/* packet-eapol.c * Routines for EAPOL 802.1X authentication header disassembly * (From IEEE Draft P802.1X/D11; is there a later draft, or a * final standard? If so, check it.) * * Wireshark - 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include #include #include #include "packet-eapol.h" void proto_register_eapol(void); void proto_reg_handoff_eapol(void); static int proto_eapol = -1; static int hf_eapol_version = -1; static int hf_eapol_type = -1; static int hf_eapol_len = -1; static int hf_eapol_keydes_type = -1; static int hf_eapol_keydes_body = -1; static int hf_eapol_keydes_key_len = -1; static int hf_eapol_keydes_replay_counter = -1; static int hf_eapol_keydes_key_iv = -1; static int hf_eapol_keydes_key_index = -1; static int hf_eapol_keydes_key_index_type = -1; static int hf_eapol_keydes_key_index_number = -1; static int hf_eapol_keydes_key_signature = -1; static int hf_eapol_keydes_key = -1; static int hf_eapol_keydes_key_generated_locally = -1; static gint ett_eapol = -1; static gint ett_eapol_key_index = -1; static gint ett_keyinfo = -1; static dissector_table_t eapol_type_dissector_table; static dissector_table_t eapol_keydes_type_dissector_table; static dissector_handle_t eapol_handle; #define EAPOL_HDR_LEN 4 #define EAPOL_2001 1 #define EAPOL_2004 2 #define EAPOL_2010 3 static const value_string eapol_version_vals[] = { { EAPOL_2001, "802.1X-2001" }, { EAPOL_2004, "802.1X-2004" }, { EAPOL_2010, "802.1X-2010" }, { 0, NULL } }; static const value_string eapol_type_vals[] = { { EAPOL_EAP, "EAP Packet" }, { EAPOL_START, "Start" }, { EAPOL_LOGOFF, "Logoff" }, { EAPOL_KEY, "Key" }, { EAPOL_ENCAP_ASF_ALERT, "Encapsulated ASF Alert" }, { EAPOL_MKA, "MKA" }, { 0, NULL } }; static const value_string eapol_keydes_type_vals[] = { { EAPOL_RC4_KEY, "RC4 Descriptor" }, { EAPOL_RSN_KEY, "EAPOL RSN Key" }, { EAPOL_WPA_KEY, "EAPOL WPA Key" }, { 0, NULL } }; static const true_false_string keytype_tfs = { "Unicast", "Broadcast" }; #define KEYDES_KEY_INDEX_TYPE_MASK 0x80 #define KEYDES_KEY_INDEX_NUMBER_MASK 0x7F static int dissect_eapol(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { int offset = 0; guint8 eapol_type; guint16 eapol_len; guint len; proto_tree *ti; proto_tree *eapol_tree; tvbuff_t *next_tvb; col_set_str(pinfo->cinfo, COL_PROTOCOL, "EAPOL"); col_clear(pinfo->cinfo, COL_INFO); ti = proto_tree_add_item(tree, proto_eapol, tvb, 0, -1, ENC_NA); eapol_tree = proto_item_add_subtree(ti, ett_eapol); proto_tree_add_item(eapol_tree, hf_eapol_version, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; eapol_type = tvb_get_guint8(tvb, offset); proto_tree_add_item(eapol_tree, hf_eapol_type, tvb, offset, 1, ENC_BIG_ENDIAN); col_add_str(pinfo->cinfo, COL_INFO, val_to_str(eapol_type, eapol_type_vals, "Unknown Type (0x%02X)")); offset++; eapol_len = tvb_get_ntohs(tvb, offset); len = EAPOL_HDR_LEN + eapol_len; set_actual_length(tvb, len); if (tree) { proto_item_set_len(ti, len); proto_tree_add_item(eapol_tree, hf_eapol_len, tvb, offset, 2, ENC_BIG_ENDIAN); } offset += 2; next_tvb = tvb_new_subset_remaining(tvb, offset); if (!dissector_try_uint_new(eapol_type_dissector_table, eapol_type, next_tvb, pinfo, tree, FALSE, eapol_tree)) { call_data_dissector(next_tvb, pinfo, tree); } return tvb_captured_length(tvb); } static int dissect_eapol_key(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree _U_, void* data) { guint8 keydesc_type; int offset = 0; tvbuff_t *next_tvb; proto_tree* eapol_tree = (proto_tree*)data; keydesc_type = tvb_get_guint8(tvb, offset); proto_tree_add_item(eapol_tree, hf_eapol_keydes_type, tvb, offset, 1, ENC_BIG_ENDIAN); offset += 1; next_tvb = tvb_new_subset_remaining(tvb, offset); if (!dissector_try_uint_new(eapol_keydes_type_dissector_table, keydesc_type, next_tvb, pinfo, eapol_tree, FALSE, NULL)) { proto_tree_add_item(eapol_tree, hf_eapol_keydes_body, tvb, offset, -1, ENC_NA); } return tvb_captured_length(tvb); } static int dissect_eapol_rc4_key(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void *data _U_) { int offset = 0; guint16 eapol_key_len; gboolean generated_locally; proto_tree *ti; proto_tree *key_index_tree; gint eapol_len; eapol_key_len = tvb_get_ntohs(tvb, offset); proto_tree_add_item(tree, hf_eapol_keydes_key_len, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; proto_tree_add_item(tree, hf_eapol_keydes_replay_counter, tvb, offset, 8, ENC_BIG_ENDIAN); offset += 