Unauthenticated DH client certificate fix.

Fix to prevent use of DH client certificates without sending
certificate verify message.

If we've used a client certificate to generate the premaster secret
ssl3_get_client_key_exchange returns 2 and ssl3_get_cert_verify is
never called.

We can only skip the certificate verify message in
ssl3_get_cert_verify if the client didn't send a certificate.

Thanks to Karthikeyan Bhargavan for reporting this issue.
CVE-2015-0205
Reviewed-by: Matt Caswell <matt@openssl.org>

diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index 0dce557df93df948fbe30bf61d4a36635879588d..df51bf9c71d72e964df02472ad99482b81b1c0bb 100644 (file)
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -2765,7 +2765,7 @@ int ssl3_get_cert_verify(SSL *s)
        if (s->s3->tmp.message_type != SSL3_MT_CERTIFICATE_VERIFY)
                {
                s->s3->tmp.reuse_message=1;
-               if ((peer != NULL) && (type & EVP_PKT_SIGN))
+               if (peer != NULL)
                        {
                        al=SSL_AD_UNEXPECTED_MESSAGE;
                        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY,SSL_R_MISSING_VERIFY_MESSAGE);