/* packet-stcsig.c * Routines for dissecting Spirent Test Center Signatures * Copyright 2018 Joerg Mayer (see AUTHORS file) * Based on disassembly of Spirent's modified version of Wireshark 1.10.3 * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* The logic is based on the dissassembly of libwireshark.dll which was * part of wireshark-win64-1.10.3-spirent-2.exe, distributed by Spirent * to customers of their Spirent Test Center. * As the installer displays the normal GPLv2+ license the choice was * made to go with dissassembly instead of finding out who to ask for * the source code. * * Please report errors or missing features when compared to the original. */ /* TODO: * - Find out the meaning of the unknown trailer (perhaps some fcs or * some prbseq related stuff?) * - Find out meaning of prbseq * - Is there a (fixed) structure in the csp field? * - Validate the timestamp decoding: The seconds value is identical to * Spirent's stcsig dissector, the ns value differs significantly * - Find out what the TSLR really stands for - currently just a guess */ #include "config.h" #include #include void proto_register_stcsig(void); void proto_reg_handoff_stcsig(void); #define PROTO_SHORT_NAME "STCSIG" #define PROTO_LONG_NAME "Spirent Test Center Signature" static int proto_stcsig; static int hf_stcsig_csp; static int hf_stcsig_iv; static int hf_stcsig_prbseq; static int hf_stcsig_rawdata; static int hf_stcsig_seqnum_complement; static int hf_stcsig_seqnum_edm; static int hf_stcsig_seqnum_sm; static int hf_stcsig_streamid; static int hf_stcsig_streamindex; static int hf_stcsig_streamtype; static int hf_stcsig_timestamp; static int hf_stcsig_tslr; static int hf_stcsig_unknown; static int ett_stcsig; static int ett_stcsig_streamid; static const true_false_string tfs_end_start = { "EndOfFrame", "StartOfFrame" }; static const true_false_string tfs_hard_soft = { "Hard", "Soft" }; /* * For the last 20 bytes of the data section to be a Spirent Signature * the fist byte (offset 0) plus the 11th byte (offset 10) of the deocded * signature must add up to 255 */ static bool is_signature(tvbuff_t *tvb, int sigoffset) { /* * How to generate the table below: * * static uint8_t runit = 1; * for(int k=0; k<256; k++) { * obfuscation_value = k; * for(int i=1; i<=10; i++) { * obfuscation_value = deobfuscate_this[obfuscation_value]; * } * printf("0x%02x, ", obfuscation_value); * if (k%8 == 7) printf("\n"); * } */ static const uint8_t deobfuscate_offset_10[256] = { 0x00, 0x86, 0x0d, 0x8b, 0x9d, 0x1b, 0x90, 0x16, 0xbc, 0x3a, 0xb1, 0x37, 0x21, 0xa7, 0x2c, 0xaa, 0x78, 0xfe, 0x75, 0xf3, 0xe5, 0x63, 0xe8, 0x6e, 0xc4, 0x42, 0xc9, 0x4f, 0x59, 0xdf, 0x54, 0xd2, 0xf1, 0x77, 0xfc, 0x7a, 0x6c, 0xea, 0x61, 0xe7, 0x4d, 0xcb, 0x40, 0xc6, 0xd0, 0x56, 0xdd, 0x5b, 0x89, 0x0f, 0x84, 0x02, 0x14, 0x92, 0x19, 0x9f, 0x35, 0xb3, 0x38, 0xbe, 0xa8, 0x2e, 0xa5, 0x23, 0xe2, 0x64, 0xef, 0x69, 0x7f, 0xf9, 0x72, 0xf4, 0x5e, 0xd8, 0x53, 0xd5, 0xc3, 0x45, 0xce, 