Digest cached records if not sending a certificate.

If server requests a certificate, but the client doesn't send one, cache
digested records. This is an optimisation and ensures the correct finished
mac is used when extended master secret is used with client authentication.
Reviewed-by: NTim Hudson <tjh@openssl.org>

ssl/s3_clnt.c

@@ -3348,6 +3348,11 @@ int ssl3_send_client_certificate(SSL *s)
                 return (1);
             } else {
                 s->s3->tmp.cert_req = 2;
+                if (s->s3->handshake_buffer && !ssl3_digest_cached_records(s)) {
+                    ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+                    s->state = SSL_ST_ERR;
+                    return 0;
+                }
             }
         }