unleashed-firmware/lib/nfc/protocols/emv.c
Emily Trau 4dc4d34d04
emv: parse track1&2 equivalent data ()
* emv: parse track1&2 equivalent data
* emv: alternate expiry parser
* nfc: log EMV track1&2 data to trace output

Co-authored-by: gornekich <n.gorbadey@gmail.com>
Co-authored-by: あく <alleteam@gmail.com>
2023-01-27 12:10:08 +07:00

444 lines
16 KiB
C

#include "emv.h"
#include <core/common_defines.h>
#define TAG "Emv"
const PDOLValue pdol_term_info = {0x9F59, {0xC8, 0x80, 0x00}}; // Terminal transaction information
const PDOLValue pdol_term_type = {0x9F5A, {0x00}}; // Terminal transaction type
const PDOLValue pdol_merchant_type = {0x9F58, {0x01}}; // Merchant type indicator
const PDOLValue pdol_term_trans_qualifies = {
0x9F66,
{0x79, 0x00, 0x40, 0x80}}; // Terminal transaction qualifiers
const PDOLValue pdol_addtnl_term_qualifies = {
0x9F40,
{0x79, 0x00, 0x40, 0x80}}; // Terminal transaction qualifiers
const PDOLValue pdol_amount_authorise = {
0x9F02,
{0x00, 0x00, 0x00, 0x10, 0x00, 0x00}}; // Amount, authorised
const PDOLValue pdol_amount = {0x9F03, {0x00, 0x00, 0x00, 0x00, 0x00, 0x00}}; // Amount
const PDOLValue pdol_country_code = {0x9F1A, {0x01, 0x24}}; // Terminal country code
const PDOLValue pdol_currency_code = {0x5F2A, {0x01, 0x24}}; // Transaction currency code
const PDOLValue pdol_term_verification = {
0x95,
{0x00, 0x00, 0x00, 0x00, 0x00}}; // Terminal verification results
const PDOLValue pdol_transaction_date = {0x9A, {0x19, 0x01, 0x01}}; // Transaction date
const PDOLValue pdol_transaction_type = {0x9C, {0x00}}; // Transaction type
const PDOLValue pdol_transaction_cert = {0x98, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0}}; // Transaction cert
const PDOLValue pdol_unpredict_number = {0x9F37, {0x82, 0x3D, 0xDE, 0x7A}}; // Unpredictable number
const PDOLValue* const pdol_values[] = {
&pdol_term_info,
&pdol_term_type,
&pdol_merchant_type,
&pdol_term_trans_qualifies,
&pdol_addtnl_term_qualifies,
&pdol_amount_authorise,
&pdol_amount,
&pdol_country_code,
&pdol_currency_code,
&pdol_term_verification,
&pdol_transaction_date,
&pdol_transaction_type,
&pdol_transaction_cert,
&pdol_unpredict_number,
};
static const uint8_t select_ppse_ans[] = {0x6F, 0x29, 0x84, 0x0E, 0x32, 0x50, 0x41, 0x59, 0x2E,
0x53, 0x59, 0x53, 0x2E, 0x44, 0x44, 0x46, 0x30, 0x31,
0xA5, 0x17, 0xBF, 0x0C, 0x14, 0x61, 0x12, 0x4F, 0x07,
0xA0, 0x00, 0x00, 0x00, 0x03, 0x10, 0x10, 0x50, 0x04,
0x56, 0x49, 0x53, 0x41, 0x87, 0x01, 0x01, 0x90, 0x00};
static const uint8_t select_app_ans[] = {0x6F, 0x20, 0x84, 0x07, 0xA0, 0x00, 0x00, 0x00, 0x03,
0x10, 0x10, 0xA5, 0x15, 0x50, 0x04, 0x56, 0x49, 0x53,
0x41, 0x9F, 0x38, 0x0C, 0x9F, 0x66, 0x04, 0x9F, 0x02,
0x06, 0x9F, 0x37, 0x04, 0x5F, 0x2A, 0x02, 0x90, 0x00};
static const uint8_t pdol_ans[] = {0x77, 0x40, 0x82, 0x02, 0x20, 0x00, 0x57, 0x13, 0x55, 0x70,
0x73, 0x83, 0x85, 0x87, 0x73, 0x31, 0xD1, 0x80, 0x22, 0x01,
0x38, 0x84, 0x77, 0x94, 0x00, 0x00, 0x1F, 0x5F, 0x34, 0x01,
0x00, 0x9F, 0x10, 0x07, 0x06, 0x01, 0x11, 0x03, 0x80, 0x00,
0x00, 0x9F, 0x26, 0x08, 0x7A, 0x65, 0x7F, 0xD3, 0x52, 0x96,
0xC9, 0x85, 0x9F, 0x27, 0x01, 0x00, 0x9F, 0x36, 0x02, 0x06,
0x0C, 0x9F, 0x6C, 0x02, 0x10, 0x00, 0x90, 0x00};
static void emv_trace(FuriHalNfcTxRxContext* tx_rx, const char* message) {
if(furi_log_get_level() == FuriLogLevelTrace) {
FURI_LOG_T(TAG, "%s", message);
printf("TX: ");
