret(state->session, &s);
+ gc = ddump(&c);
+ gs = ddump(&s);
+ debug_printf("CLIENT_RANDOM %.*s %.*s\n", (int)gc->ptr, gc->s, (int)gs->ptr, gs->s);
+ }
+else
+ debug_printf("To get keying info for TLS1.3 is hard:\n"
+ " Set environment variable SSLKEYLOGFILE to a filename relative to the spool directory,\n"
+ " and make sure it is writable by the Exim runtime user.\n"
+ " Add SSLKEYLOGFILE to keep_environment in the exim config.\n"
+ " Start Exim as root.\n"
+ " If using sudo, add SSLKEYLOGFILE to env_keep in /etc/sudoers\n"
+ " (works for TLS1.2 also, and saves cut-paste into file).\n"
+ " Trying to use add_environment for this will not work\n");
+#endif
+}
+
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+static int
+tls_server_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when,
+ unsigned incoming, const gnutls_datum_t * msg)
+{
+DEBUG(D_tls) debug_printf("newticket cb\n");
+tls_in.resumption |= RESUME_CLIENT_REQUESTED;
+return 0;
+}
+
+static void
+tls_server_resume_prehandshake(exim_gnutls_state_st * state)
+{
+/* Should the server offer session resumption? */
+tls_in.resumption = RESUME_SUPPORTED;
+if (verify_check_host(&tls_resumption_hosts) == OK)
+ {
+ int rc;
+ /* GnuTLS appears to not do ticket overlap, but does emit a fresh ticket when
+ an offered resumption is unacceptable. We lose one resumption per ticket
+ lifetime, and sessions cannot be indefinitely re-used. There seems to be no
+ way (3.6.7) of changing the default number of 2 TLS1.3 tickets issued, but at
+ least they go out in a single packet. */
+
+ if (!(rc = gnutls_session_ticket_enable_server(state->session,
+ &server_sessticket_key)))
+ tls_in.resumption |= RESUME_SERVER_TICKET;
+ else
+ DEBUG(D_tls)
+ debug_printf("enabling session tickets: %s\n", US gnutls_strerror(rc));
+
+ /* Try to tell if we see a ticket request */
+ gnutls_handshake_set_hook_function(state->session,
+ GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb);
+ }
+}
+
+static void
+tls_server_resume_posthandshake(exim_gnutls_state_st * state)
+{
+if (gnutls_session_resumption_requested(state->session))
+ {
+ /* This tells us the client sent a full ticket. We use a
+ callback on session-ticket request, elsewhere, to tell
+ if a client asked for a ticket. */
+
+ tls_in.resumption |= RESUME_CLIENT_SUGGESTED;
+ DEBUG(D_tls) debug_printf("client requested resumption\n");
+ }
+if (gnutls_session_is_resumed(state->session))
+ {
+ tls_in.resumption |= RESUME_USED;
+ DEBUG(D_tls) debug_printf("Session resumed\n");
+ }
+}
+#endif
/* ------------------------------------------------------------------------ */
/* Exported functions */
Arguments:
require_ciphers list of allowed ciphers or NULL
+ errstr pointer to error string
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(const uschar * require_ciphers, uschar ** errstr)
{
int rc;
-const char *error;
-exim_gnutls_state_st *state = NULL;
+exim_gnutls_state_st * state = NULL;
/* Check for previous activation */
-/* nb: this will not be TLS callout safe, needs reworking as part of that. */
-
-if (tls_active >= 0)
+if (tls_in.active.sock >= 0)
{
- tls_error(US"STARTTLS received after TLS started", "", NULL);
- smtp_printf("554 Already in TLS\r\n");
+ tls_error(US"STARTTLS received after TLS started", US "", NULL, errstr);
+ smtp_printf("554 Already in TLS\r\n", FALSE);
return FAIL;
}
DEBUG(D_tls) debug_printf("initialising GnuTLS as a server\n");
-rc = tls_init(NULL, tls_certificate, tls_privatekey,
- NULL, tls_verify_certificates, tls_crl,
- require_ciphers, &state);
-if (rc != OK) return rc;
+ {
+#ifdef MEASURE_TIMING
+ struct timeval t0;
+ gettimeofday(&t0, NULL);
+#endif
+
+ if ((rc = tls_init(NULL, tls_certificate, tls_privatekey,
+ NULL, tls_verify_certificates, tls_crl,
+ require_ciphers, &state, &tls_in, errstr)) != OK) return rc;
+
+#ifdef MEASURE_TIMING
+ report_time_since(&t0, US"server tls_init (delta)");
+#endif
+ }
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+tls_server_resume_prehandshake(state);
+#endif
/* If this is a host for which certificate verification is mandatory or
optional, set up appropriately. */
if (verify_check_host(&tls_verify_hosts) == OK)
{
- DEBUG(D_tls) debug_printf("TLS: a client certificate will be required.\n");
+ DEBUG(D_tls)
+ debug_printf("TLS: a client certificate will be required.\n");
state->verify_requirement = VERIFY_REQUIRED;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE);
}
else if (verify_check_host(&tls_try_verify_hosts) == OK)
{
- DEBUG(D_tls) debug_printf("TLS: a client certificate will be requested but not required.\n");
+ DEBUG(D_tls)
+ debug_printf("TLS: a client certificate will be requested but not required.\n");
state->verify_requirement = VERIFY_OPTIONAL;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST);
}
else
{
- DEBUG(D_tls) debug_printf("TLS: a client certificate will not be requested.\n");
+ DEBUG(D_tls)
+ debug_printf("TLS: a client certificate will not be requested.\n");
state->verify_requirement = VERIFY_NONE;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE);
}
+#ifndef DISABLE_EVENT
+if (event_action)
+ {
+ state->event_action = event_action;
+ gnutls_session_set_ptr(state->session, state);
+ gnutls_certificate_set_verify_function(state->x509_cred, verify_cb);
+ }
+#endif
+
/* Register SNI handling; always, even if not in tls_certificate, so that the
expansion variable $tls_sni is always available. */
the response. Other smtp_printf() calls do not need it, because in non-TLS
mode, the fflush() happens when smtp_getc() is called. */
-if (!tls_on_connect)
+if (!state->tlsp->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 GnuTLS library doesn't. */
+that the GnuTLS library doesn't.
