commit b79cc84635ac6012b9ee522e0199ca792d121467
author David Benjamin <davidben@google.com> Wed Dec 07 15:57:14 2016 -0500
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> Thu Dec 08 16:57:57 2016 +0000
tree 78fae5752b0f80d7e711c689f2d619ce66eb40c5
parent 30c4c30d4aa306de0e5869dc9812bf8223aec164

Fix SSL_clear's interaction with session resumption.

Prior to 87eab4902d1003983079881d3ee8a66ec2eaccc2, due to some
confusions between configuration and connection state, SSL_clear had the
side effect of offering the previously established session on the new
connection.

wpa_supplicant relies on this behavior, so restore it for TLS 1.2 and
below and add a test. (This behavior is largely incompatible with TLS
1.3's post-handshake tickets, so it won't work in 1.3. It'll act as if
we configured an unresumable session instead.)

Change-Id: Iaee8c0afc1cb65c0ab7397435602732b901b1c2d
Reviewed-on: https://boringssl-review.googlesource.com/12632
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

ssl/ssl_lib.c

diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 47ecd48..eed82b0 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -2877,6 +2877,15 @@
 }
 
 int SSL_clear(SSL *ssl) {
+  /* In OpenSSL, reusing a client |SSL| with |SSL_clear| causes the previously
+   * established session to be offered the next time around. wpa_supplicant
+   * depends on this behavior, so emulate it. */
+  SSL_SESSION *session = NULL;
+  if (!ssl->server && ssl->s3->established_session != NULL) {
+    session = ssl->s3->established_session;
+    SSL_SESSION_up_ref(session);
+  }
+
   /* TODO(davidben): Some state on |ssl| is reset both in |SSL_new| and
    * |SSL_clear| because it is per-connection state rather than configuration
    * state. Per-connection state should be on |ssl->s3| and |ssl->d1| so it is
@@ -2902,6 +2911,7 @@
 
   ssl->method->ssl_free(ssl);
   if (!ssl->method->ssl_new(ssl)) {
+    SSL_SESSION_free(session);
     return 0;
   }
 
@@ -2909,6 +2919,11 @@
     ssl->d1->mtu = mtu;
   }
 
+  if (session != NULL) {
+    SSL_set_session(ssl, session);
+    SSL_SESSION_free(session);
+  }
+
   return 1;
 }