for(size_t i = 0; i < tx_rx->tx_bits / 8; i++) {
printf("%02X ", tx_rx->tx_data[i]);
}
printf("\r\nRX: ");
for(size_t i = 0; i < tx_rx->rx_bits / 8; i++) {
printf("%02X ", tx_rx->rx_data[i]);
}
printf("\r\n");
}
}
static bool emv_decode_response(uint8_t* buff, uint16_t len, EmvApplication* app) {
uint16_t i = 0;
uint16_t tag = 0, first_byte = 0;
uint16_t tlen = 0;
bool success = false;
while(i < len) {
first_byte = buff[i];
if((first_byte & 31) == 31) { // 2-byte tag
tag = buff[i] << 8 | buff[i + 1];
i++;
FURI_LOG_T(TAG, " 2-byte TLV EMV tag: %x", tag);
} else {
tag = buff[i];
FURI_LOG_T(TAG, " 1-byte TLV EMV tag: %x", tag);
}
i++;
tlen = buff[i];
if((tlen & 128) == 128) { // long length value
i++;
tlen = buff[i];
FURI_LOG_T(TAG, " 2-byte TLV length: %d", tlen);
} else {
FURI_LOG_T(TAG, " 1-byte TLV length: %d", tlen);
}
i++;
if((first_byte & 32) == 32) { // "Constructed" -- contains more TLV data to parse
FURI_LOG_T(TAG, "Constructed TLV %x", tag);
if(!emv_decode_response(&buff[i], tlen, app)) {
FURI_LOG_T(TAG, "Failed to decode response for %x", tag);
// return false;
} else {
success = true;
}
} else {
switch(tag) {
case EMV_TAG_AID:
app->aid_len = tlen;
memcpy(app->aid, &buff[i], tlen);
success = true;
FURI_LOG_T(TAG, "found EMV_TAG_AID %x", tag);
break;
case EMV_TAG_PRIORITY:
memcpy(&app->priority, &buff[i], tlen);
success = true;
break;
case EMV_TAG_CARD_NAME:
memcpy(app->name, &buff[i], tlen);
app->name[tlen] = '\0';
app->name_found = true;
success = true;
FURI_LOG_T(TAG, "found EMV_TAG_CARD_NAME %x : %s", tag, app->name);
break;
case EMV_TAG_PDOL:
memcpy(app->pdol.data, &buff[i], tlen);
app->pdol.size = tlen;
success = true;
FURI_LOG_T(TAG, "found EMV_TAG_PDOL %x (len=%d)", tag, tlen);
break;
case EMV_TAG_AFL:
memcpy(app->afl.data, &buff[i], tlen);
app->afl.size = tlen;
success = true;
FURI_LOG_T(TAG, "found EMV_TAG_AFL %x (len=%d)", tag, tlen);
break;
case EMV_TAG_TRACK_1_EQUIV: {
char track_1_equiv[80];
memcpy(track_1_equiv, &buff[i], tlen);
track_1_equiv[tlen] = '\0';
success = true;
FURI_LOG_T(TAG, "found EMV_TAG_TRACK_1_EQUIV %x : %s", tag, track_1_equiv);
break;
}
case EMV_TAG_TRACK_2_EQUIV: {
// 0xD0 delimits PAN from expiry (YYMM)
for(int x = 1; x < tlen; x++) {
if(buff[i + x + 1] > 0xD0) {
memcpy(app->card_number, &buff[i], x + 1);
app->card_number_len = x + 1;
app->exp_year = (buff[i + x + 1] << 4) | (buff[i + x + 2] >> 4);
app->exp_month = (buff[i + x + 2] << 4) | (buff[i + x + 3] >> 4);
break;
}
}
// Convert 4-bit to ASCII representation
char track_2_equiv[41];
uint8_t track_2_equiv_len = 0;
for(int x = 0; x < tlen; x++) {
char top = (buff[i + x] >> 4) + '0';
char bottom = (buff[i + x] & 0x0F) + '0';
track_2_equiv[x * 2] = top;
track_2_equiv_len++;
if(top == '?') break;
track_2_equiv[x * 2 + 1] = bottom;
track_2_equiv_len++;
if(bottom == '?') break;
}
track_2_equiv[track_2_equiv_len] = '\0';
success = true;
FURI_LOG_T(TAG, "found EMV_TAG_TRACK_2_EQUIV %x : %s", tag, track_2_equiv);
break;
}
case EMV_TAG_PAN:
memcpy(app->card_number, &buff[i], tlen);
app->card_number_len = tlen;
success = true;
break;
case EMV_TAG_EXP_DATE:
app->exp_year = buff[i];
app->exp_month = buff[i + 1];
success = true;
break;
case EMV_TAG_CURRENCY_CODE:
app->currency_code = (buff[i] << 8 | buff[i + 1]);
success = true;
break;
case EMV_TAG_COUNTRY_CODE:
app->country_code = (buff[i] << 8 | buff[i + 1]);
