X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/4f59c424dabfc69b7313d84685df68dd406d6ff9..09c17790eec23907b93df1ec7cee746b28dfc836:/src/src/tls-openssl.c

diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c
index b77ed32e1..63bf83b1d 100644
--- a/src/src/tls-openssl.c
+++ b/src/src/tls-openssl.c
@@ -38,6 +38,13 @@ functions from the OpenSSL library. */
 #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
 # define EXIM_HAVE_OPENSSL_TLSEXT
 #endif
+#if OPENSSL_VERSION_NUMBER >= 0x010100000L
+# define EXIM_HAVE_OPENSSL_CHECKHOST
+#endif
+#if OPENSSL_VERSION_NUMBER >= 0x010000000L \
+    && (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L
+# define EXIM_HAVE_OPENSSL_CHECKHOST
+#endif
 
 #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP)
 # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile"
@@ -120,7 +127,7 @@ typedef struct tls_ext_ctx_cb {
 #ifdef EXPERIMENTAL_CERTNAMES
   uschar * verify_cert_hostnames;
 #endif
-#ifdef EXPERIMENTAL_TPDA
+#ifdef EXPERIMENTAL_EVENT
   uschar * event_action;
 #endif
 } tls_ext_ctx_cb;
@@ -167,27 +174,28 @@ Returns:    OK/DEFER/FAIL
 static int
 tls_error(uschar *prefix, 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;
-  }
 }
 
 
@@ -287,6 +295,10 @@ verify_callback(int state, X509_STORE_CTX *x509ctx,
 X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
 int depth = X509_STORE_CTX_get_error_depth(x509ctx);
 static uschar txt[256];
+#ifdef EXPERIMENTAL_EVENT
+uschar * ev;
+uschar * yield;
+#endif
 
 X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt));
 
@@ -296,7 +308,6 @@ if (state == 0)
     depth,
     X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)),
     txt);
-  tlsp->certificate_verified = FALSE;
   *calledp = TRUE;
   if (!*optionalp)
     {
@@ -321,18 +332,20 @@ else if (depth != 0)
       ERR_clear_error();
     }
 #endif
-#ifdef EXPERIMENTAL_TPDA
-  if (tlsp == &tls_out && client_static_cbinfo->event_action)
+#ifdef EXPERIMENTAL_EVENT
+  ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action;
+  if (ev)
     {
     tlsp->peercert = X509_dup(cert);
-    if (tpda_raise_event(client_static_cbinfo->event_action,
-		    US"tls:cert", string_sprintf("%d", depth)) == DEFER)
+    if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth))))
       {
       log_write(0, LOG_MAIN, "SSL verify denied by event-action: "
-			      "depth=%d cert=%s", depth, txt);
-      tlsp->certificate_verified = FALSE;
+			      "depth=%d cert=%s: %s", depth, txt, yield);
       *calledp = TRUE;
-      return 0;			    /* reject */
+      if (!*optionalp)
+	return 0;			    /* reject */
+      DEBUG(D_tls) debug_printf("Event-action verify failure overridden "
+	"(host in tls_try_verify_hosts)\n");
       }
     X509_free(tlsp->peercert);
     tlsp->peercert = NULL;
@@ -353,9 +366,12 @@ else
      && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames)))
      	/* client, wanting hostname check */
 
-# if OPENSSL_VERSION_NUMBER >= 0x010100000L || OPENSSL_VERSION_NUMBER >= 0x010002000L
+# if EXIM_HAVE_OPENSSL_CHECKHOST
 #  ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
 #   define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0
+#  endif
+#  ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS
+#   define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0
 #  endif
     {
     int sep = 0;
@@ -364,7 +380,8 @@ else
     int rc;
     while ((name = string_nextinlist(&list, &sep, NULL, 0)))
       if ((rc = X509_check_host(cert, name, 0,
-		  X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)))
+		  X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
+		  | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS)))
 	{
 	if (rc < 0)
 	  {
@@ -377,7 +394,11 @@ else
       {
       log_write(0, LOG_MAIN,
 	"SSL verify error: certificate name mismatch: \"%s\"\n", txt);
-      return 0;				/* reject */
+      *calledp = TRUE;
+      if (!*optionalp)
+	return 0;			    /* reject */
+      DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
+	"tls_try_verify_hosts)\n");
       }
     }
 # else
@@ -385,24 +406,28 @@ else
       {
       log_write(0, LOG_MAIN,
 	"SSL verify error: certificate name mismatch: \"%s\"\n", txt);
-      return 0;				/* reject */
+      *calledp = TRUE;
+      if (!*optionalp)
+	return 0;			    /* reject */
+      DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
+	"tls_try_verify_hosts)\n");
       }
 # endif
 #endif	/*EXPERIMENTAL_CERTNAMES*/
 
