* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2014 */
+/* Copyright (c) University of Cambridge 1995 - 2016 */
/* See the file NOTICE for conditions of use and distribution. */
/* Portions Copyright (c) The OpenSSL Project 1999 */
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
+#ifndef OPENSSL_NO_ECDH
+# include <openssl/ec.h>
+#endif
#ifndef DISABLE_OCSP
# include <openssl/ocsp.h>
#endif
+#ifdef EXPERIMENTAL_DANE
+# include <danessl.h>
+#endif
+
#ifndef DISABLE_OCSP
# define EXIM_OCSP_SKEW_SECONDS (300L)
#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_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
+# if OPENSSL_VERSION_NUMBER < 0x10100000L
+# define EXIM_HAVE_OPENSSL_ECDH_AUTO
+# endif
+# 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"
uschar *server_cipher_list;
/* only passed down to tls_error: */
host_item *host;
-
-#ifdef EXPERIMENTAL_CERTNAMES
- uschar * verify_cert_hostnames;
+ const uschar * verify_cert_hostnames;
+#ifndef DISABLE_EVENT
+ uschar * event_action;
#endif
} tls_ext_ctx_cb;
*/
static int
-tls_error(uschar *prefix, host_item *host, uschar *msg)
+tls_error(uschar * prefix, const host_item * host, uschar * msg)
{
-if (msg == NULL)
+if (!msg)
{
ERR_error_string(ERR_get_error(), ssl_errstring);
msg = (uschar *)ssl_errstring;
}
-if (host == NULL)
+if (host)
+ {
+ log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection (%s): %s",
+ host->name, host->address, prefix, msg);
+ return FAIL;
+ }
+else
{
uschar *conn_info = smtp_get_connection_info();
if (Ustrncmp(conn_info, US"SMTP ", 5) == 0)
conn_info += 5;
+ /* I'd like to get separated H= here, but too hard for now */
log_write(0, LOG_MAIN, "TLS error on %s (%s): %s",
conn_info, prefix, msg);
return DEFER;
}
-else
- {
- log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s): %s",
- host->name, host->address, prefix, msg);
- return FAIL;
- }
}
+#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
{
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,
+verify_callback(int preverify_ok, X509_STORE_CTX *x509ctx,
tls_support *tlsp, BOOL *calledp, BOOL *optionalp)
{
X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
-static uschar txt[256];
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+uschar dn[256];
-X509_NAME_oneline(X509_get_subject_name(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",
- X509_STORE_CTX_get_error_depth(x509ctx),
+ 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)),
- txt);
- tlsp->certificate_verified = FALSE;
+ dn);
*calledp = TRUE;
if (!*optionalp)
{
- tlsp->peercert = X509_dup(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");
}
-else if (X509_STORE_CTX_get_error_depth(x509ctx) != 0)
+else if (depth != 0)
{
- DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n",
- X509_STORE_CTX_get_error_depth(x509ctx), txt);
+ 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,
cert))
ERR_clear_error();
}
+#endif
+#ifndef DISABLE_EVENT
+ if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL"))
+ return 0; /* reject, with peercert set */
#endif
}
else
{
-#ifdef EXPERIMENTAL_CERTNAMES
- uschar * verify_cert_hostnames;
-#endif
-
- tlsp->peerdn = txt;
- tlsp->peercert = X509_dup(cert);
+ const uschar * verify_cert_hostnames;
-#ifdef EXPERIMENTAL_CERTNAMES
if ( tlsp == &tls_out
&& ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames)))
/* client, wanting hostname check */
-
-# if OPENSSL_VERSION_NUMBER >= 0x010100000L || OPENSSL_VERSION_NUMBER >= 0x010002000L
-# ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
-# define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0
-# endif
{
+
+#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;
- uschar * list = verify_cert_hostnames;
+ const uschar * list = verify_cert_hostnames;
uschar * name;
int rc;
while ((name = string_nextinlist(&list, &sep, NULL, 0)))
- if ((rc = X509_check_host(cert, name, 0,
- X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)))
+ 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, "SSL verify error: internal error\n");
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address);
name = NULL;
}
break;
}
if (!name)
- {
- log_write(0, LOG_MAIN,
- "SSL verify error: certificate name mismatch: \"%s\"\n", txt);
- return 0; /* reject */
- }
- }
-# else
+#else
if (!tls_is_name_for_cert(verify_cert_hostnames, cert))
+#endif
{
log_write(0, LOG_MAIN,
- "SSL verify error: certificate name mismatch: \"%s\"\n", txt);
- return 0; /* reject */
+ "[%s] SSL verify error: certificate name mismatch: \"%s\"",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ dn);
+ *calledp = TRUE;
+ if (!*optionalp)
+ {
+ if (!tlsp->peercert)
+ tlsp->peercert = X509_dup(cert); /* record failing cert */
+ return 0; /* reject */
+ }
+ DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
+ "tls_try_verify_hosts)\n");
}
-# endif
-#endif /*EXPERIMENTAL_CERTNAMES*/
+ }
+
+#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", txt);
+ *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);
}
itself.
