vtls: Fail on unrecognized param for CURLOPT_SSLVERSION

- Fix GnuTLS code for CURL_SSLVERSION_TLSv1_2 that broke when the
TLS 1.3 support was added in 6ad3add.

- Homogenize across code for all backends the error message when TLS 1.3
is not available to "<backend>: TLS 1.3 is not yet supported".

- Return an error when a user-specified ssl version is unrecognized.

---

Prior to this change our code for some of the backends used the
'default' label in the switch statement (ie ver unrecognized) for
ssl.version and treated it the same as CURL_SSLVERSION_DEFAULT.

Bug: https://curl.haxx.se/mail/lib-2016-11/0048.html
Reported-by: Kamil Dudka

9 files changed, 81 insertions, 30 deletions

diff --git a/lib/vtls/cyassl.c b/lib/vtls/cyassl.c
index 5d6dbfb8c..39248d2c7 100644
--- a/lib/vtls/cyassl.c
+++ b/lib/vtls/cyassl.c
@@ -174,12 +174,15 @@ cyassl_connect_step1(struct connectdata *conn,
     req_method = TLSv1_2_client_method();
     use_sni(TRUE);
     break;
+  case CURL_SSLVERSION_TLSv1_3:
+    failf(data, "CyaSSL: TLS 1.3 is not yet supported");
+    return CURLE_SSL_CONNECT_ERROR;
   case CURL_SSLVERSION_SSLv3:
 #ifdef WOLFSSL_ALLOW_SSLV3
     req_method = SSLv3_client_method();
     use_sni(FALSE);
 #else
-    failf(data, "No support for SSLv3");
+    failf(data, "CyaSSL does not support SSLv3");
     return CURLE_NOT_BUILT_IN;
 #endif
     break;
diff --git a/lib/vtls/darwinssl.c b/lib/vtls/darwinssl.c
index 6aa30d451..73491c457 100644
--- a/lib/vtls/darwinssl.c
+++ b/lib/vtls/darwinssl.c
@@ -1053,7 +1053,6 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn,
 #if CURL_BUILD_MAC_10_8 || CURL_BUILD_IOS
   if(SSLSetProtocolVersionMax != NULL) {
     switch(data->set.ssl.version) {
-      default:
       case CURL_SSLVERSION_DEFAULT:
       case CURL_SSLVERSION_TLSv1:
         (void)SSLSetProtocolVersionMin(connssl->ssl_ctx, kTLSProtocol1);
@@ -1072,7 +1071,7 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn,
         (void)SSLSetProtocolVersionMax(connssl->ssl_ctx, kTLSProtocol12);
         break;
       case CURL_SSLVERSION_TLSv1_3:
-        failf(data, "TLSv1.3 is not yet supported with this TLS backend");
+        failf(data, "DarwinSSL: TLS 1.3 is not yet supported");
         return CURLE_SSL_CONNECT_ERROR;
       case CURL_SSLVERSION_SSLv3:
         err = SSLSetProtocolVersionMin(connssl->ssl_ctx, kSSLProtocol3);
@@ -1089,6 +1088,10 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn,
           return CURLE_SSL_CONNECT_ERROR;
         }
         (void)SSLSetProtocolVersionMax(connssl->ssl_ctx, kSSLProtocol2);
+        break;
+      default:
+        failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+        return CURLE_SSL_CONNECT_ERROR;
     }
   }
   else {
@@ -1097,7 +1100,6 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn,
                                        kSSLProtocolAll,
                                        false);
     switch (data->set.ssl.version) {
-      default:
       case CURL_SSLVERSION_DEFAULT:
       case CURL_SSLVERSION_TLSv1:
         (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
@@ -1126,7 +1128,7 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn,
                                            true);
         break;
       case CURL_SSLVERSION_TLSv1_3:
-        failf(data, "TLSv1.3 is not yet supported with this TLS backend");
+        failf(data, "DarwinSSL: TLS 1.3 is not yet supported");
         return CURLE_SSL_CONNECT_ERROR;
       case CURL_SSLVERSION_SSLv3:
         err = SSLSetProtocolVersionEnabled(connssl->ssl_ctx,
@@ -1146,13 +1148,15 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn,
           return CURLE_SSL_CONNECT_ERROR;
         }
         break;
+      default:
+        failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+        return CURLE_SSL_CONNECT_ERROR;
     }
 #endif  /* CURL_SUPPORT_MAC_10_8 */
   }
 #else
   (void)SSLSetProtocolVersionEnabled(connssl->ssl_ctx, kSSLProtocolAll, false);
   switch(data->set.ssl.version) {
-    default:
     case CURL_SSLVERSION_DEFAULT:
     case CURL_SSLVERSION_TLSv1:
     case CURL_SSLVERSION_TLSv1_0:
@@ -1187,6 +1191,9 @@ static CURLcode darwinssl_connect_step1(struct connectdata *conn,
         return CURLE_SSL_CONNECT_ERROR;
       }
       break;
+    default:
+      failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+      return CURLE_SSL_CONNECT_ERROR;
   }
 #endif /* CURL_BUILD_MAC_10_8 || CURL_BUILD_IOS */
 
