From Peter Wu

Add RFC6066 CertificateUrl TLS extension

This is not supported by OpenSSL or NSS, the extension itself seems
unsafe, but some implementations seem to support it[1].

Untested, no capture available.

 [1]: http://www.ietf.org/mail-archive/web/tls/current/msg02535.html

svn path=/trunk/; revision=53417

3 files changed, 120 insertions, 0 deletions

diff --git a/epan/dissectors/packet-ssl-utils.c b/epan/dissectors/packet-ssl-utils.c
index 020f0105dc..19e9d85de7 100644
--- a/epan/dissectors/packet-ssl-utils.c
+++ b/epan/dissectors/packet-ssl-utils.c
@@ -484,6 +484,7 @@ const value_string ssl_31_handshake_type[] = {
     { SSL_HND_CERT_VERIFY,       "Certificate Verify" },
     { SSL_HND_CLIENT_KEY_EXCHG,  "Client Key Exchange" },
     { SSL_HND_FINISHED,          "Finished" },
+    { SSL_HND_CERT_URL,          "Client Certificate URL" },
     { SSL_HND_CERT_STATUS,       "Certificate Status" },
     { SSL_HND_ENCRYPTED_EXTS,    "Encrypted Extensions" },
     { 0x00, NULL }
@@ -1075,6 +1076,11 @@ const value_string tls_certificate_type[] = {
     { 0, NULL }
 };
 
+const value_string tls_cert_chain_type[] = {
+    { SSL_HND_CERT_URL_TYPE_INDIVIDUAL_CERT,    "Individual Certificates" },
+    { SSL_HND_CERT_URL_TYPE_PKIPATH,            "PKI Path" },
+};
+
 const value_string tls_cert_status_type[] = {
     { SSL_HND_CERT_STATUS_TYPE_OCSP,            "OCSP" },
     { SSL_HND_CERT_STATUS_TYPE_OCSP_MULTI,      "OCSP Multi" },
diff --git a/epan/dissectors/packet-ssl-utils.h b/epan/dissectors/packet-ssl-utils.h
index e2d3bb911c..9697398fe2 100644
--- a/epan/dissectors/packet-ssl-utils.h
+++ b/epan/dissectors/packet-ssl-utils.h
@@ -87,6 +87,7 @@
 #define SSL_HND_CERT_VERIFY            15
 #define SSL_HND_CLIENT_KEY_EXCHG       16
 #define SSL_HND_FINISHED               20
+#define SSL_HND_CERT_URL               21
 #define SSL_HND_CERT_STATUS            22
 /* Encrypted Extensions was NextProtocol in draft-agl-tls-nextprotoneg-03 and
  * changed in draft 04 */
@@ -161,6 +162,8 @@
 #define SSL_HND_HELLO_EXT_STATUS_REQUEST_V2  0x0011
 #define SSL_HND_HELLO_EXT_RENEG_INFO         0xff01
 #define SSL_HND_HELLO_EXT_NPN                0x3374
+#define SSL_HND_CERT_URL_TYPE_INDIVIDUAL_CERT       1
+#define SSL_HND_CERT_URL_TYPE_PKIPATH               2
 #define SSL_HND_CERT_STATUS_TYPE_OCSP        1
 #define SSL_HND_CERT_STATUS_TYPE_OCSP_MULTI  2
 