+From 3.1.0 there is gnutls_handshake_set_timeout() - but it requires you
+to set (and clear down afterwards) up a pull-timeout callback function that does
+a select, so we're no better off unless avoiding signals becomes an issue. */
gnutls_transport_set_ptr2(state->session,
- (gnutls_transport_ptr)fileno(smtp_in),
- (gnutls_transport_ptr)fileno(smtp_out));
+ (gnutls_transport_ptr_t)(long) fileno(smtp_in),
+ (gnutls_transport_ptr_t)(long) fileno(smtp_out));
state->fd_in = fileno(smtp_in);
state->fd_out = fileno(smtp_out);
sigalrm_seen = FALSE;
-if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
+if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout);
do
- {
rc = gnutls_handshake(state->session);
- } while ((rc == GNUTLS_E_AGAIN) ||
- (rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen));
-alarm(0);
+while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen);
+ALARM_CLR(0);
if (rc != GNUTLS_E_SUCCESS)
{
- tls_error(US"gnutls_handshake",
- sigalrm_seen ? "timed out" : gnutls_strerror(rc), NULL);
/* It seems that, except in the case of a timeout, we have to close the
connection right here; otherwise if the other end is running OpenSSL it hangs
until the server times out. */
- if (!sigalrm_seen)
+ if (sigalrm_seen)
{
+ tls_error(US"gnutls_handshake", US"timed out", NULL, errstr);
+ gnutls_db_remove_session(state->session);
+ }
+ else
+ {
+ tls_error_gnu(US"gnutls_handshake", rc, NULL, errstr);
+ (void) gnutls_alert_send_appropriate(state->session, rc);
+ gnutls_deinit(state->session);
+ gnutls_certificate_free_credentials(state->x509_cred);
+ millisleep(500);
+ shutdown(state->fd_out, SHUT_WR);
+ for (int i = 1024; fgetc(smtp_in) != EOF && i > 0; ) i--; /* drain skt */
(void)fclose(smtp_out);
(void)fclose(smtp_in);
+ smtp_out = smtp_in = NULL;
}
return FAIL;
}
-DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n");
+#ifdef GNUTLS_SFLAGS_EXT_MASTER_SECRET
+if (gnutls_session_get_flags(state->session) & GNUTLS_SFLAGS_EXT_MASTER_SECRET)
+ tls_in.ext_master_secret = TRUE;
+#endif
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+tls_server_resume_posthandshake(state);
+#endif
+
+DEBUG(D_tls) post_handshake_debug(state);
/* Verify after the fact */
-if (state->verify_requirement != VERIFY_NONE)
+if (!verify_certificate(state, errstr))
{
- if (!verify_certificate(state, &error))
+ if (state->verify_requirement != VERIFY_OPTIONAL)
{
- if (state->verify_requirement == VERIFY_OPTIONAL)
- {
- DEBUG(D_tls)
- debug_printf("TLS: continuing on only because verification was optional, after: %s\n",
- error);
- }
- else
- {
- tls_error(US"certificate verification failed", error, NULL);
- return FAIL;
- }
+ (void) tls_error(US"certificate verification failed", *errstr, NULL, errstr);
+ return FAIL;
}
+ DEBUG(D_tls)
+ debug_printf("TLS: continuing on only because verification was optional, after: %s\n",
+ *errstr);
}
-/* Figure out peer DN, and if authenticated, etc. */
-
-rc = peer_status(state);
-if (rc != OK) return rc;
-
/* Sets various Exim expansion variables; always safe within server */
extract_exim_vars_from_tls_state(state);
state->xfer_buffer = store_malloc(ssl_xfer_buffer_size);
receive_getc = tls_getc;
+receive_getbuf = tls_getbuf;
+receive_get_cache = tls_get_cache;
receive_ungetc = tls_ungetc;
receive_feof = tls_feof;
receive_ferror = tls_ferror;
+static void
+tls_client_setup_hostname_checks(host_item * host, exim_gnutls_state_st * state,
+ smtp_transport_options_block * ob)
+{
+if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK)
+ {
+ state->exp_tls_verify_cert_hostnames =
+#ifdef SUPPORT_I18N
+ string_domain_utf8_to_alabel(host->name, NULL);
+#else
+ host->name;
+#endif
+ DEBUG(D_tls)
+ debug_printf("TLS: server cert verification includes hostname: \"%s\".\n",
+ state->exp_tls_verify_cert_hostnames);
+ }
+}
+
+
+
+
+#ifdef SUPPORT_DANE
+/* Given our list of RRs from the TLSA lookup, build a lookup block in
+GnuTLS-DANE's preferred format. Hang it on the state str for later
+use in DANE verification.
