* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2014 */
+/* Copyright (c) University of Cambridge 1995 - 2017 */
/* See the file NOTICE for conditions of use and distribution. */
/* Portions Copyright (c) The OpenSSL Project 1999 */
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
-#ifdef EXPERIMENTAL_OCSP
-#include <openssl/ocsp.h>
+#ifndef OPENSSL_NO_ECDH
+# include <openssl/ec.h>
#endif
+#ifndef DISABLE_OCSP
+# include <openssl/ocsp.h>
+#endif
+#ifdef EXPERIMENTAL_DANE
+# include <danessl.h>
+#endif
+
-#ifdef EXPERIMENTAL_OCSP
-#define EXIM_OCSP_SKEW_SECONDS (300L)
-#define EXIM_OCSP_MAX_AGE (-1L)
+#ifndef DISABLE_OCSP
+# define EXIM_OCSP_SKEW_SECONDS (300L)
+# define EXIM_OCSP_MAX_AGE (-1L)
#endif
#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
-#define EXIM_HAVE_OPENSSL_TLSEXT
+# define EXIM_HAVE_OPENSSL_TLSEXT
+#endif
+#if OPENSSL_VERSION_NUMBER >= 0x00908000L
+# define EXIM_HAVE_RSA_GENKEY_EX
+#endif
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+# define EXIM_HAVE_OCSP_RESP_COUNT
+#else
+# define EXIM_HAVE_EPHEM_RSA_KEX
+# define EXIM_HAVE_RAND_PSEUDO
+#endif
+#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
+# define EXIM_HAVE_SHA256
+#endif
+
+/*
+ * X509_check_host provides sane certificate hostname checking, but was added
+ * to OpenSSL late, after other projects forked off the code-base. So in
+ * addition to guarding against the base version number, beware that LibreSSL
+ * does not (at this time) support this function.
+ *
+ * If LibreSSL gains a different API, perhaps via libtls, then we'll probably
+ * opt to disentangle and ask a LibreSSL user to provide glue for a third
+ * crypto provider for libtls instead of continuing to tie the OpenSSL glue
+ * into even twistier knots. If LibreSSL gains the same API, we can just
+ * change this guard and punt the issue for a while longer.
+ */
+#ifndef LIBRESSL_VERSION_NUMBER
+# if OPENSSL_VERSION_NUMBER >= 0x010100000L
+# define EXIM_HAVE_OPENSSL_CHECKHOST
+# endif
+# if OPENSSL_VERSION_NUMBER >= 0x010000000L \
+ && (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L
+# define EXIM_HAVE_OPENSSL_CHECKHOST
+# endif
+#endif
+
+#if !defined(LIBRESSL_VERSION_NUMBER) \
+ || LIBRESSL_VERSION_NUMBER >= 0x20010000L
+# if !defined(OPENSSL_NO_ECDH)
+# if OPENSSL_VERSION_NUMBER >= 0x0090800fL
+# define EXIM_HAVE_ECDH
+# endif
+# if OPENSSL_VERSION_NUMBER >= 0x10002000L
+# define EXIM_HAVE_OPENSSL_EC_NIST2NID
+# endif
+# endif
+#endif
+
+#if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP)
+# warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile"
+# define DISABLE_OCSP
#endif
/* Structure for collecting random data for seeding. */
typedef struct tls_ext_ctx_cb {
uschar *certificate;
uschar *privatekey;
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
BOOL is_server;
+ STACK_OF(X509) *verify_stack; /* chain for verifying the proof */
union {
struct {
uschar *file;
OCSP_RESPONSE *response;
} server;
struct {
- X509_STORE *verify_store;
+ X509_STORE *verify_store; /* non-null if status requested */
+ BOOL verify_required;
} client;
} u_ocsp;
#endif
uschar *server_cipher_list;
/* only passed down to tls_error: */
host_item *host;
+ const uschar * verify_cert_hostnames;
+#ifndef DISABLE_EVENT
+ uschar * event_action;
+#endif
} tls_ext_ctx_cb;
/* should figure out a cleanup of API to handle state preserved per
static int
setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
- int (*cert_vfy_cb)(int, X509_STORE_CTX *) );
+ int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr );
/* Callbacks */
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg);
#endif
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
static int tls_server_stapling_cb(SSL *s, void *arg);
#endif
host NULL if setting up a server;
the connected host if setting up a client
msg error message or NULL if we should ask OpenSSL
+ errstr pointer to output error message
Returns: OK/DEFER/FAIL
*/
static int
-tls_error(uschar *prefix, host_item *host, uschar *msg)
+tls_error(uschar * prefix, const host_item * host, uschar * msg, uschar ** errstr)
{
-if (msg == NULL)
+if (!msg)
{
ERR_error_string(ERR_get_error(), ssl_errstring);
- msg = (uschar *)ssl_errstring;
+ msg = US ssl_errstring;
}
-if (host == NULL)
- {
- 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",
- conn_info, prefix, msg);
- return DEFER;
- }
-else
- {
- log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s): %s",
- host->name, host->address, prefix, msg);
- return FAIL;
- }
+if (errstr) *errstr = string_sprintf("(%s): %s", prefix, msg);
+return host ? FAIL : DEFER;
}
+#ifdef EXIM_HAVE_EPHEM_RSA_KEX
/*************************************************
* Callback to generate RSA key *
*************************************************/
rsa_callback(SSL *s, int export, int keylength)
{
RSA *rsa_key;
+#ifdef EXIM_HAVE_RSA_GENKEY_EX
+BIGNUM *bn = BN_new();
+#endif
+
export = export; /* Shut picky compilers up */
DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength);
-rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL);
-if (rsa_key == NULL)
+
+#ifdef EXIM_HAVE_RSA_GENKEY_EX
+if ( !BN_set_word(bn, (unsigned long)RSA_F4)
+ || !(rsa_key = RSA_new())
+ || !RSA_generate_key_ex(rsa_key, keylength, bn, NULL)
+ )
+#else
+if (!(rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL)))
+#endif
+
{
ERR_error_string(ERR_get_error(), ssl_errstring);
log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s",
}
return rsa_key;
}
+#endif
/* Extreme debug
-#if defined(EXPERIMENTAL_OCSP)
+#ifndef DISABLE_OCSP
void
x509_store_dump_cert_s_names(X509_STORE * store)
{
{
X509 * current_cert= tmp_obj->data.x509;
X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name));
+ name[sizeof(name)-1] = '\0';
debug_printf(" %s\n", name);
}
}
*/
+#ifndef DISABLE_EVENT
+static int
+verify_event(tls_support * tlsp, X509 * cert, int depth, const uschar * dn,
+ BOOL *calledp, const BOOL *optionalp, const uschar * what)
+{
+uschar * ev;
+uschar * yield;
+X509 * old_cert;
+
+ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action;
+if (ev)
+ {
+ DEBUG(D_tls) debug_printf("verify_event: %s %d\n", what, depth);
+ old_cert = tlsp->peercert;
+ tlsp->peercert = X509_dup(cert);
+ /* NB we do not bother setting peerdn */
+ if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth))))
+ {
+ log_write(0, LOG_MAIN, "[%s] %s verify denied by event-action: "
+ "depth=%d cert=%s: %s",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ what, depth, dn, yield);
+ *calledp = TRUE;
+ if (!*optionalp)
+ {
+ if (old_cert) tlsp->peercert = old_cert; /* restore 1st failing cert */
+ return 1; /* reject (leaving peercert set) */
+ }
+ DEBUG(D_tls) debug_printf("Event-action verify failure overridden "
+ "(host in tls_try_verify_hosts)\n");
+ }
+ X509_free(tlsp->peercert);
+ tlsp->peercert = old_cert;
+ }
+return 0;
+}
+#endif
+
/*************************************************
* Callback for verification *
*************************************************/
/* The SSL library does certificate verification if set up to do so. This
callback has the current yes/no state is in "state". If verification succeeded,
-we set up the tls_peerdn string. If verification failed, what happens depends
-on whether the client is required to present a verifiable certificate or not.
+we set the certificate-verified flag. If verification failed, what happens
+depends on whether the client is required to present a verifiable certificate
+or not.
If verification is optional, we change the state to yes, but still log the
verification error. For some reason (it really would help to have proper
documentation of OpenSSL), this callback function then gets called again, this
-time with state = 1. In fact, that's useful, because we can set up the peerdn
-value, but we must take care not to set the private verified flag on the second
-time through.
+time with state = 1. We must take care not to set the private verified flag on
+the second time through.
Note: this function is not called if the client fails to present a certificate
when asked. We get here only if a certificate has been received. Handling of
optional verification for this case is done when requesting SSL to verify, by
setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case.
+May be called multiple times for different issues with a certificate, even
+for a given "depth" in the certificate chain.
+
Arguments:
- state current yes/no state as 1/0
- x509ctx certificate information.
- client TRUE for client startup, FALSE for server startup
+ preverify_ok current yes/no state as 1/0
+ x509ctx certificate information.