@@ -196,6 +199,7 @@ extern const value_string tls_hello_extension_types[];
 extern const value_string tls_hash_algorithm[];
 extern const value_string tls_signature_algorithm[];
 extern const value_string tls_certificate_type[];
+extern const value_string tls_cert_chain_type[];
 extern const value_string tls_cert_status_type[];
 extern const value_string ssl_extension_curves[];
 extern const value_string ssl_extension_ec_point_formats[];
diff --git a/epan/dissectors/packet-ssl.c b/epan/dissectors/packet-ssl.c
index af5f8c5186..18193c4e16 100644
--- a/epan/dissectors/packet-ssl.c
+++ b/epan/dissectors/packet-ssl.c
@@ -181,6 +181,13 @@ static gint hf_ssl_handshake_extension_server_name_type = -1;
 static gint hf_ssl_handshake_extension_server_name = -1;
 static gint hf_ssl_hs_ext_cert_status_type                      = -1;
 static gint hf_ssl_hs_ext_cert_status_request_len               = -1;
+static gint hf_ssl_hs_ext_cert_url_type              = -1;
+static gint hf_ssl_hs_ext_cert_url_url_hash_list_len = -1;
+static gint hf_ssl_hs_ext_cert_url_item              = -1;
+static gint hf_ssl_hs_ext_cert_url_url_len           = -1;
+static gint hf_ssl_hs_ext_cert_url_url               = -1;
+static gint hf_ssl_hs_ext_cert_url_padding           = -1;
+static gint hf_ssl_hs_ext_cert_url_sha1              = -1;
 static gint hf_ssl_hs_ext_cert_status_responder_id_list_len     = -1;
 static gint hf_ssl_hs_ext_cert_status_request_extensions_len    = -1;
 static gint hf_ssl_handshake_session_ticket_lifetime_hint = -1;
@@ -300,6 +307,7 @@ static gint ett_ssl_extension_alpn    = -1;
 static gint ett_ssl_extension_npn     = -1;
 static gint ett_ssl_extension_reneg_info = -1;
 static gint ett_ssl_extension_server_name = -1;
+static gint ett_ssl_urlhash           = -1;
 static gint ett_ssl_certs             = -1;
 static gint ett_ssl_cert_types        = -1;
 static gint ett_ssl_sig_hash_algs     = -1;
@@ -654,6 +662,9 @@ static void dissect_ssl3_hnd_finished(tvbuff_t *tvb,
                                       const guint32 offset,
                                       const guint *conv_version);
 
+static void dissect_ssl3_hnd_cert_url(tvbuff_t *tvb, proto_tree *tree,
+                                      guint32 offset);
+
 static void dissect_ssl3_hnd_cert_status(tvbuff_t *tvb,
                                          proto_tree *tree,
                                          guint32 offset,
@@ -1960,6 +1971,7 @@ dissect_ssl3_handshake(tvbuff_t *tvb, packet_info *pinfo,
      *             case certificate_verify:  CertificateVerify;
      *             case client_key_exchange: ClientKeyExchange;
      *             case finished:            Finished;
+     *             case certificate_url:     CertificateURL;
      *             case certificate_status:  CertificateStatus;
      *             case encrypted_extensions:NextProtocolNegotiationEncryptedExtension;
      *         } body;
@@ -2278,6 +2290,10 @@ dissect_ssl3_handshake(tvbuff_t *tvb, packet_info *pinfo,
                                           offset, conv_version);
                 break;
 
+            case SSL_HND_CERT_URL:
+                dissect_ssl3_hnd_cert_url(tvb, ssl_hand_tree, offset);
+                break;
+
             case SSL_HND_CERT_STATUS:
                 dissect_ssl3_hnd_cert_status(tvb, ssl_hand_tree, offset, pinfo);
                 break;
@@ -2724,6 +2740,64 @@ dissect_ssl3_hnd_hello_ext_server_name(tvbuff_t *tvb,
    return offset;
 }
 