-#ifdef EXPERIMENTAL_TPDA
-  if (tlsp == &tls_out)
-    {
-    if (tpda_raise_event(client_static_cbinfo->event_action,
-		    US"tls:cert", US"0") == DEFER)
+#ifdef EXPERIMENTAL_EVENT
+  ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action;
+  if (ev)
+    if ((yield = event_raise(ev, US"tls:cert", US"0")))
       {
       log_write(0, LOG_MAIN, "SSL verify denied by event-action: "
-			      "depth=0 cert=%s", txt);
-      tlsp->certificate_verified = FALSE;
+			      "depth=0 cert=%s: %s", txt, yield);
       *calledp = TRUE;
-      return 0;			    /* reject */
+      if (!*optionalp)
+	return 0;			    /* reject */
+      DEBUG(D_tls) debug_printf("Event-action verify failure overridden "
+	"(host in tls_try_verify_hosts)\n");
       }
-    }
 #endif
 
   DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n",
@@ -437,8 +462,9 @@ verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx)
 {
 X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
 static uschar txt[256];
-#ifdef EXPERIMENTAL_TPDA
+#ifdef EXPERIMENTAL_EVENT
 int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+uschar * yield;
 #endif
 
 X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt));
@@ -447,14 +473,14 @@ DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s\n", txt);
 tls_out.peerdn = txt;
 tls_out.peercert = X509_dup(cert);
 
-#ifdef EXPERIMENTAL_TPDA
+#ifdef EXPERIMENTAL_EVENT
   if (client_static_cbinfo->event_action)
     {
-    if (tpda_raise_event(client_static_cbinfo->event_action,
-		    US"tls:cert", string_sprintf("%d", depth)) == DEFER)
+    if ((yield = event_raise(client_static_cbinfo->event_action,
+		    US"tls:cert", string_sprintf("%d", depth))))
       {
       log_write(0, LOG_MAIN, "DANE verify denied by event-action: "
-			      "depth=%d cert=%s", depth, txt);
+			      "depth=%d cert=%s: %s", depth, txt, yield);
       tls_out.certificate_verified = FALSE;
       return 0;			    /* reject */
       }
@@ -1139,7 +1165,7 @@ else
 cbinfo->dhparam = dhparam;
 cbinfo->server_cipher_list = NULL;
 cbinfo->host = host;
-#ifdef EXPERIMENTAL_TPDA
+#ifdef EXPERIMENTAL_EVENT
 cbinfo->event_action = NULL;
 #endif
 
@@ -1377,7 +1403,16 @@ if (expcerts != NULL && *expcerts != '\0')
       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.  XXX only for file source, not dir? */
+    to the client.  This is only for the one-file tls_verify_certificates
+    variant.
+    If a list isn't loaded into the server, but
+    some verify locations are set, the server end appears to make
+    a wildcard reqest for client certs.
+    Meanwhile, the client library as deafult behaviour *ignores* the list
+    we send over the wire - see man SSL_CTX_set_client_cert_cb.
+    Because of this, and that the dir variant is likely only used for
+    the public-CA bundle (not for a private CA), not worth fixing.
+    */
     if (file != NULL)
       {
       STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file);
@@ -1702,22 +1737,23 @@ for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
   uint8_t usage, selector, mtype;
   const char * mdname;
 
-  found++;
   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:
-      log_write(0, LOG_MAIN,
-		"DANE error: TLSA record w/bad mtype 0x%x", mtype);
-      return FAIL;
-    case 0:	mdname = NULL; break;
-    case 1:	mdname = "sha256"; break;
-    case 2:	mdname = "sha512"; break;
+    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:
@@ -1732,7 +1768,7 @@ for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
 if (found)
   return OK;
 
-log_write(0, LOG_MAIN, "DANE error: No TLSA records");
+log_write(0, LOG_MAIN, "DANE error: No usable TLSA records");
 return FAIL;
 }
 #endif	/*EXPERIMENTAL_DANE*/
@@ -1924,8 +1960,8 @@ if (request_ocsp)
   }
 #endif
 
-#ifdef EXPERIMENTAL_TPDA
-client_static_cbinfo->event_action = tb->tpda_event_action;
+#ifdef EXPERIMENTAL_EVENT
+client_static_cbinfo->event_action = tb->event_action;
 #endif
 
 /* There doesn't seem to be a built-in timeout on connection. */