+ tlsp per-direction (client vs. server) support data
+ calledp has-been-called flag
+ optionalp verification-is-optional flag
-Returns: 1 if verified, 0 if not
+Returns: 0 if verification should fail, otherwise 1
*/
static int
-verify_callback(int state, X509_STORE_CTX *x509ctx, tls_support *tlsp, BOOL *calledp, BOOL *optionalp)
+verify_callback(int preverify_ok, X509_STORE_CTX *x509ctx,
+ tls_support *tlsp, BOOL *calledp, BOOL *optionalp)
{
-static uschar txt[256];
+X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+uschar dn[256];
-X509_NAME_oneline(X509_get_subject_name(x509ctx->current_cert),
- CS txt, sizeof(txt));
+X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn));
+dn[sizeof(dn)-1] = '\0';
-if (state == 0)
+if (preverify_ok == 0)
{
- log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s",
- x509ctx->error_depth,
- X509_verify_cert_error_string(x509ctx->error),
- txt);
- tlsp->certificate_verified = FALSE;
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: depth=%d error=%s cert=%s",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ depth,
+ X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)),
+ dn);
*calledp = TRUE;
if (!*optionalp)
{
- tlsp->peercert = X509_dup(x509ctx->current_cert);
- return 0; /* reject */
+ if (!tlsp->peercert)
+ tlsp->peercert = X509_dup(cert); /* record failing cert */
+ return 0; /* reject */
}
DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
"tls_try_verify_hosts)\n");
- return 1; /* accept */
}
-if (x509ctx->error_depth != 0)
+else if (depth != 0)
{
- DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d cert=%s\n",
- x509ctx->error_depth, txt);
-#ifdef EXPERIMENTAL_OCSP
+ DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, dn);
+#ifndef DISABLE_OCSP
if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store)
{ /* client, wanting stapling */
/* Add the server cert's signing chain as the one
for the verification of the OCSP stapled information. */
-
+
if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store,
- x509ctx->current_cert))
+ cert))
ERR_clear_error();
+ sk_X509_push(client_static_cbinfo->verify_stack, cert);
}
+#endif
+#ifndef DISABLE_EVENT
+ if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL"))
+ return 0; /* reject, with peercert set */
#endif
}
else
{
- DEBUG(D_tls) debug_printf("SSL%s peer: %s\n",
- *calledp ? "" : " authenticated", txt);
- tlsp->peerdn = txt;
- tlsp->peercert = X509_dup(x509ctx->current_cert);
- }
+ const uschar * verify_cert_hostnames;
-/*XXX JGH: this looks bogus - we set "verified" first time through, which
-will be for the root CS cert (calls work down the chain). Why should it
-not be on the last call, where we're setting peerdn?
+ if ( tlsp == &tls_out
+ && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames)))
+ /* client, wanting hostname check */
+ {
-To test: set up a chain anchored by a good root-CA but with a bad server cert.
-Does certificate_verified get set?
-*/
-if (!*calledp) tlsp->certificate_verified = TRUE;
-*calledp = TRUE;
+#ifdef EXIM_HAVE_OPENSSL_CHECKHOST
+# ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
+# define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0
+# endif
+# ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS
+# define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0
+# endif
+ int sep = 0;
+ const uschar * list = verify_cert_hostnames;
+ uschar * name;
+ int rc;
+ while ((name = string_nextinlist(&list, &sep, NULL, 0)))
+ if ((rc = X509_check_host(cert, CCS name, 0,
+ X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
+ | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS,
+ NULL)))
+ {
+ if (rc < 0)
+ {
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error",
+ deliver_host_address);
+ name = NULL;
+ }
+ break;
+ }
+ if (!name)
+#else
+ if (!tls_is_name_for_cert(verify_cert_hostnames, cert))
+#endif
+ {
+ log_write(0, LOG_MAIN,
+ "[%s] SSL verify error: certificate name mismatch: "
+ "DN=\"%s\" H=\"%s\"",
+ deliver_host_address, dn, verify_cert_hostnames);
+ *calledp = TRUE;
+ if (!*optionalp)
+ {
+ if (!tlsp->peercert)
+ tlsp->peercert = X509_dup(cert); /* record failing cert */
+ return 0; /* reject */
+ }
+ DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
+ "tls_try_verify_hosts)\n");
+ }
+ }
+
+#ifndef DISABLE_EVENT
+ if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL"))
+ return 0; /* reject, with peercert set */
+#endif
+
+ DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n",
+ *calledp ? "" : " authenticated", dn);
+ if (!*calledp) tlsp->certificate_verified = TRUE;
+ *calledp = TRUE;
+ }
-return 1; /* accept */
+return 1; /* accept, at least for this level */
}
static int
-verify_callback_client(int state, X509_STORE_CTX *x509ctx)
+verify_callback_client(int preverify_ok, X509_STORE_CTX *x509ctx)
{
-return verify_callback(state, x509ctx, &tls_out, &client_verify_callback_called, &client_verify_optional);
+return verify_callback(preverify_ok, x509ctx, &tls_out,
+ &client_verify_callback_called, &client_verify_optional);
}
static int
-verify_callback_server(int state, X509_STORE_CTX *x509ctx)
+verify_callback_server(int preverify_ok, X509_STORE_CTX *x509ctx)
{
-return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, &server_verify_optional);
+return verify_callback(preverify_ok, x509ctx, &tls_in,
+ &server_verify_callback_called, &server_verify_optional);
}
+#ifdef EXPERIMENTAL_DANE
+
+/* This gets called *by* the dane library verify callback, which interposes
+itself.
+*/
+static int
+verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx)
+{
+X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
+uschar dn[256];
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+#ifndef DISABLE_EVENT
+BOOL dummy_called, optional = FALSE;
+#endif
+
+X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn));
+dn[sizeof(dn)-1] = '\0';
+
+DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n",
+ preverify_ok ? "ok":"BAD", depth, dn);
+
+#ifndef DISABLE_EVENT
+ if (verify_event(&tls_out, cert, depth, dn,
+ &dummy_called, &optional, US"DANE"))
+ return 0; /* reject, with peercert set */
+#endif
+
+if (preverify_ok == 1)
+ tls_out.dane_verified =
+ tls_out.certificate_verified = TRUE;
+else
+ {
+ int err = X509_STORE_CTX_get_error(x509ctx);
+ DEBUG(D_tls)
+ debug_printf(" - err %d '%s'\n", err, X509_verify_cert_error_string(err));
+ if (err == X509_V_ERR_APPLICATION_VERIFICATION)
+ preverify_ok = 1;
+ }
+return preverify_ok;
+}
+
+#endif /*EXPERIMENTAL_DANE*/
+
/*************************************************
* Information callback *
/* If dhparam is set, expand it, and load up the parameters for DH encryption.
Arguments:
+ sctx The current SSL CTX (inbound or outbound)
dhparam DH parameter file or fixed parameter identity string
host connected host, if client; NULL if server
+ errstr error string pointer
Returns: TRUE if OK (nothing to set up, or setup worked)
*/
static BOOL
-init_dh(SSL_CTX *sctx, uschar *dhparam, host_item *host)
+init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host, uschar ** errstr)
{
BIO *bio;
DH *dh;
uschar *dhexpanded;
const char *pem;
-if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded))
+if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded, errstr))
return FALSE;
-if (dhexpanded == NULL || *dhexpanded == '\0')
- {
+if (!dhexpanded || !*dhexpanded)
bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1);
- }
else if (dhexpanded[0] == '/')
{
- bio = BIO_new_file(CS dhexpanded, "r");
- if (bio == NULL)
+ if (!(bio = BIO_new_file(CS dhexpanded, "r")))
{
tls_error(string_sprintf("could not read dhparams file %s", dhexpanded),
- host, US strerror(errno));
+ host, US strerror(errno), errstr);
return FALSE;
}
}
return TRUE;
}
- pem = std_dh_prime_named(dhexpanded);
- if (!pem)
+ if (!(pem = std_dh_prime_named(dhexpanded)))
{
tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded),
- host, US strerror(errno));
+ host, US strerror(errno), errstr);
return FALSE;
}
bio = BIO_new_mem_buf(CS pem, -1);
}
-dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
-if (dh == NULL)
+if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL)))
{
BIO_free(bio);
tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded),
- host, NULL);
+ host, NULL, errstr);
return FALSE;
}
if ((8*DH_size(dh)) > tls_dh_max_bits)
{
DEBUG(D_tls)
- debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d",
+ debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d\n",
8*DH_size(dh), tls_dh_max_bits);
}
else
-#ifdef EXPERIMENTAL_OCSP
/*************************************************
-* Load OCSP information into state *
+* Initialize for ECDH *
*************************************************/
+/* Load parameters for ECDH encryption.
+
+For now, we stick to NIST P-256 because: it's simple and easy to configure;
+it avoids any patent issues that might bite redistributors; despite events in
+the news and concerns over curve choices, we're not cryptographers, we're not
+pretending to be, and this is "good enough" to be better than no support,
+protecting against most adversaries. Given another year or two, there might
+be sufficient clarity about a "right" way forward to let us make an informed
+decision, instead of a knee-jerk reaction.
+
+Longer-term, we should look at supporting both various named curves and
+external files generated with "openssl ecparam", much as we do for init_dh().
+We should also support "none" as a value, to explicitly avoid initialisation.
+
+Patches welcome.
