/* packet-btsmp.c

 * Routines for Bluetooth Security Manager Protocol dissection

 *

 * Copyright 2012, Allan M. Madsen <allan.m@madsen.dk>

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

#include "config.h"

#include <epan/packet.h>

#include "packet-bluetooth.h"

#include "packet-btl2cap.h"

/* Initialize the protocol and registered fields */

static int proto_btsmp;

static int hf_btsmp_opcode;

static int hf_btsmp_io_capabilities;

static int hf_btsmp_oob_data_flags;

static int hf_btsmp_reason;

static int hf_btsmp_cfm_value;

static int hf_btsmp_random;

static int hf_btsmp_long_term_key;

static int hf_btsmp_id_resolving_key;

static int hf_btsmp_signature_key;

static int hf_btsmp_bonding_flags;

static int hf_btsmp_mitm_flag;

static int hf_btsmp_secure_connection_flag;

static int hf_btsmp_keypress_flag;

static int hf_btsmp_ct2_flag;

static int hf_btsmp_reserved_flag;

static int hf_btsmp_max_enc_key_size;

static int hf_btsmp_key_dist_enc;

static int hf_btsmp_key_dist_id;

static int hf_btsmp_key_dist_sign;

static int hf_btsmp_key_dist_linkkey;

static int hf_btsmp_key_dist_reserved;

static int hf_btsmp_ediv;

static int hf_btsmp_authreq;

static int hf_btsmp_initiator_key_distribution;

static int hf_btsmp_responder_key_distribution;

static int hf_bd_addr;

static int hf_address_type;

static int hf_btsmp_public_key_x;

static int hf_btsmp_public_key_y;

static int hf_btsmp_dhkey_check;

static int hf_btsmp_notification_type;

static int * const hfx_btsmp_key_distribution[] = {

    &hf_btsmp_key_dist_reserved,

    &hf_btsmp_key_dist_linkkey,

    &hf_btsmp_key_dist_sign,

    &hf_btsmp_key_dist_id,

    &hf_btsmp_key_dist_enc,

    NULL

};

static int * const hfx_btsmp_authreq[] = {

    &hf_btsmp_reserved_flag,

    &hf_btsmp_ct2_flag,

    &hf_btsmp_keypress_flag,

    &hf_btsmp_secure_connection_flag,

    &hf_btsmp_mitm_flag,

    &hf_btsmp_bonding_flags,

    NULL

};

/* Initialize the subtree pointers */

static int ett_btsmp;

static int ett_btsmp_auth_req;

static int ett_btsmp_key_dist;

static dissector_handle_t btsmp_handle;

/* Opcodes */

static const value_string opcode_vals[] = {

    {0x01, "Pairing Request"},

    {0x02, "Pairing Response"},

    {0x03, "Pairing Confirm"},

    {0x04, "Pairing Random"},

    {0x05, "Pairing Failed"},

    {0x06, "Encryption Information"},

    {0x07, "Central Identification"},

    {0x08, "Identity Information"},

    {0x09, "Identity Address Information"},

    {0x0A, "Signing Information"},

    {0x0B, "Security Request"},

    {0x0C, "Pairing Public Key"},

    {0x0D, "Pairing DHKey Check"},

    {0x0E, "Pairing Keypress Notification"},

    {0x0, NULL}

};

/* IO capabilities */

static const value_string io_capability_vals[] = {

    {0x00, "Display Only"},

    {0x01, "Display Yes/No"},

    {0x02, "Keyboard Only"},

    {0x03, "No Input, No Output"},

    {0x04, "Keyboard, Display"},

    {0x0, NULL}

};

/* OOB Data present Flag */

static const value_string oob_data_flag_vals[] = {

    {0x00, "OOB Auth. Data Not Present"},

    {0x01, "OOB Auth. Data From Remote Device Present"},

    {0x0, NULL}

};

/* Bonding flags */

static const value_string bonding_flag_vals[] = {

    {0x00, "No Bonding"},

    {0x01, "Bonding"},

    {0x0, NULL}

};