0x48, 0x9a, 0x1c, 0x97, 0x11, 0x07, 0x81, 0x0a, 0x8c, 0x26, 0xa0, 0x2b, 0xad, 0xbb, 0x3d, 0xb6, 0x30, 0x13, 0x95, 0x1e, 0x98, 0x8e, 0x08, 0x83, 0x05, 0xaf, 0x29, 0xa2, 0x24, 0x32, 0xb4, 0x3f, 0xb9, 0x6b, 0xed, 0x66, 0xe0, 0xf6, 0x70, 0xfb, 0x7d, 0xd7, 0x51, 0xda, 0x5c, 0x4a, 0xcc, 0x47, 0xc1, 0x43, 0xc5, 0x4e, 0xc8, 0xde, 0x58, 0xd3, 0x55, 0xff, 0x79, 0xf2, 0x74, 0x62, 0xe4, 0x6f, 0xe9, 0x3b, 0xbd, 0x36, 0xb0, 0xa6, 0x20, 0xab, 0x2d, 0x87, 0x01, 0x8a, 0x0c, 0x1a, 0x9c, 0x17, 0x91, 0xb2, 0x34, 0xbf, 0x39, 0x2f, 0xa9, 0x22, 0xa4, 0x0e, 0x88, 0x03, 0x85, 0x93, 0x15, 0x9e, 0x18, 0xca, 0x4c, 0xc7, 0x41, 0x57, 0xd1, 0x5a, 0xdc, 0x76, 0xf0, 0x7b, 0xfd, 0xeb, 0x6d, 0xe6, 0x60, 0xa1, 0x27, 0xac, 0x2a, 0x3c, 0xba, 0x31, 0xb7, 0x1d, 0x9b, 0x10, 0x96, 0x80, 0x06, 0x8d, 0x0b, 0xd9, 0x5f, 0xd4, 0x52, 0x44, 0xc2, 0x49, 0xcf, 0x65, 0xe3, 0x68, 0xee, 0xf8, 0x7e, 0xf5, 0x73, 0x50, 0xd6, 0x5d, 0xdb, 0xcd, 0x4b, 0xc0, 0x46, 0xec, 0x6a, 0xe1, 0x67, 0x71, 0xf7, 0x7c, 0xfa, 0x28, 0xae, 0x25, 0xa3, 0xb5, 0x33, 0xb8, 0x3e, 0x94, 0x12, 0x99, 0x1f, 0x09, 0x8f, 0x04, 0x82 }; uint8_t byte0; uint8_t byte10; /* Byte 0 also is the initialization vector for the obfuscation of offsets 1 - 15 */ byte0 = tvb_get_uint8(tvb, sigoffset); byte10 = tvb_get_uint8(tvb, sigoffset + 10); if (byte0 + (byte10 ^ deobfuscate_offset_10[byte0]) == 255) { return true; } else { return false; } } static void decode_signature(uint8_t* decode_buffer) { static const uint8_t deobfuscate_this[256] = { 0x00, 0x71, 0xe3, 0x92, 0xb6, 0xc7, 0x55, 0x24, 0x1c, 0x6d, 0xff, 0x8e, 0xaa, 0xdb, 0x49, 0x38, 0x39, 0x48, 0xda, 0xab, 0x8f, 0xfe, 0x6c, 0x1d, 0x25, 0x54, 0xc6, 0xb7, 0x93, 0xe2, 0x70, 0x01, 0x72, 0x03, 0x91, 0xe0, 0xc4, 0xb5, 0x27, 0x56, 0x6e, 0x1f, 0x8d, 0xfc, 0xd8, 0xa9, 0x3b, 0x4a, 0x4b, 0x3a, 0xa8, 0xd9, 0xfd, 0x8c, 0x1e, 0x6f, 0x57, 0x26, 0xb4, 0xc5, 0xe1, 0x90, 0x02, 0x73, 0xe4, 0x95, 0x07, 0x76, 0x52, 0x23, 0xb1, 0xc0, 0xf8, 0x89, 0x1b, 0x6a, 0x4e, 0x3f, 0xad, 0xdc, 0xdd, 0xac, 0x3e, 0x4f, 0x6b, 0x1a, 0x88, 0xf9, 0xc1, 0xb0, 0x22, 0x53, 0x77, 0x06, 0x94, 0xe5, 0x96, 0xe7, 0x75, 0x04, 0x20, 0x51, 0xc3, 0xb2, 0x8a, 0xfb, 0x69, 0x18, 0x3c, 0x4d, 0xdf, 0xae, 0xaf, 0xde, 0x4c, 0x3d, 0x19, 0x68, 0xfa, 0x8b, 0xb3, 0xc2, 0x50, 0x21, 0x05, 0x74, 0xe6, 0x97, 0xb8, 0xc9, 0x5b, 0x2a, 0x0e, 0x7f, 0xed, 0x9c, 0xa4, 0xd5, 0x47, 0x36, 0x12, 0x63, 0xf1, 0x80, 0x81, 0xf0, 0x62, 0x13, 0x37, 0x46, 0xd4, 0xa5, 0x9d, 0xec, 0x7e, 0x0f, 0x2b, 0x5a, 0xc8, 0xb9, 0xca, 0xbb, 0x29, 0x58, 0x7c, 0x0d, 0x9f, 0xee, 0xd6, 0xa7, 0x35, 0x44, 0x60, 0x11, 0x83, 0xf2, 0xf3, 0x82, 0x10, 0x61, 0x45, 0x34, 0xa6, 0xd7, 0xef, 0x9e, 0x0c, 0x7d, 0x59, 0x28, 0xba, 0xcb, 0x5c, 0x2d, 0xbf, 0xce, 0xea, 0x9b, 0x09, 0x78, 0x40, 0x31, 0xa3, 0xd2, 0xf6, 0x87, 0x15, 0x64, 0x65, 0x14, 0x86, 0xf7, 0xd3, 0xa2, 0x30, 0x41, 0x79, 0x08, 0x9a, 0xeb, 0xcf, 0xbe, 0x2c, 0x5d, 0x2e, 0x5f, 0xcd, 0xbc, 0x98, 0xe9, 0x7b, 0x0a, 0x32, 0x43, 0xd1, 0xa0, 0x84, 0xf5, 0x67, 0x16, 0x17, 0x66, 0xf4, 0x85, 0xa1, 0xd0, 0x42, 0x33, 0x0b, 