*/
static int
-verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx)
+verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx)
{
X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
-static uschar txt[256];
+uschar dn[256];
+#ifndef DISABLE_EVENT
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+BOOL dummy_called, optional = FALSE;
+#endif
-X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt));
+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\n", txt);
-tls_out.peerdn = txt;
-tls_out.peercert = X509_dup(cert);
+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 (state == 1)
+if (preverify_ok == 1)
tls_out.dane_verified =
tls_out.certificate_verified = TRUE;
-return 1;
+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*/
/* 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
*/
static BOOL
-init_dh(SSL_CTX *sctx, uschar *dhparam, host_item *host)
+init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host)
{
BIO *bio;
DH *dh;
+/*************************************************
+* 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
+
+Returns: TRUE if OK (nothing to set up, or setup worked)
+*/
+
+static BOOL
+init_ecdh(SSL_CTX * sctx, host_item * host)
+{
+#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))
+ return FALSE;
+if (!exp_curve || !*exp_curve)
+ return TRUE;
+
+# ifdef EXIM_HAVE_OPENSSL_ECDH_AUTO
+/* check if new enough library to support auto ECDH temp key parameter selection */
+if (Ustrcmp(exp_curve, "auto") == 0)
+ {
+ DEBUG(D_tls) debug_printf(
+ "ECDH temp key parameter settings: OpenSSL 1.2+ autoselection\n");
+ SSL_CTX_set_ecdh_auto(sctx, 1);
+ return TRUE;
+ }
+# 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);
+ return FALSE;
+ }
+
+if (!(ecdh = EC_KEY_new_by_curve_name(nid)))
+ {
+ tls_error(US"Unable to create ec curve", host, NULL);
+ 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);
+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 *
{
extern char ** environ;
uschar ** p;
- for (p = USS environ; *p != NULL; 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");
+/* Create and install a selfsigned certificate, for use in server mode */
+
+static int
+tls_install_selfsign(SSL_CTX * sctx)
+{
+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"assiging 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, "UK", -1, -1, 0);
+X509_NAME_add_entry_by_txt(name, "O",
+ MBSTRING_ASC, "Exim Developers", -1, -1, 0);
+X509_NAME_add_entry_by_txt(name, "CN",
+ MBSTRING_ASC, CS 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);
+ if (x509) X509_free(x509);
+ if (pkey) EVP_PKEY_free(pkey);
+ return DEFER;
+}
+
+
+
+
/*************************************************
* Expand key and cert file specs *
*************************************************/
{
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) != 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))
+ 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);
+ }
-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))
+ 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);
+ }
}
#ifndef DISABLE_OCSP
-if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL)
+if (cbinfo->is_server && cbinfo->u_ocsp.server.file)
{
if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded))
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(" - value unchanged, using existing values\n");
+ }
+ else
{
- DEBUG(D_tls)
- debug_printf("tls_ocsp_file value unchanged, using existing values.\n");
- } else {
- ocsp_load_response(sctx, cbinfo, expanded);
+ ocsp_load_response(sctx, cbinfo, expanded);
}
}
}
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)
+ || !init_ecdh(server_sni, NULL)
+ )
+ return SSL_TLSEXT_ERR_NOACK;
+
if (cbinfo->server_cipher_list)
SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list);
#ifndef DISABLE_OCSP
/* do this after setup_certs, because this can require the certs for verifying
OCSP information. */
-rc = tls_expand_session_files(server_sni, cbinfo);
-if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
-