+static void
+dissect_ssl3_hnd_cert_url(tvbuff_t *tvb, proto_tree *tree, guint32 offset)
+{
+    guint16  url_hash_len;
+
+    /* enum {
+     *     individual_certs(0), pkipath(1), (255)
+     * } CertChainType;
+     *
+     * struct {
+     *     CertChainType type;
+     *     URLAndHash url_and_hash_list<1..2^16-1>;
+     * } CertificateURL;
+     *
+     * struct {
+     *     opaque url<1..2^16-1>;
+     *     unint8 padding;
+     *     opaque SHA1Hash[20];
+     * } URLAndHash;
+     */
+
+    proto_tree_add_item(tree, hf_ssl_hs_ext_cert_url_type,
+                        tvb, offset, 1, ENC_NA);
+    offset++;
+
+    url_hash_len = tvb_get_ntohs(tvb, offset);
+    proto_tree_add_item(tree, hf_ssl_hs_ext_cert_url_url_hash_list_len,
+                        tvb, offset, 2, ENC_BIG_ENDIAN);
+    offset += 2;
+    while (url_hash_len-- > 0) {
+        proto_item  *urlhash_item;
+        proto_tree  *urlhash_tree;
+        guint16      url_len;
+
+        urlhash_item = proto_tree_add_item(tree, hf_ssl_hs_ext_cert_url_item,
+                                           tvb, offset, -1, ENC_NA);
+        urlhash_tree = proto_item_add_subtree(urlhash_item, ett_ssl_urlhash);
+
+        url_len = tvb_get_ntohs(tvb, offset);
+        proto_tree_add_item(urlhash_tree, hf_ssl_hs_ext_cert_url_url_len,
+                            tvb, offset, 2, ENC_BIG_ENDIAN);
+        offset += 2;
+
+        proto_tree_add_item(urlhash_tree, hf_ssl_hs_ext_cert_url_url,
+                            tvb, offset, url_len, ENC_ASCII);
+        offset += url_len;
+
+        proto_tree_add_item(urlhash_tree, hf_ssl_hs_ext_cert_url_padding,
+                            tvb, offset, 1, ENC_NA);
+        offset++;
+        /* Note: RFC 6066 says that padding must be 0x01 */
+
+        proto_tree_add_item(urlhash_tree, hf_ssl_hs_ext_cert_url_sha1,
+                            tvb, offset, 20, ENC_NA);
+        offset += 20;
+    }
+}
+
 static gint
 dissect_ssl3_hnd_hello_ext_status_request(tvbuff_t *tvb, proto_tree *tree,
                                           guint32 offset, gboolean has_length)
@@ -5678,6 +5752,41 @@ proto_register_ssl(void)
             FT_STRING, BASE_NONE, NULL, 0x0,
             NULL, HFILL }
         },
+        { &hf_ssl_hs_ext_cert_url_type,
+          { "Certificate Chain Type", "ssl.handshake.cert_url_type",
+            FT_UINT8, BASE_DEC, VALS(tls_cert_chain_type), 0x0,
+            "Certificate Chain Type for Client Certificate URL", HFILL }
+        },
+        { &hf_ssl_hs_ext_cert_url_url_hash_list_len,
+          { "URL and Hash list Length", "ssl.handshake.cert_url.url_hash_len",
+            FT_UINT16, BASE_DEC, NULL, 0x0,
+            NULL, HFILL }
+        },
+        { &hf_ssl_hs_ext_cert_url_item,
+          { "URL and Hash", "ssl.handshake.cert_url.url_hash",
+            FT_NONE, BASE_NONE, NULL, 0x0,
+            NULL, HFILL }
+        },
+        { &hf_ssl_hs_ext_cert_url_url_len,
+          { "URL Length", "ssl.handshake.cert_url.url_len",
+            FT_UINT16, BASE_DEC, NULL, 0x0,
+            NULL, HFILL }
+        },
+        { &hf_ssl_hs_ext_cert_url_url,
+          { "URL", "ssl.handshake.cert_url.url_hash_len",
+            FT_STRING, BASE_NONE, NULL, 0x0,
+            "URL used to fetch the certificate(s)", HFILL }
+        },
+        { &hf_ssl_hs_ext_cert_url_padding,
+          { "Padding", "ssl.handshake.cert_url.padding",
+            FT_NONE, BASE_NONE, NULL, 0x0,
+            "Padding that MUST be 0x01 for backwards compatibility", HFILL }
+        },
+        { &hf_ssl_hs_ext_cert_url_sha1,
+          { "SHA1 Hash", "ssl.handshake.cert_url.sha1",
+            FT_BYTES, BASE_NONE, NULL, 0x0,
+            "SHA1 Hash of the certificate", HFILL }
+        },
         { &hf_ssl_hs_ext_cert_status_type,
           { "Certificate Status Type", "ssl.handshake.extensions_status_request_type",
             FT_UINT8, BASE_DEC, VALS(tls_cert_status_type), 0x0,
@@ -6207,6 +6316,7 @@ proto_register_ssl(void)
         &ett_ssl_extension_npn,
         &ett_ssl_extension_reneg_info,
         &ett_ssl_extension_server_name,
+        &ett_ssl_urlhash,
         &ett_ssl_certs,
         &ett_ssl_cert_types,
         &ett_ssl_sig_hash_algs,