Commit bf87bf45 authored Apr 16, 2018 by Benjamin Kaduk Committed by Benjamin Kaduk May 01, 2018

Fix regression with session cache use by clients



Commit d316cdcf introduced some extra
checks into the session-cache update procedure, intended to prevent
the caching of sessions whose resumption would lead to a handshake
failure, since if the server is authenticating the client, there needs to
be an application-set "session id context" to match up to the authentication
context.  While that change is effective for its stated purpose, there
was also some collatoral damage introduced along with the fix -- clients
that set SSL_VERIFY_PEER are not expected to set an sid_ctx, and so
their usage of session caching was erroneously denied.

Fix the scope of the original commit by limiting it to only acting
when the SSL is a server SSL.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5967)

(cherry picked from commit c4fa1f7f)

parent 14e55560

ssl/ssl_lib.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -3035,12 +3035,13 @@ void ssl_update_cache(SSL *s, int mode)
		/*
		* If sid_ctx_length is 0 there is no specific application context
		* associated with this session, so when we try to resume it and
		* SSL_VERIFY_PEER is requested, we have no indication that this is
		* actually a session for the proper application context, and the
		* handshake will fail, not just the resumption attempt.
		* Do not cache these sessions that are not resumable.
		* SSL_VERIFY_PEER is requested to verify the client identity, we have no
		* indication that this is actually a session for the proper application
		* context, and the handshake will fail, not just the resumption attempt.
		* Do not cache (on the server) these sessions that are not resumable
		* (clients can set SSL_VERIFY_PEER without needing a sid_ctx set).
		*/
		if (s->session->sid_ctx_length == 0
		if (s->server && s->session->sid_ctx_length == 0
		&& (s->verify_mode & SSL_VERIFY_PEER) != 0)
		return;