/* packet-ssl.c * Routines for ssl dissection * Copyright (c) 2000-2001, Scott Renfro * * $Id: packet-ssl.c,v 1.24 2002/08/28 21:00:35 jmayer Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Notes: * * - Uses conversations in a no-malloc fashion. Since we just want to * remember the version of the conversation, we store the version * integer directly in the void *data member of the conversation * structure. This means that we don't have to manage any memory, * but will cause problems if anyone assumes that all data pointers * are actually pointers to memory allocated by g_mem_chunk_alloc. * * - Does not support decryption of encrypted frames, nor dissection * of frames that would require state maintained between frames * (e.g., single ssl records spread across multiple tcp frames) * * - Identifies, but does not fully dissect the following messages: * * - SSLv3/TLS (These need more state from previous handshake msgs) * - Server Key Exchange * - Client Key Exchange * - Certificate Verify * * - SSLv2 (These don't appear in the clear) * - Error * - Client Finished * - Server Verify * - Server Finished * - Request Certificate * - Client Certificate * */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include #include "prefs.h" static gboolean ssl_desegment = TRUE; /********************************************************************* * * Protocol Constants, Variables, Data Structures * *********************************************************************/ /* Initialize the protocol and registered fields */ static int proto_ssl = -1; static int hf_ssl_record = -1; static int hf_ssl_record_content_type = -1; static int hf_ssl_record_version = -1; static int hf_ssl_record_length = -1; static int hf_ssl_record_appdata = -1; static int hf_ssl2_record = -1; static int hf_ssl2_record_is_escape = -1; static int hf_ssl2_record_padding_length = -1; static int hf_ssl2_msg_type = -1; static int hf_pct_msg_type = -1; static int hf_ssl_change_cipher_spec = -1; static int hf_ssl_alert_message = -1; static int hf_ssl_alert_message_level = -1; static int hf_ssl_alert_message_description = -1; static int hf_ssl_handshake_protocol = -1; static int hf_ssl_handshake_type = -1; static int hf_ssl_handshake_length = -1; static int hf_ssl_handshake_client_version = -1; static int hf_ssl_handshake_server_version = -1; static int hf_ssl_handshake_random_time = -1; static int hf_ssl_handshake_random_bytes = -1; static int hf_ssl_handshake_cipher_suites_len = -1; static int hf_ssl_handshake_cipher_suites = -1; static int hf_ssl_handshake_cipher_suite = -1; static int hf_ssl_handshake_session_id = -1; static int hf_ssl_handshake_comp_methods_len = -1; static int hf_ssl_handshake_comp_methods = -1; static int hf_ssl_handshake_comp_method = -1; static int hf_ssl_handshake_certificates_len = -1; static int hf_ssl_handshake_certificates = -1; static int hf_ssl_handshake_certificate = -1; static int hf_ssl_handshake_certificate_len = -1; static int hf_ssl_handshake_cert_types_count = -1; static int hf_ssl_handshake_cert_types = -1; static int hf_ssl_handshake_cert_type = -1; static int hf_ssl_handshake_finished = -1; static int hf_ssl_handshake_md5_hash = -1; static int hf_ssl_handshake_sha_hash = -1; static int hf_ssl_handshake_session_id_len = -1; static int hf_ssl_handshake_dnames_len = -1; static int hf_ssl_handshake_dnames = -1; static int hf_ssl_handshake_dname_len = -1; static int hf_ssl_handshake_dname = -1; static int hf_ssl2_handshake_cipher_spec_len = -1; static int hf_ssl2_handshake_session_id_len = -1; static int hf_ssl2_handshake_challenge_len = -1; static int hf_ssl2_handshake_cipher_spec = -1; static int hf_ssl2_handshake_challenge = -1; static int hf_ssl2_handshake_clear_key_len = -1; static int hf_ssl2_handshake_enc_key_len = -1; static int hf_ssl2_handshake_key_arg_len = -1; static int hf_ssl2_handshake_clear_key = -1; static int hf_ssl2_handshake_enc_key = -1; static int hf_ssl2_handshake_key_arg = -1; static int hf_ssl2_handshake_session_id_hit = -1; static int hf_ssl2_handshake_cert_type = -1; static int hf_ssl2_handshake_connection_id_len = -1; static int hf_ssl2_handshake_connection_id = -1; /* Initialize the subtree pointers */ static gint ett_ssl = -1; static gint ett_ssl_record = -1; static gint ett_ssl_alert = -1; static gint ett_ssl_handshake = -1; static gint ett_ssl_cipher_suites = -1; static gint ett_ssl_comp_methods = -1; static gint ett_ssl_certs = -1; static gint ett_ssl_cert_types = -1; static gint ett_ssl_dnames = -1; /* The TCP port to associate with by default */ #define TCP_PORT_SSL 443 #define TCP_PORT_SSL_LDAP 636 #define TCP_PORT_SSL_IMAP 993 #define TCP_PORT_SSL_POP 995 /* version state tables */ #define SSL_VER_UNKNOWN 0 #define SSL_VER_SSLv2 1 #define SSL_VER_SSLv3 2 #define SSL_VER_TLS 3 #define SSL_VER_PCT 4 /* corresponds to the #defines above */ static gchar* ssl_version_short_names[] = { "SSL", "SSLv2", "SSLv3", "TLS", "PCT" }; /* other defines */ #define SSL_ID_CHG_CIPHER_SPEC 0x14 #define SSL_ID_ALERT 0x15 #define SSL_ID_HANDSHAKE 0x16 #define SSL_ID_APP_DATA 0x17 #define SSL_HND_HELLO_REQUEST 0x00 #define SSL_HND_CLIENT_HELLO 0x01 #define SSL_HND_SERVER_HELLO 0x02 #define SSL_HND_CERTIFICATE 0x0b #define SSL_HND_SERVER_KEY_EXCHG 0x0c #define SSL_HND_CERT_REQUEST 0x0d #define SSL_HND_SVR_HELLO_DONE 0x0e #define SSL_HND_CERT_VERIFY 0x0f #define SSL_HND_CLIENT_KEY_EXCHG 0x10 #define SSL_HND_FINISHED 0x14 #define SSL2_HND_ERROR 0x00 #define SSL2_HND_CLIENT_HELLO 0x01 #define SSL2_HND_CLIENT_MASTER_KEY 0x02 #define SSL2_HND_CLIENT_FINISHED 0x03 #define SSL2_HND_SERVER_HELLO 0x04 #define SSL2_HND_SERVER_VERIFY 0x05 #define SSL2_HND_SERVER_FINISHED 0x06 #define SSL2_HND_REQUEST_CERTIFICATE 0x07 #define SSL2_HND_CLIENT_CERTIFICATE 0x08 #define PCT_VERSION_1 0x8001 #define PCT_MSG_CLIENT_HELLO 0x01 #define PCT_MSG_SERVER_HELLO 0x02 #define PCT_MSG_CLIENT_MASTER_KEY 0x03 #define PCT_MSG_SERVER_VERIFY 0x04 #define PCT_MSG_ERROR 0x05 /* * Lookup tables * */ static const value_string ssl_20_msg_types[] = { { SSL2_HND_ERROR, "Error" }, { SSL2_HND_CLIENT_HELLO, "Client Hello" }, { SSL2_HND_CLIENT_MASTER_KEY, "Client Master Key" }, { SSL2_HND_CLIENT_FINISHED, "Client Finished" }, { SSL2_HND_SERVER_HELLO, "Server Hello" }, { SSL2_HND_SERVER_VERIFY, "Server Verify" }, { SSL2_HND_SERVER_FINISHED, "Server Finished" }, { SSL2_HND_REQUEST_CERTIFICATE, "Request Certificate" }, { SSL2_HND_CLIENT_CERTIFICATE, "Client Certificate" }, { 0x00, NULL }, }; static const value_string ssl_20_cipher_suites[] = { { 0x010080, "SSL2_RC4_128_WITH_MD5" }, { 0x020080, "SSL2_RC4_128_EXPORT40_WITH_MD5" }, { 0x030080, "SSL2_RC2_CBC_128_CBC_WITH_MD5" }, { 0x040080, "SSL2_RC2_CBC_128_CBC_WITH_MD5" }, { 0x050080, "SSL2_IDEA_128_CBC_WITH_MD5" }, { 0x060040, "SSL2_DES_64_CBC_WITH_MD5" }, { 0x0700c0, "SSL2_DES_192_EDE3_CBC_WITH_MD5" }, { 0x080080, "SSL2_RC4_64_WITH_MD5" }, { 0x000000, "TLS_NULL_WITH_NULL_NULL" }, { 0x000001, "TLS_RSA_WITH_NULL_MD5" }, { 0x000002, "TLS_RSA_WITH_NULL_SHA" }, { 0x000003, "TLS_RSA_EXPORT_WITH_RC4_40_MD5" }, { 0x000004, "TLS_RSA_WITH_RC4_128_MD5" }, { 0x000005, "TLS_RSA_WITH_RC4_128_SHA" }, { 0x000006, "TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5" }, { 0x000007, "TLS_RSA_WITH_IDEA_CBC_SHA" }, { 0x000008, "TLS_RSA_EXPORT_WITH_DES40_CBC_SHA" }, { 0x000009, "TLS_RSA_WITH_DES_CBC_SHA" }, { 0x00000a, "TLS_RSA_WITH_3DES_EDE_CBC_SHA" }, { 0x00000b, "TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA" }, { 0x00000c, "TLS_DH_DSS_WITH_DES_CBC_SHA" }, { 0x00000d, "TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA" }, { 0x00000e, "TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA" }, { 0x00000f, "TLS_DH_RSA_WITH_DES_CBC_SHA" }, { 0x000010, "TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA" }, { 0x000011, "TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA" }, { 0x000012, "TLS_DHE_DSS_WITH_DES_CBC_SHA" }, { 0x000013, "TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA" }, { 0x000014, "TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA" }, { 0x000015, "TLS_DHE_RSA_WITH_DES_CBC_SHA" }, { 0x000016, "TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA" }, { 0x000017, "TLS_DH_anon_EXPORT_WITH_RC4_40_MD5" }, { 0x000018, "TLS_DH_anon_WITH_RC4_128_MD5" }, { 0x000019, "TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA" }, { 0x00001a, "TLS_DH_anon_WITH_DES_CBC_SHA" }, { 0x00001b, "TLS_DH_anon_WITH_3DES_EDE_CBC_SHA" }, { 0x00001c, "SSL_FORTEZZA_KEA_WITH_NULL_SHA" }, { 0x00001d, "SSL_FORTEZZA_KEA_WITH_FORTEZZA_CBC_SHA" }, { 0x00001e, "SSL_FORTEZZA_KEA_WITH_RC4_128_SHA" }, { 0x000060, "TLS_RSA_EXPORT1024_WITH_RC4_56_MD5" }, { 0x000061, "TLS_RSA_EXPORT1024_WITH_RC2_CBC_56_MD5" }, { 0x000062, "TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA" }, { 0x000063, "TLS_DHE_DSS_EXPORT1024_WITH_DES_CBC_SHA" }, { 0x000064, "TLS_RSA_EXPORT1024_WITH_RC4_56_SHA" }, { 0x000065, "TLS_DHE_DSS_EXPORT1024_WITH_RC4_56_SHA" }, { 0x000066, "TLS_DHE_DSS_WITH_RC4_128_SHA" }, /* these from http://www.mozilla.org/projects/ security/pki/nss/ssl/fips-ssl-ciphersuites.html */ { 0x00fefe, "SSL_RSA_FIPS_WITH_DES_CBC_SHA"}, { 0x00feff, "SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA" }, { 0x00ffe0, "SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA" }, { 0x00ffe1, "SSL_RSA_FIPS_WITH_DES_CBC_SHA"}, /* Microsoft's old PCT protocol. These are from Eric Rescorla's book "SSL and TLS" */ { 0x8f8001, "PCT_SSL_COMPAT | PCT_VERSION_1" }, { 0x800003, "PCT_SSL_CERT_TYPE | PCT1_CERT_X509_CHAIN" }, { 0x800001, "PCT_SSL_CERT_TYPE | PCT1_CERT_X509" }, { 0x810001, "PCT_SSL_HASH_TYPE | PCT1_HASH_MD5" }, { 0x810003, "PCT_SSL_HASH_TYPE | PCT1_HASH_SHA" }, { 0x820001, "PCT_SSL_EXCH_TYPE | PCT1_EXCH_RSA_PKCS1" }, { 0x830004, "PCT_SSL_CIPHER_TYPE_1ST_HALF | PCT1_CIPHER_RC4" }, { 0x848040, "PCT_SSL_CIPHER_TYPE_2ND_HALF | PCT1_ENC_BITS_128 | PCT1_MAC_BITS_128" }, { 0x842840, "PCT_SSL_CIPHER_TYPE_2ND_HALF | PCT1_ENC_BITS_40 | PCT1_MAC_BITS_128" }, /* note that ciphersuites of {0x00????