+
+Arguments:
+ sctx The current SSL CTX (inbound or outbound)
+ host connected host, if client; NULL if server
+ errstr error string pointer
+
+Returns: TRUE if OK (nothing to set up, or setup worked)
+*/
+
+static BOOL
+init_ecdh(SSL_CTX * sctx, host_item * host, uschar ** errstr)
+{
+#ifdef OPENSSL_NO_ECDH
+return TRUE;
+#else
+
+EC_KEY * ecdh;
+uschar * exp_curve;
+int nid;
+BOOL rv;
+
+if (host) /* No ECDH setup for clients, only for servers */
+ return TRUE;
+
+# ifndef EXIM_HAVE_ECDH
+DEBUG(D_tls)
+ debug_printf("No OpenSSL API to define ECDH parameters, skipping\n");
+return TRUE;
+# else
+
+if (!expand_check(tls_eccurve, US"tls_eccurve", &exp_curve, errstr))
+ return FALSE;
+if (!exp_curve || !*exp_curve)
+ return TRUE;
+
+/* "auto" needs to be handled carefully.
+ * OpenSSL < 1.0.2: we do not select anything, but fallback to prime256v1
+ * OpenSSL < 1.1.0: we have to call SSL_CTX_set_ecdh_auto
+ * (openssl/ssl.h defines SSL_CTRL_SET_ECDH_AUTO)
+ * OpenSSL >= 1.1.0: we do not set anything, the libray does autoselection
+ * https://github.com/openssl/openssl/commit/fe6ef2472db933f01b59cad82aa925736935984b
+ */
+if (Ustrcmp(exp_curve, "auto") == 0)
+ {
+#if OPENSSL_VERSION_NUMBER < 0x10002000L
+ DEBUG(D_tls) debug_printf(
+ "ECDH OpenSSL < 1.0.2: temp key parameter settings: overriding \"auto\" with \"prime256v1\"\n");
+ exp_curve = US"prime256v1";
+#else
+# if defined SSL_CTRL_SET_ECDH_AUTO
+ DEBUG(D_tls) debug_printf(
+ "ECDH OpenSSL 1.0.2+ temp key parameter settings: autoselection\n");
+ SSL_CTX_set_ecdh_auto(sctx, 1);
+ return TRUE;
+# else
+ DEBUG(D_tls) debug_printf(
+ "ECDH OpenSSL 1.1.0+ temp key parameter settings: default selection\n");
+ return TRUE;
+# endif
+#endif
+ }
+
+DEBUG(D_tls) debug_printf("ECDH: curve '%s'\n", exp_curve);
+if ( (nid = OBJ_sn2nid (CCS exp_curve)) == NID_undef
+# ifdef EXIM_HAVE_OPENSSL_EC_NIST2NID
+ && (nid = EC_curve_nist2nid(CCS exp_curve)) == NID_undef
+# endif
+ )
+ {
+ tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", exp_curve),
+ host, NULL, errstr);
+ return FALSE;
+ }
+
+if (!(ecdh = EC_KEY_new_by_curve_name(nid)))
+ {
+ tls_error(US"Unable to create ec curve", host, NULL, errstr);
+ return FALSE;
+ }
+
+/* The "tmp" in the name here refers to setting a temporary key
+not to the stability of the interface. */
+
+if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0))
+ tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), host, NULL, errstr);
+else
+ DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve);
+
+EC_KEY_free(ecdh);
+return !rv;
+
+# endif /*EXIM_HAVE_ECDH*/
+#endif /*OPENSSL_NO_ECDH*/
+}
+
+
+
+
+#ifndef DISABLE_OCSP
+/*************************************************
+* Load OCSP information into state *
+*************************************************/
/* Called to load the server OCSP response from the given file into memory, once
caller has determined this is needed. Checks validity. Debugs a message
if invalid.
static void
ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded)
{
-BIO *bio;
-OCSP_RESPONSE *resp;
-OCSP_BASICRESP *basic_response;
-OCSP_SINGLERESP *single_response;
-ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
-X509_STORE *store;
+BIO * bio;
+OCSP_RESPONSE * resp;
+OCSP_BASICRESP * basic_response;
+OCSP_SINGLERESP * single_response;
+ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd;
+STACK_OF(X509) * sk;
unsigned long verify_flags;
int status, reason, i;
cbinfo->u_ocsp.server.response = NULL;
}
-bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb");
-if (!bio)
+if (!(bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb")))
{
DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n",
cbinfo->u_ocsp.server.file_expanded);
return;
}
-status = OCSP_response_status(resp);
-if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL)
+if ((status = OCSP_response_status(resp)) != OCSP_RESPONSE_STATUS_SUCCESSFUL)
{
DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n",
OCSP_response_status_str(status), status);
goto bad;
}
-basic_response = OCSP_response_get1_basic(resp);
-if (!basic_response)
+if (!(basic_response = OCSP_response_get1_basic(resp)))
{
DEBUG(D_tls)
debug_printf("OCSP response parse error: unable to extract basic response.\n");
goto bad;
}
-store = SSL_CTX_get_cert_store(sctx);
+sk = cbinfo->verify_stack;
verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */
/* May need to expose ability to adjust those flags?
OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT
OCSP_TRUSTOTHER OCSP_NOINTERN */
-i = OCSP_basic_verify(basic_response, NULL, store, verify_flags);
-if (i <= 0)
+/* This does a full verify on the OCSP proof before we load it for serving
+up; possibly overkill - just date-checks might be nice enough.
+
+OCSP_basic_verify takes a "store" arg, but does not
+use it for the chain verification, which is all we do
+when OCSP_NOVERIFY is set. The content from the wire
+"basic_response" and a cert-stack "sk" are all that is used.
+
+We have a stack, loaded in setup_certs() if tls_verify_certificates
+was a file (not a directory, or "system"). It is unfortunate we
+cannot used the connection context store, as that would neatly
+handle the "system" case too, but there seems to be no library
+function for getting a stack from a store.
+[ In OpenSSL 1.1 - ? X509_STORE_CTX_get0_chain(ctx) ? ]
+We do not free the stack since it could be needed a second time for
+SNI handling.
+
+Separately we might try to replace using OCSP_basic_verify() - which seems to not
+be a public interface into the OpenSSL library (there's no manual entry) -
+But what with? We also use OCSP_basic_verify in the client stapling callback.
+And there we NEED it; we must verify that status... unless the
+library does it for us anyway? */
+
+if ((i = OCSP_basic_verify(basic_response, sk, NULL, verify_flags)) < 0)
{
- DEBUG(D_tls) {
+ DEBUG(D_tls)
+ {
ERR_error_string(ERR_get_error(), ssl_errstring);
debug_printf("OCSP response verify failure: %s\n", US ssl_errstring);
}
right cert in the stack and then calls OCSP_single_get0_status()).
