TLS13: add Encrypted Extensions

See https://tools.ietf.org/html/draft-ietf-tls-tls13-18#section-4.3.1

Change-Id: I35e049d991be4c242ef2b84db3a322c6a13d2f96
Ping-Bug: 12779
Reviewed-on: https://code.wireshark.org/review/19860
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

4 files changed, 34 insertions, 1 deletions

diff --git a/epan/dissectors/packet-dtls.c b/epan/dissectors/packet-dtls.c
index a90c8e0432..0f526fa179 100644
--- a/epan/dissectors/packet-dtls.c
+++ b/epan/dissectors/packet-dtls.c
@@ -1339,6 +1339,7 @@ dissect_dtls_handshake(tvbuff_t *tvb, packet_info *pinfo,
           case SSL_HND_CERT_STATUS:
           case SSL_HND_SUPPLEMENTAL_DATA:
           case SSL_HND_ENCRYPTED_EXTS:
+          case SSL_HND_ENCRYPTED_EXTENSIONS: /* TLS 1.3 */
             /* TODO: does this need further dissection? */
             break;
         }
diff --git a/epan/dissectors/packet-ssl-utils.c b/epan/dissectors/packet-ssl-utils.c
index 58c2dd7acb..adefd3ca29 100644
--- a/epan/dissectors/packet-ssl-utils.c
+++ b/epan/dissectors/packet-ssl-utils.c
@@ -553,6 +553,8 @@ const value_string ssl_31_handshake_type[] = {
     { SSL_HND_SERVER_HELLO,      "Server Hello" },
     { SSL_HND_HELLO_VERIFY_REQUEST, "Hello Verify Request"},
     { SSL_HND_NEWSESSION_TICKET, "New Session Ticket" },
+    { SSL_HND_HELLO_RETRY_REQUEST, "Hello Retry Request" },
+    { SSL_HND_ENCRYPTED_EXTENSIONS, "Encrypted Extensions" },
     { SSL_HND_CERTIFICATE,       "Certificate" },
     { SSL_HND_SERVER_KEY_EXCHG,  "Server Key Exchange" },
     { SSL_HND_CERT_REQUEST,      "Certificate Request" },
@@ -6469,6 +6471,7 @@ ssl_is_valid_handshake_type(guint8 hs_type, gboolean is_dtls)
     case SSL_HND_SERVER_HELLO:
     case SSL_HND_NEWSESSION_TICKET:
     case SSL_HND_HELLO_RETRY_REQUEST:
+    case SSL_HND_ENCRYPTED_EXTENSIONS:
     case SSL_HND_CERTIFICATE:
     case SSL_HND_SERVER_KEY_EXCHG:
     case SSL_HND_CERT_REQUEST:
@@ -6820,6 +6823,21 @@ ssl_dissect_hnd_hello_retry_request(ssl_common_dissect_t *hf, tvbuff_t *tvb,
     }
 }
 
+void
+ssl_dissect_hnd_encrypted_extensions(ssl_common_dissect_t *hf, tvbuff_t *tvb,
+                                     packet_info* pinfo, proto_tree *tree, guint32 offset, guint32 length,
+                                     SslSession *session, SslDecryptSession *ssl,
+                                     gboolean is_dtls)
+{
+    /* struct {
+     *     Extension extensions<0..2^16-1>;
+     * } EncryptedExtensions;
+     */
+    ssl_dissect_hnd_hello_ext(hf, tvb, tree, pinfo, offset,
+                              length, SSL_HND_ENCRYPTED_EXTENSIONS,
+                              session, ssl, is_dtls);
+}
+
 /* Certificate and Certificate Request dissections. {{{ */
 void
 ssl_dissect_hnd_cert(ssl_common_dissect_t *hf, tvbuff_t *tvb, proto_tree *tree,
diff --git a/epan/dissectors/packet-ssl-utils.h b/epan/dissectors/packet-ssl-utils.h
index 67c09766ce..091c3f1c0f 100644
--- a/epan/dissectors/packet-ssl-utils.h
+++ b/epan/dissectors/packet-ssl-utils.h
@@ -63,6 +63,7 @@ typedef enum {
     SSL_HND_HELLO_VERIFY_REQUEST   = 3,
     SSL_HND_NEWSESSION_TICKET      = 4,
     SSL_HND_HELLO_RETRY_REQUEST    = 6,
+    SSL_HND_ENCRYPTED_EXTENSIONS   = 8,
     SSL_HND_CERTIFICATE            = 11,
     SSL_HND_SERVER_KEY_EXCHG       = 12,
     SSL_HND_CERT_REQUEST           = 13,
@@ -74,7 +75,7 @@ typedef enum {
     SSL_HND_CERT_STATUS            = 22,
     SSL_HND_SUPPLEMENTAL_DATA      = 23,
     /* Encrypted Extensions was NextProtocol in draft-agl-tls-nextprotoneg-03
-     * and changed in draft 04 */
+     * and changed in draft 04. Not to be confused with TLS 1.3 EE. */
     SSL_HND_ENCRYPTED_EXTS         = 67
 } HandshakeType;
 
@@ -865,6 +866,12 @@ ssl_dissect_hnd_hello_retry_request(ssl_common_dissect_t *hf, tvbuff_t *tvb, pac
                                     gboolean is_dtls);
 
 extern void
+ssl_dissect_hnd_encrypted_extensions(ssl_common_dissect_t *hf, tvbuff_t *tvb, packet_info* pinfo,
+                                     proto_tree *tree, guint32 offset, guint32 length,
+                                     SslSession *session, SslDecryptSession *ssl,
+                                     gboolean is_dtls);
+
+extern void
 ssl_dissect_hnd_new_ses_ticket(ssl_common_dissect_t *hf, tvbuff_t *tvb,
                                proto_tree *tree, guint32 offset,
                                SslDecryptSession *ssl,
diff --git a/epan/dissectors/packet-ssl.c b/epan/dissectors/packet-ssl.c
index 7e9bd5376f..9e3946cd4a 100644
--- a/epan/dissectors/packet-ssl.c
+++ b/epan/dissectors/packet-ssl.c
@@ -2098,6 +2098,13 @@ dissect_ssl3_handshake(tvbuff_t *tvb, packet_info *pinfo,
                                                     offset, length, session, ssl, FALSE);
                 break;
 
+            case SSL_HND_ENCRYPTED_EXTENSIONS:
+                /* XXX expert info if used with non-TLS 1.3? */
+                ssl_dissect_hnd_encrypted_extensions(&dissect_ssl3_hf, tvb, pinfo, ssl_hand_tree,
+                                                     offset, length, session, ssl, FALSE);
+
+                break;
+
             case SSL_HND_CERTIFICATE:
                 ssl_dissect_hnd_cert(&dissect_ssl3_hf, tvb, ssl_hand_tree,
                         offset, pinfo, session, ssl, ssl_key_hash, is_from_server);