} are TLS cipher suites in * a sslv2 client hello message; the ???? above is the two-byte * tls cipher suite id */ { 0x00, NULL } }; static const value_string ssl_20_certificate_type[] = { { 0x00, "N/A" }, { 0x01, "X.509 Certificate" }, { 0x00, NULL }, }; static const value_string ssl_31_content_type[] = { { 20, "Change Cipher Spec" }, { 21, "Alert" }, { 22, "Handshake" }, { 23, "Application Data" }, { 0x00, NULL } }; static const value_string ssl_versions[] = { { 0x0301, "TLS 1.0" }, { 0x0300, "SSL 3.0" }, { 0x0002, "SSL 2.0" }, { 0x00, NULL } }; static const value_string ssl_31_change_cipher_spec[] = { { 1, "Change Cipher Spec" }, { 0x00, NULL }, }; static const value_string ssl_31_alert_level[] = { { 1, "Warning" }, { 2, "Fatal" }, { 0x00, NULL } }; static const value_string ssl_31_alert_description[] = { { 0, "Close Notify" }, { 10, "Unexpected Message" }, { 20, "Bad Record MAC" }, { 21, "Decryption Failed" }, { 22, "Record Overflow" }, { 30, "Decompression Failure" }, { 40, "Handshake Failure" }, { 42, "Bad Certificate" }, { 43, "Unsupported Certificate" }, { 44, "Certificate Revoked" }, { 45, "Certificate Expired" }, { 46, "Certificate Unknown" }, { 47, "Illegal Parameter" }, { 48, "Unknown CA" }, { 49, "Access Denied" }, { 50, "Decode Error" }, { 51, "Decrypt Error" }, { 60, "Export Restriction" }, { 70, "Protocol Version" }, { 71, "Insufficient Security" }, { 80, "Internal Error" }, { 90, "User Canceled" }, { 100, "No Renegotiation" }, { 0x00, NULL } }; static const value_string ssl_31_handshake_type[] = { { SSL_HND_HELLO_REQUEST, "Hello Request" }, { SSL_HND_CLIENT_HELLO, "Client Hello" }, { SSL_HND_SERVER_HELLO, "Server Hello" }, { SSL_HND_CERTIFICATE, "Certificate" }, { SSL_HND_SERVER_KEY_EXCHG, "Server Key Exchange" }, { SSL_HND_CERT_REQUEST, "Certificate Request" }, { SSL_HND_SVR_HELLO_DONE, "Server Hello Done" }, { SSL_HND_CERT_VERIFY, "Certificate Verify" }, { SSL_HND_CLIENT_KEY_EXCHG, "Client Key Exchange" }, { SSL_HND_FINISHED, "Finished" }, { 0x00, NULL } }; static const value_string ssl_31_compression_method[] = { { 0, "null" }, { 0x00, NULL } }; static const value_string ssl_31_key_exchange_algorithm[] = { { 0, "RSA" }, { 1, "Diffie Hellman" }, { 0x00, NULL } }; static const value_string ssl_31_signature_algorithm[] = { { 0, "Anonymous" }, { 1, "RSA" }, { 2, "DSA" }, { 0x00, NULL } }; static const value_string ssl_31_client_certificate_type[] = { { 1, "RSA Sign" }, { 2, "DSS Sign" }, { 3, "RSA Fixed DH" }, { 4, "DSS Fixed DH" }, { 0x00, NULL } }; static const value_string ssl_31_public_value_encoding[] = { { 0, "Implicit" }, { 1, "Explicit" }, { 0x00, NULL } }; static const value_string ssl_31_ciphersuite[] = { { 0x0000, "TLS_NULL_WITH_NULL_NULL" }, { 0x0001, "TLS_RSA_WITH_NULL_MD5" }, { 0x0002, "TLS_RSA_WITH_NULL_SHA" }, { 0x0003, "TLS_RSA_EXPORT_WITH_RC4_40_MD5" }, { 0x0004, "TLS_RSA_WITH_RC4_128_MD5" }, { 0x0005, "TLS_RSA_WITH_RC4_128_SHA" }, { 0x0006, "TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5" }, { 0x0007, "TLS_RSA_WITH_IDEA_CBC_SHA" }, { 0x0008, "TLS_RSA_EXPORT_WITH_DES40_CBC_SHA" }, { 0x0009, "TLS_RSA_WITH_DES_CBC_SHA" }, { 0x000a, "TLS_RSA_WITH_3DES_EDE_CBC_SHA" }, { 0x000b, "TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA" }, { 0x000c, "TLS_DH_DSS_WITH_DES_CBC_SHA" }, { 0x000d, "TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA" }, { 0x000e, "TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA" }, { 0x000f, "TLS_DH_RSA_WITH_DES_CBC_SHA" }, { 0x0010, "TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA" }, { 0x0011, "TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA" }, { 0x0012, "TLS_DHE_DSS_WITH_DES_CBC_SHA" }, { 0x0013, "TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA" }, { 0x0014, "TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA" }, { 0x0015, "TLS_DHE_RSA_WITH_DES_CBC_SHA" }, { 0x0016, "TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA" }, { 0x0017, "TLS_DH_anon_EXPORT_WITH_RC4_40_MD5" }, { 0x0018, "TLS_DH_anon_WITH_RC4_128_MD5" }, { 0x0019, "TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA" }, { 0x001a, "TLS_DH_anon_WITH_DES_CBC_SHA" }, { 0x001b, "TLS_DH_anon_WITH_3DES_EDE_CBC_SHA" }, { 0x001c, "SSL_FORTEZZA_KEA_WITH_NULL_SHA" }, { 0x001d, "SSL_FORTEZZA_KEA_WITH_FORTEZZA_CBC_SHA" }, { 0x001e, "SSL_FORTEZZA_KEA_WITH_RC4_128_SHA" }, { 0x0062, "TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA" }, { 0x0063, "TLS_DHE_DSS_EXPORT1024_WITH_DES_CBC_SHA" }, { 0x0064, "TLS_RSA_EXPORT1024_WITH_RC4_56_SHA" }, { 0x0065, "TLS_DHE_DSS_EXPORT1024_WITH_RC4_56_SHA" }, { 0x0066, "TLS_DHE_DSS_WITH_RC4_128_SHA" }, /* these from http://www.mozilla.org/projects/ security/pki/nss/ssl/fips-ssl-ciphersuites.html */ { 0xfefe, "SSL_RSA_FIPS_WITH_DES_CBC_SHA"}, { 0xfeff, "SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA" }, { 0xffe0, "SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA" }, { 0xffe1, "SSL_RSA_FIPS_WITH_DES_CBC_SHA"}, /* note that ciphersuites 0xff00 - 0xffff are private */ { 0x00, NULL } }; static const value_string pct_msg_types[] = { { PCT_MSG_CLIENT_HELLO, "Client Hello" }, { PCT_MSG_SERVER_HELLO, "Server Hello" }, { PCT_MSG_CLIENT_MASTER_KEY, "Client Master Key" }, { PCT_MSG_SERVER_VERIFY, "Server Verify" }, { PCT_MSG_ERROR, "Error" }, { 0x00, NULL }, }; /********************************************************************* * * Forward Declarations * *********************************************************************/ /* * SSL version 3 and TLS dissectors * */ /* record layer dissector */ static int dissect_ssl3_record(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint *conv_version, gboolean *need_desegmentation); /* change cipher spec dissector */ static void dissect_ssl3_change_cipher_spec(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint *conv_version); /* alert message dissector */ static void dissect_ssl3_alert(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint *conv_version); /* handshake protocol dissector */ static void dissect_ssl3_handshake(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint32 record_length, guint *conv_version); static void dissect_ssl3_hnd_cli_hello(tvbuff_t *tvb, proto_tree *tree, guint32 offset); static void dissect_ssl3_hnd_srv_hello(tvbuff_t *tvb, proto_tree *tree, guint32 offset); static void dissect_ssl3_hnd_cert(tvbuff_t *tvb, proto_tree *tree, guint32 offset); static void dissect_ssl3_hnd_cert_req(tvbuff_t *tvb, proto_tree *tree, guint32 offset); static void dissect_ssl3_hnd_finished(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint *conv_version); /* * SSL version 2 dissectors * */ /* record layer dissector */ static int dissect_ssl2_record(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint *conv_version, gboolean *need_desegmentation); /* client hello dissector */ static void dissect_ssl2_hnd_client_hello(tvbuff_t *tvb, proto_tree *tree, guint32 offset); /* client master key dissector */ static void dissect_ssl2_hnd_client_master_key(tvbuff_t *tvb, proto_tree *tree, guint32 offset); /* server hello dissector */ static void dissect_ssl2_hnd_server_hello(tvbuff_t *tvb, proto_tree *tree, guint32 offset); /* * Support Functions * */ static void ssl_set_conv_version(packet_info *pinfo, guint version); static int ssl_is_valid_handshake_type(guint8 type); static int ssl_is_valid_content_type(guint8 type); static int ssl_is_valid_ssl_version(guint16 version); static int ssl_is_authoritative_version_message(guint8 content_type, guint8 next_byte); static int ssl_is_v2_client_hello(tvbuff_t *tvb, guint32 offset); static int ssl_looks_like_sslv2(tvbuff_t *tvb, guint32 offset); static int ssl_looks_like_sslv3(tvbuff_t *tvb, guint32 offset); static int ssl_looks_like_valid_v2_handshake(tvbuff_t *tvb, guint32 offset, guint32 record_length); static int ssl_looks_like_valid_pct_handshake(tvbuff_t *tvb, guint32 offset, guint32 record_length); /********************************************************************* * * Main dissector * *********************************************************************/ /* * Code to actually dissect the packets */ static void dissect_ssl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { conversation_t *conversation; void *conv_data; guint conv_version = SSL_VER_UNKNOWN; proto_item *ti = NULL; proto_tree *ssl_tree = NULL; guint32 offset = 0; gboolean first_record_in_frame = TRUE; gboolean need_desegmentation; /* Track the version using conversations to reduce the * chance that a packet that simply *looks* like a v2 or * v3 packet is dissected improperly. This also allows * us to more frequently set the protocol