-if (!init_dh(server_sni, cbinfo->dhparam, NULL))
+if ((rc = tls_expand_session_files(server_sni, cbinfo)) != OK)
return SSL_TLSEXT_ERR_NOACK;
DEBUG(D_tls) debug_printf("Switching SSL context.\n");
int response_der_len;
DEBUG(D_tls)
- debug_printf("Received TLS status request (OCSP stapling); %s response.",
+ 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(!p)
{
/* Expect this when we requested ocsp but got none */
- if ( cbinfo->u_ocsp.client.verify_required
- && log_extra_selector & LX_tls_cipher)
+ 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");
if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
{
tls_out.ocsp = OCSP_FAILED;
- if (log_extra_selector & LX_tls_cipher)
- log_write(0, LOG_MAIN, "Received TLS status response, parse error");
+ 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)))
{
tls_out.ocsp = OCSP_FAILED;
- if (log_extra_selector & LX_tls_cipher)
- log_write(0, LOG_MAIN, "Received TLS status response, error parsing response");
+ 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);
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 = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
- 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
{
tls_out.ocsp = OCSP_FAILED;
log_write(0, LOG_MAIN, "OCSP stapling "
"with multiple responses not handled");
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
- goto out;
+ goto failed;
}
single = OCSP_resp_get0(bs, 0);
status = OCSP_single_get0_status(single, &reason, &rev,
tls_out.ocsp = OCSP_FAILED;
DEBUG(D_tls) ERR_print_errors(bp);
log_write(0, LOG_MAIN, "Server OSCP dates invalid");
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
}
else
{
case V_OCSP_CERTSTATUS_GOOD:
tls_out.ocsp = OCSP_VFIED;
i = 1;
- break;
+ 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);
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
break;
default:
tls_out.ocsp = OCSP_FAILED;
log_write(0, LOG_MAIN,
"Server certificate status unknown, in OCSP stapling");
- i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
break;
}
}
- out:
+ failed:
+ i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
+ good:
BIO_free(bp);
}
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->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());
+*ctxp = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method());
-if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL);
+if (!*ctxp) return tls_error(US"SSL_CTX_new", host, NULL);
/* 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
/* 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(*ctxp, (void (*)())info_callback);
/* Automatically re-try reads/writes after renegotiation. */
(void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY);
DEBUG(D_tls) debug_printf("no SSL CTX options to set\n");
/* Initialize with DH parameters if supplied */
+/* Initialize ECDH temp key parameter selection */
-if (!init_dh(*ctxp, dhparam, host)) return DEFER;
+if ( !init_dh(*ctxp, dhparam, host)
+ || !init_ecdh(*ctxp, host)
+ )
+ 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(*ctxp, cbinfo)) != OK)
+ return rc;
/* If we need to handle SNI, do so */
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
# endif
#endif
-#ifdef EXPERIMENTAL_CERTNAMES
cbinfo->verify_cert_hostnames = NULL;
-#endif
+#ifdef EXIM_HAVE_EPHEM_RSA_KEX
/* Set up the RSA callback */
-
SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback);
+#endif
/* Finally, set the timeout, and we are done */
}
+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;
+}
+
+
if (!expand_check(certs, US"tls_verify_certificates", &expcerts))
return DEFER;
-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);
- 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; }
+
+ /* 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);
+
+ /* Load the list of CAs for which we will accept certs, for sending
+ to the client. This is only for the one-file tls_verify_certificates
+ variant.
+ If a list isn't loaded into the server, but
+ some verify locations are set, the server end appears to make
+ a wildcard reqest for client certs.
