Abort on unrecognised warning alerts

A peer continually sending unrecognised warning alerts could mean that we
make no progress on a connection. We should abort rather than continuing if
we receive an unrecognised warning alert.

Thanks to Shi Lei for reporting this issue.

Reviewed-by: Rich Salz <rsalz@openssl.org>

diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index df124cf52caf019f665a4f794196a8fe4fe32c5b..91f0c58fb2c4bb49916a6bc4418fb6aed17ce4d9 100644 (file)
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -1462,8 +1462,13 @@ int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
             }
 #ifdef SSL_AD_MISSING_SRP_USERNAME
             else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME)
-                return (0);
+                return 0;
 #endif
+            else {
+                al = SSL_AD_HANDSHAKE_FAILURE;
+                SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
+                goto f_err;
+            }
         } else if (alert_level == SSL3_AL_FATAL) {
             char tmp[16];