I'm hoping to avoid reworking a bunch more of how we handle state here. */
-single_response = OCSP_resp_get0(basic_response, 0);
-if (!single_response)
+
+if (!(single_response = OCSP_resp_get0(basic_response, 0)))
{
DEBUG(D_tls)
debug_printf("Unable to get first response from OCSP basic response.\n");
}
supply_response:
-cbinfo->u_ocsp.server.response = resp;
+ cbinfo->u_ocsp.server.response = resp;
return;
bad:
-if (running_in_test_harness)
- {
- extern char ** environ;
- uschar ** p;
- for (p = USS environ; *p != NULL; p++)
- if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0)
- {
- DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n");
- goto supply_response;
- }
- }
+ if (running_in_test_harness)
+ {
+ extern char ** environ;
+ uschar ** p;
+ if (environ) for (p = USS environ; *p != NULL; p++)
+ if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0)
+ {
+ DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n");
+ goto supply_response;
+ }
+ }
return;
}
-#endif /*EXPERIMENTAL_OCSP*/
+#endif /*!DISABLE_OCSP*/
+
+
+
+
+/* Create and install a selfsigned certificate, for use in server mode */
+
+static int
+tls_install_selfsign(SSL_CTX * sctx, uschar ** errstr)
+{
+X509 * x509 = NULL;
+EVP_PKEY * pkey;
+RSA * rsa;
+X509_NAME * name;
+uschar * where;
+
+where = US"allocating pkey";
+if (!(pkey = EVP_PKEY_new()))
+ goto err;
+
+where = US"allocating cert";
+if (!(x509 = X509_new()))
+ goto err;
+
+where = US"generating pkey";
+ /* deprecated, use RSA_generate_key_ex() */
+if (!(rsa = RSA_generate_key(1024, RSA_F4, NULL, NULL)))
+ goto err;
+
+where = US"assigning pkey";
+if (!EVP_PKEY_assign_RSA(pkey, rsa))
+ goto err;
+
+X509_set_version(x509, 2); /* N+1 - version 3 */
+ASN1_INTEGER_set(X509_get_serialNumber(x509), 0);
+X509_gmtime_adj(X509_get_notBefore(x509), 0);
+X509_gmtime_adj(X509_get_notAfter(x509), (long)60 * 60); /* 1 hour */
+X509_set_pubkey(x509, pkey);
+
+name = X509_get_subject_name(x509);
+X509_NAME_add_entry_by_txt(name, "C",
+ MBSTRING_ASC, CUS "UK", -1, -1, 0);
+X509_NAME_add_entry_by_txt(name, "O",
+ MBSTRING_ASC, CUS "Exim Developers", -1, -1, 0);
+X509_NAME_add_entry_by_txt(name, "CN",
+ MBSTRING_ASC, CUS smtp_active_hostname, -1, -1, 0);
+X509_set_issuer_name(x509, name);
+
+where = US"signing cert";
+if (!X509_sign(x509, pkey, EVP_md5()))
+ goto err;
+
+where = US"installing selfsign cert";
+if (!SSL_CTX_use_certificate(sctx, x509))
+ goto err;
+
+where = US"installing selfsign key";
+if (!SSL_CTX_use_PrivateKey(sctx, pkey))
+ goto err;
+
+return OK;
+
+err:
+ (void) tls_error(where, NULL, NULL, errstr);
+ if (x509) X509_free(x509);
+ if (pkey) EVP_PKEY_free(pkey);
+ return DEFER;
+}
Arguments:
sctx the SSL_CTX* to update
cbinfo various parts of session state
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
-tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo)
+tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo,
+ uschar ** errstr)
{
uschar *expanded;
-if (cbinfo->certificate == NULL)
- return OK;
-
-if (Ustrstr(cbinfo->certificate, US"tls_sni") ||
- Ustrstr(cbinfo->certificate, US"tls_in_sni") ||
- Ustrstr(cbinfo->certificate, US"tls_out_sni")
- )
- reexpand_tls_files_for_sni = TRUE;
-
-if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded))
- return DEFER;
-
-if (expanded != NULL)
+if (!cbinfo->certificate)
{
- DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded);
- if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded))
- return tls_error(string_sprintf(
- "SSL_CTX_use_certificate_chain_file file=%s", expanded),
- cbinfo->host, NULL);
+ if (cbinfo->host) /* client */
+ return OK;
+ /* server */
+ if (tls_install_selfsign(sctx, errstr) != OK)
+ return DEFER;
}
+else
+ {
+ if (Ustrstr(cbinfo->certificate, US"tls_sni") ||
+ Ustrstr(cbinfo->certificate, US"tls_in_sni") ||
+ Ustrstr(cbinfo->certificate, US"tls_out_sni")
+ )
+ reexpand_tls_files_for_sni = TRUE;
-if (cbinfo->privatekey != NULL &&
- !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded))
- return DEFER;
+ if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded, errstr))
+ return DEFER;
-/* If expansion was forced to fail, key_expanded will be NULL. If the result
-of the expansion is an empty string, ignore it also, and assume the private
-key is in the same file as the certificate. */
+ if (expanded != NULL)
+ {
+ DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded);
+ if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded))
+ return tls_error(string_sprintf(
+ "SSL_CTX_use_certificate_chain_file file=%s", expanded),
+ cbinfo->host, NULL, errstr);
+ }
-if (expanded != NULL && *expanded != 0)
- {
- DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded);
- if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM))
- return tls_error(string_sprintf(
- "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL);
+ if (cbinfo->privatekey != NULL &&
+ !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded, errstr))
+ return DEFER;
+
+ /* If expansion was forced to fail, key_expanded will be NULL. If the result
+ of the expansion is an empty string, ignore it also, and assume the private
+ key is in the same file as the certificate. */
+
+ if (expanded && *expanded)
+ {
+ DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded);
+ if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM))
+ return tls_error(string_sprintf(
+ "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL, errstr);
+ }
}
-#ifdef EXPERIMENTAL_OCSP
-if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL)
+#ifndef DISABLE_OCSP
+if (cbinfo->is_server && cbinfo->u_ocsp.server.file)
{
- if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded))
+ if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded, errstr))
return DEFER;
- if (expanded != NULL && *expanded != 0)
+ if (expanded && *expanded)
{
DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded);
- if (cbinfo->u_ocsp.server.file_expanded &&
- (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0))
+ if ( cbinfo->u_ocsp.server.file_expanded
+ && (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0))
{
- DEBUG(D_tls)
- debug_printf("tls_ocsp_file value unchanged, using existing values.\n");
- } else {
- ocsp_load_response(sctx, cbinfo, expanded);
+ DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n");
}
+ else
+ ocsp_load_response(sctx, cbinfo, expanded);
}
}
#endif
tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
int rc;
int old_pool = store_pool;
+uschar * dummy_errstr;
if (!servername)
return SSL_TLSEXT_ERR_OK;
not confident that memcpy wouldn't break some internal reference counting.
Especially since there's a references struct member, which would be off. */
-server_sni = SSL_CTX_new(SSLv23_server_method());
-if (!server_sni)
+if (!(server_sni = SSL_CTX_new(SSLv23_server_method())))
{
ERR_error_string(ERR_get_error(), ssl_errstring);
DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring);
SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx));
SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb);
SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo);
+
+if ( !init_dh(server_sni, cbinfo->dhparam, NULL, &dummy_errstr)
+ || !init_ecdh(server_sni, NULL, &dummy_errstr)
+ )
+ return SSL_TLSEXT_ERR_NOACK;
+
if (cbinfo->server_cipher_list)
SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list);
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
if (cbinfo->u_ocsp.server.file)
{
SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb);
}
#endif
-rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server);
-if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
+if ((rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE,
+ verify_callback_server, &dummy_errstr)) != OK)
+ return SSL_TLSEXT_ERR_NOACK;
/* do this after setup_certs, because this can require the certs for verifying
OCSP information. */
-rc = tls_expand_session_files(server_sni, cbinfo);
-if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
-
-rc = init_dh(server_sni, cbinfo->dhparam, NULL);
-if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
+if ((rc = tls_expand_session_files(server_sni, cbinfo, &dummy_errstr)) != OK)
+ return SSL_TLSEXT_ERR_NOACK;
DEBUG(D_tls) debug_printf("Switching SSL context.\n");
SSL_set_SSL_CTX(s, server_sni);
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
/*************************************************
* Callback to handle OCSP Stapling *
uschar *response_der;
int response_der_len;
-if (log_extra_selector & LX_tls_cipher)
- log_write(0, LOG_MAIN, "[%s] Recieved OCSP stapling req;%s responding",
- sender_host_address, cbinfo->u_ocsp.server.response ? "":" not");
-else
- DEBUG(D_tls) debug_printf("Received TLS status request (OCSP stapling); %s response.",
+DEBUG(D_tls)
+ debug_printf("Received TLS status request (OCSP stapling); %s response\n",
cbinfo->u_ocsp.server.response ? "have" : "lack");
+tls_in.ocsp = OCSP_NOT_RESP;
if (!cbinfo->u_ocsp.server.response)
return SSL_TLSEXT_ERR_NOACK;
response_der = NULL;
-response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response, &response_der);
+response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response,
+ &response_der);
if (response_der_len <= 0)
return SSL_TLSEXT_ERR_NOACK;
SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len);
+tls_in.ocsp = OCSP_VFIED;
return SSL_TLSEXT_ERR_OK;
}
len = SSL_get_tlsext_status_ocsp_resp(s, &p);
if(!p)
{
- if (log_extra_selector & LX_tls_cipher)
- log_write(0, LOG_MAIN, "Received TLS status response, null content");
+ /* Expect this when we requested ocsp but got none */
+ if (cbinfo->u_ocsp.client.verify_required && LOGGING(tls_cipher))
+ log_write(0, LOG_MAIN, "Received TLS status callback, null content");
else
DEBUG(D_tls) debug_printf(" null\n");
- return 0; /* This is the fail case for require-ocsp; none from server */
+ return cbinfo->u_ocsp.client.verify_required ? 0 : 1;
}
+
if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
{
- if (log_extra_selector & LX_tls_cipher)
- log_write(0, LOG_MAIN, "Received TLS status response, parse error");
+ tls_out.ocsp = OCSP_FAILED;
+ if (LOGGING(tls_cipher))
+ log_write(0, LOG_MAIN, "Received TLS cert status response, parse error");
else
DEBUG(D_tls) debug_printf(" parse error\n");
return 0;
if(!(bs = OCSP_response_get1_basic(rsp)))
{
- if (log_extra_selector & LX_tls_cipher)
- log_write(0, LOG_MAIN, "Received TLS status response, error parsing response");
+ tls_out.ocsp = OCSP_FAILED;
+ if (LOGGING(tls_cipher))
+ log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response");
else
DEBUG(D_tls) debug_printf(" error parsing response\n");
OCSP_RESPONSE_free(rsp);
/* We'd check the nonce here if we'd put one in the request. */
/* However that would defeat cacheability on the server so we don't. */
-
/* This section of code reworked from OpenSSL apps source;
The OpenSSL Project retains copyright:
Copyright (c) 1999 The OpenSSL Project. All rights reserved.