diff --git a/lib/vtls/gskit.c b/lib/vtls/gskit.c
index 9760c93ab..e1dd9b6b0 100644
--- a/lib/vtls/gskit.c
+++ b/lib/vtls/gskit.c
@@ -614,8 +614,6 @@ static CURLcode gskit_connect_step1(struct connectdata *conn, int sockindex)
     return result;
 
   /* Determine which SSL/TLS version should be enabled. */
-  protoflags = CURL_GSKPROTO_TLSV10_MASK | CURL_GSKPROTO_TLSV11_MASK |
-               CURL_GSKPROTO_TLSV12_MASK;
   sni = conn->host.name;
   switch (data->set.ssl.version) {
   case CURL_SSLVERSION_SSLv2:
@@ -626,6 +624,7 @@ static CURLcode gskit_connect_step1(struct connectdata *conn, int sockindex)
     protoflags = CURL_GSKPROTO_SSLV3_MASK;
     sni = (char *) NULL;
     break;
+  case CURL_SSLVERSION_DEFAULT:
   case CURL_SSLVERSION_TLSv1:
     protoflags = CURL_GSKPROTO_TLSV10_MASK |
                  CURL_GSKPROTO_TLSV11_MASK | CURL_GSKPROTO_TLSV12_MASK;
@@ -640,8 +639,11 @@ static CURLcode gskit_connect_step1(struct connectdata *conn, int sockindex)
     protoflags = CURL_GSKPROTO_TLSV12_MASK;
     break;
   case CURL_SSLVERSION_TLSv1_3:
-    failf(data, "TLS 1.3 not yet supported");
-    return CURLE_SSL_CIPHER;
+    failf(data, "GSKit: TLS 1.3 is not yet supported");
+    return CURLE_SSL_CONNECT_ERROR;
+  default:
+    failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+    return CURLE_SSL_CONNECT_ERROR;
   }
 
   /* Process SNI. Ignore if not supported (on OS400 < V7R1). */
diff --git a/lib/vtls/gtls.c b/lib/vtls/gtls.c
index d47d80fc5..6eb3a9992 100644
--- a/lib/vtls/gtls.c
+++ b/lib/vtls/gtls.c
@@ -409,7 +409,6 @@ gtls_connect_step1(struct connectdata *conn,
   if(!gtls_inited)
     Curl_gtls_init();
 
-  /* GnuTLS only supports SSLv3 and TLSv1 */
   if(data->set.ssl.version == CURL_SSLVERSION_SSLv2) {
     failf(data, "GnuTLS does not support SSLv2");
     return CURLE_SSL_CONNECT_ERROR;
@@ -569,15 +568,16 @@ gtls_connect_step1(struct connectdata *conn,
       break;
     case CURL_SSLVERSION_TLSv1_2:
       protocol_priority[0] = GNUTLS_TLS1_2;
+      break;
     case CURL_SSLVERSION_TLSv1_3:
-      failf(data, "GnuTLS does not support TLSv1.3");
+      failf(data, "GnuTLS: TLS 1.3 is not yet supported");
       return CURLE_SSL_CONNECT_ERROR;
-    break;
-      case CURL_SSLVERSION_SSLv2:
-    default:
+    case CURL_SSLVERSION_SSLv2:
       failf(data, "GnuTLS does not support SSLv2");
       return CURLE_SSL_CONNECT_ERROR;
-      break;
+    default:
+      failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+      return CURLE_SSL_CONNECT_ERROR;
   }
   rc = gnutls_protocol_set_priority(session, protocol_priority);
   if(rc != GNUTLS_E_SUCCESS) {
@@ -611,13 +611,14 @@ gtls_connect_step1(struct connectdata *conn,
                      "+VERS-TLS1.2:" GNUTLS_SRP;
       break;
     case CURL_SSLVERSION_TLSv1_3:
-      failf(data, "GnuTLS does not support TLSv1.3");
+      failf(data, "GnuTLS: TLS 1.3 is not yet supported");
       return CURLE_SSL_CONNECT_ERROR;
     case CURL_SSLVERSION_SSLv2:
-    default:
       failf(data, "GnuTLS does not support SSLv2");
       return CURLE_SSL_CONNECT_ERROR;
-      break;
+    default:
+      failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+      return CURLE_SSL_CONNECT_ERROR;
   }
   rc = gnutls_priority_set_direct(session, prioritylist, &err);
   if((rc == GNUTLS_E_INVALID_REQUEST) && err) {
diff --git a/lib/vtls/mbedtls.c b/lib/vtls/mbedtls.c
index 9f29ff055..7797c3e40 100644
--- a/lib/vtls/mbedtls.c
+++ b/lib/vtls/mbedtls.c
@@ -351,8 +351,11 @@ mbed_connect_step1(struct connectdata *conn,
                                  MBEDTLS_SSL_MINOR_VERSION_3);
     infof(data, "mbedTLS: Set SSL version to TLS 1.2\n");
     break;
+  case CURL_SSLVERSION_TLSv1_3:
+    failf(data, "mbedTLS: TLS 1.3 is not yet supported");
+    return CURLE_SSL_CONNECT_ERROR;
   default:
-    failf(data, "mbedTLS: Unsupported SSL protocol version");
+    failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
     return CURLE_SSL_CONNECT_ERROR;
   }
 
