Increase limit on SMTP confirmation message copy size. Bug 1572

[users/jgh/exim.git] / src / src / tls-openssl.c

diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c
index e37b1add5001ad6ba8b6a2f02f07dee08f8b34df..96ac72c3c16cabdea5a1b4b5764835164a89b222 100644 (file)
--- a/src/src/tls-openssl.c
+++ b/src/src/tls-openssl.c
@@ -25,6 +25,10 @@ functions from the OpenSSL library. */
 #ifndef DISABLE_OCSP
 # include <openssl/ocsp.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)
 
 #ifndef DISABLE_OCSP
 # define EXIM_OCSP_SKEW_SECONDS (300L)


@@ -34,6 +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 >= 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"
 
 #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP)
 # warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile"


@@ -112,9 +123,9 @@ typedef struct tls_ext_ctx_cb {
   uschar *server_cipher_list;
   /* only passed down to tls_error: */
   host_item *host;
   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;
+#ifdef EXPERIMENTAL_EVENT
+  uschar * event_action;

 #endif
 } tls_ext_ctx_cb;
 
 #endif
 } tls_ext_ctx_cb;
 


@@ -158,29 +169,30 @@ Returns:    OK/DEFER/FAIL
 */
 
 static int
 */
 
 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;
   }
 
   {
   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;
   {
   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;
   }
   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;
-  }

 }
 
 
 }
 
 


@@ -233,6 +245,7 @@ for(i= 0; i<sk_X509_OBJECT_num(roots); i++)
     {
     X509 * current_cert= tmp_obj->data.x509;
     X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name));
     {
     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);
     }
   }
     debug_printf(" %s\n", name);
     }
   }


@@ -241,27 +254,67 @@ for(i= 0; i<sk_X509_OBJECT_num(roots); i++)
 */
 
 
 */
 
 

+#ifdef EXPERIMENTAL_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)
+  {
+  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,
 /*************************************************
 *        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
 
 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.
 
 
 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.
 Arguments:
   state      current yes/no state as 1/0
   x509ctx    certificate information.


@@ -275,31 +328,33 @@ verify_callback(int state, X509_STORE_CTX *x509ctx,
   tls_support *tlsp, BOOL *calledp, BOOL *optionalp)
 {
 X509 * cert = X509_STORE_CTX_get_current_cert(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 (state == 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)),
     X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)),

-    txt);
-  tlsp->certificate_verified = FALSE;
+    dn);

   *calledp = TRUE;
   if (!*optionalp)
     {
   *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");
   }
 
     }
   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  */
 #ifndef DISABLE_OCSP
   if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store)
     {  /* client, wanting stapling  */


@@ -310,66 +365,78 @@ else if (X509_STORE_CTX_get_error_depth(x509ctx) != 0)
                              cert))
       ERR_clear_error();
     }
                              cert))
       ERR_clear_error();
     }

+#endif
+#ifdef EXPERIMENTAL_EVENT
+    if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL"))
+      return 0;                                /* reject, with peercert set */

 #endif
   }
 else
   {
 #endif
   }
 else
   {

-#ifdef EXPERIMENTAL_CERTNAMES
-  uschar * verify_cert_hostnames;
-#endif
+  const uschar * verify_cert_hostnames;

 
 

-  tlsp->peerdn = txt;
-  tlsp->peercert = X509_dup(cert);
-
-#ifdef EXPERIMENTAL_CERTNAMES

   if (  tlsp == &tls_out
      && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames)))
        /* client, wanting hostname check */
   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

     {
     {

+
+#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;
     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,
     uschar * name;
     int rc;
     while ((name = string_nextinlist(&list, &sep, NULL, 0)))
       if ((rc = X509_check_host(cert, name, 0,

-                 X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS)))
+                 X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
+                 | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS)))

        {
        if (rc < 0)
          {
        {
        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)
          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))
     if (!tls_is_name_for_cert(verify_cert_hostnames, cert))