+
+We point at the dnsa data not copy it, so it must remain valid until
+after verification is done.*/
+
+static BOOL
+dane_tlsa_load(exim_gnutls_state_st * state, dns_answer * dnsa)
+{
+dns_scan dnss;
+int i;
+const char ** dane_data;
+int * dane_data_len;
+
+i = 1;
+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) i++;
+
+dane_data = store_get(i * sizeof(uschar *), FALSE);
+dane_data_len = store_get(i * sizeof(int), FALSE);
+
+i = 0;
+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 && rr->size > 3)
+ {
+ const uschar * p = rr->data;
+/*XXX need somehow to mark rr and its data as tainted. Doues this mean copying it? */
+ uint8_t usage = p[0], sel = p[1], type = p[2];
+
+ DEBUG(D_tls)
+ debug_printf("TLSA: %d %d %d size %d\n", usage, sel, type, rr->size);
+
+ if ( (usage != DANESSL_USAGE_DANE_TA && usage != DANESSL_USAGE_DANE_EE)
+ || (sel != 0 && sel != 1)
+ )
+ continue;
+ switch(type)
+ {
+ case 0: /* Full: cannot check at present */
+ break;
+ case 1: if (rr->size != 3 + 256/8) continue; /* sha2-256 */
+ break;
+ case 2: if (rr->size != 3 + 512/8) continue; /* sha2-512 */
+ break;
+ default: continue;
+ }
+
+ tls_out.tlsa_usage |= 1<<usage;
+ dane_data[i] = CS p;
+ dane_data_len[i++] = rr->size;
+ }
+
+if (!i) return FALSE;
+
+dane_data[i] = NULL;
+dane_data_len[i] = 0;
+
+state->dane_data = (char * const *)dane_data;
+state->dane_data_len = dane_data_len;
+return TRUE;
+}
+#endif
+
+
+
+#ifdef EXPERIMENTAL_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. Although
+there is a gnutls_session_ticket_enable_client() interface it is
+documented as unnecessary (as of 3.6.7) as "session tickets are emabled
+by deafult". There seems to be no way to disable them, so even hosts not
+enabled by the transport option will be sent a ticket request. We will
+however avoid storing and retrieving session information. */
+
+static void
+tls_retrieve_session(tls_support * tlsp, gnutls_session_t session,
+ host_item * host, smtp_transport_options_block * ob)
+{
+tlsp->resumption = RESUME_SUPPORTED;
+if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, host) == OK)
+ {
+ dbdata_tls_session * dt;
+ int len, rc;
+ open_db dbblock, * dbm_file;
+
+ DEBUG(D_tls)
+ debug_printf("check for resumable session for %s\n", host->address);
+ tlsp->host_resumable = TRUE;
+ tlsp->resumption |= RESUME_CLIENT_REQUESTED;
+ if ((dbm_file = dbfn_open(US"tls", O_RDONLY, &dbblock, FALSE, FALSE)))
+ {
+ /* Key for the db is the IP. We'd like to filter the retrieved session
+ for ticket advisory expiry, but 3.6.1 seems to give no access to that */
+
+ if ((dt = dbfn_read_with_length(dbm_file, host->address, &len)))
+ if (!(rc = gnutls_session_set_data(session,
+ CUS dt->session, (size_t)len - sizeof(dbdata_tls_session))))
+ {
+ DEBUG(D_tls) debug_printf("good session\n");
+ tlsp->resumption |= RESUME_CLIENT_SUGGESTED;
+ }
+ else DEBUG(D_tls) debug_printf("setting session resumption data: %s\n",
+ US gnutls_strerror(rc));
+ dbfn_close(dbm_file);
+ }
+ }
+}
+
+
+static void
+tls_save_session(tls_support * tlsp, gnutls_session_t session, const host_item * host)
+{
+/* TLS 1.2 - we get both the callback and the direct posthandshake call,
+but this flag is not set until the second. TLS 1.3 it's the other way about.
+Keep both calls as the session data cannot be extracted before handshake
+completes. */
+
+if (gnutls_session_get_flags(session) & GNUTLS_SFLAGS_SESSION_TICKET)
+ {
+ gnutls_datum_t tkt;
+ int rc;
+
+ DEBUG(D_tls) debug_printf("server offered session ticket\n");
+ tlsp->ticket_received = TRUE;
+ tlsp->resumption |= RESUME_SERVER_TICKET;
+
+ if (tlsp->host_resumable)
+ if (!(rc = gnutls_session_get_data2(session, &tkt)))
+ {
+ open_db dbblock, * dbm_file;
+ int dlen = sizeof(dbdata_tls_session) + tkt.size;
+ dbdata_tls_session * dt = store_get(dlen, TRUE);
+
+ DEBUG(D_tls) debug_printf("session data size %u\n", (unsigned)tkt.size);
+ memcpy(dt->session, tkt.data, tkt.size);
+ gnutls_free(tkt.data);
+
+ if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE)))
+ {
+ /* key for the db is the IP */
+ dbfn_delete(dbm_file, host->address);
+ dbfn_write(dbm_file, host->address, dt, dlen);
+ dbfn_close(dbm_file);
+
+ DEBUG(D_tls)
+ debug_printf("wrote session db (len %u)\n", (unsigned)dlen);
+ }
+ }
+ else DEBUG(D_tls)
+ debug_printf("extract session data: %s\n", US gnutls_strerror(rc));
+ }
+}
+
+
+/* With a TLS1.3 session, the ticket(s) are not seen until
+the first data read is attempted. And there's often two of them.
