/* TLS negotiation failed; give an error. From outside, this function may
be called again to try in clear on a new connection, if the options permit
it for this host. */
-#ifdef USE_GNUTLS
- GNUTLS_CONN_FAILED:
-#endif
+ TLS_CONN_FAILED:
DEBUG(D_tls) debug_printf("TLS session fail: %s\n", tls_errstr);
# ifdef SUPPORT_DANE
goto TLS_FAILED;
}
- /* TLS session is set up */
+ /* TLS session is set up. Check the inblock fill level. If there is
+ content then as we have not yet done a tls read it must have arrived before
+ the TLS handshake, in-clear. That violates the sync requirement of the
+ STARTTLS RFC, so fail. */
+
+ if (sx->inblock.ptr != sx->inblock.ptrend)
+ {
+ DEBUG(D_tls)
+ {
+ int i = sx->inblock.ptrend - sx->inblock.ptr;
+ debug_printf("unused data in input buffer after ack for STARTTLS:\n"
+ "'%.*s'%s\n",
+ i > 100 ? 100 : i, sx->inblock.ptr, i > 100 ? "..." : "");
+ }
+ tls_errstr = US"synch error before connect";
+ goto TLS_CONN_FAILED;
+ }
smtp_peer_options_wrap = smtp_peer_options;
for (address_item * addr = sx->addrlist; addr; addr = addr->next)
Can it do that, with all the flexibility we need? */
tls_errstr = US"error on first read";
- goto GNUTLS_CONN_FAILED;
+ goto TLS_CONN_FAILED;
}
#else
goto RESPONSE_FAILED;