[openssl-dev] TLS 1.3 client hello issue

[Mahesh Bhoothapuri]

Hi,

I am sending a Tls 1.3 client hello, and am seeing an issue with

ossl_statem_client_write_transition in statem_clnt.c.


    /*
     * Note that immediately before/after a ClientHello we don't know what
     * version we are going to negotiate yet, so we don't take this branch
until
     * later
     */

/*
 * ossl_statem_client_write_transition() works out what handshake state to
 * move to next when the client is writing messages to be sent to the
server.
 */
WRITE_TRAN ossl_statem_client_write_transition(SSL *s)
{

    if (SSL_IS_TLS13(s))
        return ossl_statem_client13_write_transition(s);
}

And in:


/*
 * ossl_statem_client_write_transition() works out what handshake state to
 * move to next when the client is writing messages to be sent to the
server.
 */
WRITE_TRAN ossl_statem_client_write_transition(SSL *s)
{

   /*
     * Note: There are no cases for TLS_ST_BEFORE because we haven't
negotiated
     * TLSv1.3 yet at that point. They are handled by
     * ossl_statem_client_write_transition().
     */

    switch (st->hand_state) {
    default:
        /* Shouldn't happen */
        return WRITE_TRAN_ERROR;

}

With a TLS 1.3 client hello, using tls 1.3 version, the st->hand_state is
TLS_ST_BEFORE and so, the default error is returned.

When I added :

    case TLS_ST_BEFORE:
        st->hand_state = TLS_ST_CW_CLNT_HELLO;
        return WRITE_TRAN_CONTINUE;

The client hello gets sent out, but I only saw a TLS 1.2 version being sent.
Is this a bug?

Thanks,
Mahesh
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