/* Reason codes */

static const value_string reason_vals[] = {

    {0x01, "Passkey Entry Failed"},

    {0x02, "OOB Not Available"},

    {0x03, "Authentication Requirements"},

    {0x04, "Confirm Value Failed"},

    {0x05, "Pairing Not Supported"},

    {0x06, "Encryption Key Size"},

    {0x07, "Command Not Supported"},

    {0x08, "Unspecified Reason"},

    {0x09, "Repeated Attempts"},

    {0x0A, "Invalid Parameters"},

    {0x0B, "DHKey Check Failed"},

    {0x0C, "Numeric Comparison Failed"},

    {0x0D, "BR/EDR pairing in progress"},

    {0x0E, "Cross-transport Key Derivation/Generation not allowed"},

    {0x0, NULL}

};

static const value_string notification_type_vals[] = {

    {0x00, "Passkey Entry Started"},

    {0x01, "Passkey Digit Entered"},

    {0x02, "Passkey Digit Erased"},

    {0x03, "Passkey Cleared"},

    {0x04, "Passkey Entry Completed"},

    {0x0, NULL}

};

/* X coordinate of debug public key. Little-endian. */

static const uint8_t debug_public_key_x[32] = {

    0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc,

    0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef,

    0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e,

    0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20,

};

/* Y coordinate of debug public key. Little-endian. */

static const uint8_t debug_public_key_y[32] = {

    0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74,

    0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76,

    0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63,

    0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc

};

void proto_register_btsmp(void);

void proto_reg_handoff_btsmp(void);

static int

dissect_btsmp_auth_req(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)

{

    uint8_t value;

    const uint8_t *ph;

    col_append_str(pinfo->cinfo, COL_INFO, "AuthReq: ");

    proto_tree_add_bitmask(tree, tvb, offset, hf_btsmp_authreq, ett_btsmp_auth_req, hfx_btsmp_authreq, ENC_LITTLE_ENDIAN);

    value = tvb_get_uint8(tvb, offset);

    ph = val_to_str_const(value & 0x03, bonding_flag_vals, "<unknown>");

    col_append_sep_str(pinfo->cinfo, COL_INFO, "", ph);

    if (value & 0x04)

        col_append_sep_str(pinfo->cinfo, COL_INFO, ", ", "MITM");

    if (value & 0x08)

        col_append_sep_str(pinfo->cinfo, COL_INFO, ", ", "SecureConnection");

    if (value & 0x10)

        col_append_sep_str(pinfo->cinfo, COL_INFO, ", ", "Keypress");

    if (value & 0xE0)

        col_append_sep_str(pinfo->cinfo, COL_INFO, ", ", "Reserved");

    return offset + 1;

}

static int

dissect_btsmp_key_dist(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, bool initiator)

{

    uint8_t value;

    bool next = false;

    if (initiator) {

        col_append_str(pinfo->cinfo, COL_INFO, " | Initiator Key(s): ");

        proto_tree_add_bitmask(tree, tvb, offset, hf_btsmp_initiator_key_distribution, ett_btsmp_key_dist, hfx_btsmp_key_distribution, ENC_LITTLE_ENDIAN);

    } else {

        col_append_str(pinfo->cinfo, COL_INFO, " | Responder Key(s): ");

        proto_tree_add_bitmask(tree, tvb, offset, hf_btsmp_responder_key_distribution, ett_btsmp_key_dist, hfx_btsmp_key_distribution, ENC_LITTLE_ENDIAN);

    }

    value = tvb_get_uint8(tvb, offset);

    if (value & 0x01) {

        col_append_str(pinfo->cinfo, COL_INFO, "LTK");

        next = true;

    }

    if (value & 0x02) {

        col_append_sep_str(pinfo->cinfo, COL_INFO, next ? ", " : "", "IRK");

        next = true;

    }

    if (value & 0x04) {

        col_append_sep_str(pinfo->cinfo, COL_INFO, next ? ", " : "", "CSRK");

        next = true;

    }

    if (value & 0x08) {

        col_append_sep_str(pinfo->cinfo, COL_INFO, next ? ", " : "", "Linkkey");

        next = true;

    }

    if (value & 0xF0) {

        col_append_sep_str(pinfo->cinfo, COL_INFO, next ? ", " : "", "Reserved");

    }

    if (!next) {

        col_append_str(pinfo->cinfo, COL_INFO, "<none>");

    }

    return offset + 1;

}

static int

dissect_btsmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)