column properly * for continuation data frames. * * Also: We use the copy in conv_version as our cached copy, * so that we don't have to search the conversation * table every time we want the version; when setting * the conv_version, must set the copy in the conversation * in addition to conv_version */ conversation = find_conversation(&pinfo->src, &pinfo->dst, pinfo->ptype, pinfo->srcport, pinfo->destport, 0); if (!conversation) { /* create a new conversation */ conversation = conversation_new(&pinfo->src, &pinfo->dst, pinfo->ptype, pinfo->srcport, pinfo->destport, 0); } conv_data = conversation_get_proto_data(conversation, proto_ssl); if (conv_data != NULL) { conv_version = (guint)conv_data; } /* Initialize the protocol column; we'll set it later when we * figure out what flavor of SSL it is (assuming we don't * throw an exception before we get the chance to do so). */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) { col_set_str(pinfo->cinfo, COL_PROTOCOL, "SSL"); } /* clear the the info column */ if (check_col(pinfo->cinfo, COL_INFO)) col_clear(pinfo->cinfo, COL_INFO); /* TCP packets and SSL records are orthogonal. * A tcp packet may contain multiple ssl records and an ssl * record may be spread across multiple tcp packets. * * This loop accounts for multiple ssl records in a single * frame, but not a single ssl record across multiple tcp * packets. * * Handling the single ssl record across multiple packets * may be possible using ethereal conversations, but * probably not cleanly. May have to wait for tcp stream * reassembly. */ /* Create display subtree for SSL as a whole */ if (tree) { ti = proto_tree_add_item(tree, proto_ssl, tvb, 0, -1, FALSE); ssl_tree = proto_item_add_subtree(ti, ett_ssl); } /* iterate through the records in this tvbuff */ while (tvb_reported_length_remaining(tvb, offset) != 0) { /* on second and subsequent records per frame * add a delimiter on info column */ if (!first_record_in_frame && check_col(pinfo->cinfo, COL_INFO)) { col_append_str(pinfo->cinfo, COL_INFO, ", "); } /* * Assume, for now, that this doesn't need desegmentation. */ need_desegmentation = FALSE; /* first try to dispatch off the cached version * known to be associated with the conversation */ switch(conv_version) { case SSL_VER_SSLv2: case SSL_VER_PCT: offset = dissect_ssl2_record(tvb, pinfo, ssl_tree, offset, &conv_version, &need_desegmentation); break; case SSL_VER_SSLv3: case SSL_VER_TLS: /* the version tracking code works too well ;-) * at times, we may visit a v2 client hello after * we already know the version of the connection; * work around that here by detecting and calling * the v2 dissector instead */ if (ssl_is_v2_client_hello(tvb, offset)) { offset = dissect_ssl2_record(tvb, pinfo, ssl_tree, offset, &conv_version, &need_desegmentation); } else { offset = dissect_ssl3_record(tvb, pinfo, ssl_tree, offset, &conv_version, &need_desegmentation); } break; /* that failed, so apply some heuristics based * on this individual packet */ default: if (ssl_looks_like_sslv2(tvb, offset)) { /* looks like sslv2 or pct client hello */ offset = dissect_ssl2_record(tvb, pinfo, ssl_tree, offset, &conv_version, &need_desegmentation); } else if (ssl_looks_like_sslv3(tvb, offset)) { /* looks like sslv3 or tls */ offset = dissect_ssl3_record(tvb, pinfo, ssl_tree, offset, &conv_version, &need_desegmentation); } else { /* looks like something unknown, so lump into * continuation data */ offset = tvb_length(tvb); if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "Continuation Data"); /* Set the protocol column */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) { col_set_str(pinfo->cinfo, COL_PROTOCOL, ssl_version_short_names[conv_version]); } } break; } /* Desegmentation return check */ if (need_desegmentation) return; /* If we haven't already set the version information for * this conversation, do so. */ if (conv_data == NULL) { conv_data = (void *)conv_version; conversation_add_proto_data(conversation, proto_ssl, conv_data); } /* set up for next record in frame, if any */ first_record_in_frame = FALSE; } } /********************************************************************* * * SSL version 3 and TLS Dissection Routines * *********************************************************************/ static int dissect_ssl3_record(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint *conv_version, gboolean *need_desegmentation) { /* * struct { * uint8 major, minor; * } ProtocolVersion; * * * enum { * change_cipher_spec(20), alert(21), handshake(22), * application_data(23), (255) * } ContentType; * * struct { * ContentType type; * ProtocolVersion version; * uint16 length; * opaque fragment[TLSPlaintext.length]; * } TLSPlaintext; */ guint32 record_length; guint16 version; guint8 content_type; guint8 next_byte; proto_tree *ti = NULL; proto_tree *ssl_record_tree = NULL; guint32 available_bytes = 0; available_bytes = tvb_length_remaining(tvb, offset); /* * Can we do reassembly? */ if (ssl_desegment && pinfo->can_desegment) { /* * Yes - is the record header split across segment boundaries? */ if (available_bytes < 5) { /* * Yes. Tell the TCP dissector where the data for this * message starts in the data it handed us, and how many * more bytes we need, and return. */ pinfo->desegment_offset = offset; pinfo->desegment_len = 5 - available_bytes; *need_desegmentation = TRUE; return offset; } } /* * Get the record layer fields of interest */ content_type = tvb_get_guint8(tvb, offset); version = tvb_get_ntohs(tvb, offset + 1); record_length = tvb_get_ntohs(tvb, offset + 3); if (ssl_is_valid_content_type(content_type)) { /* * Can we do reassembly? */ if (ssl_desegment && pinfo->can_desegment) { /* * Yes - is the record split across segment boundaries? */ if (available_bytes < record_length + 5) { /* * Yes. Tell the TCP dissector where the data for this * message starts in the data it handed us, and how many * more bytes we need, and return. */ pinfo->desegment_offset = offset; pinfo->desegment_len = (record_length + 5) - available_bytes; *need_desegmentation = TRUE; return offset; } } } else { /* if we don't have a valid content_type, there's no sense * continuing any further */ if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "Continuation Data"); /* Set the protocol column */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) { col_set_str(pinfo->cinfo, COL_PROTOCOL, ssl_version_short_names[*conv_version]); } return offset + 5 + record_length; } /* * If GUI, fill in record layer part of tree */ if (tree) { /* add the record layer subtree header */ ti = proto_tree_add_item(tree, hf_ssl_record, tvb, offset, 5 + record_length, 0); ssl_record_tree = proto_item_add_subtree(ti, ett_ssl_record); } if (ssl_record_tree) { /* show the one-byte content type */ proto_tree_add_item(ssl_record_tree, hf_ssl_record_content_type, tvb, offset, 1, 0); offset++; /* add the version */ proto_tree_add_item(ssl_record_tree, hf_ssl_record_version, tvb, offset, 2, FALSE); offset += 2; /* add the length */ proto_tree_add_uint(ssl_record_tree, hf_ssl_record_length, tvb, offset, 2, record_length); offset += 2; /* move past length field itself */ } else { /* if no GUI tree, then just skip over those fields */ offset += 5; } /* * if we don't already have a version set for this conversation, * but this message's version is authoritative (i.e., it's * not client_hello, then save the version to to conversation * structure and print the column version */ next_byte = tvb_get_guint8(tvb, offset); if (*conv_version == SSL_VER_UNKNOWN && ssl_is_authoritative_version_message(content_type, next_byte)) { if (version == 0x0300) { *conv_version = SSL_VER_SSLv3; ssl_set_conv_version(pinfo, *conv_version); } else if (version == 0x0301) { *conv_version = SSL_VER_TLS; ssl_set_conv_version(pinfo, *conv_version); } } if (check_col(pinfo->cinfo, COL_PROTOCOL)) { if (version == 0x0300) { col_set_str(pinfo->cinfo, COL_PROTOCOL, ssl_version_short_names[SSL_VER_SSLv3]); } else if (version == 0x0301) { col_set_str(pinfo->cinfo, COL_PROTOCOL, ssl_version_short_names[SSL_VER_TLS]); } else { col_set_str(pinfo->cinfo, COL_PROTOCOL, ssl_version_short_names[*conv_version]); } } /* * now dissect the next layer */ switch (content_type) { case SSL_ID_CHG_CIPHER_SPEC: if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "Change Cipher Spec"); dissect_ssl3_change_cipher_spec(tvb, ssl_record_tree, offset, conv_version); break; case SSL_ID_ALERT: dissect_ssl3_alert(tvb, pinfo, ssl_record_tree, offset, conv_version); break; case SSL_ID_HANDSHAKE: dissect_ssl3_handshake(tvb, pinfo, ssl_record_tree, offset, record_length, conv_version); break; case SSL_ID_APP_DATA: if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "Application Data"); if (ssl_record_tree) { proto_item_set_text(ssl_record_tree, "%s Record Layer: Application Data", ssl_version_short_names[*conv_version]); proto_tree_add_item(ssl_record_tree, hf_ssl_record_appdata, tvb, offset, record_length, 0); } break; default: /* shouldn't get here since we check above for valid types */ if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "Bad SSLv3 Content Type"); break; } offset += record_length; /* skip to end of record */ return offset; } /* dissects the change cipher spec procotol, filling in the tree */ static void dissect_ssl3_change_cipher_spec(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint *conv_version) { /* * struct { * enum { change_cipher_spec(1), (255) } type; * } ChangeCipherSpec; * */ if (tree) { proto_item_set_text(tree, "%s Record Layer: Change Cipher Spec", ssl_version_short_names[*conv_version]); proto_tree_add_item(tree, hf_ssl_change_cipher_spec, tvb, offset++, 1, FALSE); } } /* dissects the alert message, filling in the tree */ static void dissect_ssl3_alert(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint *conv_version) { /* struct { * AlertLevel level; * AlertDescription description; * } Alert; */ proto_tree *ti; proto_tree *ssl_alert_tree = NULL; gchar *level; gchar *desc; guint8 byte; if (tree) { ti = proto_tree_add_item(tree, hf_ssl_alert_message, tvb, offset, 2, 0); ssl_alert_tree = proto_item_add_subtree(ti, ett_ssl_alert); } /* * set the record layer label */ /* first lookup the names for the alert level and description */ byte = tvb_get_guint8(tvb, offset); /* grab the level byte */ level = match_strval(byte, ssl_31_alert_level); byte = tvb_get_guint8(tvb, offset+1); /* grab the desc byte */ desc = match_strval(byte, ssl_31_alert_description); /* now set the text in the record layer line */ if (level && desc) { if (check_col(pinfo->cinfo, COL_INFO)) col_append_fstr(pinfo->cinfo, COL_INFO, "Alert (Level: %s, Description: %s)", level, desc); } else { if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "Encrypted Alert"); } if (tree) { if (level && desc) { proto_item_set_text(tree, "%s Record Layer: Alert " "(Level: %s, Description: %s)", ssl_version_short_names[*conv_version], level, desc); proto_tree_add_item(ssl_alert_tree, hf_ssl_alert_message_level, tvb, offset++, 1, FALSE); proto_tree_add_item(ssl_alert_tree, hf_ssl_alert_message_description, tvb, offset++, 1, FALSE); } else { proto_item_set_text(tree, "%s Record Layer: Encrypted Alert", ssl_version_short_names[*conv_version]); proto_item_set_text(ssl_alert_tree, "Alert Message: Encrypted Alert"); } } } /* dissects the handshake protocol, filling the tree */ static void dissect_ssl3_handshake(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint32 record_length, guint *conv_version) { /* struct { * HandshakeType msg_type; * uint24 length; * select (HandshakeType) { * case hello_request: HelloRequest; * case client_hello: ClientHello; * case server_hello: ServerHello; * case certificate: Certificate; * case server_key_exchange: ServerKeyExchange; * case certificate_request: CertificateRequest; * case server_hello_done: ServerHelloDone; * case certificate_verify: CertificateVerify; * case client_key_exchange: ClientKeyExchange; * case finished: Finished; * } body; * } Handshake; */ proto_tree *ti = NULL; proto_tree *ssl_hand_tree = NULL; gchar *msg_type_str = NULL; guint8 msg_type; guint32 length; gboolean first_iteration = TRUE; /* just as there can be multiple records per packet, there * can be multiple messages per record as long as they have * the same content type * * we really only care about this for handshake messages */ /* set record_length to the max offset */ record_length += offset; while (offset < record_length) { msg_type = tvb_get_guint8(tvb, offset); msg_type_str = match_strval(msg_type, ssl_31_handshake_type); length = tvb_get_ntoh24(tvb, offset + 1); if (!msg_type_str && !first_iteration) { /* only dissect / report messages if they're * either the first message in this record * or they're a valid message type */ return; } /* on second and later iterations, add comma to info col */ if (!first_iteration) { if (check_col(pinfo->cinfo, COL_INFO)) col_append_fstr(pinfo->cinfo, COL_INFO, ", "); } /* * Update our info string */ if (check_col(pinfo->cinfo, COL_INFO)) col_append_fstr(pinfo->cinfo, COL_INFO, "%s", (msg_type_str != NULL) ? msg_type_str : "Encrypted Handshake Message"); if (tree) { /* set the label text on the record layer expanding node */ if (first_iteration) { proto_item_set_text(tree, "%s Record Layer: %s", ssl_version_short_names[*conv_version], (msg_type_str!=NULL) ? msg_type_str : "Encrypted Handshake Message"); } else { proto_item_set_text(tree, "%s Record Layer: %s", ssl_version_short_names[*conv_version], "Multiple Handshake Messages"); } /* add a subtree for the handshake protocol */ ti = proto_tree_add_item(tree, hf_ssl_handshake_protocol, tvb, offset, length + 4, 0); ssl_hand_tree = proto_item_add_subtree(ti, ett_ssl_handshake); if (ssl_hand_tree) { /* set the text label on the subtree node */ proto_item_set_text(ssl_hand_tree, "Handshake Protocol: %s", (msg_type_str != NULL) ? msg_type_str : "Encrypted Handshake Message"); } } /* if we don't have a valid handshake type, just quit dissecting */ if (!msg_type_str) { return; } if (ssl_hand_tree) { /* add nodes for the message type and message length */ proto_tree_add_item(ssl_hand_tree, hf_ssl_handshake_type, tvb, offset, 1, msg_type); offset++; proto_tree_add_uint(ssl_hand_tree, hf_ssl_handshake_length, tvb, offset, 3, length); offset += 3; /* now dissect the handshake message, if necessary */ switch (msg_type) { case SSL_HND_HELLO_REQUEST: /* hello_request has no fields, so nothing to do! */ break; case SSL_HND_CLIENT_HELLO: dissect_ssl3_hnd_cli_hello(tvb, ssl_hand_tree, offset); break; case SSL_HND_SERVER_HELLO: dissect_ssl3_hnd_srv_hello(tvb, ssl_hand_tree, offset); break; case SSL_HND_CERTIFICATE: dissect_ssl3_hnd_cert(tvb, ssl_hand_tree, offset); break; case SSL_HND_CERT_REQUEST: dissect_ssl3_hnd_cert_req(tvb, ssl_hand_tree, offset); break; case SSL_HND_SVR_HELLO_DONE: /* server_hello_done has no fields, so nothing to do! */ break; case SSL_HND_FINISHED: dissect_ssl3_hnd_finished(tvb, ssl_hand_tree, offset, conv_version); break; case SSL_HND_SERVER_KEY_EXCHG: case SSL_HND_CERT_VERIFY: case SSL_HND_CLIENT_KEY_EXCHG: /* unimplemented */ break; } } else { offset += 4; /* skip the handshake header */ } offset += length; first_iteration = FALSE; /* set up for next pass, if any */ } } static int dissect_ssl3_hnd_hello_common(tvbuff_t *tvb, proto_tree *tree, guint32 offset) { /* show the client's random challenge */ guint32 initial_offset = offset; nstime_t gmt_unix_time; guint8 session_id_length = 0; if (tree) { /* show the time */ gmt_unix_time.secs = tvb_get_ntohl(tvb, offset); gmt_unix_time.nsecs = 0; proto_tree_add_time(tree, hf_ssl_handshake_random_time, tvb, offset, 4, &gmt_unix_time); offset += 4; /* show the random bytes */ proto_tree_add_item(tree, hf_ssl_handshake_random_bytes, tvb, offset, 28, 0); offset += 28; /* show the session id */ session_id_length = tvb_get_guint8(tvb, offset); proto_tree_add_item(tree, hf_ssl_handshake_session_id_len, tvb, offset++, 1, 0); if (session_id_length > 0) { proto_tree_add_bytes_format(tree, hf_ssl_handshake_session_id, tvb, offset, session_id_length, tvb_get_ptr(tvb, offset, session_id_length), "Session ID (%u byte%s)", session_id_length, plurality(session_id_length, "", "s")); offset += session_id_length; } } return offset - initial_offset; } static void dissect_ssl3_hnd_cli_hello(tvbuff_t *tvb, proto_tree *tree, guint32 offset) { /* struct { * ProtocolVersion client_version; * Random random; * SessionID session_id; * CipherSuite cipher_suites<2..2^16-1>; * CompressionMethod compression_methods<1..2^8-1>; * } ClientHello; * */ proto_tree *ti; proto_tree *cs_tree; guint16 cipher_suite_length = 0; guint8 compression_methods_length = 0; if (tree) { /* show the client version */ proto_tree_add_item(tree, hf_ssl_handshake_client_version, tvb, offset, 2, FALSE); offset += 2; /* show the fields in common with server hello */ offset += dissect_ssl3_hnd_hello_common(tvb, tree, offset); /* tell the user how many cipher suites there are */ cipher_suite_length = tvb_get_ntohs(tvb, offset); proto_tree_add_uint(tree, hf_ssl_handshake_cipher_suites_len, tvb, offset, 2, cipher_suite_length); offset += 2; /* skip opaque length */ if (cipher_suite_length > 0) { ti = proto_tree_add_none_format(tree, hf_ssl_handshake_cipher_suites, tvb, offset, cipher_suite_length, "Cipher Suites (%u suite%s)", cipher_suite_length / 2, plurality(cipher_suite_length/2, "", "s")); /* make this a subtree */ cs_tree = proto_item_add_subtree(ti, ett_ssl_cipher_suites); if (!cs_tree) { cs_tree = tree; /* failsafe */ } while (cipher_suite_length > 0) { proto_tree_add_item(cs_tree, hf_ssl_handshake_cipher_suite, tvb, offset, 2, FALSE); offset += 2; cipher_suite_length -= 2; } } /* tell the user how man compression methods there are */ compression_methods_length = tvb_get_guint8(tvb, offset); proto_tree_add_uint(tree, hf_ssl_handshake_comp_methods_len, tvb, offset, 1, compression_methods_length); offset++; if (compression_methods_length > 0) { ti = proto_tree_add_none_format(tree, hf_ssl_handshake_comp_methods, tvb, offset, compression_methods_length, "Compression Methods (%u method%s)", compression_methods_length, plurality(compression_methods_length, "", "s")); /* make this a subtree */ cs_tree = proto_item_add_subtree(ti, ett_ssl_comp_methods); if (!cs_tree) { cs_tree = tree; /* failsafe */ } while (compression_methods_length > 0) { proto_tree_add_item(cs_tree, hf_ssl_handshake_comp_method, tvb, offset, 1, FALSE); offset++; compression_methods_length--; } } } } static void dissect_ssl3_hnd_srv_hello(tvbuff_t *tvb, proto_tree *tree, guint32 offset) { /* struct { * ProtocolVersion server_version; * Random random; * SessionID session_id; * CipherSuite cipher_suite; * CompressionMethod compression_method; * } ServerHello; */ if (tree) { /* show the server version */ proto_tree_add_item(tree, hf_ssl_handshake_server_version, tvb, offset, 2, FALSE); offset += 2; /* first display the elements conveniently in * common with client hello */ offset += dissect_ssl3_hnd_hello_common(tvb, tree, offset); /* now the server-selected cipher suite */ proto_tree_add_item(tree, hf_ssl_handshake_cipher_suite, tvb, offset, 2, FALSE); offset += 2; /* and the server-selected compression method */ proto_tree_add_item(tree, hf_ssl_handshake_comp_method, tvb, offset, 1, FALSE); } } static void dissect_ssl3_hnd_cert(tvbuff_t *tvb, proto_tree *tree, guint32 offset) { /* opaque ASN.1Cert<2^24-1>; * * struct { * ASN.1Cert certificate_list<1..2^24-1>; * } Certificate; */ guint32 certificate_list_length; proto_tree *ti; proto_tree *subtree; if (tree) { certificate_list_length = tvb_get_ntoh24(tvb, offset); proto_tree_add_uint(tree, hf_ssl_handshake_certificates_len, tvb, offset, 3, certificate_list_length); offset += 3; /* 24-bit length value */ if (certificate_list_length > 0) { ti = proto_tree_add_none_format(tree, hf_ssl_handshake_certificates, tvb, offset, certificate_list_length, "Certificates (%u byte%s)", certificate_list_length, plurality(certificate_list_length, "", "s")); /* make it a subtree */ subtree = proto_item_add_subtree(ti, ett_ssl_certs); if (!subtree) { subtree = tree; /* failsafe */ } /* iterate through each certificate */ while (certificate_list_length > 0) { /* get the length of the current certificate */ guint32 cert_length = tvb_get_ntoh24(tvb, offset); certificate_list_length -= 3 + cert_length; proto_tree_add_item(subtree, hf_ssl_handshake_certificate_len, tvb, offset, 3, FALSE); offset += 3; proto_tree_add_bytes_format(subtree, hf_ssl_handshake_certificate, tvb, offset, cert_length, tvb_get_ptr(tvb, offset, cert_length), "Certificate (%u byte%s)", cert_length, plurality(cert_length, "", "s")); offset += cert_length; } } } } static void dissect_ssl3_hnd_cert_req(tvbuff_t *tvb, proto_tree *tree, guint32 offset) { /* * enum { * rsa_sign(1), dss_sign(2), rsa_fixed_dh(3), dss_fixed_dh(4), * (255) * } ClientCertificateType; * * opaque DistinguishedName<1..2^16-1>; * * struct { * ClientCertificateType certificate_types<1..2^8-1>; * DistinguishedName certificate_authorities<3..2^16-1>; * } CertificateRequest; * */ proto_tree *ti; proto_tree *subtree; guint8 cert_types_count = 0; int dnames_length = 0; if (tree) { cert_types_count = tvb_get_guint8(tvb, offset); proto_tree_add_uint(tree, hf_ssl_handshake_cert_types_count, tvb, offset, 1, cert_types_count); offset++; if (cert_types_count > 0) { ti = proto_tree_add_none_format(tree, hf_ssl_handshake_cert_types, tvb, offset, cert_types_count, "Certificate types (%u type%s)", cert_types_count, plurality(cert_types_count, "", "s")); subtree = proto_item_add_subtree(ti, ett_ssl_cert_types); if (!subtree) { subtree = tree; } while (cert_types_count > 0) { proto_tree_add_item(subtree, hf_ssl_handshake_cert_type, tvb, offset, 1, FALSE); offset++; cert_types_count--; } } dnames_length = tvb_get_ntohs(tvb, offset); proto_tree_add_uint(tree, hf_ssl_handshake_dnames_len, tvb, offset, 2, dnames_length); offset += 2; if (dnames_length > 0) { ti = proto_tree_add_none_format(tree, hf_ssl_handshake_dnames, tvb, offset, dnames_length, "Distinguished Names (%d byte%s)", dnames_length, plurality(dnames_length, "", "s")); subtree = proto_item_add_subtree(ti, ett_ssl_dnames); if (!subtree) { subtree = tree; } while (dnames_length > 0) { /* get the length of the current certificate */ guint16 name_length = tvb_get_ntohs(tvb, offset); dnames_length -= 2 + name_length; proto_tree_add_item(subtree, hf_ssl_handshake_dname_len, tvb, offset, 2, FALSE); offset += 2; proto_tree_add_bytes_format(subtree, hf_ssl_handshake_dname, tvb, offset, name_length, tvb_get_ptr(tvb, offset, name_length), "Distinguished Name (%u byte%s)", name_length, plurality(name_length, "", "s")); offset += name_length; } } } } static void dissect_ssl3_hnd_finished(tvbuff_t *tvb, proto_tree *tree, guint32 offset, guint *conv_version) { /* For TLS: * struct { * opaque verify_data[12]; * } Finished; * * For SSLv3: * struct { * opaque md5_hash[16]; * opaque sha_hash[20]; * } Finished; */ /* this all needs a tree, so bail if we don't have one */ if (!tree) { return; } switch(*conv_version) { case SSL_VER_TLS: proto_tree_add_item(tree, hf_ssl_handshake_finished, tvb, offset, 12, FALSE); break; case SSL_VER_SSLv3: proto_tree_add_item(tree, hf_ssl_handshake_md5_hash, tvb, offset, 16, FALSE); offset += 16; proto_tree_add_item(tree, hf_ssl_handshake_sha_hash, tvb, offset, 20, FALSE); offset += 20; break; } } /********************************************************************* * * SSL version 2 Dissectors * *********************************************************************/ /* record layer dissector */ static int dissect_ssl2_record(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, guint32 offset, guint *conv_version, gboolean *need_desegmentation) { guint32 initial_offset = offset; guint8 byte = 0; guint8 record_length_length = 0; guint32 record_length = 0; gint is_escape = -1; gint16 padding_length = -1; guint8 msg_type = 0; gchar *msg_type_str = NULL; guint32 available_bytes = 0; proto_tree *ti; proto_tree *ssl_record_tree = NULL; /* pull first byte; if high bit is set, then record * length is three bytes due to padding; otherwise * record length is two bytes */ byte = tvb_get_guint8(tvb, offset); record_length_length = (byte & 0x80) ? 2 : 3; /* * Can we do reassembly? */ available_bytes = tvb_length_remaining(tvb, offset); if (ssl_desegment && pinfo->can_desegment) { /* * Yes - is the record header split across segment boundaries? */ if (available_bytes < record_length_length) { /* * Yes. Tell the TCP dissector where the data for this * message starts in the data it handed us, and how many * more bytes we need, and return. */ pinfo->desegment_offset = offset; pinfo->desegment_len = record_length_length - available_bytes; *need_desegmentation = TRUE; return offset; } } /* parse out the record length */ switch(record_length_length) { case 2: /* two-byte record length */ record_length = (byte & 0x7f) << 8; byte = tvb_get_guint8(tvb, offset + 1); record_length += byte; break; case 3: /* three-byte record length */ is_escape = (byte & 0x40) ? TRUE : FALSE; record_length = (byte & 0x3f) << 8; byte = tvb_get_guint8(tvb, offset + 1); record_length += byte; byte = tvb_get_guint8(tvb, offset + 2); padding_length = byte; } /* * Can we do reassembly? */ if (ssl_desegment && pinfo->can_desegment) { /* * Yes - is the record split across segment boundaries? */ if (available_bytes < (record_length_length + record_length)) { /* * Yes. Tell the TCP dissector where the data for this * message starts in the data it handed us, and how many * more bytes we need, and return. */ pinfo->desegment_offset = offset; pinfo->desegment_len = (record_length_length + record_length) - available_bytes; *need_desegmentation = TRUE; return offset; } } offset += record_length_length; /* add the record layer subtree header */ ti = proto_tree_add_item(tree, hf_ssl2_record, tvb, initial_offset, record_length_length + record_length, 0); ssl_record_tree = proto_item_add_subtree(ti, ett_ssl_record); /* pull the msg_type so we can bail if it's unknown */ msg_type = tvb_get_guint8(tvb, initial_offset + record_length_length); /* if we get a server_hello or later handshake in v2, then set * this to sslv2 */ if (*conv_version == SSL_VER_UNKNOWN) { if (ssl_looks_like_valid_pct_handshake(tvb, (initial_offset + record_length_length), record_length)) { *conv_version = SSL_VER_PCT; ssl_set_conv_version(pinfo, *conv_version); } else if (msg_type >= 2 && msg_type <= 8) { *conv_version = SSL_VER_SSLv2; ssl_set_conv_version(pinfo, *conv_version); } } /* if we get here, but don't have a version set for the * conversation, then set a version for just this frame * (e.g., on a client hello) */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) { col_set_str(pinfo->cinfo, COL_PROTOCOL, (*conv_version == SSL_VER_PCT) ? "PCT" : "SSLv2"); } /* see if the msg_type is valid; if not the payload is * probably encrypted, so note that fact and bail */ msg_type_str = match_strval(msg_type, (*conv_version == SSL_VER_PCT) ? pct_msg_types : ssl_20_msg_types); if (!msg_type_str || ((*conv_version != SSL_VER_PCT) && !ssl_looks_like_valid_v2_handshake(tvb, initial_offset + record_length_length, record_length)) || ((*conv_version == SSL_VER_PCT) && !ssl_looks_like_valid_pct_handshake(tvb, initial_offset + record_length_length, record_length))) { if (ssl_record_tree) { proto_item_set_text(ssl_record_tree, "%s Record Layer: %s", (*conv_version == SSL_VER_PCT) ? "PCT" : "SSLv2", "Encrypted Data"); } if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, "Encrypted Data"); return initial_offset + record_length_length + record_length; } else { if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, msg_type_str); if (ssl_record_tree) { proto_item_set_text(ssl_record_tree, "%s Record Layer: %s", (*conv_version == SSL_VER_PCT) ? "PCT" : "SSLv2", msg_type_str); } } /* We have a valid message type, so move foward, filling in the * tree by adding the length, is_escape boolean and padding_length, * if present in the original packet */ if (ssl_record_tree) { /* add the record length */ ti = proto_tree_add_uint (ssl_record_tree, hf_ssl_record_length, tvb, initial_offset, record_length_length, record_length); } if (ssl_record_tree && is_escape != -1) { proto_tree_add_boolean(ssl_record_tree, hf_ssl2_record_is_escape, tvb, initial_offset, 1, is_escape); } if (ssl_record_tree && padding_length != -1) { proto_tree_add_uint(ssl_record_tree, hf_ssl2_record_padding_length, tvb, initial_offset + 2, 1, padding_length); } /* * dissect the record data */ /* jump forward to the start of the record data */ offset = initial_offset + record_length_length; /* add the message type */ if (ssl_record_tree) { proto_tree_add_item(ssl_record_tree, (*conv_version == SSL_VER_PCT) ? hf_pct_msg_type : hf_ssl2_msg_type, tvb, offset, 1, 0); } offset++; /* move past msg_type byte */ if (*conv_version != SSL_VER_PCT) { /* dissect the message (only handle client hello right now) */ switch (msg_type) { case SSL2_HND_CLIENT_HELLO: dissect_ssl2_hnd_client_hello(tvb, ssl_record_tree, offset); break; case SSL2_HND_CLIENT_MASTER_KEY: dissect_ssl2_hnd_client_master_key(tvb, ssl_record_tree, offset); break; case SSL2_HND_SERVER_HELLO: dissect_ssl2_hnd_server_hello(tvb, ssl_record_tree, offset); break; case SSL2_HND_ERROR: case SSL2_HND_CLIENT_FINISHED: case SSL2_HND_SERVER_VERIFY: case SSL2_HND_SERVER_FINISHED: case SSL2_HND_REQUEST_CERTIFICATE: case SSL2_HND_CLIENT_CERTIFICATE: /* unimplemented */ break; default: /* unknown */ break; } } else { /* dissect the message */ switch (msg_type) { case PCT_MSG_CLIENT_HELLO: case PCT_MSG_SERVER_HELLO: case PCT_MSG_CLIENT_MASTER_KEY: case PCT_MSG_SERVER_VERIFY: case PCT_MSG_ERROR: /* unimplemented */ break; default: /* unknown */ break; } } return (initial_offset + record_length_length + record_length); } static void dissect_ssl2_hnd_client_hello(tvbuff_t *tvb, proto_tree *tree, guint32 offset) { /* struct { * uint8 msg_type; * Version version; * uint16 cipher_spec_length; * uint16 session_id_length; * uint16 challenge_length; * V2CipherSpec cipher_specs[V2ClientHello.cipher_spec_length]; * opaque session_id[V2ClientHello.session_id_length]; * Random challenge; * } V2ClientHello; * * Note: when we get here, offset's already pointing at Version * */ guint16 version; guint16 cipher_spec_length; guint16 session_id_length; guint16 challenge_length; proto_tree *ti; proto_tree *cs_tree; version = tvb_get_ntohs(tvb, offset); if (!ssl_is_valid_ssl_version(version)) { /* invalid version; probably encrypted data */ return; } if (tree) { /* show the version */ proto_tree_add_item(tree, hf_ssl_record_version, tvb, offset, 2, FALSE); offset += 2; cipher_spec_length = tvb_get_ntohs(tvb, offset); proto_tree_add_item(tree, hf_ssl2_handshake_cipher_spec_len, tvb, offset, 2, FALSE); offset += 2; session_id_length = tvb_get_ntohs(tvb, offset); proto_tree_add_item(tree, hf_ssl2_handshake_session_id_len, tvb, offset, 2, FALSE); offset += 2; challenge_length = tvb_get_ntohs(tvb, offset); proto_tree_add_item(tree, hf_ssl2_handshake_challenge_len, tvb, offset, 2, FALSE); offset += 2; /* tell the user how many cipher specs they've won */ ti = proto_tree_add_none_format(tree, hf_ssl_handshake_cipher_suites, tvb, offset, cipher_spec_length, "Cipher Specs (%u specs)", cipher_spec_length/3); /* make this a subtree and expand the actual specs below */ cs_tree = proto_item_add_subtree(ti, ett_ssl_cipher_suites); if (!cs_tree) { cs_tree = tree; /* failsafe */ } /* iterate through the cipher specs, showing them */ while (cipher_spec_length > 0) { proto_tree_add_item(cs_tree, hf_ssl2_handshake_cipher_spec, tvb, offset, 3, FALSE); offset += 3; /* length of one cipher spec */ cipher_spec_length -= 3; } /* if there's a session id, show it */ if (session_id_length > 0) { proto_tree_add_bytes_format(tree, hf_ssl_handshake_session_id, tvb, offset, session_id_length, tvb_get_ptr(tvb, offset, session_id_length), "Session ID (%u byte%s)", session_id_length, plurality(session_id_length, "", "s")); offset += session_id_length; } /* if there's a challenge, show it */ if (challenge_length > 0) { proto_tree_add_item(tree, hf_ssl2_handshake_challenge, tvb, offset, challenge_length, 0); offset += challenge_length; } } } static void dissect_ssl2_hnd_client_master_key(tvbuff_t *tvb, proto_tree *tree, guint32 offset) { /* struct { * uint8 msg_type; * V2Cipherspec cipher; * uint16 clear_key_length; * uint16 encrypted_key_length; * uint16 key_arg_length; * opaque clear_key_data[V2ClientMasterKey.clear_key_length]; * opaque encrypted_key_data[V2ClientMasterKey.encrypted_key_length]; * opaque key_arg_data[V2ClientMasterKey.key_arg_length]; * } V2ClientMasterKey; * * Note: when we get here, offset's already pointing at cipher */ guint16 clear_key_length; guint16 encrypted_key_length; guint16 key_arg_length; /* at this point, everything we do involves the tree, * so quit now if we don't have one ;-) */ if (!tree) { return; } /* show the selected cipher */ proto_tree_add_item(tree, hf_ssl2_handshake_cipher_spec, tvb, offset, 3, FALSE); offset += 3; /* get the fixed fields */ clear_key_length = tvb_get_ntohs(tvb, offset); proto_tree_add_item(tree, hf_ssl2_handshake_clear_key_len, tvb, offset, 2, FALSE); offset += 2; encrypted_key_length = tvb_get_ntohs(tvb, offset); proto_tree_add_item(tree, hf_ssl2_handshake_enc_key_len, tvb, offset, 2, FALSE); offset += 2; key_arg_length = tvb_get_ntohs(tvb, offset); proto_tree_add_item(tree, hf_ssl2_handshake_key_arg_len, tvb, offset, 2, FALSE); offset += 2; /* show the variable length fields */ if (clear_key_length > 0) { proto_tree_add_item(tree, hf_ssl2_handshake_clear_key, tvb, offset, clear_key_length, FALSE); offset += clear_key_length; } if (encrypted_key_length > 0) { proto_tree_add_item(tree, hf_ssl2_handshake_enc_key, tvb, offset, encrypted_key_length, FALSE); offset += encrypted_key_length; } if (key_arg_length > 0) { proto_tree_add_item(tree, hf_ssl2_handshake_key_arg, tvb, offset, key_arg_length, FALSE); offset += key_arg_length; } } static void dissect_ssl2_hnd_server_hello(tvbuff_t *tvb, proto_tree *tree, guint32 offset) { /* struct { * uint8 msg_type; * uint8 session_id_hit; * uint8 certificate_type; * uint16 server_version; * uint16 certificate_length; * uint16 cipher_specs_length; * uint16 connection_id_length; * opaque certificate_data[V2ServerHello.certificate_length]; * opaque cipher_specs_data[V2ServerHello.cipher_specs_length]; * opaque connection_id_data[V2ServerHello.connection_id_length]; * } V2ServerHello; * * Note: when we get here, offset's already pointing at session_id_hit */ guint16 certificate_length; guint16 cipher_spec_length; guint16 connection_id_length; guint16 version; proto_tree *ti; proto_tree *subtree; /* everything we do only makes sense with a tree, so * quit now if we don't have one */ if (!tree) { return; } version = tvb_get_ntohs(tvb, offset + 2); if (!ssl_is_valid_ssl_version(version)) { /* invalid version; probably encrypted data */ return; } /* is there a hit? */ proto_tree_add_item(tree, hf_ssl2_handshake_session_id_hit, tvb, offset, 1, FALSE); offset++; /* what type of certificate is this? */ proto_tree_add_item(tree, hf_ssl2_handshake_cert_type, tvb, offset, 1, FALSE); offset++; /* now the server version */ proto_tree_add_item(tree, hf_ssl_handshake_server_version, tvb, offset, 2, FALSE); offset += 2; /* get the fixed fields */ certificate_length = tvb_get_ntohs(tvb, offset); proto_tree_add_uint(tree, hf_ssl_handshake_certificate_len, tvb, offset, 2, certificate_length); offset += 2; cipher_spec_length = tvb_get_ntohs(tvb, offset); proto_tree_add_uint(tree, hf_ssl2_handshake_cipher_spec_len, tvb, offset, 2, cipher_spec_length); offset += 2; connection_id_length = tvb_get_ntohs(tvb, offset); proto_tree_add_uint(tree, hf_ssl2_handshake_connection_id_len, tvb, offset, 2, connection_id_length); offset += 2; /* now the variable length fields */ if (certificate_length > 0) { proto_tree_add_bytes_format(tree, hf_ssl_handshake_certificate, tvb, offset, certificate_length, tvb_get_ptr(tvb, offset, certificate_length), "Certificate (%u byte%s)", certificate_length, plurality(certificate_length, "", "s")); offset += certificate_length; } if (cipher_spec_length > 0) { /* provide a collapsing node for the cipher specs */ ti = proto_tree_add_none_format(tree, hf_ssl_handshake_cipher_suites, tvb, offset, cipher_spec_length, "Cipher Specs (%u spec%s)", cipher_spec_length/3, plurality(cipher_spec_length/3, "", "s")); subtree = proto_item_add_subtree(ti, ett_ssl_cipher_suites); if (!subtree) { subtree = tree; } /* iterate through the cipher specs */ while (cipher_spec_length > 0) { proto_tree_add_item(subtree, hf_ssl2_handshake_cipher_spec, tvb, offset, 3, FALSE); offset += 3; cipher_spec_length -= 3; } } if (connection_id_length > 0) { proto_tree_add_item(tree, hf_ssl2_handshake_connection_id, tvb, offset, connection_id_length, FALSE); offset += connection_id_length; } } /********************************************************************* * * Support Functions * *********************************************************************/ static void ssl_set_conv_version(packet_info *pinfo, guint version) { conversation_t *conversation; if (pinfo->fd->flags.visited) { /* We've already processed this frame; no need to do any more * work on it. */ return; } conversation = find_conversation(&pinfo->src, &pinfo->dst, pinfo->ptype, pinfo->srcport, pinfo->destport, 0); if (conversation == NULL) { /* create a new conversation */ conversation = conversation_new(&pinfo->src, &pinfo->dst, pinfo->ptype, pinfo->srcport, pinfo->destport, 0); } if (conversation_get_proto_data(conversation, proto_ssl) != NULL) { /* get rid of the current data */ conversation_delete_proto_data(conversation, proto_ssl); } conversation_add_proto_data(conversation, proto_ssl, (void *)version); } static int ssl_is_valid_handshake_type(guint8 type) { switch (type) { case SSL_HND_HELLO_REQUEST: case SSL_HND_CLIENT_HELLO: case SSL_HND_SERVER_HELLO: case SSL_HND_CERTIFICATE: case SSL_HND_SERVER_KEY_EXCHG: case SSL_HND_CERT_REQUEST: case SSL_HND_SVR_HELLO_DONE: case SSL_HND_CERT_VERIFY: case SSL_HND_CLIENT_KEY_EXCHG: case SSL_HND_FINISHED: return 1; } return 0; } static int ssl_is_valid_content_type(guint8 type) { if (type >= 0x14 && type <= 0x17) { return 1; } return 0; } static int ssl_is_valid_ssl_version(guint16 version) { gchar *version_str = match_strval(version, ssl_versions); return version_str != NULL; } static int ssl_is_authoritative_version_message(guint8 content_type, guint8 next_byte) { if (content_type == SSL_ID_HANDSHAKE && ssl_is_valid_handshake_type(next_byte)) { return (next_byte != SSL_HND_CLIENT_HELLO); } else if (ssl_is_valid_content_type(content_type) && content_type != SSL_ID_HANDSHAKE) { return 1; } return 0; } static int ssl_is_v2_client_hello(tvbuff_t *tvb, guint32 offset) { guint8 byte; byte = tvb_get_guint8(tvb, offset); if (byte != 0x80) /* v2 client hello should start this way */ { return 0; } byte = tvb_get_guint8(tvb, offset+2); if (byte != 0x01) /* v2 client hello msg type */ { return 0; } /* 1 in 2^16 of being right; improve later if necessary */ return 1; } /* this applies a heuristic to determine whether * or not the data beginning at offset looks like a * valid sslv2 record. this isn't really possible, * but we'll try to do a reasonable job anyway. */ static int ssl_looks_like_sslv2(tvbuff_t *tvb, guint32 offset) { /* here's the current approach: * * we only try to catch unencrypted handshake messages, so we can * assume that there is not padding. This means that the * first byte must be >= 0x80 and there must be a valid sslv2 * msg_type in the third byte */ /* get the first byte; must have high bit set */ guint8 byte = tvb_get_guint8(tvb, offset); if (byte < 0x80) { return 0; } /* get the supposed msg_type byte; since we only care about * unencrypted handshake messages (we can't tell the type for * encrypted messages), we just check against that list */ byte = tvb_get_guint8(tvb, offset + 2); switch(byte) { case SSL2_HND_ERROR: case SSL2_HND_CLIENT_HELLO: case SSL2_HND_CLIENT_MASTER_KEY: case SSL2_HND_SERVER_HELLO: case PCT_MSG_CLIENT_MASTER_KEY: case PCT_MSG_ERROR: return 1; } return 0; } /* this applies a heuristic to determine whether * or not the data beginning at offset looks like a * valid sslv3 record. this is somewhat more reliable * than sslv2 due to the structure of the v3 protocol */ static int ssl_looks_like_sslv3(tvbuff_t *tvb, guint32 offset) { /* have to have a valid content type followed by a valid * protocol version */ guint8 byte; guint16 version; /* see if the first byte is a valid content type */ byte = tvb_get_guint8(tvb, offset); if (!ssl_is_valid_content_type(byte)) { return 0; } /* now check to see if the version byte appears valid */ version = tvb_get_ntohs(tvb, offset + 1); if (version != 0x0300 && version != 0x0301) { return 0; } return 1; } /* applies a heuristic to determine whether * or not the data beginning at offset looks * like a valid, unencrypted v2 handshake message. * since it isn't possible to completely tell random * data apart from a valid message without state, * we try to help the odds. */ static int ssl_looks_like_valid_v2_handshake(tvbuff_t *tvb, guint32 offset, guint32 record_length) { /* first byte should be a msg_type. * * - we know we only see client_hello, client_master_key, * and server_hello in the clear, so check to see if * msg_type is one of those (this gives us a 3 in 2^8 * chance of saying yes with random payload) * * - for those three types that we know about, do some * further validation to reduce the chance of an error */ guint8 msg_type; guint16 version; guint32 sum; /* fetch the msg_type */ msg_type = tvb_get_guint8(tvb, offset); switch (msg_type) { case SSL2_HND_CLIENT_HELLO: /* version follows msg byte, so verify that this is valid */ version = tvb_get_ntohs(tvb, offset+1); return ssl_is_valid_ssl_version(version); break; case SSL2_HND_SERVER_HELLO: /* version is three bytes after msg_type */ version = tvb_get_ntohs(tvb, offset+3); return ssl_is_valid_ssl_version(version); break; case SSL2_HND_CLIENT_MASTER_KEY: /* sum of clear_key_length, encrypted_key_length, and key_arg_length * must be less than record length */ sum = tvb_get_ntohs(tvb, offset + 4); /* clear_key_length */ sum += tvb_get_ntohs(tvb, offset + 6); /* encrypted_key_length */ sum += tvb_get_ntohs(tvb, offset + 8); /* key_arg_length */ if (sum > record_length) { return 0; } return 1; break; default: return 0; } return 0; } /* applies a heuristic to determine whether * or not the data beginning at offset looks * like a valid, unencrypted v2 handshake message. * since it isn't possible to completely tell random * data apart from a valid message without state, * we try to help the odds. */ static int ssl_looks_like_valid_pct_handshake(tvbuff_t *tvb, guint32 offset, guint32 record_length) { /* first byte should be a msg_type. * * - we know we only see client_hello, client_master_key, * and server_hello in the clear, so check to see if * msg_type is one of those (this gives us a 3 in 2^8 * chance of saying yes with random payload) * * - for those three types that we know about, do some * further validation to reduce the chance of an error */ guint8 msg_type; guint16 version; guint32 sum; /* fetch the msg_type */ msg_type = tvb_get_guint8(tvb, offset); switch (msg_type) { case PCT_MSG_CLIENT_HELLO: /* version follows msg byte, so verify that this is valid */ version = tvb_get_ntohs(tvb, offset+1); return version == PCT_VERSION_1; break; case PCT_MSG_SERVER_HELLO: /* version is one byte after msg_type */ version = tvb_get_ntohs(tvb, offset+2); return version == PCT_VERSION_1; break; case PCT_MSG_CLIENT_MASTER_KEY: /* sum of various length fields must be less than record length */ sum = tvb_get_ntohs(tvb, offset + 6); /* clear_key_length */ sum += tvb_get_ntohs(tvb, offset + 8); /* encrypted_key_length */ sum += tvb_get_ntohs(tvb, offset + 10); /* key_arg_length */ sum += tvb_get_ntohs(tvb, offset + 12); /* verify_prelude_length */ sum += tvb_get_ntohs(tvb, offset + 14); /* client_cert_length */ sum += tvb_get_ntohs(tvb, offset + 16); /* response_length */ if (sum > record_length) { return 0; } return 1; break; case PCT_MSG_SERVER_VERIFY: /* record is 36 bytes longer than response_length */ sum = tvb_get_ntohs(tvb, offset + 34); /* response_length */ if ((sum + 36) == record_length) return 1; else return 0; break; default: return 0; } return 0; } /********************************************************************* * * Standard Ethereal Protocol Registration and housekeeping * *********************************************************************/ void proto_register_ssl(void) { /* Setup list of header fields See Section 1.6.1 for details*/ static hf_register_info hf[] = { { &hf_ssl_record, { "Record Layer", "ssl.record", FT_NONE, BASE_NONE, NULL, 0x0, "Record layer", HFILL } }, { &hf_ssl_record_content_type, { "Content Type", "ssl.record.content_type", FT_UINT8, BASE_DEC, VALS(ssl_31_content_type), 0x0, "Content type", HFILL} }, { &hf_ssl2_msg_type, { "Handshake Message Type", "ssl.handshake.type", FT_UINT8, BASE_DEC, VALS(ssl_20_msg_types), 0x0, "SSLv2 handshake message type", HFILL} }, { &hf_pct_msg_type, { "Handshake Message Type", "ssl.pct_handshake.type", FT_UINT8, BASE_DEC, VALS(pct_msg_types), 0x0, "PCT handshake message type", HFILL} }, { &hf_ssl_record_version, { "Version", "ssl.record.version", FT_UINT16, BASE_HEX, VALS(ssl_versions), 0x0, "Record layer version.", HFILL } }, { &hf_ssl_record_length, { "Length", "ssl.record.length", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of SSL record data", HFILL } }, { &hf_ssl_record_appdata, { "Application Data", "ssl.app_data", FT_NONE, BASE_NONE, NULL, 0x0, "Payload is application data", HFILL } }, { & hf_ssl2_record, { "SSLv2/PCT Record Header", "ssl.record", FT_NONE, BASE_DEC, NULL, 0x0, "SSLv2/PCT record data", HFILL } }, { &hf_ssl2_record_is_escape, { "Is Escape", "ssl.record.is_escape", FT_BOOLEAN, BASE_NONE, NULL, 0x0, "Indicates a security escape", HFILL} }, { &hf_ssl2_record_padding_length, { "Padding Length", "ssl.record.padding_length", FT_UINT8, BASE_DEC, NULL, 0x0, "Length of padding at end of record", HFILL } }, { &hf_ssl_change_cipher_spec, { "Change Cipher Spec Message", "ssl.change_cipher_spec", FT_NONE, BASE_NONE, NULL, 