+ Meanwhile, the client library as 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 (expcrl && *expcrl)
{
struct stat statbufcrl;
if (Ustat(expcrl, &statbufcrl) < 0)
}
}
- #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
+#endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
/* If verification is optional, don't fail if no certificate */
int rc;
uschar *expciphers;
tls_ext_ctx_cb *cbinfo;
+static uschar peerdn[256];
static uschar cipherbuf[256];
/* Check for previous activation */
/* 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
-#ifdef EXPERIMENTAL_CERTNAMES
- , tls_ext_ctx_cb * cbinfo
-#endif
+ host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo
)
{
int rc;
-/* stick to the old behaviour for compatibility if tls_verify_certificates is
+/* stick to the old behaviour for compatibility if tls_verify_certificates is
set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only
the specified host patterns if one of them is defined */
-if ((!ob->tls_verify_hosts && !ob->tls_try_verify_hosts) ||
- (verify_check_host(&ob->tls_verify_hosts) == OK))
- {
- if ((rc = setup_certs(ctx, ob->tls_verify_certificates,
- ob->tls_crl, host, FALSE, verify_callback_client)) != OK)
- return rc;
+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;
-#ifdef EXPERIMENTAL_CERTNAMES
- if (ob->tls_verify_cert_hostnames)
- {
- if (!expand_check(ob->tls_verify_cert_hostnames,
- US"tls_verify_cert_hostnames",
- &cbinfo->verify_cert_hostnames))
- return FAIL;
- if (cbinfo->verify_cert_hostnames)
- DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n",
- cbinfo->verify_cert_hostnames);
- }
+if ((rc = setup_certs(ctx, ob->tls_verify_certificates,
+ ob->tls_crl, host, client_verify_optional, verify_callback_client)) != 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);
}
-else if (verify_check_host(&ob->tls_try_verify_hosts) == OK)
+return OK;
+}
+
+
+#ifdef EXPERIMENTAL_DANE
+static int
+dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa)
+{
+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);
+
+for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
+ rr;
+ rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
+ ) if (rr->type == T_TLSA)
{
- if ((rc = setup_certs(ctx, ob->tls_verify_certificates,
- ob->tls_crl, host, TRUE, verify_callback_client)) != OK)
- return rc;
- client_verify_optional = TRUE;
+ 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);
+ case 0: /* action not taken */
+ case 1: break;
+ }
+
+ tls_out.tlsa_usage |= 1<<usage;
}
-return OK;
+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
- ob smtp transport options
+ tb transport (always smtp)
+ tlsa_dnsa tlsa lookup, if DANE, else null
Returns: OK on success
FAIL otherwise - note that tls_error() will not give DEFER
int
tls_client_start(int fd, host_item *host, address_item *addr,
- void *v_ob)
+ transport_instance *tb
+#ifdef EXPERIMENTAL_DANE
+ , dns_answer * tlsa_dnsa
+#endif
+ )
{
-smtp_transport_options_block * ob = v_ob;
-static uschar txt[256];
+smtp_transport_options_block * ob =
+ (smtp_transport_options_block *)tb->options_block;
+static uschar peerdn[256];
uschar * expciphers;
-X509 * server_cert;
int rc;
static uschar cipherbuf[256];
BOOL request_ocsp = FALSE;
BOOL require_ocsp = FALSE;
#endif
-#ifdef EXPERIMENTAL_DANE
-dns_answer tlsa_dnsa;
-BOOL dane = FALSE;
-BOOL dane_required;
-#endif
#ifdef EXPERIMENTAL_DANE
-dane_required = verify_check_this_host(&ob->hosts_require_dane, NULL,
- host->name, host->address, NULL) == OK;
+tls_out.tlsa_usage = 0;
+#endif
-if (host->dnssec == DS_YES)
+#ifndef DISABLE_OCSP
{
- if( dane_required
- || verify_check_this_host(&ob->hosts_try_dane, NULL,
- host->name, host->address, NULL) == OK
- )
+# ifdef EXPERIMENTAL_DANE
+ if ( tlsa_dnsa
+ && ob->hosts_request_ocsp[0] == '*'
+ && ob->hosts_request_ocsp[1] == '\0'
+ )
{
- /* move this out to host.c given the similarity to dns_lookup() ? */
- uschar buffer[300];
- uschar * fullname = buffer;
-