*/
{
BIO * bp = NULL;
- OCSP_CERTID *id;
int status, reason;
ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
/* Use the chain that verified the server cert to verify the stapled info */
/* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */
- if ((i = OCSP_basic_verify(bs, NULL, cbinfo->u_ocsp.client.verify_store, 0)) <= 0)
+ if ((i = OCSP_basic_verify(bs, cbinfo->verify_stack,
+ cbinfo->u_ocsp.client.verify_store, 0)) <= 0)
{
+ tls_out.ocsp = OCSP_FAILED;
+ if (LOGGING(tls_cipher))
+ log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable");
BIO_printf(bp, "OCSP response verify failure\n");
ERR_print_errors(bp);
- i = 0;
- goto out;
+ goto failed;
}
BIO_printf(bp, "OCSP response well-formed and signed OK\n");
+ /*XXX So we have a good stapled OCSP status. How do we know
+ it is for the cert of interest? OpenSSL 1.1.0 has a routine
+ OCSP_resp_find_status() which matches on a cert id, which presumably
+ we should use. Making an id needs OCSP_cert_id_new(), which takes
+ issuerName, issuerKey, serialNumber. Are they all in the cert?
+
+ For now, carry on blindly accepting the resp. */
+
{
- STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses;
OCSP_SINGLERESP * single;
+#ifdef EXIM_HAVE_OCSP_RESP_COUNT
+ if (OCSP_resp_count(bs) != 1)
+#else
+ STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses;
if (sk_OCSP_SINGLERESP_num(sresp) != 1)
+#endif
{
- log_write(0, LOG_MAIN, "OCSP stapling with multiple responses not handled");
- goto out;
+ tls_out.ocsp = OCSP_FAILED;
+ log_write(0, LOG_MAIN, "OCSP stapling "
+ "with multiple responses not handled");
+ goto failed;
}
single = OCSP_resp_get0(bs, 0);
- status = OCSP_single_get0_status(single, &reason, &rev, &thisupd, &nextupd);
+ status = OCSP_single_get0_status(single, &reason, &rev,
+ &thisupd, &nextupd);
}
- i = 0;
DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd);
DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd);
- if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
+ if (!OCSP_check_validity(thisupd, nextupd,
+ EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
{
+ tls_out.ocsp = OCSP_FAILED;
DEBUG(D_tls) ERR_print_errors(bp);
log_write(0, LOG_MAIN, "Server OSCP dates invalid");
- goto out;
}
-
- DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n", OCSP_cert_status_str(status));
- switch(status)
+ else
{
- case V_OCSP_CERTSTATUS_GOOD:
- i = 1;
- break;
- case V_OCSP_CERTSTATUS_REVOKED:
- log_write(0, LOG_MAIN, "Server certificate revoked%s%s",
- reason != -1 ? "; reason: " : "", reason != -1 ? OCSP_crl_reason_str(reason) : "");
- DEBUG(D_tls) time_print(bp, "Revocation Time", rev);
- i = 0;
- break;
- default:
- log_write(0, LOG_MAIN, "Server certificate status unknown, in OCSP stapling");
- i = 0;
- break;
+ DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n",
+ OCSP_cert_status_str(status));
+ switch(status)
+ {
+ case V_OCSP_CERTSTATUS_GOOD:
+ tls_out.ocsp = OCSP_VFIED;
+ i = 1;
+ goto good;
+ case V_OCSP_CERTSTATUS_REVOKED:
+ tls_out.ocsp = OCSP_FAILED;
+ log_write(0, LOG_MAIN, "Server certificate revoked%s%s",
+ reason != -1 ? "; reason: " : "",
+ reason != -1 ? OCSP_crl_reason_str(reason) : "");
+ DEBUG(D_tls) time_print(bp, "Revocation Time", rev);
+ break;
+ default:
+ tls_out.ocsp = OCSP_FAILED;
+ log_write(0, LOG_MAIN,
+ "Server certificate status unknown, in OCSP stapling");
+ break;
+ }
}
- out:
+ failed:
+ i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
+ good:
BIO_free(bp);
}
OCSP_RESPONSE_free(rsp);
return i;
}
-#endif /*EXPERIMENTAL_OCSP*/
-
+#endif /*!DISABLE_OCSP*/
/*************************************************
* Initialize for TLS *
*************************************************/
-/* Called from both server and client code, to do preliminary initialization of
-the library.
+/* Called from both server and client code, to do preliminary initialization
+of the library. We allocate and return a context structure.
Arguments:
+ ctxp returned SSL context
host connected host, if client; NULL if server
dhparam DH parameter file
certificate certificate file
privatekey private key
ocsp_file file of stapling info (server); flag for require ocsp (client)
addr address if client; NULL if server (for some randomness)
+ cbp place to put allocated callback context
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate,
uschar *privatekey,
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
uschar *ocsp_file,
#endif
- address_item *addr, tls_ext_ctx_cb ** cbp)
+ address_item *addr, tls_ext_ctx_cb ** cbp, uschar ** errstr)
{
+SSL_CTX * ctx;
long init_options;
int rc;
-BOOL okay;
-tls_ext_ctx_cb *cbinfo;
+tls_ext_ctx_cb * cbinfo;
cbinfo = store_malloc(sizeof(tls_ext_ctx_cb));
cbinfo->certificate = certificate;
cbinfo->privatekey = privatekey;
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
+cbinfo->verify_stack = NULL;
if ((cbinfo->is_server = host==NULL))
{
cbinfo->u_ocsp.server.file = ocsp_file;
cbinfo->u_ocsp.client.verify_store = NULL;
#endif
cbinfo->dhparam = dhparam;
+cbinfo->server_cipher_list = NULL;
cbinfo->host = host;
+#ifndef DISABLE_EVENT
+cbinfo->event_action = NULL;
+#endif
SSL_load_error_strings(); /* basic set up */
OpenSSL_add_ssl_algorithms();
-#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
+#ifdef EXIM_HAVE_SHA256
/* SHA256 is becoming ever more popular. This makes sure it gets added to the
list of available digests. */
EVP_add_digest(EVP_sha256());
By disabling with openssl_options, we can let admins re-enable with the
existing knob. */
-*ctxp = SSL_CTX_new((host == NULL)?
- SSLv23_server_method() : SSLv23_client_method());
-
-if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL);
+if (!(ctx = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method())))
+ return tls_error(US"SSL_CTX_new", host, NULL, errstr);
/* It turns out that we need to seed the random number generator this early in
order to get the full complement of ciphers to work. It took me roughly a day
if (!RAND_status())
return tls_error(US"RAND_status", host,
- US"unable to seed random number generator");
+ US"unable to seed random number generator", errstr);
}
/* Set up the information callback, which outputs if debugging is at a suitable
level. */
-SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback);
+DEBUG(D_tls) SSL_CTX_set_info_callback(ctx, (void (*)())info_callback);
/* Automatically re-try reads/writes after renegotiation. */
-(void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY);
+(void) SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY);
/* Apply administrator-supplied work-arounds.
Historically we applied just one requested option,
No OpenSSL version number checks: the options we accept depend upon the
availability of the option value macros from OpenSSL. */
-okay = tls_openssl_options_parse(openssl_options, &init_options);
-if (!okay)
- return tls_error(US"openssl_options parsing failed", host, NULL);
+if (!tls_openssl_options_parse(openssl_options, &init_options))
+ return tls_error(US"openssl_options parsing failed", host, NULL, errstr);
if (init_options)
{
DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options);
- if (!(SSL_CTX_set_options(*ctxp, init_options)))
+ if (!(SSL_CTX_set_options(ctx, init_options)))
return tls_error(string_sprintf(
- "SSL_CTX_set_option(%#lx)", init_options), host, NULL);
+ "SSL_CTX_set_option(%#lx)", init_options), host, NULL, errstr);
}
else
DEBUG(D_tls) debug_printf("no SSL CTX options to set\n");
+/* Disable session cache unconditionally */
+
+(void) SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
+
/* Initialize with DH parameters if supplied */
+/* Initialize ECDH temp key parameter selection */
-if (!init_dh(*ctxp, dhparam, host)) return DEFER;
+if ( !init_dh(ctx, dhparam, host, errstr)
+ || !init_ecdh(ctx, host, errstr)
+ )
+ return DEFER;
/* Set up certificate and key (and perhaps OCSP info) */
-rc = tls_expand_session_files(*ctxp, cbinfo);
-if (rc != OK) return rc;
+if ((rc = tls_expand_session_files(ctx, cbinfo, errstr)) != OK)
+ return rc;
+
+/* If we need to handle SNI or OCSP, do so */
-/* If we need to handle SNI, do so */
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
+# ifndef DISABLE_OCSP
+ if (!(cbinfo->verify_stack = sk_X509_new_null()))
+ {
+ DEBUG(D_tls) debug_printf("failed to create stack for stapling verify\n");
+ return FAIL;
+ }
+# endif
+
if (host == NULL) /* server */
{
-# ifdef EXPERIMENTAL_OCSP
+# ifndef DISABLE_OCSP
/* We check u_ocsp.server.file, not server.response, because we care about if
the option exists, not what the current expansion might be, as SNI might
change the certificate and OCSP file in use between now and the time the
callback is invoked. */
if (cbinfo->u_ocsp.server.file)
{
- SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb);
- SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo);
+ SSL_CTX_set_tlsext_status_cb(ctx, tls_server_stapling_cb);
+ SSL_CTX_set_tlsext_status_arg(ctx, cbinfo);
}
# endif
/* We always do this, so that $tls_sni is available even if not used in
tls_certificate */
- SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb);
- SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo);
+ SSL_CTX_set_tlsext_servername_callback(ctx, tls_servername_cb);
+ SSL_CTX_set_tlsext_servername_arg(ctx, cbinfo);
}
-# ifdef EXPERIMENTAL_OCSP
+# ifndef DISABLE_OCSP
else /* client */
if(ocsp_file) /* wanting stapling */
{
DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n");
return FAIL;
}
- SSL_CTX_set_tlsext_status_cb(*ctxp, tls_client_stapling_cb);
- SSL_CTX_set_tlsext_status_arg(*ctxp, cbinfo);
+ SSL_CTX_set_tlsext_status_cb(ctx, tls_client_stapling_cb);
+ SSL_CTX_set_tlsext_status_arg(ctx, cbinfo);
}
# endif
#endif
-/* Set up the RSA callback */
+cbinfo->verify_cert_hostnames = NULL;
-SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback);
+#ifdef EXIM_HAVE_EPHEM_RSA_KEX
+/* Set up the RSA callback */
+SSL_CTX_set_tmp_rsa_callback(ctx, rsa_callback);
+#endif
/* Finally, set the timeout, and we are done */
-SSL_CTX_set_timeout(*ctxp, ssl_session_timeout);
+SSL_CTX_set_timeout(ctx, ssl_session_timeout);
DEBUG(D_tls) debug_printf("Initialized TLS\n");
*cbp = cbinfo;
+*ctxp = ctx;
return OK;
}
}
+static void
+peer_cert(SSL * ssl, tls_support * tlsp, uschar * peerdn, unsigned bsize)
+{
+/*XXX we might consider a list-of-certs variable for the cert chain.
