Fix DTLS anonymous EC(DH) denial of service

CVE-2014-3510

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>

diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c
index 9a94de00d8492a292995a90b3f0c45b1fe85e087..0a006a75342893fd4f2fdd30f930ec220b7694fa 100644 (file)
--- a/ssl/s3_clnt.c
+++ b/ssl/s3_clnt.c
@@ -2385,6 +2385,13 @@ int ssl3_send_client_key_exchange(SSL *s)
                        RSA *rsa;
                        unsigned char tmp_buf[SSL_MAX_MASTER_KEY_LENGTH];
 
+                       if (s->session->sess_cert == NULL)
+                               {
+                               /* We should always have a server certificate with SSL_kRSA. */
+                               SSLerr(SSL_F_SSL3_SEND_CLIENT_KEY_EXCHANGE,ERR_R_INTERNAL_ERROR);
+                               goto err;
+                               }
+
                        if (s->session->sess_cert->peer_rsa_tmp != NULL)
                                rsa=s->session->sess_cert->peer_rsa_tmp;
                        else