{

    int          offset = 0;

    proto_item  *ti;

    proto_tree  *st;

    uint8_t     opcode;

    uint32_t    interface_id;

    uint32_t    adapter_id;

    int         previous_proto;

    interface_id = HCI_INTERFACE_DEFAULT;

    adapter_id = HCI_ADAPTER_DEFAULT;

    previous_proto = (GPOINTER_TO_INT(wmem_list_frame_data(wmem_list_frame_prev(wmem_list_tail(pinfo->layers)))));

    if (data && previous_proto == proto_btl2cap) {

        btl2cap_data_t *l2cap_data;

        l2cap_data = (btl2cap_data_t *) data;

        if (l2cap_data) {

            interface_id = l2cap_data->interface_id;

            adapter_id = l2cap_data->adapter_id;

        }

    }

    ti = proto_tree_add_item(tree, proto_btsmp, tvb, 0, tvb_captured_length(tvb), ENC_NA);

    st = proto_item_add_subtree(ti, ett_btsmp);

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "SMP");

    switch (pinfo->p2p_dir) {

        case P2P_DIR_SENT:

            col_set_str(pinfo->cinfo, COL_INFO, "Sent ");

            break;

        case P2P_DIR_RECV:

            col_set_str(pinfo->cinfo, COL_INFO, "Rcvd ");

            break;

        default:

            col_set_str(pinfo->cinfo, COL_INFO, "UnknownDirection ");

            break;

    }

    if (tvb_reported_length(tvb) < 1)

        return false;

    proto_tree_add_item(st, hf_btsmp_opcode, tvb, 0, 1, ENC_LITTLE_ENDIAN);

    opcode = tvb_get_uint8(tvb, 0);

    offset++;

    col_append_str(pinfo->cinfo, COL_INFO, val_to_str_const(opcode, opcode_vals, "<unknown>"));

    switch (opcode) {

    case 0x01: /* Pairing Request */

    case 0x02: /* Pairing Response */

    {

        col_append_str(pinfo->cinfo, COL_INFO, ": ");

        proto_tree_add_item(st, hf_btsmp_io_capabilities, tvb, offset, 1, ENC_LITTLE_ENDIAN);

        offset++;

        proto_tree_add_item(st, hf_btsmp_oob_data_flags, tvb, offset, 1, ENC_LITTLE_ENDIAN);

        offset++;

        offset = dissect_btsmp_auth_req(tvb, offset, pinfo, st);

        proto_tree_add_item(st, hf_btsmp_max_enc_key_size, tvb, offset, 1, ENC_LITTLE_ENDIAN);

        offset++;

        offset = dissect_btsmp_key_dist(tvb, offset, pinfo, st, true);

        offset = dissect_btsmp_key_dist(tvb, offset, pinfo, st, false);

        break;

    }

    case 0x03: /* Pairing Confirm */

        proto_tree_add_item(st, hf_btsmp_cfm_value, tvb, offset, 16, ENC_NA);

        offset += 16;

        break;

    case 0x04: /* Pairing Random */

        proto_tree_add_item(st, hf_btsmp_random, tvb, offset, 16, ENC_NA);

        offset += 16;

        break;

    case 0x05: /* Pairing Failed */

        proto_tree_add_item(st, hf_btsmp_reason, tvb, offset, 1, ENC_LITTLE_ENDIAN);

        col_append_fstr(pinfo->cinfo, COL_INFO, ": %s", val_to_str_const(tvb_get_uint8(tvb, offset), reason_vals, "<unknown>"));

        offset++;

        break;

    case 0x06: /* Encryption Information */

        proto_tree_add_item(st, hf_btsmp_long_term_key, tvb, offset, 16, ENC_NA);

        offset += 16;

        break;

    case 0x07: /* Central Identification */

        proto_tree_add_item(st, hf_btsmp_ediv, tvb, offset, 2, ENC_LITTLE_ENDIAN);

        offset += 2;

        proto_tree_add_item(st, hf_btsmp_random, tvb, offset, 8, ENC_NA);

        offset += 8;

        break;

    case 0x08: /* Identity Information */

        proto_tree_add_item(st, hf_btsmp_id_resolving_key, tvb, offset, 16, ENC_NA);

        offset += 16;

        break;