success = true;
break;
}
}
i += tlen;
}
return success;
}
static bool emv_select_ppse(FuriHalNfcTxRxContext* tx_rx, EmvApplication* app) {
bool app_aid_found = false;
const uint8_t emv_select_ppse_cmd[] = {
0x00, 0xA4, // SELECT ppse
0x04, 0x00, // P1:By name, P2: empty
0x0e, // Lc: Data length
0x32, 0x50, 0x41, 0x59, 0x2e, 0x53, 0x59, // Data string:
0x53, 0x2e, 0x44, 0x44, 0x46, 0x30, 0x31, // 2PAY.SYS.DDF01 (PPSE)
0x00 // Le
};
memcpy(tx_rx->tx_data, emv_select_ppse_cmd, sizeof(emv_select_ppse_cmd));
tx_rx->tx_bits = sizeof(emv_select_ppse_cmd) * 8;
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
FURI_LOG_D(TAG, "Send select PPSE");
if(furi_hal_nfc_tx_rx(tx_rx, 300)) {
emv_trace(tx_rx, "Select PPSE answer:");
if(emv_decode_response(tx_rx->rx_data, tx_rx->rx_bits / 8, app)) {
app_aid_found = true;
} else {
FURI_LOG_E(TAG, "Failed to parse application");
}
} else {
FURI_LOG_E(TAG, "Failed select PPSE");
}
return app_aid_found;
}
static bool emv_select_app(FuriHalNfcTxRxContext* tx_rx, EmvApplication* app) {
app->app_started = false;
const uint8_t emv_select_header[] = {
0x00,
0xA4, // SELECT application
0x04,
0x00 // P1:By name, P2:First or only occurence
};
uint16_t size = sizeof(emv_select_header);
// Copy header
memcpy(tx_rx->tx_data, emv_select_header, size);
// Copy AID
tx_rx->tx_data[size++] = app->aid_len;
memcpy(&tx_rx->tx_data[size], app->aid, app->aid_len);
size += app->aid_len;
tx_rx->tx_data[size++] = 0x00;
tx_rx->tx_bits = size * 8;
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
FURI_LOG_D(TAG, "Start application");
if(furi_hal_nfc_tx_rx(tx_rx, 300)) {
emv_trace(tx_rx, "Start application answer:");
if(emv_decode_response(tx_rx->rx_data, tx_rx->rx_bits / 8, app)) {
app->app_started = true;
} else {
FURI_LOG_E(TAG, "Failed to read PAN or PDOL");
}
} else {
FURI_LOG_E(TAG, "Failed to start application");
}
return app->app_started;
}
static uint16_t emv_prepare_pdol(APDU* dest, APDU* src) {
bool tag_found;
for(uint16_t i = 0; i < src->size; i++) {
tag_found = false;
for(uint8_t j = 0; j < sizeof(pdol_values) / sizeof(PDOLValue*); j++) {
if(src->data[i] == pdol_values[j]->tag) {
// Found tag with 1 byte length
uint8_t len = src->data[++i];
memcpy(dest->data + dest->size, pdol_values[j]->data, len);
dest->size += len;
tag_found = true;
break;
} else if(((src->data[i] << 8) | src->data[i + 1]) == pdol_values[j]->tag) {
// Found tag with 2 byte length
i += 2;
uint8_t len = src->data[i];
memcpy(dest->data + dest->size, pdol_values[j]->data, len);
dest->size += len;
tag_found = true;
break;
}
}
if(!tag_found) {
// Unknown tag, fill zeros
i += 2;
uint8_t len = src->data[i];
memset(dest->data + dest->size, 0, len);
dest->size += len;
}
}
return dest->size;
}
static bool emv_get_processing_options(FuriHalNfcTxRxContext* tx_rx, EmvApplication* app) {
bool card_num_read = false;
const uint8_t emv_gpo_header[] = {0x80, 0xA8, 0x00, 0x00};
uint16_t size = sizeof(emv_gpo_header);
// Copy header
memcpy(tx_rx->tx_data, emv_gpo_header, size);
APDU pdol_data = {0, {0}};
// Prepare and copy pdol parameters
emv_prepare_pdol(&pdol_data, &app->pdol);
tx_rx->tx_data[size++] = 0x02 + pdol_data.size;
tx_rx->tx_data[size++] = 0x83;
tx_rx->tx_data[size++] = pdol_data.size;
memcpy(tx_rx->tx_data + size, pdol_data.data, pdol_data.size);
size += pdol_data.size;
tx_rx->tx_data[size++] = 0;
