Be selective as to when ChangeCipherSpec messages will be accepted.

Without this an early ChangeCipherSpec message would result in session
keys being generated, along with the Finished hash for the handshake,
using an empty master secret.

For a detailed analysis see:

  https://www.imperialviolet.org/2014/06/05/earlyccs.html

This is a fix for CVE-2014-0224, from OpenSSL.

This issue was reported to OpenSSL by KIKUCHI Masashi. Unfortunately the
recent OpenSSL commit was the first we were made aware of the issue.

ok deraadt@ sthen@

1 files changed, 2 insertions, 1 deletions

diff --git a/src/lib/libssl/s3_clnt.c b/src/lib/libssl/s3_clnt.c
index 66fb26345e..60a17ce11b 100644
--- a/src/lib/libssl/s3_clnt.c
+++ b/src/lib/libssl/s3_clnt.c
@@ -556,7 +556,7 @@ ssl3_connect(SSL *s)
 
                 case SSL3_ST_CR_FINISHED_A:
                 case SSL3_ST_CR_FINISHED_B:
-
+                        s->s3->flags |= SSL3_FLAGS_CCS_OK;
                         ret = ssl3_get_finished(s, SSL3_ST_CR_FINISHED_A,
                             SSL3_ST_CR_FINISHED_B);
                         if (ret <= 0)
@@ -895,6 +895,7 @@ ssl3_get_server_hello(SSL *s)
                             SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
                         goto f_err;
                 }
+                s->s3->flags |= SSL3_FLAGS_CCS_OK;
                 s->hit = 1;
         } else {
                 /* a miss or crap from the other end */