+#endif

       {
       log_write(0, LOG_MAIN,
       {
       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*/
+    }
+
+#ifdef EXPERIMENTAL_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",
 
   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;
   }
 
   if (!*calledp) tlsp->certificate_verified = TRUE;
   *calledp = TRUE;
   }
 

-return 1;   /* accept */
+return 1;   /* accept, at least for this level */

 }
 
 static int
 }
 
 static int


@@ -386,6 +453,7 @@ return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called,
 
 
 #ifdef EXPERIMENTAL_DANE
 
 
 #ifdef EXPERIMENTAL_DANE

+

 /* This gets called *by* the dane library verify callback, which interposes
 itself.
 */
 /* This gets called *by* the dane library verify callback, which interposes
 itself.
 */


@@ -393,19 +461,31 @@ static int
 verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx)
 {
 X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
 verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx)
 {
 X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);

-static uschar txt[256];
+uschar dn[256];
+#ifdef EXPERIMENTAL_EVENT
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+uschar * yield;
+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\n", dn);
+
+#ifdef EXPERIMENTAL_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 (state == 1)

+  tls_out.dane_verified =

   tls_out.certificate_verified = TRUE;
 return 1;
 }
   tls_out.certificate_verified = TRUE;
 return 1;
 }

-#endif
+
+#endif /*EXPERIMENTAL_DANE*/

 
 
 /*************************************************
 
 
 /*************************************************


@@ -448,7 +528,7 @@ Returns:    TRUE if OK (nothing to set up, or setup worked)
 */
 
 static BOOL
 */
 
 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;
 {
 BIO *bio;
 DH *dh;


@@ -910,7 +990,7 @@ if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
  {
   tls_out.ocsp = OCSP_FAILED;
   if (log_extra_selector & LX_tls_cipher)
  {
   tls_out.ocsp = OCSP_FAILED;
   if (log_extra_selector & LX_tls_cipher)

-    log_write(0, LOG_MAIN, "Received TLS status response, parse error");
+    log_write(0, LOG_MAIN, "Received TLS cert status response, parse error");

   else
     DEBUG(D_tls) debug_printf(" parse error\n");
   return 0;
   else
     DEBUG(D_tls) debug_printf(" parse error\n");
   return 0;


@@ -920,7 +1000,7 @@ if(!(bs = OCSP_response_get1_basic(rsp)))
   {
   tls_out.ocsp = OCSP_FAILED;
   if (log_extra_selector & LX_tls_cipher)
   {
   tls_out.ocsp = OCSP_FAILED;
   if (log_extra_selector & LX_tls_cipher)

-    log_write(0, LOG_MAIN, "Received TLS status response, error parsing response");
+    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);
   else
     DEBUG(D_tls) debug_printf(" error parsing response\n");
   OCSP_RESPONSE_free(rsp);


@@ -950,6 +1030,8 @@ if(!(bs = OCSP_response_get1_basic(rsp)))
              cbinfo->u_ocsp.client.verify_store, 0)) <= 0)
       {
       tls_out.ocsp = OCSP_FAILED;
              cbinfo->u_ocsp.client.verify_store, 0)) <= 0)
       {
       tls_out.ocsp = OCSP_FAILED;

+      if (log_extra_selector & LX_tls_cipher)
+       log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable");

       BIO_printf(bp, "OCSP response verify failure\n");
       ERR_print_errors(bp);
       i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
       BIO_printf(bp, "OCSP response verify failure\n");
       ERR_print_errors(bp);
       i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;


@@ -1052,7 +1134,7 @@ tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate,
 long init_options;
 int rc;
 BOOL okay;
 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 = store_malloc(sizeof(tls_ext_ctx_cb));
 cbinfo->certificate = certificate;


@@ -1070,6 +1152,9 @@ else
 cbinfo->dhparam = dhparam;
 cbinfo->server_cipher_list = NULL;
 cbinfo->host = host;
 cbinfo->dhparam = dhparam;
 cbinfo->server_cipher_list = NULL;
 cbinfo->host = host;