+Pick them up with this callback. We are also called for 1.2
+but we do nothing.
+*/
+static int
+tls_client_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when,
+ unsigned incoming, const gnutls_datum_t * msg)
+{
+exim_gnutls_state_st * state = gnutls_session_get_ptr(sess);
+tls_support * tlsp = state->tlsp;
+
+DEBUG(D_tls) debug_printf("newticket cb\n");
+
+if (!tlsp->ticket_received)
+ tls_save_session(tlsp, sess, state->host);
+return 0;
+}
+
+
+static void
+tls_client_resume_prehandshake(exim_gnutls_state_st * state,
+ tls_support * tlsp, host_item * host,
+ smtp_transport_options_block * ob)
+{
+gnutls_session_set_ptr(state->session, state);
+gnutls_handshake_set_hook_function(state->session,
+ GNUTLS_HANDSHAKE_NEW_SESSION_TICKET, GNUTLS_HOOK_POST, tls_client_ticket_cb);
+
+tls_retrieve_session(tlsp, state->session, host, ob);
+}
+
+static void
+tls_client_resume_posthandshake(exim_gnutls_state_st * state,
+ tls_support * tlsp, host_item * host)
+{
+if (gnutls_session_is_resumed(state->session))
+ {
+ DEBUG(D_tls) debug_printf("Session resumed\n");
+ tlsp->resumption |= RESUME_USED;
+ }
+
+tls_save_session(tlsp, state->session, host);
+}
+#endif /* EXPERIMENTAL_TLS_RESUME */
+
+
/*************************************************
* Start a TLS session in a client *
*************************************************/
/* Called from the smtp transport after STARTTLS has been accepted.
Arguments:
- fd the fd of the connection
- host connected host (for messages)
- addr the first address (not used)
- dhparam DH parameter file (ignored, we're a client)
- certificate certificate file
- privatekey private key file
- sni TLS SNI to send to remote host
- verify_certs file for certificate verify
- verify_crl CRL for verify
- require_ciphers list of allowed ciphers or NULL
- timeout startup timeout
-
-Returns: OK/DEFER/FAIL (because using common functions),
- but for a client, DEFER and FAIL have the same meaning
+ cctx connection context
+ conn_args connection details
+ cookie datum for randomness (not used)
+ tlsp record details of channel configuration here; must be non-NULL
+ errstr error string pointer
+
+Returns: TRUE for success with TLS session context set in smtp context,
+ FALSE on error
*/
-int
-tls_client_start(int fd, host_item *host,
- address_item *addr ARG_UNUSED, uschar *dhparam ARG_UNUSED,
- uschar *certificate, uschar *privatekey, uschar *sni,
- uschar *verify_certs, uschar *verify_crl,
- uschar *require_ciphers, int timeout)
+BOOL
+tls_client_start(client_conn_ctx * cctx, smtp_connect_args * conn_args,
+ void * cookie ARG_UNUSED,
+ tls_support * tlsp, uschar ** errstr)
{
+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;
int rc;
-const char *error;
-exim_gnutls_state_st *state = NULL;
+exim_gnutls_state_st * state = NULL;
+uschar * cipher_list = NULL;
+
+#ifndef DISABLE_OCSP
+BOOL require_ocsp =
+ verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK;
+BOOL request_ocsp = require_ocsp ? TRUE
+ : verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK;
+#endif
+
+DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", cctx->sock);
+
+#ifdef SUPPORT_DANE
+/* If dane is flagged, have either request or require dane for this host, and
+a TLSA record found. Therefore, dane verify required. Which implies cert must
+be requested and supplied, dane verify must pass, and cert verify irrelevant
+(incl. hostnames), and (caller handled) require_tls */
+
+if (conn_args->dane && ob->dane_require_tls_ciphers)
+ {
+ /* not using expand_check_tlsvar because not yet in state */
+ if (!expand_check(ob->dane_require_tls_ciphers, US"dane_require_tls_ciphers",
+ &cipher_list, errstr))
+ return FALSE;
+ cipher_list = cipher_list && *cipher_list
+ ? ob->dane_require_tls_ciphers : ob->tls_require_ciphers;
+ }
+#endif
-DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", fd);
+if (!cipher_list)
+ cipher_list = ob->tls_require_ciphers;
-rc = tls_init(host, certificate, privatekey,
- sni, verify_certs, verify_crl, require_ciphers, &state);
-if (rc != OK) return rc;
+ {
+#ifdef MEASURE_TIMING
+ struct timeval t0;
+ gettimeofday(&t0, NULL);
+#endif
-gnutls_dh_set_prime_bits(state->session, EXIM_CLIENT_DH_MIN_BITS);
+ if (tls_init(host, ob->tls_certificate, ob->tls_privatekey,
+ ob->tls_sni, ob->tls_verify_certificates, ob->tls_crl,
+ cipher_list, &state, tlsp, errstr) != OK)
+ return FALSE;
+
+#ifdef MEASURE_TIMING
+ report_time_since(&t0, US"client tls_init (delta)");
+#endif
+ }
-if (verify_certs == NULL)
{
- DEBUG(D_tls) debug_printf("TLS: server certificate verification not required\n");
- state->verify_requirement = VERIFY_NONE;
- /* we still ask for it, to log it, etc */
- gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST);
+ int dh_min_bits = ob->tls_dh_min_bits;
+ if (dh_min_bits < EXIM_CLIENT_DH_MIN_MIN_BITS)
+ {
+ DEBUG(D_tls)
+ debug_printf("WARNING: tls_dh_min_bits far too low,"
+ " clamping %d up to %d\n",
+ dh_min_bits, EXIM_CLIENT_DH_MIN_MIN_BITS);
+ dh_min_bits = EXIM_CLIENT_DH_MIN_MIN_BITS;
+ }
+
+ DEBUG(D_tls) debug_printf("Setting D-H prime minimum"
+ " acceptable bits to %d\n",
+ dh_min_bits);
+ gnutls_dh_set_prime_bits(state->session, dh_min_bits);
+ }
+
+/* Stick to the old behaviour for compatibility if tls_verify_certificates is
+set but both tls_verify_hosts and tls_try_verify_hosts are unset. Check only
+the specified host patterns if one of them is defined */
+
+#ifdef SUPPORT_DANE
+if (conn_args->dane && dane_tlsa_load(state, &conn_args->tlsa_dnsa))
+ {
+ DEBUG(D_tls)
+ debug_printf("TLS: server certificate DANE required.\n");
+ state->verify_requirement = VERIFY_DANE;
+ gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE);
}
else
+#endif
+ if ( ( state->exp_tls_verify_certificates
+ && !ob->tls_verify_hosts
+ && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts)
+ )
+ || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK
+ )
{
- DEBUG(D_tls) debug_printf("TLS: server certificate verification required\n");
+ tls_client_setup_hostname_checks(host, state, ob);
+ DEBUG(D_tls)
+ debug_printf("TLS: server certificate verification required.\n");
state->verify_requirement = VERIFY_REQUIRED;
gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE);
}
+else if (verify_check_given_host(CUSS &ob->tls_try_verify_hosts, host) == OK)
+ {
+ tls_client_setup_hostname_checks(host, state, ob);
+ DEBUG(D_tls)
+ debug_printf("TLS: server certificate verification optional.\n");
+ state->verify_requirement = VERIFY_OPTIONAL;
+ gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST);
+ }
+else
+ {
+ DEBUG(D_tls)
+ debug_printf("TLS: server certificate verification not required.\n");
+ state->verify_requirement = VERIFY_NONE;
+ gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE);
+ }
+
+#ifndef DISABLE_OCSP
+ /* supported since GnuTLS 3.1.3 */
+if (request_ocsp)
+ {
+ DEBUG(D_tls) debug_printf("TLS: will request OCSP stapling\n");
+ if ((rc = gnutls_ocsp_status_request_enable_client(state->session,
+ NULL, 0, NULL)) != OK)
+ {
+ tls_error_gnu(US"cert-status-req", rc, state->host, errstr);
+ return FALSE;
+ }
+ tlsp->ocsp = OCSP_NOT_RESP;
+ }
+#endif
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+tls_client_resume_prehandshake(state, tlsp, host, ob);
+#endif
+
+#ifndef DISABLE_EVENT
+if (tb && tb->event_action)
+ {
+ state->event_action = tb->event_action;
+ gnutls_session_set_ptr(state->session, state);
+ gnutls_certificate_set_verify_function(state->x509_cred, verify_cb);
+ }
+#endif
-gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr)fd);
-state->fd_in = fd;
-state->fd_out = fd;
+gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr_t)(long) cctx->sock);
+state->fd_in = cctx->sock;
+state->fd_out = cctx->sock;
+DEBUG(D_tls) debug_printf("about to gnutls_handshake\n");
/* There doesn't seem to be a built-in timeout on connection. */
sigalrm_seen = FALSE;
-alarm(timeout);
+ALARM(ob->command_timeout);
do
- {
rc = gnutls_handshake(state->session);
- } while ((rc == GNUTLS_E_AGAIN) ||
- (rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen));
-alarm(0);
+while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen);
+ALARM_CLR(0);
if (rc != GNUTLS_E_SUCCESS)
- return tls_error(US"gnutls_handshake",
- sigalrm_seen ? "timed out" : gnutls_strerror(rc), state->host);
+ {
+ if (sigalrm_seen)
+ {
+ gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_USER_CANCELED);
+ tls_error(US"gnutls_handshake", US"timed out", state->host, errstr);
+ }
+ else
+ tls_error_gnu(US"gnutls_handshake", rc, state->host, errstr);
+ return FALSE;
+ }
-DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n");
+DEBUG(D_tls) post_handshake_debug(state);
/* Verify late */
-if (state->verify_requirement != VERIFY_NONE &&
- !verify_certificate(state, &error))
- return tls_error(US"certificate verification failed", error, state->host);
+if (!verify_certificate(state, errstr))
+ {
+ tls_error(US"certificate verification failed", *errstr, state->host, errstr);
+ return FALSE;
+ }
-/* Figure out peer DN, and if authenticated, etc. */
+#ifdef GNUTLS_SFLAGS_EXT_MASTER_SECRET
+if (gnutls_session_get_flags(state->session) & GNUTLS_SFLAGS_EXT_MASTER_SECRET)
+ tlsp->ext_master_secret = TRUE;
+#endif
-rc = peer_status(state);
-if (rc != OK) return rc;
+#ifndef DISABLE_OCSP
+if (request_ocsp)
+ {
+ DEBUG(D_tls)
+ {
+ gnutls_datum_t stapling;
+ gnutls_ocsp_resp_t resp;
