/* packet-kerberos4.c * Routines for Kerberos v4 packet dissection * * Ronnie Sahlberg 2004 * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* * PDU structure based on the document: * * Athena Technical Plan * Section E.2.1 * Kerberos Authentication and Authorization System * by S. P. Miller, B. C. Neuman, J. I. Schiller, and J. H. Saltzer * * http://web.mit.edu/Saltzer/www/publications/athenaplan/e.2.1.pdf * * 7. Appendix I Design Specifications */ #include "config.h" #include void proto_register_krb4(void); void proto_reg_handoff_krb4(void); static int proto_krb4; static int hf_krb4_version; static int hf_krb4_auth_msg_type; static int hf_krb4_m_type; static int hf_krb4_byte_order; static int hf_krb4_name; static int hf_krb4_instance; static int hf_krb4_realm; static int hf_krb4_time_sec; static int hf_krb4_exp_date; static int hf_krb4_req_date; static int hf_krb4_lifetime; static int hf_krb4_s_name; static int hf_krb4_s_instance; static int hf_krb4_kvno; static int hf_krb4_length; static int hf_krb4_ticket_length; static int hf_krb4_request_length; static int hf_krb4_ticket_blob; static int hf_krb4_request_blob; static int hf_krb4_encrypted_blob; static int hf_krb4_unknown_transarc_blob; static int ett_krb4; static int ett_krb4_auth_msg_type; static dissector_handle_t krb4_handle; #define UDP_PORT_KRB4 750 #define TRANSARC_SPECIAL_VERSION 0x63 static const value_string byte_order_vals[] = { { 0, "Big Endian" }, { 1, "Little Endian" }, { 0, NULL } }; #define AUTH_MSG_KDC_REQUEST 1 #define AUTH_MSG_KDC_REPLY 2 #define AUTH_MSG_APPL_REQUEST 3 #define AUTH_MSG_APPL_REQUEST_MUTUAL 4 #define AUTH_MSG_ERR_REPLY 5 #define AUTH_MSG_PRIVATE 6 #define AUTH_MSG_SAFE 7 #define AUTH_MSG_APPL_ERR 8 #define AUTH_MSG_DIE 63 static const value_string m_type_vals[] = { { AUTH_MSG_KDC_REQUEST, "KDC Request" }, { AUTH_MSG_KDC_REPLY, "KDC Reply" }, { AUTH_MSG_APPL_REQUEST, "Appl Request" }, { AUTH_MSG_APPL_REQUEST_MUTUAL, "Appl Request Mutual" }, { AUTH_MSG_ERR_REPLY, "Err Reply" }, { AUTH_MSG_PRIVATE, "Private" }, { AUTH_MSG_SAFE, "Safe" }, { AUTH_MSG_APPL_ERR, "Appl Err" }, { AUTH_MSG_DIE, "Die" }, { 0, NULL } }; static int dissect_krb4_string(packet_info *pinfo _U_, int hf_index, proto_tree *tree, tvbuff_t *tvb, int offset) { int length; proto_tree_add_item_ret_length(tree, hf_index, tvb, offset, -1, ENC_ASCII|ENC_NA, &length); return offset + length; } static int dissect_krb4_kdc_request(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset, const unsigned encoding, int version) { uint8_t lifetime; if(version==TRANSARC_SPECIAL_VERSION){ proto_tree_add_item(tree, hf_krb4_unknown_transarc_blob, tvb, offset, 8, ENC_NA); offset+=8; } /* Name */ offset=dissect_krb4_string(pinfo, hf_krb4_name, tree, tvb, offset); /* Instance */ offset=dissect_krb4_string(pinfo, hf_krb4_instance, tree, tvb, offset); /* Realm */ offset=dissect_krb4_string(pinfo, hf_krb4_realm, tree, tvb, offset); /* Time sec */ proto_tree_add_item(tree, hf_krb4_time_sec, tvb, offset, 4, ENC_TIME_SECS|encoding); offset+=4; /* lifetime */ lifetime=tvb_get_uint8(tvb, offset); proto_tree_add_uint_format_value(tree, hf_krb4_lifetime, tvb, offset, 1, lifetime, "%d (%d minutes)", lifetime, lifetime*5); offset++; /* service Name */ offset=dissect_krb4_string(pinfo, hf_krb4_s_name, tree, tvb, offset); /* service Instance */ offset=dissect_krb4_string(pinfo, hf_krb4_s_instance, tree, tvb, offset); return offset; } static int dissect_krb4_kdc_reply(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset, const unsigned encoding) { uint32_t length; /* Name */ offset=dissect_krb4_string(pinfo, hf_krb4_name, tree, tvb, offset); /* Instance */ offset=dissect_krb4_string(pinfo, hf_krb4_instance, tree, tvb, offset); /* Realm */ offset=dissect_krb4_string(pinfo, hf_krb4_realm, tree, tvb, offset); /* Time sec */ proto_tree_add_item(tree, hf_krb4_time_sec, tvb, offset, 