Support TLS_FALLBACK_SCSV.

[openssl.git] / ssl / s3_lib.c

diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c
index a15625b91182cb9d7313988f8eaaa01924294f4a..361f2955215b965826726c76da56f4753680fd90 100644 (file)
--- a/ssl/s3_lib.c
+++ b/ssl/s3_lib.c
@@ -3598,6 +3598,33 @@ long ssl3_ctrl(SSL *s, int cmd, long larg, void *parg)
                return (int)sess->tlsext_ecpointformatlist_length;
                }
 #endif
+
+       case SSL_CTRL_CHECK_PROTO_VERSION:
+               /* For library-internal use; checks that the current protocol
+                * is the highest enabled version (according to s->ctx->method,
+                * as version negotiation may have changed s->method). */
+               if (s->version == s->ctx->method->version)
+                       return 1;
+               /* Apparently we're using a version-flexible SSL_METHOD
+                * (not at its highest protocol version). */
+               if (s->ctx->method->version == SSLv23_method()->version)
+                       {
+#if TLS_MAX_VERSION != TLS1_2_VERSION
+#  error Code needs update for SSLv23_method() support beyond TLS1_2_VERSION.
+#endif
+                       if (!(s->options & SSL_OP_NO_TLSv1_2))
+                               return s->version == TLS1_2_VERSION;
+                       if (!(s->options & SSL_OP_NO_TLSv1_1))
+                               return s->version == TLS1_1_VERSION;
+                       if (!(s->options & SSL_OP_NO_TLSv1))
+                               return s->version == TLS1_VERSION;
+                       if (!(s->options & SSL_OP_NO_SSLv3))
+                               return s->version == SSL3_VERSION;
+                       if (!(s->options & SSL_OP_NO_SSLv2))
+                               return s->version == SSL2_VERSION;
+                       }
+               return 0; /* Unexpected state; fail closed. */
+
        default:
                break;
                }
@@ -4519,4 +4546,3 @@ long ssl_get_algorithm2(SSL *s)
                return SSL_HANDSHAKE_MAC_SHA256 | TLS1_PRF_SHA256;
        return alg2;
        }
-