+ gnutls_datum_t printed;
+ unsigned idx = 0;
+
+ for (;
+# ifdef GNUTLS_OCSP_STATUS_REQUEST_GET2
+ (rc = gnutls_ocsp_status_request_get2(state->session, idx, &stapling)) == 0;
+#else
+ (rc = gnutls_ocsp_status_request_get(state->session, &stapling)) == 0;
+#endif
+ idx++)
+ if ( (rc= gnutls_ocsp_resp_init(&resp)) == 0
+ && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0
+ && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_COMPACT, &printed)) == 0
+ )
+ {
+ debug_printf("%.4096s", printed.data);
+ gnutls_free(printed.data);
+ }
+ else
+ (void) tls_error_gnu(US"ocsp decode", rc, state->host, errstr);
+ if (idx == 0 && rc)
+ (void) tls_error_gnu(US"ocsp decode", rc, state->host, errstr);
+ }
+
+ if (gnutls_ocsp_status_request_is_checked(state->session, 0) == 0)
+ {
+ tlsp->ocsp = OCSP_FAILED;
+ tls_error(US"certificate status check failed", NULL, state->host, errstr);
+ if (require_ocsp)
+ return FALSE;
+ }
+ else
+ {
+ DEBUG(D_tls) debug_printf("Passed OCSP checking\n");
+ tlsp->ocsp = OCSP_VFIED;
+ }
+ }
+#endif
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+tls_client_resume_posthandshake(state, tlsp, host);
+#endif
/* Sets various Exim expansion variables; may need to adjust for ACL callouts */
extract_exim_vars_from_tls_state(state);
-return OK;
+cctx->tls_ctx = state;
+return TRUE;
}
daemon, to shut down the TLS library, without actually doing a shutdown (which
would tamper with the TLS session in the parent process).
-Arguments: TRUE if gnutls_bye is to be called
+Arguments:
+ ct_ctx client context pointer, or NULL for the one global server context
+ shutdown 1 if TLS close-alert is to be sent,
+ 2 if also response to be waited for
+
Returns: nothing
*/
void
-tls_close(BOOL shutdown)
+tls_close(void * ct_ctx, int shutdown)
{
-exim_gnutls_state_st *state = current_global_tls_state;
+exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server;
+tls_support * tlsp = state->tlsp;
-if (tls_active < 0) return; /* TLS was not active */
+if (!tlsp || tlsp->active.sock < 0) return; /* TLS was not active */
if (shutdown)
{
- DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS\n");
- gnutls_bye(state->session, GNUTLS_SHUT_WR);
+ DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n",
+ shutdown > 1 ? " (with response-wait)" : "");
+
+ ALARM(2);
+ gnutls_bye(state->session, shutdown > 1 ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR);
+ ALARM_CLR(0);
+ }
+
+if (!ct_ctx) /* server */
+ {
+ receive_getc = smtp_getc;
+ receive_getbuf = smtp_getbuf;
+ receive_get_cache = smtp_get_cache;
+ receive_ungetc = smtp_ungetc;
+ receive_feof = smtp_feof;
+ receive_ferror = smtp_ferror;
+ receive_smtp_buffered = smtp_buffered;
}
gnutls_deinit(state->session);
+gnutls_certificate_free_credentials(state->x509_cred);
+
+tlsp->active.sock = -1;
+tlsp->active.tls_ctx = NULL;
+/* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */
+tlsp->channelbinding = NULL;
+
+if (state->xfer_buffer) store_free(state->xfer_buffer);
memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init));
+}
+
+
-if ((state_server.session == NULL) && (state_client.session == NULL))
+
+static BOOL
+tls_refill(unsigned lim)
+{
+exim_gnutls_state_st * state = &state_server;
+ssize_t inbytes;
+
+DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(session=%p, buffer=%p, buffersize=%u)\n",
+ state->session, state->xfer_buffer, ssl_xfer_buffer_size);
+
+sigalrm_seen = FALSE;
+if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout);
+
+do
+ inbytes = gnutls_record_recv(state->session, state->xfer_buffer,
+ MIN(ssl_xfer_buffer_size, lim));
+while (inbytes == GNUTLS_E_AGAIN);
+
+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();
+
+/* Timeouts do not get this far. A zero-byte return appears to mean that the
+TLS session has been closed down, not that the socket itself has been closed
+down. Revert to non-TLS handling. */
+
+if (sigalrm_seen)
{
- gnutls_global_deinit();
- exim_gnutls_base_init_done = FALSE;
+ DEBUG(D_tls) debug_printf("Got tls read timeout\n");
+ state->xfer_error = TRUE;
+ return FALSE;
}
-tls_active = -1;
-}
-
+else if (inbytes == 0)
+ {
+ DEBUG(D_tls) debug_printf("Got TLS_EOF\n");
+ tls_close(NULL, TLS_NO_SHUTDOWN);
+ return FALSE;
+ }
+/* Handle genuine errors */
+else if (inbytes < 0)
+ {
+ DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv\n", __FUNCTION__);
+ record_io_error(state, (int) inbytes, US"recv", NULL);
+ state->xfer_error = TRUE;
+ return FALSE;
+ }
+#ifndef DISABLE_DKIM
+dkim_exim_verify_feed(state->xfer_buffer, inbytes);
+#endif
+state->xfer_buffer_hwm = (int) inbytes;
+state->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 GnuTLS reading function.