+#ifdef EXPERIMENTAL_EVENT
+cbinfo->event_action = NULL;
+#endif

 
 SSL_load_error_strings();          /* basic set up */
 OpenSSL_add_ssl_algorithms();
 
 SSL_load_error_strings();          /* basic set up */
 OpenSSL_add_ssl_algorithms();


@@ -1119,7 +1204,7 @@ if (!RAND_status())
 /* Set up the information callback, which outputs if debugging is at a suitable
 level. */
 
 /* 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);
 
 /* Automatically re-try reads/writes after renegotiation. */
 (void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY);


@@ -1191,9 +1276,7 @@ else                      /* client */
 # endif
 #endif
 
 # endif
 #endif
 

-#ifdef EXPERIMENTAL_CERTNAMES

 cbinfo->verify_cert_hostnames = NULL;
 cbinfo->verify_cert_hostnames = NULL;

-#endif

 
 /* Set up the RSA callback */
 
 
 /* Set up the RSA callback */
 


@@ -1245,6 +1328,29 @@ DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf);
 }
 
 
 }
 
 

+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;
+}
+
+

 
 
 
 
 
 


@@ -1277,36 +1383,65 @@ if (!expand_check(certs, US"tls_verify_certificates", &expcerts))
 
 if (expcerts != NULL && *expcerts != '\0')
   {
 
 if (expcerts != NULL && *expcerts != '\0')
   {

-  struct stat statbuf;
-  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)
+  if (Ustrcmp(expcerts, "system") == 0)

     {
     {

-    log_write(0, LOG_MAIN|LOG_PANIC,
-      "failed to stat %s for certificates", expcerts);
-    return DEFER;
+    /* Tell the library to use its compiled-in location for the system default
+    CA bundle, only */
+
+    if (!SSL_CTX_set_default_verify_paths(sctx))
+      return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL);

     }
   else
     {
     }
   else
     {

-    uschar *file, *dir;
-    if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
-      { file = NULL; dir = expcerts; }
-    else
-      { file = expcerts; dir = NULL; }
+    struct stat statbuf;

 
 

-    /* 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. */
+    /* Tell the library to use its compiled-in location for the system default
+    CA bundle. Those given by the exim config are additional to these */

 
 

-    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);
+    if (!SSL_CTX_set_default_verify_paths(sctx))
+      return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL);

 
 

-    if (file != NULL)
+    if (Ustat(expcerts, &statbuf) < 0)
+      {
+      log_write(0, LOG_MAIN|LOG_PANIC,
+       "failed to stat %s for certificates", expcerts);
+      return DEFER;
+      }
+    else

       {
       {

-      SSL_CTX_set_client_CA_list(sctx, SSL_load_client_CA_file(CS file));
+      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);
+
+      /* Load the list of CAs for which we will accept certs, for sending
+      to the client.  This is only for the one-file tls_verify_certificates
+      variant.
+      If a list isn't loaded into the server, but
+      some verify locations are set, the server end appears to make
+      a wildcard reqest for client certs.
+      Meanwhile, the client library as deafult behaviour *ignores* the list
+      we send over the wire - see man SSL_CTX_set_client_cert_cb.
+      Because of this, and that the dir variant is likely only used for
+      the public-CA bundle (not for a private CA), not worth fixing.
+      */
+      if (file != NULL)
+       {
+       STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file);
+  DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n",
+                                   sk_X509_NAME_num(names));
+       SSL_CTX_set_client_CA_list(sctx, names);
+       }

       }
     }
 
       }
     }
 


@@ -1398,6 +1533,8 @@ tls_server_start(const uschar *require_ciphers)
 int rc;
 uschar *expciphers;
 tls_ext_ctx_cb *cbinfo;
 int rc;
 uschar *expciphers;
 tls_ext_ctx_cb *cbinfo;

+X509 * peercert;
+static uschar peerdn[256];

 static uschar cipherbuf[256];
 
 /* Check for previous activation */
 static uschar cipherbuf[256];
 
