diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
commit | e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch) | |
tree | 68cb5ef9081156392f1dd62a00c6ccc1451b93df /epan/dissectors/packet-dtcp-ip.c | |
parent | Initial commit. (diff) | |
download | wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip |
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'epan/dissectors/packet-dtcp-ip.c')
-rw-r--r-- | epan/dissectors/packet-dtcp-ip.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/epan/dissectors/packet-dtcp-ip.c b/epan/dissectors/packet-dtcp-ip.c new file mode 100644 index 0000000..c5c545c --- /dev/null +++ b/epan/dissectors/packet-dtcp-ip.c @@ -0,0 +1,300 @@ +/* packet-dtcp-ip.c + * Routines for DTCP-IP dissection + * (Digital Transmission Content Protection over IP) + * + * Copyright 2012, Martin Kaiser <martin@kaiser.cx> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +/* + * quote from www.dtcp.com: + * "DTCP is a method of protecting audio and audiovisual entertainment + * content on home and personal networks over highbandwidth bidirectional + * digital interfaces" + * + * this dissector supports DTCP on top of TCP/IP + * for now, only the AKE (authentication and key exchange) + * messages are implemented + * + * the dissector is based on the publicly available (informative) specifications + * obtained from http://www.dtcp.com/specifications.aspx + * (complete specifications are available only to licensees) + */ + +#include "config.h" + +#include <epan/packet.h> + +static int proto_dtcp_ip = -1; + +void proto_register_dtcp_ip(void); +void proto_reg_handoff_dtcp_ip(void); + +static dissector_handle_t dtcp_ip_handle; + +static gint ett_dtcp_ip = -1; +static gint ett_dtcp_ip_ctrl = -1; +static gint ett_dtcp_ip_ake_procedure = -1; + +static int hf_dtcp_ip_type = -1; +static int hf_dtcp_ip_length = -1; +static int hf_dtcp_ip_ctype = -1; +static int hf_dtcp_ip_category = -1; +static int hf_dtcp_ip_ake_id = -1; +static int hf_dtcp_ip_subfct = -1; +static int hf_dtcp_ip_ake_procedure = -1; +static int hf_dtcp_ip_ake_proc_full = -1; +static int hf_dtcp_ip_ake_proc_ex_full = -1; +static int hf_dtcp_ip_ake_xchg_key = -1; +static int hf_dtcp_ip_subfct_dep = -1; +static int hf_dtcp_ip_ake_label = -1; +static int hf_dtcp_ip_number = -1; +static int hf_dtcp_ip_status = -1; +static int hf_dtcp_ip_ake_info = -1; + +#define CTRL_LEN 8 /* control block is 8 bytes long */ + +/* these definitions are taken from the public DTCP specification + it sounds like the private version defines more subfunctions */ +static const value_string subfct[] = { + { 0x01, "challenge" }, + { 0x02, "response" }, + { 0x03, "exchange_key" }, + { 0, NULL } +}; + +static int * const ake_procedure_fields[] = { /* must be int, not gint */ + &hf_dtcp_ip_ake_proc_full, + &hf_dtcp_ip_ake_proc_ex_full, + NULL +}; + +/* only one bit may be set in exchange_key, we can use a value string */ +static const value_string xchg_key[] = { + { 0x00, "None" }, + { 0x08, "Exchange key (K_X) for AES-128" }, + { 0x20, "Session Exchange key (K_S) for AES-128" }, + { 0x40, "Remote Exchange key (K_R) for AES-128" }, + { 0, NULL } +}; + +static const value_string ctrl_status[] = { + { 0x0, "No error" }, + { 0x1, "Support for no more authentication procedures is currently available" }, + { 0x7, "Any other error" }, + { 0xF, "No information" }, + { 0, NULL } +}; + + +/* check if the packet is actually DTCP-IP */ +static gboolean +dtcp_ip_check_packet(tvbuff_t *tvb) +{ + guint offset = 0; + guint8 type; + guint16 length; + + /* a minimum DTCP-IP AKE packet has Type (1 byte), + Length (2 bytes) and Control (8 bytes) */ + if (tvb_reported_length(tvb) < 1+2+CTRL_LEN) + return FALSE; + + type = tvb_get_guint8(tvb, offset); + /* all DTCP-IP AKE packets have type 1 */ + if (type != 1) + return FALSE; + offset++; + + /* length field is length of the control block + + length of ake_info */ + length = tvb_get_ntohs(tvb, offset); + if (length < CTRL_LEN) + return FALSE; + + return TRUE; +} + +static int +dissect_dtcp_ip(tvbuff_t *tvb, packet_info *pinfo, + proto_tree *tree, void *data _U_) +{ + guint offset = 0; + guint16 length; + proto_item *pi; + proto_tree *dtcp_ip_tree, *dtcp_ip_ctrl_tree; + guint8 subfct_val; + const gchar *subfct_str; + gint ake_info_len; + + + if (!dtcp_ip_check_packet(tvb)) + return 0; /* not a DTCP-IP packet */ + + col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTCP-IP"); + col_clear(pinfo->cinfo, COL_INFO); + + pi = proto_tree_add_protocol_format(tree, proto_dtcp_ip, + tvb, 0, -1, "DTCP-IP"); + dtcp_ip_tree = proto_item_add_subtree(pi, ett_dtcp_ip); + + proto_tree_add_item(dtcp_ip_tree, hf_dtcp_ip_type, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + + length = tvb_get_ntohs(tvb, 1); + /* overall packet length is 1 byte for tag + 2 bytes for length field + + the value encoded in the length field */ + proto_item_set_len(pi, 1+2+length); + proto_tree_add_item(dtcp_ip_tree, hf_dtcp_ip_length, + tvb, offset, 2, ENC_BIG_ENDIAN); + offset += 2; + + dtcp_ip_ctrl_tree = proto_tree_add_subtree(dtcp_ip_tree, + tvb, offset, CTRL_LEN, ett_dtcp_ip_ctrl, NULL, "Control"); + + /* for now, we don't display the 4 reserved bits */ + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_ctype, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_category, + tvb, offset, 1, ENC_BIG_ENDIAN); + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_ake_id, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + + subfct_val = tvb_get_guint8(tvb, offset); + subfct_str = val_to_str_const(subfct_val, subfct, "unknown"); + col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL, + "%s (0x%x)", subfct_str, subfct_val); + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_subfct, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + + proto_tree_add_bitmask(dtcp_ip_ctrl_tree, tvb, offset, + hf_dtcp_ip_ake_procedure, ett_dtcp_ip_ake_procedure, + ake_procedure_fields, ENC_BIG_ENDIAN); + offset++; + + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_ake_xchg_key, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_subfct_dep, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_ake_label, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_number, + tvb, offset, 1, ENC_BIG_ENDIAN); + proto_tree_add_item(dtcp_ip_ctrl_tree, hf_dtcp_ip_status, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + + ake_info_len = length-CTRL_LEN; + if (ake_info_len > 0) { + proto_tree_add_item(dtcp_ip_tree, hf_dtcp_ip_ake_info, + tvb, offset, ake_info_len, ENC_NA); + offset += (guint)ake_info_len; + } + + return offset; +} + + +void +proto_register_dtcp_ip(void) +{ + static hf_register_info hf[] = { + { &hf_dtcp_ip_type, + { "Type", "dtcp-ip.type", FT_UINT8, BASE_HEX, + NULL, 0, NULL, HFILL } }, + { &hf_dtcp_ip_length, + { "Length", "dtcp-ip.length", FT_UINT16, BASE_DEC, + NULL, 0, NULL, HFILL } }, + /* it seems that / is not allowed in a filter name ... */ + { &hf_dtcp_ip_ctype, + { "ctype/response", "dtcp-ip.ctrl.ctype_response", FT_UINT8, + BASE_HEX, NULL, 0x0F, NULL, HFILL } }, + { &hf_dtcp_ip_category, + { "Category", "dtcp-ip.ctrl.category", FT_UINT8, BASE_HEX, + NULL, 0xF0, NULL, HFILL } }, + { &hf_dtcp_ip_ake_id, + { "AKE_ID", "dtcp-ip.ctrl.ake_id", FT_UINT8, BASE_HEX, + NULL, 0x0F, NULL, HFILL } }, + { &hf_dtcp_ip_subfct, + { "Subfunction", "dtcp-ip.ctrl.subfunction", FT_UINT8, BASE_HEX, + VALS(subfct), 0, NULL, HFILL } }, + { &hf_dtcp_ip_ake_procedure, + { "AKE_procedure", "dtcp-ip.ctrl.ake_procedure", FT_UINT8, + BASE_HEX, NULL, 0, NULL, HFILL } }, + /* 8 is the bit witdh of the field */ + { &hf_dtcp_ip_ake_proc_full, + { "Full Authentication procedure", + "dtcp-ip.ctrl.ake_procedure.full_auth", FT_BOOLEAN, 8, + NULL, 0x04, NULL, HFILL } }, + { &hf_dtcp_ip_ake_proc_ex_full, + { "Extended Full Authentication procedure", + "dtcp-ip.ctrl.ake_procedure.ex_full_auth", FT_BOOLEAN, 8, + NULL, 0x08, NULL, HFILL } }, + { &hf_dtcp_ip_ake_xchg_key, + { "exchange_key", "dtcp-ip.ctrl.exchange_key", FT_UINT8, BASE_HEX, + VALS(xchg_key), 0, NULL, HFILL } }, + { &hf_dtcp_ip_subfct_dep, + { "subfunction_dependent", "dtcp-ip.ctrl.subfunction_dependent", + FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL } }, + { &hf_dtcp_ip_ake_label, + { "AKE_label", "dtcp-ip.ctrl.ake_label", FT_UINT8, BASE_HEX, + NULL, 0, NULL, HFILL } }, + { &hf_dtcp_ip_number, + { "number", "dtcp-ip.ctrl.number", FT_UINT8, BASE_HEX, + NULL, 0xF0, NULL, HFILL } }, + { &hf_dtcp_ip_status, + { "Status", "dtcp-ip.ctrl.status", FT_UINT8, BASE_HEX, + VALS(ctrl_status), 0x0F, NULL, HFILL } }, + { &hf_dtcp_ip_ake_info, + { "AKE_Info", "dtcp-ip.ake_info", FT_BYTES, BASE_NONE, + NULL, 0, NULL, HFILL } } + }; + + static gint *ett[] = { + &ett_dtcp_ip, + &ett_dtcp_ip_ctrl, + &ett_dtcp_ip_ake_procedure + }; + + proto_dtcp_ip = proto_register_protocol("Digital Transmission Content Protection over IP", "DTCP-IP", "dtcp-ip"); + + proto_register_field_array(proto_dtcp_ip, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + + dtcp_ip_handle = register_dissector("dtcp-ip", dissect_dtcp_ip, proto_dtcp_ip); +} + +void +proto_reg_handoff_dtcp_ip(void) +{ + dissector_add_for_decode_as_with_preference("tcp.port", dtcp_ip_handle); +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 4 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * vi: set shiftwidth=4 tabstop=8 expandtab: + * :indentSize=4:tabSize=8:noTabs=true: + */ |