+SSL_get_peer_cert_chain(SSL*). We'd need a new variable type and support
+in list-handling functions, also consider the difference between the entire
+chain and the elements sent by the peer. */
+
+/* Will have already noted peercert on a verify fail; possibly not the leaf */
+if (!tlsp->peercert)
+ tlsp->peercert = SSL_get_peer_certificate(ssl);
+/* Beware anonymous ciphers which lead to server_cert being NULL */
+if (tlsp->peercert)
+ {
+ X509_NAME_oneline(X509_get_subject_name(tlsp->peercert), CS peerdn, bsize);
+ peerdn[bsize-1] = '\0';
+ tlsp->peerdn = peerdn; /*XXX a static buffer... */
+ }
+else
+ tlsp->peerdn = NULL;
+}
+
+
* Set up for verifying certificates *
*************************************************/
+/* Load certs from file, return TRUE on success */
+
+static BOOL
+chain_from_pem_file(const uschar * file, STACK_OF(X509) * verify_stack)
+{
+BIO * bp;
+X509 * x;
+
+if (!(bp = BIO_new_file(CS file, "r"))) return FALSE;
+while ((x = PEM_read_bio_X509(bp, NULL, 0, NULL)))
+ sk_X509_push(verify_stack, x);
+BIO_free(bp);
+return TRUE;
+}
+
+
+
/* Called by both client and server startup
Arguments:
optional TRUE if called from a server for a host in tls_try_verify_hosts;
otherwise passed as FALSE
cert_vfy_cb Callback function for certificate verification
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
- int (*cert_vfy_cb)(int, X509_STORE_CTX *) )
+ int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr)
{
uschar *expcerts, *expcrl;
-if (!expand_check(certs, US"tls_verify_certificates", &expcerts))
+if (!expand_check(certs, US"tls_verify_certificates", &expcerts, errstr))
return DEFER;
+DEBUG(D_tls) debug_printf("tls_verify_certificates: %s\n", expcerts);
-if (expcerts != NULL && *expcerts != '\0')
+if (expcerts && *expcerts)
{
- struct stat statbuf;
+ /* Tell the library to use its compiled-in location for the system default
+ CA bundle. Then add the ones specified in the config, if any. */
+
if (!SSL_CTX_set_default_verify_paths(sctx))
- return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL);
+ return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL, errstr);
- if (Ustat(expcerts, &statbuf) < 0)
- {
- log_write(0, LOG_MAIN|LOG_PANIC,
- "failed to stat %s for certificates", expcerts);
- return DEFER;
- }
- else
+ if (Ustrcmp(expcerts, "system") != 0)
{
- uschar *file, *dir;
- if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
- { file = NULL; dir = expcerts; }
- else
- { file = expcerts; dir = NULL; }
-
- /* If a certificate file is empty, the next function fails with an
- unhelpful error message. If we skip it, we get the correct behaviour (no
- certificates are recognized, but the error message is still misleading (it
- says no certificate was supplied.) But this is better. */
-
- if ((file == NULL || statbuf.st_size > 0) &&
- !SSL_CTX_load_verify_locations(sctx, CS file, CS dir))
- return tls_error(US"SSL_CTX_load_verify_locations", host, NULL);
+ struct stat statbuf;
- if (file != NULL)
+ if (Ustat(expcerts, &statbuf) < 0)
{
- SSL_CTX_set_client_CA_list(sctx, SSL_load_client_CA_file(CS file));
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failed to stat %s for certificates", expcerts);
+ return DEFER;
+ }
+ else
+ {
+ uschar *file, *dir;
+ if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
+ { file = NULL; dir = expcerts; }
+ else
+ {
+ file = expcerts; dir = NULL;
+#ifndef DISABLE_OCSP
+ /* In the server if we will be offering an OCSP proof, load chain from
+ file for verifying the OCSP proof at load time. */
+
+ if ( !host
+ && statbuf.st_size > 0
+ && server_static_cbinfo->u_ocsp.server.file
+ && !chain_from_pem_file(file, server_static_cbinfo->verify_stack)
+ )
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failed to load cert hain from %s", file);
+ return DEFER;
+ }
+#endif
+ }
+
+ /* If a certificate file is empty, the next function fails with an
+ unhelpful error message. If we skip it, we get the correct behaviour (no
+ certificates are recognized, but the error message is still misleading (it
+ says no certificate was supplied). But this is better. */
+
+ if ( (!file || statbuf.st_size > 0)
+ && !SSL_CTX_load_verify_locations(sctx, CS file, CS dir))
+ return tls_error(US"SSL_CTX_load_verify_locations", host, NULL, errstr);
+
+ /* Load the list of CAs for which we will accept certs, for sending
+ to the client. This is only for the one-file tls_verify_certificates
+ variant.
+ If a list isn't loaded into the server, but
+ some verify locations are set, the server end appears to make
+ a wildcard request for client certs.
+ Meanwhile, the client library as default behaviour *ignores* the list
+ we send over the wire - see man SSL_CTX_set_client_cert_cb.
+ Because of this, and that the dir variant is likely only used for
+ the public-CA bundle (not for a private CA), not worth fixing.
+ */
+ if (file)
+ {
+ STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file);
+
+ DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n",
+ sk_X509_NAME_num(names));
+ SSL_CTX_set_client_CA_list(sctx, names);
+ }
}
}
/* Handle a certificate revocation list. */
- #if OPENSSL_VERSION_NUMBER > 0x00907000L
+#if OPENSSL_VERSION_NUMBER > 0x00907000L
/* This bit of code is now the version supplied by Lars Mainka. (I have
- * merely reformatted it into the Exim code style.)
+ merely reformatted it into the Exim code style.)
- * "From here I changed the code to add support for multiple crl's
- * in pem format in one file or to support hashed directory entries in
- * pem format instead of a file. This method now uses the library function
- * X509_STORE_load_locations to add the CRL location to the SSL context.
- * OpenSSL will then handle the verify against CA certs and CRLs by
- * itself in the verify callback." */
+ "From here I changed the code to add support for multiple crl's
+ in pem format in one file or to support hashed directory entries in
+ pem format instead of a file. This method now uses the library function
+ X509_STORE_load_locations to add the CRL location to the SSL context.
+ OpenSSL will then handle the verify against CA certs and CRLs by
+ itself in the verify callback." */
- if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER;
- if (expcrl != NULL && *expcrl != 0)
+ if (!expand_check(crl, US"tls_crl", &expcrl, errstr)) return DEFER;
+ if (expcrl && *expcrl)
{
struct stat statbufcrl;
if (Ustat(expcrl, &statbufcrl) < 0)
DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file);
}
if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0)
- return tls_error(US"X509_STORE_load_locations", host, NULL);
+ return tls_error(US"X509_STORE_load_locations", host, NULL, errstr);
/* setting the flags to check against the complete crl chain */
}
}
- #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
+#endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
/* If verification is optional, don't fail if no certificate */
Arguments:
require_ciphers allowed ciphers
+ errstr pointer to error message
Returns: OK on success
DEFER for errors before the start of the negotiation
- FAIL for errors during the negotation; the server can't
+ FAIL for errors during the negotiation; the server can't
continue running.