- /* TLSA lookup string */
- (void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port,
- host->name);
-
- switch (rc = dns_lookup(&tlsa_dnsa, buffer, T_TLSA, &fullname))
- {
- case DNS_AGAIN:
- return DEFER; /* just defer this TLS'd conn */
-
- default:
- case DNS_FAIL:
- if (dane_required)
- {
- log_write(0, LOG_MAIN, "DANE error: TLSA lookup failed");
- return FAIL;
- }
- break;
-
- case DNS_SUCCEED:
- if (!dns_is_secure(&tlsa_dnsa))
- {
- log_write(0, LOG_MAIN, "DANE error: TLSA lookup not DNSSEC");
- return DEFER;
- }
- dane = TRUE;
- break;
- }
+ /* 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}} } "
+ " {*}{}}";
}
- }
-else if (dane_required)
- {
- /*XXX a shame we only find this after making tcp & smtp connection */
- /* move the test earlier? */
- log_write(0, LOG_MAIN, "DANE error: previous lookup not DNSSEC");
- return FAIL;
- }
-
-#endif
+# endif
-#ifndef DISABLE_OCSP
- {
- require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp,
- NULL, host->name, host->address, NULL) == OK;
- request_ocsp = require_ocsp ? TRUE
- : verify_check_this_host(&ob->hosts_request_ocsp,
- NULL, host->name, host->address, NULL) == OK;
+ 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
if (rc != OK) return rc;
tls_out.certificate_verified = FALSE;
-#ifdef EXPERIMENTAL_DANE
-tls_out.dane_verified = FALSE;
-#endif
client_verify_callback_called = FALSE;
if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers",
}
#ifdef EXPERIMENTAL_DANE
-if (dane)
+if (tlsa_dnsa)
{
- SSL_CTX_set_verify(client_ctx, SSL_VERIFY_PEER, verify_callback_client_dane);
+ 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);
#endif
- if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob
-#ifdef EXPERIMENTAL_CERTNAMES
- , client_static_cbinfo
-#endif
- )) != OK)
+ if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob, client_static_cbinfo))
+ != OK)
return rc;
if ((client_ssl = SSL_new(client_ctx)) == NULL)
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_DANE
+if (tlsa_dnsa)
+ if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa)) != 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()) */
+# 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);
}
#endif
-#ifdef EXPERIMENTAL_DANE
-if (dane)
- {
- dns_record * rr;
- dns_scan dnss;
- uschar * hostnames[2] = { host->name, NULL };
-
- if (DANESSL_init(client_ssl, NULL, hostnames) != 1)
- return tls_error(US"hostnames load", host, NULL);
-
- for (rr = dns_next_rr(&tlsa_dnsa, &dnss, RESET_ANSWERS);
- rr;
- rr = dns_next_rr(&tlsa_dnsa, &dnss, RESET_NEXT)
- ) if (rr->type == T_TLSA)
- {
- uschar * p = rr->data;
- int usage, selector, mtype;
- const char * mdname;
-
- GETSHORT(usage, p);
- GETSHORT(selector, p);
- GETSHORT(mtype, p);
-
- switch (mtype)
- {
- default: /* log bad */ return FAIL;
- case 0: mdname = NULL; break;
- case 1: mdname = "sha256"; break;
- case 2: mdname = "sha512"; break;
- }
-
- switch (DANESSL_add_tlsa(client_ssl,
- (uint8_t) usage, (uint8_t) selector,
- mdname, p, rr->size - (p - rr->data)))
- {
- default:
- case 0: /* action not taken */
- return tls_error(US"tlsa load", host, NULL);
- case 1: break;
- }
- }
- }
+#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");
alarm(0);
#ifdef EXPERIMENTAL_DANE
-if (dane)
- DANESSL_cleanup(client_ssl); /*XXX earliest possible callpoint. Too early? */
+if (tlsa_dnsa)
+ DANESSL_cleanup(client_ssl);
#endif
if (rc <= 0)
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;
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;
return ssl_xfer_buffer[ssl_xfer_buffer_lwm++];
}
+#ifndef DISABLE_DKIM
+void
+tls_get_cache()
+{
+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
+
/*************************************************
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 (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)
#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)
{
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;
}
projects / exim.git / blobdiff