Restrict dane to DANE-TA(2) and DANE-EE(3) usage TLSA records

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

diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c
index 7d9ab8b4d7426e3685bf081eb7c5cfc46b953615..7e424f4f1a0f878fea4bc883bcd7e550696957ac 100644 (file)
--- a/src/src/tls-openssl.c
+++ b/src/src/tls-openssl.c
@@ -1702,22 +1702,23 @@ 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 +1733,7 @@ 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*/
@@ -1784,28 +1785,29 @@ tls_out.tlsa_usage = 0;
 
 #ifndef DISABLE_OCSP
   {
+# ifdef EXPERIMENTAL_DANE
+  if (  tlsa_dnsa
+     && ob->hosts_request_ocsp[0] == '*'
+     && ob->hosts_request_ocsp[1] == '\0'
+     )
+    {
+    /* Unchanged from default.  Use a safer one under DANE */
+    request_ocsp = TRUE;
+    ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} "
+                                     "   {= {4}{$tls_out_tlsa_usage}} } "
+                                " {*}{}}";
+    }
+# endif
+
   if ((require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp,
     NULL, host->name, host->address, NULL) == OK))
     request_ocsp = TRUE;
   else
-    {
 # ifdef EXPERIMENTAL_DANE
-    if (  tlsa_dnsa
-       && ob->hosts_request_ocsp[0] == '*'
-       && ob->hosts_request_ocsp[1] == '\0'
-       )
-      {
-      /* Unchanged from default.  Use a safer one under DANE */
-      request_ocsp = TRUE;
-      ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} "
-                                       "   {= {4}{$tls_out_tlsa_usage}} } "
-                                  " {*}{}}";
-      }
-    else
+    if (!request_ocsp)
 # endif
       request_ocsp = verify_check_this_host(&ob->hosts_request_ocsp,
          NULL, host->name, host->address, NULL) == OK;
-    }
   }
 #endif