*/
int
-tls_server_start(const uschar *require_ciphers)
+tls_server_start(const uschar * require_ciphers, uschar ** errstr)
{
int rc;
-uschar *expciphers;
-tls_ext_ctx_cb *cbinfo;
+uschar * expciphers;
+tls_ext_ctx_cb * cbinfo;
+static uschar peerdn[256];
static uschar cipherbuf[256];
/* Check for previous activation */
if (tls_in.active >= 0)
{
- tls_error(US"STARTTLS received after TLS started", NULL, US"");
+ tls_error(US"STARTTLS received after TLS started", NULL, US"", errstr);
smtp_printf("554 Already in TLS\r\n");
return FAIL;
}
the error. */
rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey,
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
tls_ocsp_file,
#endif
- NULL, &server_static_cbinfo);
+ NULL, &server_static_cbinfo, errstr);
if (rc != OK) return rc;
cbinfo = server_static_cbinfo;
-if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers, errstr))
return FAIL;
/* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
tests, and also for general convenience, we turn underscores into hyphens here.
*/
-if (expciphers != NULL)
+if (expciphers)
{
- uschar *s = expciphers;
+ uschar * s = expciphers;
while (*s != 0) { if (*s == '_') *s = '-'; s++; }
DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers);
if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers))
- return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL);
+ return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL, errstr);
cbinfo->server_cipher_list = expciphers;
}
optional, set up appropriately. */
tls_in.certificate_verified = FALSE;
+#ifdef EXPERIMENTAL_DANE
+tls_in.dane_verified = FALSE;
+#endif
server_verify_callback_called = FALSE;
if (verify_check_host(&tls_verify_hosts) == OK)
{
rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL,
- FALSE, verify_callback_server);
+ FALSE, verify_callback_server, errstr);
if (rc != OK) return rc;
server_verify_optional = FALSE;
}
else if (verify_check_host(&tls_try_verify_hosts) == OK)
{
rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL,
- TRUE, verify_callback_server);
+ TRUE, verify_callback_server, errstr);
if (rc != OK) return rc;
server_verify_optional = TRUE;
}
/* Prepare for new connection */
-if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL);
+if (!(server_ssl = SSL_new(server_ctx)))
+ return tls_error(US"SSL_new", NULL, NULL, errstr);
/* Warning: we used to SSL_clear(ssl) here, it was removed.
*
if (rc <= 0)
{
- tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL);
- if (ERR_get_error() == 0)
- log_write(0, LOG_MAIN,
- "TLS client disconnected cleanly (rejected our certificate?)");
+ (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr);
return FAIL;
}
/* TLS has been set up. Adjust the input functions to read via TLS,
and initialize things. */
+peer_cert(server_ssl, &tls_in, peerdn, sizeof(peerdn));
+
construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits);
tls_in.cipher = cipherbuf;
ssl_xfer_eof = ssl_xfer_error = 0;
receive_getc = tls_getc;
+receive_get_cache = tls_get_cache;
receive_ungetc = tls_ungetc;
receive_feof = tls_feof;
receive_ferror = tls_ferror;
+static int
+tls_client_basic_ctx_init(SSL_CTX * ctx,
+ host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo,
+ uschar ** errstr)
+{
+int rc;
+/* stick to the old behaviour for compatibility if tls_verify_certificates is
+ set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only
+ the specified host patterns if one of them is defined */
+
+if ( ( !ob->tls_verify_hosts
+ && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts)
+ )
+ || (verify_check_given_host(&ob->tls_verify_hosts, host) == OK)
+ )
+ client_verify_optional = FALSE;
+else if (verify_check_given_host(&ob->tls_try_verify_hosts, host) == OK)
+ client_verify_optional = TRUE;
+else
+ return OK;
+
+if ((rc = setup_certs(ctx, ob->tls_verify_certificates,
+ ob->tls_crl, host, client_verify_optional, verify_callback_client,
+ errstr)) != OK)
+ return rc;
+
+if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK)
+ {
+ cbinfo->verify_cert_hostnames =
+#ifdef SUPPORT_I18N
+ string_domain_utf8_to_alabel(host->name, NULL);
+#else
+ host->name;
+#endif
+ DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n",
+ cbinfo->verify_cert_hostnames);
+ }
+return OK;
+}
+
+
+#ifdef EXPERIMENTAL_DANE
+static int
+dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa, uschar ** errstr)
+{
+dns_record * rr;
+dns_scan dnss;
+const char * hostnames[2] = { CS host->name, NULL };
+int found = 0;
+
+if (DANESSL_init(ssl, NULL, hostnames) != 1)
+ return tls_error(US"hostnames load", host, NULL, errstr);
+
+for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
+ rr;
+ rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
+ ) if (rr->type == T_TLSA)
+ {
+ const uschar * p = rr->data;
+ uint8_t usage, selector, mtype;
+ const char * mdname;
+
+ usage = *p++;
+
+ /* Only DANE-TA(2) and DANE-EE(3) are supported */
+ if (usage != 2 && usage != 3) continue;
+
+ selector = *p++;
+ mtype = *p++;
+
+ switch (mtype)
+ {
+ default: continue; /* Only match-types 0, 1, 2 are supported */
+ case 0: mdname = NULL; break;
+ case 1: mdname = "sha256"; break;
+ case 2: mdname = "sha512"; break;
+ }
+
+ found++;
+ switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3))
+ {
+ default:
+ return tls_error(US"tlsa load", host, NULL, errstr);
+ case 0: /* action not taken */
+ case 1: break;
+ }
+
+ tls_out.tlsa_usage |= 1<<usage;
+ }
+
+if (found)
+ return OK;
+
+log_write(0, LOG_MAIN, "DANE error: No usable TLSA records");
+return DEFER;
+}
+#endif /*EXPERIMENTAL_DANE*/
+
+
/*************************************************
* Start a TLS session in a client *
fd the fd of the connection
host connected host (for messages)
addr the first address
- certificate certificate file
- privatekey private key file
- sni TLS SNI to send to remote host
- verify_certs file for certificate verify
- crl file containing CRL
- require_ciphers list of allowed ciphers
- dh_min_bits minimum number of bits acceptable in server's DH prime
- (unused in OpenSSL)
- timeout startup timeout
- verify_hosts mandatory client verification
- try_verify_hosts optional client verification
+ tb transport (always smtp)
+ tlsa_dnsa tlsa lookup, if DANE, else null
+ errstr error string pointer
Returns: OK on success
FAIL otherwise - note that tls_error() will not give DEFER
int
tls_client_start(int fd, host_item *host, address_item *addr,
- uschar *certificate, uschar *privatekey, uschar *sni,
- uschar *verify_certs, uschar *crl,
- uschar *require_ciphers,
-#ifdef EXPERIMENTAL_OCSP
- uschar *hosts_require_ocsp,
-#endif
- int dh_min_bits ARG_UNUSED, int timeout,
- uschar *verify_hosts, uschar *try_verify_hosts)
+ transport_instance * tb,
+#ifdef EXPERIMENTAL_DANE
+ dns_answer * tlsa_dnsa,
+#endif
+ uschar ** errstr)
{
-static uschar txt[256];
-uschar *expciphers;
-X509* server_cert;
+smtp_transport_options_block * ob =
+ (smtp_transport_options_block *)tb->options_block;
+static uschar peerdn[256];
+uschar * expciphers;
int rc;
static uschar cipherbuf[256];
-#ifdef EXPERIMENTAL_OCSP
-BOOL require_ocsp = verify_check_this_host(&hosts_require_ocsp,
- NULL, host->name, host->address, NULL) == OK;
+
+#ifndef DISABLE_OCSP
+BOOL request_ocsp = FALSE;
+BOOL require_ocsp = FALSE;
+#endif
+
+#ifdef EXPERIMENTAL_DANE
+tls_out.tlsa_usage = 0;
#endif
-rc = tls_init(&client_ctx, host, NULL, certificate, privatekey,
-#ifdef EXPERIMENTAL_OCSP
- require_ocsp ? US"" : NULL,
+#ifndef DISABLE_OCSP
+ {
+# ifdef EXPERIMENTAL_DANE
+ if ( tlsa_dnsa
+ && ob->hosts_request_ocsp[0] == '*'
+ && ob->hosts_request_ocsp[1] == '\0'
+ )
+ {
+ /* Unchanged from default. Use a safer one under DANE */
+ request_ocsp = TRUE;
+ ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} "
+ " {= {4}{$tls_out_tlsa_usage}} } "
+ " {*}{}}";
+ }
+# endif
+
+ if ((require_ocsp =
+ verify_check_given_host(&ob->hosts_require_ocsp, host) == OK))
+ request_ocsp = TRUE;
+ else
+# ifdef EXPERIMENTAL_DANE
+ if (!request_ocsp)
+# endif
+ request_ocsp =
+ verify_check_given_host(&ob->hosts_request_ocsp, host) == OK;
+ }
#endif
- addr, &client_static_cbinfo);
+
+rc = tls_init(&client_ctx, host, NULL,
+ ob->tls_certificate, ob->tls_privatekey,
+#ifndef DISABLE_OCSP
+ (void *)(long)request_ocsp,
+#endif
+ addr, &client_static_cbinfo, errstr);
if (rc != OK) return rc;
tls_out.certificate_verified = FALSE;
client_verify_callback_called = FALSE;
-if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers",
+ &expciphers, errstr))
return FAIL;
/* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
are separated by underscores. So that I can use either form in my tests, and