0x0, "Signals a change in cipher specifications", HFILL } }, { & hf_ssl_alert_message, { "Alert Message", "ssl.alert_message", FT_NONE, BASE_NONE, NULL, 0x0, "Alert message", HFILL } }, { & hf_ssl_alert_message_level, { "Level", "ssl.alert_message.level", FT_UINT8, BASE_DEC, VALS(ssl_31_alert_level), 0x0, "Alert message level", HFILL } }, { &hf_ssl_alert_message_description, { "Description", "ssl.alert_message.desc", FT_UINT8, BASE_DEC, VALS(ssl_31_alert_description), 0x0, "Alert message description", HFILL } }, { &hf_ssl_handshake_protocol, { "Handshake Protocol", "ssl.handshake", FT_NONE, BASE_NONE, NULL, 0x0, "Handshake protocol message", HFILL} }, { &hf_ssl_handshake_type, { "Handshake Type", "ssl.handshake.type", FT_UINT8, BASE_DEC, VALS(ssl_31_handshake_type), 0x0, "Type of handshake message", HFILL} }, { &hf_ssl_handshake_length, { "Length", "ssl.handshake.length", FT_UINT24, BASE_DEC, NULL, 0x0, "Length of handshake message", HFILL } }, { &hf_ssl_handshake_client_version, { "Version", "ssl.handshake.version", FT_UINT16, BASE_HEX, VALS(ssl_versions), 0x0, "Maximum version supported by client", HFILL } }, { &hf_ssl_handshake_server_version, { "Version", "ssl.handshake.version", FT_UINT16, BASE_HEX, VALS(ssl_versions), 0x0, "Version selected by server", HFILL } }, { &hf_ssl_handshake_random_time, { "Random.gmt_unix_time", "ssl.handshake.random_time", FT_ABSOLUTE_TIME, BASE_NONE, NULL, 0x0, "Unix time field of random structure", HFILL } }, { &hf_ssl_handshake_random_bytes, { "Random.bytes", "ssl.handshake.random", FT_NONE, BASE_NONE, NULL, 0x0, "Random challenge used to authenticate server", HFILL } }, { &hf_ssl_handshake_cipher_suites_len, { "Cipher Suites Length", "ssl.handshake.cipher_suites_length", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of cipher suites field", HFILL } }, { &hf_ssl_handshake_cipher_suites, { "Cipher Suites", "ssl.handshake.ciphersuites", FT_NONE, BASE_NONE, NULL, 0x0, "List of cipher suites supported by client", HFILL } }, { &hf_ssl_handshake_cipher_suite, { "Cipher Suite", "ssl.handshake.ciphersuite", FT_UINT16, BASE_HEX, VALS(ssl_31_ciphersuite), 0x0, "Cipher suite", HFILL } }, { &hf_ssl2_handshake_cipher_spec, { "Cipher Spec", "ssl.handshake.cipherspec", FT_UINT24, BASE_HEX, VALS(ssl_20_cipher_suites), 0x0, "Cipher specification", HFILL } }, { &hf_ssl_handshake_session_id, { "Session ID", "ssl.handshake.session_id", FT_BYTES, BASE_NONE, NULL, 0x0, "Identifies the SSL session, allowing later resumption", HFILL } }, { &hf_ssl_handshake_comp_methods_len, { "Compression Methods Length", "ssl.handshake.comp_methods_length", FT_UINT8, BASE_DEC, NULL, 0x0, "Length of compression methods field", HFILL } }, { &hf_ssl_handshake_comp_methods, { "Compression Methods", "ssl.handshake.comp_methods", FT_NONE, BASE_NONE, NULL, 0x0, "List of compression methods supported by client", HFILL } }, { &hf_ssl_handshake_comp_method, { "Compression Method", "ssl.handshake.comp_method", FT_UINT8, BASE_DEC, VALS(ssl_31_compression_method), 0x0, "Compression Method", HFILL } }, { &hf_ssl_handshake_certificates_len, { "Certificates Length", "ssl.handshake.certificates_length", FT_UINT24, BASE_DEC, NULL, 0x0, "Length of certificates field", HFILL } }, { &hf_ssl_handshake_certificates, { "Certificates", "ssl.handshake.certificates", FT_NONE, BASE_NONE, NULL, 0x0, "List of certificates", HFILL } }, { &hf_ssl_handshake_certificate, { "Certificate", "ssl.handshake.certificate", FT_BYTES, BASE_NONE, NULL, 0x0, "Certificate", HFILL } }, { &hf_ssl_handshake_certificate_len, { "Certificate Length", "ssl.handshake.certificate_length", FT_UINT24, BASE_DEC, NULL, 0x0, "Length of certificate", HFILL } }, { &hf_ssl_handshake_cert_types_count, { "Certificate types count", "ssl.handshake.cert_types_count", FT_UINT8, BASE_DEC, NULL, 0x0, "Count of certificate types", HFILL } }, { &hf_ssl_handshake_cert_types, { "Certificate types", "ssl.handshake.cert_types", FT_NONE, BASE_NONE, NULL, 0x0, "List of certificate types", HFILL } }, { &hf_ssl_handshake_cert_type, { "Certificate type", "ssl.handshake.cert_type", FT_UINT8, BASE_DEC, VALS(ssl_31_client_certificate_type), 0x0, "Certificate type", HFILL } }, { &hf_ssl_handshake_finished, { "Verify Data", "ssl.handshake.verify_data", FT_NONE, BASE_NONE, NULL, 0x0, "Opaque verification data", HFILL } }, { &hf_ssl_handshake_md5_hash, { "MD5 Hash", "ssl.handshake.md5_hash", FT_NONE, BASE_NONE, NULL, 0x0, "Hash of messages, master_secret, etc.", HFILL } }, { &hf_ssl_handshake_sha_hash, { "SHA-1 Hash", "ssl.handshake.sha_hash", FT_NONE, BASE_NONE, NULL, 0x0, "Hash of messages, master_secret, etc.", HFILL } }, { &hf_ssl_handshake_session_id_len, { "Session ID Length", "ssl.handshake.session_id_length", FT_UINT8, BASE_DEC, NULL, 0x0, "Length of session ID field", HFILL } }, { &hf_ssl_handshake_dnames_len, { "Distinguished Names Length", "ssl.handshake.dnames_len", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of list of CAs that server trusts", HFILL } }, { &hf_ssl_handshake_dnames, { "Distinguished Names", "ssl.handshake.dnames", FT_NONE, BASE_NONE, NULL, 0x0, "List of CAs that server trusts", HFILL } }, { &hf_ssl_handshake_dname_len, { "Distinguished Name Length", "ssl.handshake.dname_len", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of distinguished name", HFILL } }, { &hf_ssl_handshake_dname, { "Distinguished Name", "ssl.handshake.dname", FT_BYTES, BASE_NONE, NULL, 0x0, "Distinguished name of a CA that server trusts", HFILL } }, { &hf_ssl2_handshake_challenge, { "Challenge", "ssl.handshake.challenge", FT_NONE, BASE_NONE, NULL, 0x0, "Challenge data used to authenticate server", HFILL } }, { &hf_ssl2_handshake_cipher_spec_len, { "Cipher Spec Length", "ssl.handshake.cipher_spec_len", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of cipher specs field", HFILL } }, { &hf_ssl2_handshake_session_id_len, { "Session ID Length", "ssl.handshake.session_id_length", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of session ID field", HFILL } }, { &hf_ssl2_handshake_challenge_len, { "Challenge Length", "ssl.handshake.challenge_length", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of challenge field", HFILL } }, { &hf_ssl2_handshake_clear_key_len, { "Clear Key Data Length", "ssl.handshake.clear_key_length", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of clear key data", HFILL } }, { &hf_ssl2_handshake_enc_key_len, { "Encrypted Key Data Length", "ssl.handshake.encrypted_key_length", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of encrypted key data", HFILL } }, { &hf_ssl2_handshake_key_arg_len, { "Key Argument Length", "ssl.handshake.key_arg_length", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of key argument", HFILL } }, { &hf_ssl2_handshake_clear_key, { "Clear Key Data", "ssl.handshake.clear_key_data", FT_NONE, BASE_NONE, NULL, 0x0, "Clear portion of MASTER-KEY", HFILL } }, { &hf_ssl2_handshake_enc_key, { "Encrypted Key", "ssl.handshake.encrypted_key", FT_NONE, BASE_NONE, NULL, 0x0, "Secret portion of MASTER-KEY encrypted to server", HFILL } }, { &hf_ssl2_handshake_key_arg, { "Key Argument", "ssl.handshake.key_arg", FT_NONE, BASE_NONE, NULL, 0x0, "Key Argument (e.g., Initialization Vector)", HFILL } }, { &hf_ssl2_handshake_session_id_hit, { "Session ID Hit", "ssl.handshake.session_id_hit", FT_BOOLEAN, BASE_NONE, NULL, 0x0, "Did the server find the client's Session ID?", HFILL } }, { &hf_ssl2_handshake_cert_type, { "Certificate Type", "ssl.handshake.cert_type", FT_UINT8, BASE_DEC, VALS(ssl_20_certificate_type), 0x0, "Certificate Type", HFILL } }, { &hf_ssl2_handshake_connection_id_len, { "Connection ID Length", "ssl.handshake.connection_id_length", FT_UINT16, BASE_DEC, NULL, 0x0, "Length of connection ID", HFILL } }, { &hf_ssl2_handshake_connection_id, { "Connection ID", "ssl.handshake.connection_id", FT_NONE, BASE_NONE, NULL, 0x0, "Server's challenge to client", HFILL } }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_ssl, &ett_ssl_record, &ett_ssl_alert, &ett_ssl_handshake, &ett_ssl_cipher_suites, &ett_ssl_comp_methods, &ett_ssl_certs, &ett_ssl_cert_types, &ett_ssl_dnames, }; /* Register the protocol name and description */ proto_ssl = proto_register_protocol("Secure Socket Layer", "SSL", "ssl"); /* Required function calls to register the header fields and * subtrees used */ proto_register_field_array(proto_ssl, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); { module_t *ssl_module = prefs_register_protocol(proto_ssl, NULL); prefs_register_bool_preference(ssl_module, "desegment_ssl_records", "Desegment SSL records", "When enabled, SSL records that span multiple TCP segments are desegmented", &ssl_desegment); } register_dissector("ssl", dissect_ssl, proto_ssl); } /* If this dissector uses sub-dissector registration add a registration * routine. This format is required because a script is used to find * these routines and create the code that calls these routines. */ void proto_reg_handoff_ssl(void) { dissector_handle_t ssl_handle; ssl_handle = find_dissector("ssl"); dissector_add("tcp.port", TCP_PORT_SSL, ssl_handle); dissector_add("tcp.port", TCP_PORT_SSL_LDAP, ssl_handle); dissector_add("tcp.port", TCP_PORT_SSL_IMAP, ssl_handle); dissector_add("tcp.port", TCP_PORT_SSL_POP, ssl_handle); }