Fix DTLS anonymous EC(DH) denial of service

CVE-2014-3510

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

diff --git a/ssl/d1_clnt.c b/ssl/d1_clnt.c
index fce48e40105706e032037e7dd095c1c6d7015e76..d8cf92686c47bbd79ccd66869643c29e2df9b729 100644 (file)
--- a/ssl/d1_clnt.c
+++ b/ssl/d1_clnt.c
@@ -814,6 +814,13 @@ int dtls1_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_DTLS1_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
@@ -1004,6 +1011,13 @@ int dtls1_send_client_key_exchange(SSL *s)
                        {
                        DH *dh_srvr,*dh_clnt;
 
+                       if (s->session->sess_cert == NULL)
+                               {
+                               ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_UNEXPECTED_MESSAGE);
+                               SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,SSL_R_UNEXPECTED_MESSAGE);
+                               goto err;
+                               }
+
                        if (s->session->sess_cert->peer_dh_tmp != NULL)
                                dh_srvr=s->session->sess_cert->peer_dh_tmp;
                        else
@@ -1063,6 +1077,13 @@ int dtls1_send_client_key_exchange(SSL *s)
                        int ecdh_clnt_cert = 0;
                        int field_size = 0;
 
+                       if (s->session->sess_cert == NULL)
+                               {
+                               ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_UNEXPECTED_MESSAGE);
+                               SSLerr(SSL_F_DTLS1_SEND_CLIENT_KEY_EXCHANGE,SSL_R_UNEXPECTED_MESSAGE);
+                               goto err;
+                               }
+
                        /* Did we send out the client's
                         * ECDH share for use in premaster
                         * computation as part of client certificate?
@@ -1538,5 +1559,3 @@ int dtls1_send_client_certificate(SSL *s)
        /* SSL3_ST_CW_CERT_D */
        return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
        }
-
-

diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c
index 4e5a95353be6f02e0ac23a0199dfe09fb48538e5..acf2471a1fc78dd9be8b0f6e54005366eecb8118 100644 (file)
--- a/ssl/s3_clnt.c
+++ b/ssl/s3_clnt.c
@@ -2043,6 +2043,13 @@ 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