Delay creating s->session until resumption is resolved.
When not offering to resume a session, the client populates s->session with a
fresh SSL_SESSION before the ServerHello is processed and, in DTLS_ANY_VERSION,
before the version is even determined. Don't create a fresh SSL_SESSION until
we know we are doing a full handshake.
This brings ssl3_send_client_hello closer to ssl23_client_hello in behavior. It
also fixes ssl_version in the client in DTLS_ANY_VERSION.
SSLv23_client_method is largely unchanged. If no session is offered, s->session
continues to be NULL until the ServerHello is received. The one difference is
that s->session isn't populated until the entire ServerHello is received,
rather than just the first half, in the case of a fragmented ServerHello. Apart
from info_callback, no external hooks get called between those points, so this
shouldn't expose new missing NULL checks.
The other client methods change significantly to match SSLv23_client_method's
behavior. For TLS, any exposed missing NULL checks are also in
SSLv23_client_method (and version-specific methods are already weird), so that
should be safe. For DTLS, I've verified that accesses in d1_*.c either handle
NULL or are after the ServerHello.
Change-Id: Idcae6bd242480e28a57dbba76ce67f1ac1ae1d1d
Reviewed-on: https://boringssl-review.googlesource.com/2404
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/s23_clnt.c b/ssl/s23_clnt.c
index 7ca3a7e..ec6609d 100644
--- a/ssl/s23_clnt.c
+++ b/ssl/s23_clnt.c
@@ -555,12 +555,6 @@
goto err;
}
s->init_num=0;
-
- /* If there was no session to resume, now that the final version is
- * determined, insert a fresh one. */
- if (s->session == NULL && !ssl_get_new_session(s,0))
- goto err;
-
return(SSL_connect(s));
err:
return(-1);
diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c
index 6f47e95..8d60d8f 100644
--- a/ssl/s3_clnt.c
+++ b/ssl/s3_clnt.c
@@ -148,6 +148,7 @@
* OTHERWISE.
*/
+#include <assert.h>
#include <stdio.h>
#include <openssl/buf.h>
@@ -627,15 +628,6 @@
buf=(unsigned char *)s->init_buf->data;
if (s->state == SSL3_ST_CW_CLNT_HELLO_A)
{
- SSL_SESSION *sess = s->session;
- if (sess == NULL ||
- sess->ssl_version != s->version ||
- !sess->session_id_length ||
- sess->not_resumable)
- {
- if (!ssl_get_new_session(s,0))
- goto err;
- }
if (s->method->version == DTLS_ANY_VERSION)
{
/* Determine which DTLS version to use */
@@ -666,6 +658,18 @@
}
s->client_version = s->version;
}
+
+ /* If the configured session was created at a version
+ * higher than our maximum version, drop it. */
+ if (s->session &&
+ (s->session->session_id_length == 0 ||
+ s->session->not_resumable ||
+ (!SSL_IS_DTLS(s) && s->session->ssl_version > s->version) ||
+ (SSL_IS_DTLS(s) && s->session->ssl_version < s->version)))
+ {
+ SSL_set_session(s, NULL);
+ }
+
/* else use the pre-loaded session */
p=s->s3->client_random;
@@ -727,7 +731,7 @@
p+=SSL3_RANDOM_SIZE;
/* Session ID */
- if (s->new_session)
+ if (s->new_session || s->session == NULL)
i=0;
else
i=s->session->session_id_length;
@@ -868,7 +872,8 @@
/* Copy over the server random. */
memcpy(s->s3->server_random, CBS_data(&server_random), SSL3_RANDOM_SIZE);
- if (CBS_len(&session_id) != 0 &&
+ assert(s->session == NULL || s->session->session_id_length > 0);
+ if (s->session != NULL &&
CBS_mem_equal(&session_id,
s->session->session_id, s->session->session_id_length))
{
@@ -884,16 +889,12 @@
}
else
{
- /* The session wasn't resumed. */
+ /* The session wasn't resumed. Create a fresh SSL_SESSION to
+ * fill out. */
s->hit = 0;
- /* If we were trying for session-id reuse, make a new
- * SSL_SESSION so we don't stuff up other people */
- if (s->session->session_id_length > 0)
+ if (!ssl_get_new_session(s, 0))
{
- if (!ssl_get_new_session(s,0))
- {
- goto f_err;
- }
+ goto f_err;
}
/* Note: session_id could be empty. */
s->session->session_id_length = CBS_len(&session_id);
