openssl/openssl-0.9.7a-ssl-strict-m...

70 lines
2.8 KiB
Diff

*) In the SSL/TLS server implementation, be strict about session ID
context matching (which matters if an application uses a single
external cache for different purposes). Previously,
out-of-context reuse was forbidden only if SSL_VERIFY_PEER was
set. This did ensure strict client verification, but meant that,
with applications using a single external cache for quite
different requirements, clients could circumvent ciphersuite
restrictions for a given session ID context by starting a session
in a different context.
diff -up openssl-0.9.7a/ssl/ssl_sess.c.strict-matching openssl-0.9.7a/ssl/ssl_sess.c
--- openssl-0.9.7a/ssl/ssl_sess.c.strict-matching 2002-11-28 09:09:03.000000000 +0100
+++ openssl-0.9.7a/ssl/ssl_sess.c 2007-08-02 16:17:29.000000000 +0200
@@ -322,33 +322,35 @@ int ssl_get_prev_session(SSL *s, unsigne
/* Now ret is non-NULL, and we own one of its reference counts. */
- if((s->verify_mode&SSL_VERIFY_PEER)
- && (!s->sid_ctx_length || ret->sid_ctx_length != s->sid_ctx_length
- || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length)))
- {
+ if (ret->sid_ctx_length != s->sid_ctx_length
+ || memcmp(ret->sid_ctx,s->sid_ctx,ret->sid_ctx_length))
+ {
/* We've found the session named by the client, but we don't
* want to use it in this context. */
-
- if (s->sid_ctx_length == 0)
- {
- /* application should have used SSL[_CTX]_set_session_id_context
- * -- we could tolerate this and just pretend we never heard
- * of this session, but then applications could effectively
- * disable the session cache by accident without anyone noticing */
- SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
- fatal = 1;
- goto err;
- }
- else
- {
#if 0 /* The client cannot always know when a session is not appropriate,
- * so we shouldn't generate an error message. */
+ * so we shouldn't generate an error message. */
- SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
+ SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
#endif
- goto err; /* treat like cache miss */
- }
+ goto err; /* treat like cache miss */
+ }
+
+ if((s->verify_mode & SSL_VERIFY_PEER) && s->sid_ctx_length == 0)
+ {
+ /* We can't be sure if this session is being used out of
+ * context, which is especially important for SSL_VERIFY_PEER.
+ * The application should have used SSL[_CTX]_set_session_id_context.
+ *
+ * For this error case, we generate an error instead of treating
+ * the event like a cache miss (otherwise it would be easy for
+ * applications to effectively disable the session cache by
+ * accident without anyone noticing).
+ */
+
+ SSLerr(SSL_F_SSL_GET_PREV_SESSION,SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
+ fatal = 1;
+ goto err;
}
if (ret->cipher == NULL)