diff --git a/lib/vtls/nss.c b/lib/vtls/nss.c
index 9a3d3df5d..6e0dc5b29 100644
--- a/lib/vtls/nss.c
+++ b/lib/vtls/nss.c
@@ -1555,8 +1555,8 @@ static CURLcode nss_init_sslver(SSLVersionRange *sslver,
     break;
 
   default:
-    /* unsupported SSL/TLS version */
-    break;
+    failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+    return CURLE_SSL_CONNECT_ERROR;
   }
 
   failf(data, "TLS minor version cannot be set");
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index edfd5356d..66fa731dd 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -1731,7 +1731,6 @@ static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex)
   /* check to see if we've been told to use an explicit SSL/TLS version */
 
   switch(data->set.ssl.version) {
-  default:
   case CURL_SSLVERSION_DEFAULT:
   case CURL_SSLVERSION_TLSv1:
   case CURL_SSLVERSION_TLSv1_0:
@@ -1773,6 +1772,9 @@ static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex)
     use_sni(FALSE);
     break;
 #endif
+  default:
+    failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+    return CURLE_SSL_CONNECT_ERROR;
   }
 
   if(connssl->ctx)
@@ -1867,6 +1869,9 @@ static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex)
 #if OPENSSL_VERSION_NUMBER >= 0x1000100FL
     ctx_options |= SSL_OP_NO_TLSv1_1;
     ctx_options |= SSL_OP_NO_TLSv1_2;
+#ifdef TLS1_3_VERSION
+    ctx_options |= SSL_OP_NO_TLSv1_3;
+#endif
 #endif
     break;
 
@@ -1882,48 +1887,74 @@ static CURLcode ossl_connect_step1(struct connectdata *conn, int sockindex)
 #if OPENSSL_VERSION_NUMBER >= 0x1000100FL
     ctx_options |= SSL_OP_NO_TLSv1_1;
     ctx_options |= SSL_OP_NO_TLSv1_2;
+#ifdef TLS1_3_VERSION
+    ctx_options |= SSL_OP_NO_TLSv1_3;
+#endif
 #endif
     break;
 
-#if OPENSSL_VERSION_NUMBER >= 0x1000100FL
   case CURL_SSLVERSION_TLSv1_1:
+#if OPENSSL_VERSION_NUMBER >= 0x1000100FL
     ctx_options |= SSL_OP_NO_SSLv2;
     ctx_options |= SSL_OP_NO_SSLv3;
     ctx_options |= SSL_OP_NO_TLSv1;
     ctx_options |= SSL_OP_NO_TLSv1_2;
+#ifdef TLS1_3_VERSION
+    ctx_options |= SSL_OP_NO_TLSv1_3;
+#endif
     break;
+#else
+    failf(data, OSSL_PACKAGE " was built without TLS 1.1 support");
+    return CURLE_NOT_BUILT_IN;
+#endif
 
   case CURL_SSLVERSION_TLSv1_2:
+#if OPENSSL_VERSION_NUMBER >= 0x1000100FL
     ctx_options |= SSL_OP_NO_SSLv2;
     ctx_options |= SSL_OP_NO_SSLv3;
     ctx_options |= SSL_OP_NO_TLSv1;
     ctx_options |= SSL_OP_NO_TLSv1_1;
+#ifdef TLS1_3_VERSION
+    ctx_options |= SSL_OP_NO_TLSv1_3;
+#endif
     break;
+#else
+    failf(data, OSSL_PACKAGE " was built without TLS 1.2 support");
+    return CURLE_NOT_BUILT_IN;
 #endif
 
