[PR3597] Advance to the next state variant when reusing messages.

Previously, state variant was not advanced, which resulted in state
being stuck in the st1 variant (usually "_A").

This broke certificate callback retry logic when accepting connections
that were using SSLv2 ClientHello (hence reusing the message), because
their state never advanced to SSL3_ST_SR_CLNT_HELLO_C variant required
for the retry code path.

Reported by Yichun Zhang (agentzh).

Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>

ssl/s3_both.c

@@ -358,6 +358,7 @@ long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 			goto f_err;
 			}
 		*ok=1;
+		s->state = stn;
 		s->init_msg = s->init_buf->data + 4;
 		s->init_num = (int)s->s3->tmp.message_size;
 		return s->init_num;