tx_rx->tx_bits = size * 8;
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
FURI_LOG_D(TAG, "Get proccessing options");
if(furi_hal_nfc_tx_rx(tx_rx, 300)) {
emv_trace(tx_rx, "Get processing options answer:");
if(emv_decode_response(tx_rx->rx_data, tx_rx->rx_bits / 8, app)) {
if(app->card_number_len > 0) {
card_num_read = true;
}
}
} else {
FURI_LOG_E(TAG, "Failed to get processing options");
}
return card_num_read;
}
static bool emv_read_sfi_record(
FuriHalNfcTxRxContext* tx_rx,
EmvApplication* app,
uint8_t sfi,
uint8_t record_num) {
bool card_num_read = false;
uint8_t sfi_param = (sfi << 3) | (1 << 2);
uint8_t emv_sfi_header[] = {
0x00,
0xB2, // READ RECORD
record_num, // P1:record_number
sfi_param, // P2:SFI
0x00 // Le
};
memcpy(tx_rx->tx_data, emv_sfi_header, sizeof(emv_sfi_header));
tx_rx->tx_bits = sizeof(emv_sfi_header) * 8;
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
if(furi_hal_nfc_tx_rx(tx_rx, 300)) {
emv_trace(tx_rx, "SFI record:");
if(emv_decode_response(tx_rx->rx_data, tx_rx->rx_bits / 8, app)) {
card_num_read = true;
}
} else {
FURI_LOG_E(TAG, "Failed to read SFI record %d", record_num);
}
return card_num_read;
}
static bool emv_read_files(FuriHalNfcTxRxContext* tx_rx, EmvApplication* app) {
bool card_num_read = false;
if(app->afl.size == 0) {
return false;
}
FURI_LOG_D(TAG, "Search PAN in SFI");
// Iterate through all files
for(size_t i = 0; i < app->afl.size; i += 4) {
uint8_t sfi = app->afl.data[i] >> 3;
uint8_t record_start = app->afl.data[i + 1];
uint8_t record_end = app->afl.data[i + 2];
// Iterate through all records in file
for(uint8_t record = record_start; record <= record_end; ++record) {
card_num_read |= emv_read_sfi_record(tx_rx, app, sfi, record);
}
}
return card_num_read;
}
bool emv_read_bank_card(FuriHalNfcTxRxContext* tx_rx, EmvApplication* emv_app) {
furi_assert(tx_rx);
furi_assert(emv_app);
bool card_num_read = false;
memset(emv_app, 0, sizeof(EmvApplication));
do {
if(!emv_select_ppse(tx_rx, emv_app)) break;
if(!emv_select_app(tx_rx, emv_app)) break;
if(emv_get_processing_options(tx_rx, emv_app)) {
card_num_read = true;
} else {
card_num_read = emv_read_files(tx_rx, emv_app);
}
} while(false);
return card_num_read;
}
bool emv_card_emulation(FuriHalNfcTxRxContext* tx_rx) {
furi_assert(tx_rx);
bool emulation_complete = false;
tx_rx->tx_bits = 0;
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
do {
FURI_LOG_D(TAG, "Read select PPSE command");
if(!furi_hal_nfc_tx_rx(tx_rx, 300)) break;
memcpy(tx_rx->tx_data, select_ppse_ans, sizeof(select_ppse_ans));
tx_rx->tx_bits = sizeof(select_ppse_ans) * 8;
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
FURI_LOG_D(TAG, "Send select PPSE answer and read select App command");
if(!furi_hal_nfc_tx_rx(tx_rx, 300)) break;
memcpy(tx_rx->tx_data, select_app_ans, sizeof(select_app_ans));
tx_rx->tx_bits = sizeof(select_app_ans) * 8;
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
FURI_LOG_D(TAG, "Send select App answer and read get PDOL command");
if(!furi_hal_nfc_tx_rx(tx_rx, 300)) break;
memcpy(tx_rx->tx_data, pdol_ans, sizeof(pdol_ans));
tx_rx->tx_bits = sizeof(pdol_ans) * 8;
tx_rx->tx_rx_type = FuriHalNfcTxRxTypeDefault;
FURI_LOG_D(TAG, "Send get PDOL answer");
if(!furi_hal_nfc_tx_rx(tx_rx, 300)) break;
emulation_complete = true;
} while(false);
return emulation_complete;
}