-#ifdef TLS1_3_VERSION
   case CURL_SSLVERSION_TLSv1_3:
+#ifdef TLS1_3_VERSION
     ctx_options |= SSL_OP_NO_SSLv2;
     ctx_options |= SSL_OP_NO_SSLv3;
     ctx_options |= SSL_OP_NO_TLSv1;
     ctx_options |= SSL_OP_NO_TLSv1_1;
     ctx_options |= SSL_OP_NO_TLSv1_2;
     break;
+#else
+    failf(data, OSSL_PACKAGE " was built without TLS 1.3 support");
+    return CURLE_NOT_BUILT_IN;
 #endif
 
-#ifndef OPENSSL_NO_SSL2
   case CURL_SSLVERSION_SSLv2:
+#ifndef OPENSSL_NO_SSL2
     ctx_options |= SSL_OP_NO_SSLv3;
     ctx_options |= SSL_OP_NO_TLSv1;
 #if OPENSSL_VERSION_NUMBER >= 0x1000100FL
     ctx_options |= SSL_OP_NO_TLSv1_1;
     ctx_options |= SSL_OP_NO_TLSv1_2;
+#ifdef TLS1_3_VERSION
+    ctx_options |= SSL_OP_NO_TLSv1_3;
+#endif
 #endif
     break;
+#else
+    failf(data, OSSL_PACKAGE " was built without SSLv2 support");
+    return CURLE_NOT_BUILT_IN;
 #endif
 
   default:
-    failf(data, "Unsupported SSL protocol version");
+    failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
     return CURLE_SSL_CONNECT_ERROR;
   }
 
diff --git a/lib/vtls/polarssl.c b/lib/vtls/polarssl.c
index 4e41315b6..a6a769091 100644
--- a/lib/vtls/polarssl.c
+++ b/lib/vtls/polarssl.c
@@ -272,7 +272,6 @@ polarssl_connect_step1(struct connectdata *conn,
   }
 
   switch(data->set.ssl.version) {
-  default:
   case CURL_SSLVERSION_DEFAULT:
   case CURL_SSLVERSION_TLSv1:
     ssl_set_min_version(&connssl->ssl, SSL_MAJOR_VERSION_3,
@@ -309,6 +308,9 @@ polarssl_connect_step1(struct connectdata *conn,
   case CURL_SSLVERSION_TLSv1_3:
     failf(data, "PolarSSL: TLS 1.3 is not yet supported");
     return CURLE_SSL_CONNECT_ERROR;
+  default:
+    failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+    return CURLE_SSL_CONNECT_ERROR;
   }
 
   ssl_set_endpoint(&connssl->ssl, SSL_IS_CLIENT);
diff --git a/lib/vtls/schannel.c b/lib/vtls/schannel.c
index 63cb98a3c..528db01f9 100644
--- a/lib/vtls/schannel.c
+++ b/lib/vtls/schannel.c
@@ -197,7 +197,6 @@ schannel_connect_step1(struct connectdata *conn, int sockindex)
     }
 
     switch(data->set.ssl.version) {
-    default:
     case CURL_SSLVERSION_DEFAULT:
     case CURL_SSLVERSION_TLSv1:
       schannel_cred.grbitEnabledProtocols = SP_PROT_TLS1_0_CLIENT |
@@ -214,7 +213,7 @@ schannel_connect_step1(struct connectdata *conn, int sockindex)
       schannel_cred.grbitEnabledProtocols = SP_PROT_TLS1_2_CLIENT;
       break;
     case CURL_SSLVERSION_TLSv1_3:
-      failf(data, "schannel: TLS 1.3 is not yet supported");
+      failf(data, "Schannel: TLS 1.3 is not yet supported");
       return CURLE_SSL_CONNECT_ERROR;
     case CURL_SSLVERSION_SSLv3:
       schannel_cred.grbitEnabledProtocols = SP_PROT_SSL3_CLIENT;
@@ -222,6 +221,9 @@ schannel_connect_step1(struct connectdata *conn, int sockindex)
     case CURL_SSLVERSION_SSLv2:
       schannel_cred.grbitEnabledProtocols = SP_PROT_SSL2_CLIENT;
       break;
+    default:
+      failf(data, "Unrecognized parameter passed via CURLOPT_SSLVERSION");
+      return CURLE_SSL_CONNECT_ERROR;
     }
 
     /* allocate memory for the re-usable credential handle */