4, ENC_TIME_SECS|encoding); offset+=4; /*XXX unknown byte here */ offset++; /* exp date */ proto_tree_add_item(tree, hf_krb4_exp_date, tvb, offset, 4, ENC_TIME_SECS|encoding); offset+=4; /* kvno */ proto_tree_add_item(tree, hf_krb4_kvno, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* length2 */ proto_tree_add_item_ret_uint(tree, hf_krb4_length, tvb, offset, 2, encoding, &length); offset+=2; /* encrypted blob */ proto_tree_add_item(tree, hf_krb4_encrypted_blob, tvb, offset, length, ENC_NA); offset+=length; return offset; } static int dissect_krb4_appl_request(packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb, int offset, const unsigned encoding) { uint8_t tlen, rlen; uint8_t lifetime; /* kvno */ proto_tree_add_item(tree, hf_krb4_kvno, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* Realm */ offset=dissect_krb4_string(pinfo, hf_krb4_realm, tree, tvb, offset); /* ticket length */ tlen=tvb_get_uint8(tvb, offset); proto_tree_add_item(tree, hf_krb4_ticket_length, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* request length */ rlen=tvb_get_uint8(tvb, offset); proto_tree_add_item(tree, hf_krb4_request_length, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* ticket */ proto_tree_add_item(tree, hf_krb4_ticket_blob, tvb, offset, tlen, ENC_NA); offset+=tlen; /* request */ proto_tree_add_item(tree, hf_krb4_request_blob, tvb, offset, rlen, ENC_NA); offset+=rlen; /* request time */ proto_tree_add_item(tree, hf_krb4_req_date, tvb, offset, 4, ENC_TIME_SECS|encoding); offset+=4; /* lifetime */ lifetime=tvb_get_uint8(tvb, offset); proto_tree_add_uint_format_value(tree, hf_krb4_lifetime, tvb, offset, 1, lifetime, "%d (%d minutes)", lifetime, lifetime*5); offset++; /* service Name */ offset=dissect_krb4_string(pinfo, hf_krb4_s_name, tree, tvb, offset); /* service Instance */ offset=dissect_krb4_string(pinfo, hf_krb4_s_instance, tree, tvb, offset); return offset; } static int dissect_krb4_auth_msg_type(packet_info *pinfo, proto_tree *parent_tree, tvbuff_t *tvb, int offset, int version) { proto_tree *tree; proto_item *item; uint8_t auth_msg_type; auth_msg_type=tvb_get_uint8(tvb, offset); item = proto_tree_add_item(parent_tree, hf_krb4_auth_msg_type, tvb, offset, 1, ENC_BIG_ENDIAN); tree = proto_item_add_subtree(item, ett_krb4_auth_msg_type); /* m_type */ proto_tree_add_item(tree, hf_krb4_m_type, tvb, offset, 1, ENC_BIG_ENDIAN); col_append_fstr(pinfo->cinfo, COL_INFO, "%s%s", (version==TRANSARC_SPECIAL_VERSION)?"TRANSARC-":"", val_to_str(auth_msg_type>>1, m_type_vals, "Unknown (0x%04x)")); proto_item_append_text(item, " %s%s", (version==TRANSARC_SPECIAL_VERSION)?"TRANSARC-":"", val_to_str(auth_msg_type>>1, m_type_vals, "Unknown (0x%04x)")); /* byte order */ proto_tree_add_item(tree, hf_krb4_byte_order, tvb, offset, 1, ENC_BIG_ENDIAN); proto_item_append_text(item, " (%s)", val_to_str(auth_msg_type&0x01, byte_order_vals, "Unknown (0x%04x)")); offset++; return offset; } static gboolean dissect_krb4(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data _U_) { proto_tree *tree; proto_item *item; uint8_t version, opcode; int offset = 0; unsigned encoding; /* this should better have the value 4 or it might be a weirdo * Transarc AFS special unknown thing. */ version=tvb_get_uint8(tvb, offset); if((version!=4)&&(version!=TRANSARC_SPECIAL_VERSION)){ return FALSE; } opcode=tvb_get_uint8(tvb, offset+1); switch(opcode>>1){ case AUTH_MSG_KDC_REQUEST: case AUTH_MSG_KDC_REPLY: case AUTH_MSG_APPL_REQUEST: case AUTH_MSG_APPL_REQUEST_MUTUAL: case AUTH_MSG_ERR_REPLY: case AUTH_MSG_PRIVATE: case AUTH_MSG_SAFE: case AUTH_MSG_APPL_ERR: case AUTH_MSG_DIE: break; default: return FALSE; } /* create a tree for krb4 */ item = proto_tree_add_item(parent_tree, proto_krb4, tvb, offset, -1, ENC_NA); tree = proto_item_add_subtree(item, ett_krb4); col_set_str(pinfo->cinfo, COL_PROTOCOL, "KRB4"); col_clear(pinfo->cinfo, COL_INFO); /* version */ proto_tree_add_item(tree, hf_krb4_version, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* auth_msg_type */ offset = dissect_krb4_auth_msg_type(pinfo, tree, tvb, offset, version); encoding = opcode&0x01 ? ENC_LITTLE_ENDIAN : ENC_BIG_ENDIAN; switch(opcode>>1){ case AUTH_MSG_KDC_REQUEST: dissect_krb4_kdc_request(pinfo, tree, tvb, offset, encoding, version); break; case AUTH_MSG_KDC_REPLY: dissect_krb4_kdc_reply(pinfo, tree, tvb, offset, encoding); break; case AUTH_MSG_APPL_REQUEST: dissect_krb4_appl_request(pinfo, tree, tvb, offset, encoding); break; case AUTH_MSG_APPL_REQUEST_MUTUAL: case AUTH_MSG_ERR_REPLY: case AUTH_MSG_PRIVATE: case AUTH_MSG_SAFE: case AUTH_MSG_APPL_ERR: case AUTH_MSG_DIE: break; } return TRUE; } void proto_register_krb4(void) { static hf_register_info hf[] = { { &hf_krb4_version, { "Version", "krb4.version", FT_UINT8, BASE_DEC, NULL, 0x0, "Kerberos(v4) version number", HFILL }}, { &hf_krb4_auth_msg_type, { "Msg Type", "krb4.auth_msg_type", FT_UINT8, BASE_HEX, NULL, 0x0, "Message Type/Byte Order", HFILL }}, { &hf_krb4_m_type, { "M Type", "krb4.m_type", FT_UINT8, BASE_HEX, VALS(m_type_vals), 0xfe, "Message Type", HFILL }}, { &hf_krb4_byte_order, { "Byte Order", "krb4.byte_order", FT_UINT8, BASE_HEX, VALS(byte_order_vals), 0x01, NULL, HFILL }}, { &hf_krb4_name, { "Name", "krb4.name", FT_STRINGZ, BASE_NONE, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_instance, { "Instance", "krb4.instance", FT_STRINGZ, BASE_NONE, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_realm, { "Realm", "krb4.realm", FT_STRINGZ, BASE_NONE, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_time_sec, { "Time Sec", "krb4.time_sec", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_exp_date, { "Exp Date", "krb4.exp_date", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_req_date, { "Req Date", "krb4.req_date", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_lifetime, { "Lifetime", "krb4.lifetime", FT_UINT8, BASE_DEC, NULL, 0x00, "Lifetime (in 5 min units)", HFILL }}, { &hf_krb4_s_name, { "Service Name", "krb4.s_name", FT_STRINGZ, BASE_NONE, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_s_instance, { "Service Instance", "krb4.s_instance", FT_STRINGZ, BASE_NONE, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_kvno, { "Kvno", "krb4.kvno", FT_UINT8, BASE_DEC, NULL, 0x00, "Key Version No", HFILL }}, { &hf_krb4_length, { "Length", "krb4.length", FT_UINT32, BASE_DEC, NULL, 0x00, "Length of encrypted blob", HFILL }}, { &hf_krb4_ticket_length, { "Ticket Length", "krb4.ticket.length", FT_UINT8, BASE_DEC, NULL, 0x00, "Length of ticket", HFILL }}, { &hf_krb4_request_length, { "Request Length", "krb4.request.length", FT_UINT8, BASE_DEC, NULL, 0x00, "Length of request", HFILL }}, { &hf_krb4_ticket_blob, { "Ticket Blob", "krb4.ticket.blob", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_request_blob, { "Request Blob", "krb4.request.blob", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_encrypted_blob, { "Encrypted Blob", "krb4.encrypted_blob", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }}, { &hf_krb4_unknown_transarc_blob, { "Unknown Transarc Blob", "krb4.unknown_transarc_blob", FT_BYTES, BASE_NONE, NULL, 0x00, "Unknown blob only present in Transarc packets", HFILL }}, }; static int *ett[] = { &ett_krb4, &ett_krb4_auth_msg_type, }; proto_krb4 = proto_register_protocol("Kerberos v4", "KRB4", "krb4"); krb4_handle = register_dissector("krb4", dissect_krb4, proto_krb4); proto_register_field_array(proto_krb4, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); } void proto_reg_handoff_krb4(void) { dissector_add_uint_with_preference("udp.port", UDP_PORT_KRB4, krb4_handle); } /* * Editor modelines - https://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 8 * tab-width: 8 * indent-tabs-mode: t * End: * * vi: set shiftwidth=8 tabstop=8 noexpandtab: * :indentSize=8:tabSize=8:noTabs=false: */