libtls leak in tls_connect()

[Stuart Henderson]

As noticed by jturner, there is a leak with libtls seen when you
connect to a server multiple times.

By looking at the contents of coredumps I worked out that it wasn't
freeing the server cert, and tracked it to tls_connect_fds().

OK?


Index: tls_client.c
===================================================================
RCS file: /cvs/src/lib/libtls/tls_client.c,v
retrieving revision 1.15
diff -u -p -u -2 -4 -r1.15 tls_client.c
--- tls_client.c        11 Feb 2015 07:01:10 -0000      1.15
+++ tls_client.c        21 Mar 2015 15:03:46 -0000
@@ -246,33 +246,34 @@ tls_connect_fds(struct tls *ctx, int fd_
 
  connecting:
        if ((ret = SSL_connect(ctx->ssl_conn)) != 1) {
                err = tls_ssl_error(ctx, ret, "connect");
                if (err == TLS_READ_AGAIN || err == TLS_WRITE_AGAIN) {
                        ctx->flags |= TLS_CONNECTING;
                        return (err);
                }
                goto err;
        }
        ctx->flags &= ~TLS_CONNECTING;
 
        if (ctx->config->verify_name) {
                cert = SSL_get_peer_certificate(ctx->ssl_conn);
                if (cert == NULL) {
                        tls_set_error(ctx, "no server certificate");
                        goto err;
                }
                if ((ret = tls_check_servername(ctx, cert, servername)) != 0) {
                        if (ret != -2)
                                tls_set_error(ctx, "name `%s' not present in"
                                    " server certificate", servername);
                        goto err;
                }
+               X509_free(cert);
        }
 
        return (0);
 
 err:
        X509_free(cert);
 
        return (-1);
 }