 /* Check for previous activation */


@@ -1442,6 +1579,9 @@ if (expciphers != NULL)
 optional, set up appropriately. */
 
 tls_in.certificate_verified = FALSE;
 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)
 server_verify_callback_called = FALSE;
 
 if (verify_check_host(&tls_verify_hosts) == OK)


@@ -1517,6 +1657,8 @@ DEBUG(D_tls) debug_printf("SSL_accept was successful\n");
 /* TLS has been set up. Adjust the input functions to read via TLS,
 and initialize things. */
 
 /* TLS has been set up. Adjust the input functions to read via TLS,
 and initialize things. */
 

+peer_cert(server_ssl, &tls_in, peerdn, sizeof(peerdn));
+

 construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits);
 tls_in.cipher = cipherbuf;
 
 construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits);
 tls_in.cipher = cipherbuf;
 


@@ -1557,10 +1699,7 @@ return OK;
 
 static int
 tls_client_basic_ctx_init(SSL_CTX * ctx,
 
 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;
                          )
 {
 int rc;


@@ -1568,37 +1707,89 @@ int rc;
    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 */
 
    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;
   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);
-    }
-#endif
+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 = host->name;
+  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:
+    case 0:    /* action not taken */
+      return tls_error(US"tlsa load", host, NULL);
+    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             *
 
 /*************************************************
 *    Start a TLS session in a client             *


@@ -1610,7 +1801,8 @@ Argument:
   fd               the fd of the connection
   host             connected host (for messages)
   addr             the first address
   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
 
 Returns:           OK on success
                    FAIL otherwise - note that tls_error() will not give DEFER


@@ -1619,12 +1811,16 @@ Returns:           OK on success
 
 int
 tls_client_start(int fd, host_item *host, address_item *addr,
 
 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;
 uschar * expciphers;

-X509 * server_cert;

 int rc;
 static uschar cipherbuf[256];
 
 int rc;
 static uschar cipherbuf[256];
 


@@ -1632,74 +1828,36 @@ static uschar cipherbuf[256];
 BOOL request_ocsp = FALSE;
 BOOL require_ocsp = FALSE;
 #endif
 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
 
 #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;
-  }
-
-if (!dane)     /*XXX todo: enable ocsp with dane */
-#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
 
   }
 #endif
 


@@ -1732,9 +1890,11 @@ if (expciphers != NULL)
   }
 
 #ifdef EXPERIMENTAL_DANE
   }
 
 #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);
 
   if (!DANESSL_library_init())
     return tls_error(US"library init", host, NULL);


@@ -1745,11 +1905,8 @@ else
 
 #endif
 
 
 #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)
     return rc;
 
 if ((client_ssl = SSL_new(client_ctx)) == NULL)


@@ -1781,9 +1938,32 @@ if (ob->tls_sni)
     }
   }
 
     }
   }
 

+#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()) */
 #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);
 if (request_ocsp)
   {
   SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp);


@@ -1792,51 +1972,10 @@ if (request_ocsp)
   }
 #endif
 
   }
 #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;
-      }
-    }
-  }
+#ifdef EXPERIMENTAL_EVENT
+client_static_cbinfo->event_action = tb->event_action;

 #endif
 
 #endif
 

-

 /* There doesn't seem to be a built-in timeout on connection. */
 
 DEBUG(D_tls) debug_printf("Calling SSL_connect\n");
 /* There doesn't seem to be a built-in timeout on connection. */
 
 DEBUG(D_tls) debug_printf("Calling SSL_connect\n");


@@ -1846,8 +1985,8 @@ rc = SSL_connect(client_ssl);
 alarm(0);
 
 #ifdef EXPERIMENTAL_DANE
 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)
 #endif
 
 if (rc <= 0)


@@ -1855,17 +1994,7 @@ if (rc <= 0)
 
 DEBUG(D_tls) debug_printf("SSL_connect succeeded\n");
 
 
 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;
 
 construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits);
 tls_out.cipher = cipherbuf;