8; proto_tree_add_item(tree, hf_eapol_keydes_key_iv, tvb, offset, 16, ENC_NA); offset += 16; ti = proto_tree_add_item(tree, hf_eapol_keydes_key_index, tvb, offset, 1, ENC_BIG_ENDIAN); key_index_tree = proto_item_add_subtree(ti, ett_eapol_key_index); proto_tree_add_item(key_index_tree, hf_eapol_keydes_key_index_type, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(key_index_tree, hf_eapol_keydes_key_index_number, tvb, offset, 1, ENC_BIG_ENDIAN); offset += 1; proto_tree_add_item(tree, hf_eapol_keydes_key_signature, tvb, offset, 16, ENC_NA); offset += 16; if (eapol_key_len != 0) { /* * Body length of EAPOL-Key message in which we're contained is 1 byte * larger than the reported length of the key descriptor we were handed, * that 1 byte being the Key Descriptor Type. */ eapol_len = 1 + tvb_reported_length(tvb); /* IEEE 802.1X-2004 7.6.3.6: If no bytes remain, then */ generated_locally = eapol_len <= 44; /* Size of rc4 key with no key content */ if (!generated_locally) { proto_tree_add_item(tree, hf_eapol_keydes_key, tvb, offset, eapol_key_len, ENC_NA); } proto_tree_add_boolean(tree, hf_eapol_keydes_key_generated_locally, tvb, offset, 0, generated_locally); } return tvb_captured_length(tvb); } void proto_register_eapol(void) { static hf_register_info hf[] = { { &hf_eapol_version, { "Version", "eapol.version", FT_UINT8, BASE_DEC, VALS(eapol_version_vals), 0x0, NULL, HFILL }}, { &hf_eapol_type, { "Type", "eapol.type", FT_UINT8, BASE_DEC, VALS(eapol_type_vals), 0x0, NULL, HFILL }}, { &hf_eapol_len, { "Length", "eapol.len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_eapol_keydes_type, { "Key Descriptor Type", "eapol.keydes.type", FT_UINT8, BASE_DEC, VALS(eapol_keydes_type_vals), 0x0, NULL, HFILL }}, { &hf_eapol_keydes_body, { "Key Descriptor Body", "eapol.keydes.body", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_eapol_keydes_key_len, { "Key Length", "eapol.keydes.key_len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_eapol_keydes_replay_counter, { "Replay Counter", "eapol.keydes.replay_counter", FT_UINT64, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_eapol_keydes_key_iv, { "Key IV", "eapol.keydes.key_iv", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_eapol_keydes_key_index, { "Key Index", "eapol.keydes.key_index", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }}, { &hf_eapol_keydes_key_index_type, { "Type", "eapol.keydes.key_index.type", FT_BOOLEAN, 8, TFS(&keytype_tfs), KEYDES_KEY_INDEX_TYPE_MASK , NULL, HFILL }}, { &hf_eapol_keydes_key_index_number, { "Number", "eapol.keydes.key_index.number", FT_UINT8, BASE_DEC, NULL, KEYDES_KEY_INDEX_NUMBER_MASK, NULL, HFILL }}, { &hf_eapol_keydes_key_signature, { "Key Signature", "eapol.keydes.key_signature", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_eapol_keydes_key, { "Key", "eapol.keydes.key", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_eapol_keydes_key_generated_locally, { "Key Generated Locally", "eapol.keydes.key.generated_locally", FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL }}, }; static gint *ett[] = { &ett_eapol, &ett_keyinfo, &ett_eapol_key_index }; proto_eapol = proto_register_protocol("802.1X Authentication", "EAPOL", "eapol"); eapol_handle = register_dissector("eapol", dissect_eapol, proto_eapol); proto_register_field_array(proto_eapol, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); eapol_type_dissector_table = register_dissector_table("eapol.type", "EAPOL Packet Type", proto_eapol, FT_UINT8, BASE_DEC); eapol_keydes_type_dissector_table = register_dissector_table("eapol.keydes.type", "EAPOL Key Descriptor Type", proto_eapol, FT_UINT8, BASE_DEC); } void proto_reg_handoff_eapol(void) { dissector_handle_t eapol_rc4_key_handle, eapol_key_handle; dissector_add_uint("ethertype", ETHERTYPE_EAPOL, eapol_handle); dissector_add_uint("ethertype", ETHERTYPE_RSN_PREAUTH, eapol_handle); /* * EAPOL key descriptor types. */ eapol_rc4_key_handle = create_dissector_handle(dissect_eapol_rc4_key, proto_eapol); dissector_add_uint("eapol.keydes.type", EAPOL_RC4_KEY, eapol_rc4_key_handle); eapol_key_handle = create_dissector_handle(dissect_eapol_key, proto_eapol); dissector_add_uint("eapol.type", EAPOL_KEY, eapol_key_handle); } /* * Editor modelines * * Local Variables: * c-basic-offset: 2 * tab-width: 8 * indent-tabs-mode: nil * End: * * ex: set shiftwidth=2 tabstop=8 expandtab: * :indentSize=2:tabSize=8:noTabs=true: */