    case 0x09: /* Identity Address Information */

        proto_tree_add_item(st, hf_address_type, tvb, offset, 1, ENC_NA);

        offset += 1;

        offset = dissect_bd_addr(hf_bd_addr, pinfo, st, tvb, offset, false, interface_id, adapter_id, NULL);

        break;

    case 0x0A: /* Signing Information */

        proto_tree_add_item(st, hf_btsmp_signature_key, tvb, offset, 16, ENC_NA);

        offset += 16;

        break;

     case 0x0B: /* Security Request */

        col_append_str(pinfo->cinfo, COL_INFO, ": ");

        offset = dissect_btsmp_auth_req(tvb, offset, pinfo, st);

        break;

    case 0x0C: /* Pairing Public Key */ {

        proto_item  *sub_item;

        sub_item = proto_tree_add_item(st, hf_btsmp_public_key_x, tvb, offset, 32, ENC_NA);

        if (tvb_memeql(tvb, offset, debug_public_key_x, 32) == 0)

            proto_item_append_text(sub_item, " (Debug Key)");

        offset += 32;

        sub_item = proto_tree_add_item(st, hf_btsmp_public_key_y, tvb, offset, 32, ENC_NA);

        if (tvb_memeql(tvb, offset, debug_public_key_y, 32) == 0)

            proto_item_append_text(sub_item, " (Debug Key)");

        offset += 32;

        break;}

    case 0x0D: /* Pairing DHKey Check" */

        proto_tree_add_item(st, hf_btsmp_dhkey_check, tvb, offset, 16, ENC_NA);

        offset += 16;

        break;

    case 0x0E: /* Pairing Keypress Notification */

        proto_tree_add_item(st, hf_btsmp_notification_type, tvb, offset, 1, ENC_NA);

        col_append_fstr(pinfo->cinfo, COL_INFO, ": %s", val_to_str_const(tvb_get_uint8(tvb, offset), notification_type_vals, "<unknown>"));

        offset += 1;

        break;

    default:

        break;

    }

    return offset;

}

void

proto_register_btsmp(void)

{

    static hf_register_info hf[] = {

        {&hf_btsmp_opcode,

            {"Opcode", "btsmp.opcode",

            FT_UINT8, BASE_HEX, VALS(opcode_vals), 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_reason,

            {"Reason", "btsmp.reason",

            FT_UINT8, BASE_HEX, VALS(reason_vals), 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_io_capabilities,

            {"IO Capability", "btsmp.io_capability",

            FT_UINT8, BASE_HEX, VALS(io_capability_vals), 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_oob_data_flags,

            {"OOB Data Flags", "btsmp.oob_data_flags",

            FT_UINT8, BASE_HEX, VALS(oob_data_flag_vals), 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_cfm_value,

            {"Confirm Value", "btsmp.cfm_value",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_random,

            {"Random Value", "btsmp.random_value",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_long_term_key,

            {"Long Term Key", "btsmp.long_term_key",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_id_resolving_key,

            {"Identity Resolving Key", "btsmp.id_resolving_key",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_signature_key,

            {"Signature Key", "btsmp.signature_key",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_bonding_flags,

