Support TLS_FALLBACK_SCSV.

[openssl.git] / ssl / d1_lib.c

diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
index 7d9d91ff2c34bc7af74acd3437578ce91abed5b8..25c58a8af9ad32f12f7d3692b0bd32c27f4ca092 100644 (file)
--- a/ssl/d1_lib.c
+++ b/ssl/d1_lib.c
@@ -294,6 +294,25 @@ long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
        case DTLS_CTRL_LISTEN:
                ret = dtls1_listen(s, parg);
                break;
+       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 == DTLS_method()->version)
+                       {
+#if DTLS_MAX_VERSION != DTLS1_2_VERSION
+#  error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
+#endif
+                       if (!(s->options & SSL_OP_NO_DTLSv1_2))
+                               return s->version == DTLS1_2_VERSION;
+                       if (!(s->options & SSL_OP_NO_DTLSv1))
+                               return s->version == DTLS1_VERSION;
+                       }
+               return 0; /* Unexpected state; fail closed. */
 
        default:
                ret = ssl3_ctrl(s, cmd, larg, parg);