0x7a, 0xe8, 0x99, 0xbd, 0xcc, 0x5e, 0x2f }; uint8_t obfuscation_value; obfuscation_value = decode_buffer[0]; for(int i=1; i<16; i++) { obfuscation_value = deobfuscate_this[obfuscation_value]; decode_buffer[i] ^= obfuscation_value; } /* decode_buffer[16...19] is unobfuscated */ } static int dissect_stcsig(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { int bytes, length; int sig_offset; tvbuff_t *stcsig_tvb; proto_item *ti; proto_tree *stcsig_tree; proto_tree *stcsig_streamid_tree; uint8_t *real_stcsig; uint64_t timestamp_2_5_ns; nstime_t timestamp; length = tvb_captured_length(tvb); if (length >= 21 && tvb_get_uint8(tvb, length - 21) == 0 && is_signature(tvb, length - 20)) { bytes = 20; } else if (length >= 25 && tvb_get_uint8(tvb, length - 25) == 0 && is_signature(tvb, length - 24)) { /* Sigsize + 4 bytes FCS */ bytes = 24; } else if (length >= 29 && tvb_get_uint8(tvb, length - 29) == 0 && is_signature(tvb, length - 28)) { /* Sigsize + 8 bytes FCS, i.e. FibreChannel */ bytes = 28; } else if (length >= 20 && is_signature(tvb, length - 20)) { bytes = 20; } else if (length >= 24 && is_signature(tvb, length - 24)) { /* Sigsize + 4 bytes FCS */ bytes = 24; } else if (length >= 28 && is_signature(tvb, length - 28)) { /* Sigsize + 8 bytes FCS, i.e. FibreChannel */ bytes = 28; } else { return 0; } sig_offset = length - bytes; #if 0 /* Maybe make this a preference */ col_set_str(pinfo->cinfo, COL_PROTOCOL, PROTO_SHORT_NAME); col_set_str(pinfo->cinfo, COL_INFO, PROTO_LONG_NAME); #endif real_stcsig = (uint8_t *)tvb_memdup(pinfo->pool, tvb, sig_offset, 20); decode_signature(real_stcsig); stcsig_tvb = tvb_new_child_real_data(tvb, real_stcsig, 20, 20); add_new_data_source(pinfo, stcsig_tvb, PROTO_LONG_NAME); ti = proto_tree_add_item(tree, proto_stcsig, tvb, sig_offset, 20, ENC_NA); stcsig_tree = proto_item_add_subtree(ti, ett_stcsig); proto_tree_add_item(stcsig_tree, hf_stcsig_rawdata, tvb, sig_offset, 20, ENC_NA); proto_tree_add_item(stcsig_tree, hf_stcsig_iv, stcsig_tvb, 0, 1, ENC_NA); ti = proto_tree_add_item(stcsig_tree, hf_stcsig_streamid, stcsig_tvb, 1, 4, ENC_BIG_ENDIAN); stcsig_streamid_tree = proto_item_add_subtree(ti, ett_stcsig_streamid); /* This subtree is mostly an optical hierarchy, auto expand it */ tree_expanded_set(ett_stcsig_streamid, true); proto_tree_add_item(stcsig_streamid_tree, hf_stcsig_csp, stcsig_tvb, 1, 2, ENC_BIG_ENDIAN); proto_tree_add_item(stcsig_streamid_tree, hf_stcsig_streamtype, stcsig_tvb, 3, 1, ENC_NA); proto_tree_add_item(stcsig_streamid_tree, hf_stcsig_streamindex, stcsig_tvb, 3, 2, ENC_BIG_ENDIAN); if (tvb_get_ntohs(stcsig_tvb, 5) + tvb_get_ntohs(stcsig_tvb, 7) == 0xffff) { proto_tree_add_item(stcsig_tree, hf_stcsig_seqnum_complement, stcsig_tvb, 5, 2, ENC_BIG_ENDIAN); proto_tree_add_item(stcsig_tree, hf_stcsig_seqnum_edm, stcsig_tvb, 7, 4, ENC_BIG_ENDIAN); } else { proto_tree_add_item(stcsig_tree, hf_stcsig_seqnum_sm, stcsig_tvb, 5, 6, ENC_BIG_ENDIAN); } timestamp_2_5_ns = (uint64_t)(tvb_get_uint8(stcsig_tvb, 15) & 0xfc) << 30; timestamp_2_5_ns |= tvb_get_ntohl(stcsig_tvb, 11); timestamp.secs = (time_t)(timestamp_2_5_ns / 400000000L); timestamp.nsecs = (int)(timestamp_2_5_ns % 400000000L); proto_tree_add_time(stcsig_tree, hf_stcsig_timestamp, stcsig_tvb, 11, 5, ×tamp); proto_tree_add_item(stcsig_tree, hf_stcsig_prbseq, stcsig_tvb, 15, 1, ENC_NA); proto_tree_add_item(stcsig_tree, hf_stcsig_tslr, stcsig_tvb, 15, 1, ENC_NA); proto_tree_add_item(stcsig_tree, hf_stcsig_unknown, stcsig_tvb, 16, 4, ENC_NA); /* Ignored for post-dissectors but required by function type */ return length; } void proto_register_stcsig(void) { static hf_register_info hf[] = { { &hf_stcsig_rawdata, { "Raw Data", "stcsig.rawdata", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_stcsig_iv, { "IV", "stcsig.iv", FT_UINT8, BASE_HEX, NULL, 0x0, "Deobfuscation Initialization Vector and Complement of Sequence Low Byte", HFILL } }, { &hf_stcsig_streamid, { "StreamID", "stcsig.streamid", FT_INT32, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_stcsig_csp, { "ChassisSlotPort", "stcsig.csp", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_stcsig_seqnum_complement, { "Complement (EDM)", "stcsig.complement", FT_UINT16, BASE_DEC, NULL, 0x0, "Complement of high bytes of Sequence Number", HFILL } }, { &hf_stcsig_seqnum_edm, { "Sequence Number (EDM)", "stcsig.seqnum", FT_UINT32, BASE_DEC, NULL, 0x0, "Sequence Number (Enhanced Detection Mode)", HFILL } }, { &hf_stcsig_seqnum_sm, { "Sequence Number (SM)", "stcsig.seqnum.sm", FT_UINT48, BASE_DEC, NULL, 0x0, "Sequence Number (Sequence Mode)", HFILL } }, { &hf_stcsig_streamindex, { "Stream Index", "stcsig.streamindex", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_stcsig_timestamp, { "Timestamp", "stcsig.timestamp", FT_RELATIVE_TIME, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_stcsig_prbseq, { "Pseudo-Random Binary Sequence", "stcsig.prbseq", FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL } }, { &hf_stcsig_tslr, { "TSLR", "stcsig.tslr", FT_BOOLEAN, 8, TFS(&tfs_end_start), 0x01, "Time Stamp Location Reference", HFILL } }, { &hf_stcsig_streamtype, { "StreamType", "stcsig.streamtype", FT_BOOLEAN, 8, TFS(&tfs_hard_soft), 0x80, NULL, HFILL } }, { &hf_stcsig_unknown, { "Unknown", "stcsig.unknown", FT_BYTES, BASE_NONE, NULL, 0x0, "Unknown Trailer (not obfuscated)", HFILL } }, }; static int *ett[] = { &ett_stcsig, &ett_stcsig_streamid }; dissector_handle_t stcsig_handle; proto_stcsig = proto_register_protocol(PROTO_LONG_NAME, PROTO_SHORT_NAME, "stcsig"); proto_register_field_array(proto_stcsig, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); stcsig_handle = register_dissector("stcsig", dissect_stcsig, proto_stcsig); register_postdissector(stcsig_handle); /* STCSIG is a rarely used case, disable it by default for performance reasons. */ proto_disable_by_default(proto_stcsig); } /* * 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: */