            {"Bonding Flags", "btsmp.bonding_flags",

            FT_UINT8, BASE_HEX, VALS(bonding_flag_vals), 0x03,

            NULL, HFILL}

        },

        {&hf_btsmp_mitm_flag,

            {"MITM Flag", "btsmp.mitm_flag",

            FT_BOOLEAN, 8, NULL, 0x04,

            NULL, HFILL}

        },

        {&hf_btsmp_secure_connection_flag,

            {"Secure Connection Flag", "btsmp.sc_flag",

            FT_BOOLEAN, 8, NULL, 0x08,

            NULL, HFILL}

        },

        {&hf_btsmp_keypress_flag,

            {"Keypress Flag", "btsmp.keypress_flag",

            FT_BOOLEAN, 8, NULL, 0x10,

            NULL, HFILL}

        },

        {&hf_btsmp_ct2_flag,

            {"CT2 Flag", "btsmp.ct2_flag",

            FT_BOOLEAN, 8, NULL, 0x20,

            NULL, HFILL}

        },

        {&hf_btsmp_reserved_flag,

            {"Reserved", "btsmp.reserved_flags",

            FT_UINT8, BASE_HEX, NULL, 0xC0,

            NULL, HFILL}

        },

        {&hf_btsmp_max_enc_key_size,

            {"Max Encryption Key Size", "btsmp.max_enc_key_size",

            FT_UINT8, BASE_DEC, NULL, 0x00,

            NULL, HFILL}

        },

        {&hf_btsmp_key_dist_enc,

            {"Encryption Key (LTK)", "btsmp.key_dist_enc",

            FT_BOOLEAN, 8, NULL, 0x01,

            NULL, HFILL}

        },

        {&hf_btsmp_key_dist_id,

            {"Id Key (IRK)", "btsmp.key_dist_id",

            FT_BOOLEAN, 8, NULL, 0x02,

            NULL, HFILL}

        },

        {&hf_btsmp_key_dist_sign,

            {"Signature Key (CSRK)", "btsmp.key_dist_sign",

            FT_BOOLEAN, 8, NULL, 0x04,

            NULL, HFILL}

        },

        {&hf_btsmp_key_dist_linkkey,

            {"Link Key", "btsmp.key_dist_linkkey",

            FT_BOOLEAN, 8, NULL, 0x08,

            NULL, HFILL}

        },

        {&hf_btsmp_key_dist_reserved,

            {"Reserved", "btsmp.key_dist_reserved",

            FT_UINT8, BASE_HEX, NULL, 0xF0,

            NULL, HFILL}

        },

        {&hf_btsmp_ediv,

            {"Encrypted Diversifier (EDIV)", "btsmp.ediv",

            FT_UINT16, BASE_HEX, NULL, 0x00,

            NULL, HFILL}

        },

        {&hf_btsmp_authreq,

            {"AuthReq", "btsmp.authreq",

            FT_UINT8, BASE_HEX, NULL, 0x00,

            NULL, HFILL}

        },

        {&hf_btsmp_initiator_key_distribution,

            {"Initiator Key Distribution", "btsmp.initiator_key_distribution",

            FT_UINT8, BASE_HEX, NULL, 0x00,

            NULL, HFILL}

        },

        {&hf_btsmp_responder_key_distribution,

            {"Responder Key Distribution", "btsmp.responder_key_distribution",

            FT_UINT8, BASE_HEX, NULL, 0x00,

            NULL, HFILL}

        },

        {&hf_bd_addr,

          { "BD_ADDR", "btsmp.bd_addr",

            FT_ETHER, BASE_NONE, NULL, 0x0,

            "Bluetooth Device Address", HFILL}

        },

        { &hf_address_type,

            { "Address Type", "btsmp.address_type",

            FT_UINT8, BASE_HEX, VALS(bluetooth_address_type_vals), 0x0,

            NULL, HFILL }

        },

        {&hf_btsmp_public_key_x,

            {"Public Key X", "btsmp.public_key_x",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_public_key_y,

            {"Public Key Y", "btsmp.public_key_y",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_dhkey_check,

            {"DHKey Check", "btsmp.dhkey_check",

            FT_BYTES, BASE_NONE, NULL, 0x0,

            NULL, HFILL}

        },

        {&hf_btsmp_notification_type,

            {"Notification Type", "btsmp.notification_type",

            FT_UINT8, BASE_HEX, VALS(notification_type_vals), 0x0,

            NULL, HFILL}

        },

    };

    /* Setup protocol subtree array */

    static int *ett[] = {

      &ett_btsmp,

      &ett_btsmp_auth_req,

      &ett_btsmp_key_dist

    };

    /* Register the protocol name and description */

    proto_btsmp = proto_register_protocol("Bluetooth Security Manager Protocol",

        "BT SMP", "btsmp");

    btsmp_handle = register_dissector("btsmp", dissect_btsmp, proto_btsmp);

    /* Required function calls to register the header fields and subtrees used */

    proto_register_field_array(proto_btsmp, hf, array_length(hf));

    proto_register_subtree_array(ett, array_length(ett));

}

void

proto_reg_handoff_btsmp(void)

{

    dissector_add_uint("btl2cap.cid", BTL2CAP_FIXED_CID_SMP, btsmp_handle);

    dissector_add_uint("btl2cap.cid", BTL2CAP_FIXED_CID_BR_EDR_SM, btsmp_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:

 */