+Only used by the server-side TLS.
This feeds DKIM and should be used for all message-body reads.
-Arguments: none
+Arguments: lim Maximum amount to read/buffer
Returns: the next character or EOF
*/
int
-tls_getc(void)
+tls_getc(unsigned lim)
{
-exim_gnutls_state_st *state = current_global_tls_state;
+exim_gnutls_state_st * state = &state_server;
+
if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm)
- {
- ssize_t inbytes;
+ if (!tls_refill(lim))
+ return state->xfer_error ? EOF : smtp_getc(lim);
- DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(%p, %p, %u)\n",
- state->session, state->xfer_buffer, ssl_xfer_buffer_size);
+/* Something in the buffer; return next uschar */
- if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
- inbytes = gnutls_record_recv(state->session, state->xfer_buffer,
- ssl_xfer_buffer_size);
- alarm(0);
+return state->xfer_buffer[state->xfer_buffer_lwm++];
+}
- /* A zero-byte return appears to mean that the TLS session has been
- closed down, not that the socket itself has been closed down. Revert to
- non-TLS handling. */
+uschar *
+tls_getbuf(unsigned * len)
+{
+exim_gnutls_state_st * state = &state_server;
+unsigned size;
+uschar * buf;
- if (inbytes == 0)
+if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm)
+ if (!tls_refill(*len))
{
- DEBUG(D_tls) debug_printf("Got TLS_EOF\n");
-
- receive_getc = smtp_getc;
- receive_ungetc = smtp_ungetc;
- receive_feof = smtp_feof;
- receive_ferror = smtp_ferror;
- receive_smtp_buffered = smtp_buffered;
-
- gnutls_deinit(state->session);
- state->session = NULL;
- tls_active = -1;
- tls_bits = 0;
- tls_certificate_verified = FALSE;
- tls_channelbinding_b64 = NULL;
- tls_cipher = NULL;
- tls_peerdn = NULL;
-
- return smtp_getc();
+ if (!state->xfer_error) return smtp_getbuf(len);
+ *len = 0;
+ return NULL;
}
- /* Handle genuine errors */
+if ((size = state->xfer_buffer_hwm - state->xfer_buffer_lwm) > *len)
+ size = *len;
+buf = &state->xfer_buffer[state->xfer_buffer_lwm];
+state->xfer_buffer_lwm += size;
+*len = size;
+return buf;
+}
- else if (inbytes < 0)
- {
- record_io_error(state, (int) inbytes, US"recv", NULL);
- state->xfer_error = 1;
- return EOF;
- }
+
+void
+tls_get_cache()
+{
#ifndef DISABLE_DKIM
- dkim_exim_verify_feed(state->xfer_buffer, inbytes);
+exim_gnutls_state_st * state = &state_server;
+int n = state->xfer_buffer_hwm - state->xfer_buffer_lwm;
+if (n > 0)
+ dkim_exim_verify_feed(state->xfer_buffer+state->xfer_buffer_lwm, n);
#endif
- state->xfer_buffer_hwm = (int) inbytes;
- state->xfer_buffer_lwm = 0;
- }
+}
-/* Something in the buffer; return next uschar */
-return state->xfer_buffer[state->xfer_buffer_lwm++];
+BOOL
+tls_could_read(void)
+{
+return state_server.xfer_buffer_lwm < state_server.xfer_buffer_hwm
+ || gnutls_record_check_pending(state_server.session) > 0;
}
/* This does not feed DKIM, so if the caller uses this for reading message body,
then the caller must feed DKIM.
+
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
*/
int
-tls_read(uschar *buff, size_t len)
+tls_read(void * ct_ctx, uschar *buff, size_t len)
{
-exim_gnutls_state_st *state = current_global_tls_state;
+exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server;
ssize_t inbytes;
if (len > INT_MAX)
state->xfer_buffer_hwm - state->xfer_buffer_lwm);
DEBUG(D_tls)
- debug_printf("Calling gnutls_record_recv(%p, %p, " SIZE_T_FMT ")\n",
+ debug_printf("Calling gnutls_record_recv(session=%p, buffer=%p, len=" SIZE_T_FMT ")\n",
state->session, buff, len);
-inbytes = gnutls_record_recv(state->session, buff, len);
+do
+ inbytes = gnutls_record_recv(state->session, buff, len);
+while (inbytes == GNUTLS_E_AGAIN);
+
if (inbytes > 0) return inbytes;
if (inbytes == 0)
{
DEBUG(D_tls) debug_printf("Got TLS_EOF\n");
}
-else record_io_error(state, (int)inbytes, US"recv", NULL);
+else
+ {
+ DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv\n", __FUNCTION__);
+ record_io_error(state, (int)inbytes, US"recv", NULL);
+ }
return -1;
}
/*
Arguments:
+ ct_ctx client context pointer, or NULL for the one global server context
buff buffer of data
len number of bytes
+ more more data expected soon
+
+Calling with len zero and more unset will flush buffered writes. The buff
+argument can be null for that case.