also for general convenience, we turn underscores into hyphens here. */
-if (expciphers != NULL)
+if (expciphers)
{
uschar *s = expciphers;
- while (*s != 0) { if (*s == '_') *s = '-'; s++; }
+ while (*s) { if (*s == '_') *s = '-'; s++; }
DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers);
if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers))
- return tls_error(US"SSL_CTX_set_cipher_list", host, NULL);
+ return tls_error(US"SSL_CTX_set_cipher_list", host, NULL, errstr);
}
-/* stick to the old behaviour for compatibility if tls_verify_certificates is
- set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only
- the specified host patterns if one of them is defined */
-if (((verify_hosts == NULL) && (try_verify_hosts == NULL)) ||
- (verify_check_host(&verify_hosts) == OK))
- {
- rc = setup_certs(client_ctx, verify_certs, crl, host, FALSE, verify_callback_client);
- if (rc != OK) return rc;
- client_verify_optional = FALSE;
- }
-else if (verify_check_host(&try_verify_hosts) == OK)
+#ifdef EXPERIMENTAL_DANE
+if (tlsa_dnsa)
{
- rc = setup_certs(client_ctx, verify_certs, crl, host, TRUE, verify_callback_client);
- if (rc != OK) return rc;
- client_verify_optional = TRUE;
+ SSL_CTX_set_verify(client_ctx,
+ SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
+ verify_callback_client_dane);
+
+ if (!DANESSL_library_init())
+ return tls_error(US"library init", host, NULL, errstr);
+ if (DANESSL_CTX_init(client_ctx) <= 0)
+ return tls_error(US"context init", host, NULL, errstr);
}
+else
+
+#endif
+
+ if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob,
+ client_static_cbinfo, errstr)) != OK)
+ return rc;
-if ((client_ssl = SSL_new(client_ctx)) == NULL) return tls_error(US"SSL_new", host, NULL);
+if ((client_ssl = SSL_new(client_ctx)) == NULL)
+ return tls_error(US"SSL_new", host, NULL, errstr);
SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx));
SSL_set_fd(client_ssl, fd);
SSL_set_connect_state(client_ssl);
-if (sni)
+if (ob->tls_sni)
{
- if (!expand_check(sni, US"tls_sni", &tls_out.sni))
+ if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni, errstr))
return FAIL;
- if (tls_out.sni == NULL)
+ if (!tls_out.sni)
{
DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n");
}
DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni);
SSL_set_tlsext_host_name(client_ssl, tls_out.sni);
#else
- DEBUG(D_tls)
- debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n",
+ log_write(0, LOG_MAIN, "SNI unusable with this OpenSSL library version; ignoring \"%s\"\n",
tls_out.sni);
#endif
}
}
-#ifdef EXPERIMENTAL_OCSP
+#ifdef EXPERIMENTAL_DANE
+if (tlsa_dnsa)
+ if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa, errstr)) != OK)
+ return rc;
+#endif
+
+#ifndef DISABLE_OCSP
/* Request certificate status at connection-time. If the server
does OCSP stapling we will get the callback (set in tls_init()) */
-if (require_ocsp)
+# ifdef EXPERIMENTAL_DANE
+if (request_ocsp)
+ {
+ const uschar * s;
+ if ( ((s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage"))
+ || ((s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage"))
+ )
+ { /* Re-eval now $tls_out_tlsa_usage is populated. If
+ this means we avoid the OCSP request, we wasted the setup
+ cost in tls_init(). */
+ require_ocsp = verify_check_given_host(&ob->hosts_require_ocsp, host) == OK;
+ request_ocsp = require_ocsp
+ || verify_check_given_host(&ob->hosts_request_ocsp, host) == OK;
+ }
+ }
+# endif
+
+if (request_ocsp)
+ {
SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp);
+ client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp;
+ tls_out.ocsp = OCSP_NOT_RESP;
+ }
+#endif
+
+#ifndef DISABLE_EVENT
+client_static_cbinfo->event_action = tb->event_action;
#endif
/* There doesn't seem to be a built-in timeout on connection. */
DEBUG(D_tls) debug_printf("Calling SSL_connect\n");
sigalrm_seen = FALSE;
-alarm(timeout);
+alarm(ob->command_timeout);
rc = SSL_connect(client_ssl);
alarm(0);
+#ifdef EXPERIMENTAL_DANE
+if (tlsa_dnsa)
+ DANESSL_cleanup(client_ssl);
+#endif
+
if (rc <= 0)
- return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL);
+ return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL,
+ errstr);
DEBUG(D_tls) debug_printf("SSL_connect succeeded\n");
-/* Beware anonymous ciphers which lead to server_cert being NULL */
-/*XXX server_cert is never freed... use X509_free() */
-server_cert = SSL_get_peer_certificate (client_ssl);
-if (server_cert)
- {
- tls_out.peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert),
- CS txt, sizeof(txt));
- tls_out.peerdn = txt; /*XXX a static buffer... */
- }
-else
- tls_out.peerdn = NULL;
+peer_cert(client_ssl, &tls_out, peerdn, sizeof(peerdn));
construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits);
tls_out.cipher = cipherbuf;
/* This gets the next byte from the TLS input buffer. If the buffer is empty,
it refills the buffer via the SSL reading function.
-Arguments: none
+Arguments: lim Maximum amount to read/buffer
Returns: the next character or EOF
Only used by the server-side TLS.
*/
int
-tls_getc(void)
+tls_getc(unsigned lim)
{
if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm)
{
ssl_xfer_buffer, ssl_xfer_buffer_size);
if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
- inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size);
+ inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer,
+ MIN(ssl_xfer_buffer_size, lim));
error = SSL_get_error(server_ssl, inbytes);
alarm(0);
DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
receive_getc = smtp_getc;
+ receive_get_cache = smtp_get_cache;
receive_ungetc = smtp_ungetc;
receive_feof = smtp_feof;
receive_ferror = smtp_ferror;
tls_in.peerdn = NULL;
tls_in.sni = NULL;
- return smtp_getc();
+ return smtp_getc(lim);
}
/* Handle genuine errors */
return ssl_xfer_buffer[ssl_xfer_buffer_lwm++];
}
+void
+tls_get_cache()
+{
+#ifndef DISABLE_DKIM
+int n = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm;
+if (n > 0)
+ dkim_exim_verify_feed(ssl_xfer_buffer+ssl_xfer_buffer_lwm, n);
+#endif
+}
+
/*************************************************
return -1;
}
else if (error != SSL_ERROR_NONE)
- {
return -1;
- }
return inbytes;
}
switch (error)
{
case SSL_ERROR_SSL:
- ERR_error_string(ERR_get_error(), ssl_errstring);
- log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring);
- return -1;
+ ERR_error_string(ERR_get_error(), ssl_errstring);
+ log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring);
+ return -1;
case SSL_ERROR_NONE:
- left -= outbytes;
- buff += outbytes;
- break;
+ left -= outbytes;
+ buff += outbytes;
+ break;
case SSL_ERROR_ZERO_RETURN:
- log_write(0, LOG_MAIN, "SSL channel closed on write");
- return -1;
+ log_write(0, LOG_MAIN, "SSL channel closed on write");
+ return -1;
case SSL_ERROR_SYSCALL:
- log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s",
- sender_fullhost ? sender_fullhost : US"<unknown>",
- strerror(errno));
+ log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s",
+ sender_fullhost ? sender_fullhost : US"<unknown>",
+ strerror(errno));
+ return -1;
default:
- log_write(0, LOG_MAIN, "SSL_write error %d", error);
- return -1;
+ log_write(0, LOG_MAIN, "SSL_write error %d", error);
+ return -1;
}
}
return len;
if (!(tls_require_ciphers && *tls_require_ciphers))
return NULL;
-if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers,
+ &err))
return US"failed to expand tls_require_ciphers";
if (!(expciphers && *expciphers))
if (!SSL_CTX_set_cipher_list(ctx, CS expciphers))
{
ERR_error_string(ERR_get_error(), ssl_errstring);
- err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers);
+ err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed: %s",
+ expciphers, ssl_errstring);
}
SSL_CTX_free(ctx);
if (i < needed_len)
needed_len = i;
+#ifdef EXIM_HAVE_RAND_PSEUDO
/* We do not care if crypto-strong */
i = RAND_pseudo_bytes(smallbuf, needed_len);
+#else
+i = RAND_bytes(smallbuf, needed_len);
+#endif
+
if (i < 0)
{
DEBUG(D_all)
uschar keep_c;
BOOL adding, item_parsed;
-result = 0L;
+result = SSL_OP_NO_TICKET;
/* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed
* from default because it increases BEAST susceptibility. */
#ifdef SSL_OP_NO_SSLv2
result |= SSL_OP_NO_SSLv2;
#endif
+#ifdef SSL_OP_SINGLE_DH_USE
+result |= SSL_OP_SINGLE_DH_USE;
+#endif
-if (option_spec == NULL)
+if (!option_spec)
{
*results = result;
return TRUE;
keep_c = *end;
*end = '\0';
item_parsed = tls_openssl_one_option_parse(s, &item);
+ *end = keep_c;
if (!item_parsed)
{
DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s);
result |= item;
else
result &= ~item;
- *end = keep_c;
s = end;
}
git://git.exim.org / exim.git / blobdiff