Ensure that we do not process a ChangeCipherSpec with an empty master

secret. This is an additional safeguard against early ChangeCipherSpec
handling.

From OpenSSL.

ok deraadt@

2 files changed, 2 insertions, 2 deletions

diff --git a/src/lib/libssl/s3_pkt.c b/src/lib/libssl/s3_pkt.c
index 58d8221fe4..942ab37b95 100644
--- a/src/lib/libssl/s3_pkt.c
+++ b/src/lib/libssl/s3_pkt.c
@@ -1337,7 +1337,7 @@ ssl3_do_change_cipher_spec(SSL *s)
                 i = SSL3_CHANGE_CIPHER_CLIENT_READ;
 
         if (s->s3->tmp.key_block == NULL) {
-                if (s->session == NULL) {
+                if (s->session == NULL || s->session->master_key_length == 0) {
                         /* might happen if dtls1_read_bytes() calls this */
                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,
                             SSL_R_CCS_RECEIVED_EARLY);
diff --git a/src/lib/libssl/src/ssl/s3_pkt.c b/src/lib/libssl/src/ssl/s3_pkt.c
index 58d8221fe4..942ab37b95 100644
--- a/src/lib/libssl/src/ssl/s3_pkt.c
+++ b/src/lib/libssl/src/ssl/s3_pkt.c
@@ -1337,7 +1337,7 @@ ssl3_do_change_cipher_spec(SSL *s)
                 i = SSL3_CHANGE_CIPHER_CLIENT_READ;
 
         if (s->s3->tmp.key_block == NULL) {
-                if (s->session == NULL) {
+                if (s->session == NULL || s->session->master_key_length == 0) {
                         /* might happen if dtls1_read_bytes() calls this */
                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,
                             SSL_R_CCS_RECEIVED_EARLY);