Returns: the number of bytes after a successful write,
-1 after a failed write
*/
int
-tls_write(const uschar *buff, size_t len)
+tls_write(void * ct_ctx, const uschar * buff, size_t len, BOOL more)
{
ssize_t outbytes;
size_t left = len;
-exim_gnutls_state_st *state = current_global_tls_state;
+exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server;
+
+#ifdef SUPPORT_CORK
+if (more && !state->corked)
+ {
+ DEBUG(D_tls) debug_printf("gnutls_record_cork(session=%p)\n", state->session);
+ gnutls_record_cork(state->session);
+ state->corked = TRUE;
+ }
+#endif
+
+DEBUG(D_tls) debug_printf("%s(%p, " SIZE_T_FMT "%s)\n", __FUNCTION__,
+ buff, left, more ? ", more" : "");
-DEBUG(D_tls) debug_printf("tls_do_write(%p, " SIZE_T_FMT ")\n", buff, left);
while (left > 0)
{
- DEBUG(D_tls) debug_printf("gnutls_record_send(SSL, %p, " SIZE_T_FMT ")\n",
- buff, left);
- outbytes = gnutls_record_send(state->session, buff, left);
+ DEBUG(D_tls) debug_printf("gnutls_record_send(session=%p, buffer=%p, left=" SIZE_T_FMT ")\n",
+ state->session, buff, left);
+
+ do
+ outbytes = gnutls_record_send(state->session, buff, left);
+ while (outbytes == GNUTLS_E_AGAIN);
DEBUG(D_tls) debug_printf("outbytes=" SSIZE_T_FMT "\n", outbytes);
+
if (outbytes < 0)
{
+ DEBUG(D_tls) debug_printf("%s: gnutls_record_send err\n", __FUNCTION__);
record_io_error(state, outbytes, US"send", NULL);
return -1;
}
len = INT_MAX;
}
+#ifdef SUPPORT_CORK
+if (!more && state->corked)
+ {
+ DEBUG(D_tls) debug_printf("gnutls_record_uncork(session=%p)\n", state->session);
+ do
+ /* We can't use GNUTLS_RECORD_WAIT here, as it retries on
+ GNUTLS_E_AGAIN || GNUTLS_E_INTR, which would break our timeout set by alarm().
+ The GNUTLS_E_AGAIN should not happen ever, as our sockets are blocking anyway.
+ But who knows. (That all relies on the fact that GNUTLS_E_INTR and GNUTLS_E_AGAIN
+ match the EINTR and EAGAIN errno values.) */
+ outbytes = gnutls_record_uncork(state->session, 0);
+ while (outbytes == GNUTLS_E_AGAIN);
+
+ if (outbytes < 0)
+ {
+ record_io_error(state, len, US"uncork", NULL);
+ return -1;
+ }
+
+ state->corked = FALSE;
+ }
+#endif
+
return (int) len;
}
{
unsigned int r;
int i, needed_len;
-uschar *p;
uschar smallbuf[sizeof(r)];
if (max <= 1)
needed_len = sizeof(r);
/* Don't take 8 times more entropy than needed if int is 8 octets and we were
- * asked for a number less than 10. */
+asked for a number less than 10. */
+
for (r = max, i = 0; r; ++i)
r >>= 1;
i = (i + 7) / 8;
return vaguely_random_number_fallback(max);
}
r = 0;
-for (p = smallbuf; needed_len; --needed_len, ++p)
- {
- r *= 256;
- r += *p;
- }
+for (uschar * p = smallbuf; needed_len; --needed_len, ++p)
+ r = r * 256 + *p;
/* We don't particularly care about weighted results; if someone wants
* smooth distribution and cares enough then they should submit a patch then. */
uschar *expciphers = NULL;
gnutls_priority_t priority_cache;
const char *errpos;
+uschar * dummy_errstr;
-#define validate_check_rc(Label) do { \
+#ifdef GNUTLS_AUTO_GLOBAL_INIT
+# define validate_check_rc(Label) do { \
+ if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) \
+ return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0)
+# define return_deinit(Label) do { return (Label); } while (0)
+#else
+# define validate_check_rc(Label) do { \
if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) gnutls_global_deinit(); \
- return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0)
-#define return_deinit(Label) do { gnutls_global_deinit(); return (Label); } while (0)
+ return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0)
+# define return_deinit(Label) do { gnutls_global_deinit(); return (Label); } while (0)
+#endif
if (exim_gnutls_base_init_done)
log_write(0, LOG_MAIN|LOG_PANIC,
"already initialised GnuTLS, Exim developer bug");
+#if defined(HAVE_GNUTLS_PKCS11) && !defined(GNUTLS_AUTO_PKCS11_MANUAL)
+if (!gnutls_allow_auto_pkcs11)
+ {
+ rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL);
+ validate_check_rc(US"gnutls_pkcs11_init");
+ }
+#endif
+#ifndef GNUTLS_AUTO_GLOBAL_INIT
rc = gnutls_global_init();
validate_check_rc(US"gnutls_global_init()");
+#endif
exim_gnutls_base_init_done = TRUE;
if (!(tls_require_ciphers && *tls_require_ciphers))
return_deinit(NULL);
-if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers,
+ &dummy_errstr))
return_deinit(US"failed to expand tls_require_ciphers");
if (!(expciphers && *expciphers))
#undef return_deinit
#undef validate_check_rc
+#ifndef GNUTLS_AUTO_GLOBAL_INIT
gnutls_global_deinit();
+#endif
return NULL;
}
gnutls_check_version(NULL));
}
+#endif /*!MACRO_PREDEF*/
+/* vi: aw ai sw=2
+*/
/* End of tls-gnu.c */
git://git.exim.org / exim.git / blobdiff