RRG-Proxmark3/armsrc/sam_common.c
2025-01-07 00:30:49 +01:00

374 lines
11 KiB
C

//-----------------------------------------------------------------------------
// Copyright (C) Proxmark3 contributors. See AUTHORS.md for details.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// See LICENSE.txt for the text of the license.
//-----------------------------------------------------------------------------
// Routines to support MFC <-> SAM communication
//-----------------------------------------------------------------------------
#include <string.h>
#include "sam_common.h"
#include "iclass.h"
#include "proxmark3_arm.h"
#include "BigBuf.h"
#include "commonutil.h"
#include "ticks.h"
#include "dbprint.h"
#include "i2c.h"
#include "iso15693.h"
#include "protocols.h"
/**
* @brief Transmits data to and receives data from a HID®'s iCLASS® SE™ Processor.
*
* This function sends a specified number of bytes to the SAM and receives a response.
*
* @param data Pointer to the data to be transmitted.
* @param n Number of bytes to be transmitted.
* @param resp Pointer to the buffer where the response will be stored.
* @param resplen Pointer to the variable where the length of the response will be stored.
* @return Status code indicating success or failure of the operation.
*/
int sam_rxtx(const uint8_t *data, uint16_t n, uint8_t *resp, uint16_t *resplen) {
bool res = I2C_BufferWrite(data, n, I2C_DEVICE_CMD_SEND_T0, I2C_DEVICE_ADDRESS_MAIN);
if (res == false) {
DbpString("failed to send to SIM CARD");
goto out;
}
*resplen = ISO7816_MAX_FRAME;
res = sc_rx_bytes(resp, resplen, SIM_WAIT_DELAY);
if (res == false) {
DbpString("failed to receive from SIM CARD");
goto out;
}
if (*resplen < 2) {
DbpString("received too few bytes from SIM CARD");
res = false;
goto out;
}
uint16_t more_len = 0;
if (resp[*resplen - 2] == 0x61 || resp[*resplen - 2] == 0x9F) {
more_len = resp[*resplen - 1];
} else {
// we done, return
goto out;
}
// Don't discard data we already received except the SW code.
// If we only received 1 byte, this is the echo of INS, we discard it.
*resplen -= 2;
if (*resplen == 1) {
*resplen = 0;
}
uint8_t cmd_getresp[] = {0x00, ISO7816_GET_RESPONSE, 0x00, 0x00, more_len};
res = I2C_BufferWrite(cmd_getresp, sizeof(cmd_getresp), I2C_DEVICE_CMD_SEND_T0, I2C_DEVICE_ADDRESS_MAIN);
if (res == false) {
DbpString("failed to send to SIM CARD 2");
goto out;
}
more_len = 255 - *resplen;
res = sc_rx_bytes(resp + *resplen, &more_len, SIM_WAIT_DELAY);
if (res == false) {
DbpString("failed to receive from SIM CARD 2");
goto out;
}
*resplen += more_len;
out:
return res;
}
static inline void swap_clock_counters(volatile unsigned int *a, unsigned int *b) {
unsigned int c = *a;
*a = *b;
*b = c;
}
/**
* @brief Swaps the timer counter values.
*
* AT91SAM7S512 has a single Timer-Counter, that is reused in clocks Ticks
* and CountSspClk. This function stops the current clock and restores previous
* values. It is used to switch between different clock sources.
* It probably makes communication timing off, but at least makes it work.
*/
static void swap_clocks(void) {
static unsigned int tc0, tc1, tc2 = 0;
StopTicks();
swap_clock_counters(&(AT91C_BASE_TC0->TC_CV), &tc0);
swap_clock_counters(&(AT91C_BASE_TC1->TC_CV), &tc1);
swap_clock_counters(&(AT91C_BASE_TC2->TC_CV), &tc2);
}
void switch_clock_to_ticks(void) {
swap_clocks();
StartTicks();
}
void switch_clock_to_countsspclk(void) {
swap_clocks();
StartCountSspClk();
}
/**
* @brief Sends a payload to the SAM
*
* This function prepends the payload with the necessary APDU and application
* headers and sends it to the SAM.
*
* @param addr_src 0x14 for command from NFC, 0x44 for command from application
* @param addr_dest 0x0A for command to SAM
* @param addr_reply same as add_src or 0x00 if no reply is expected
* @param payload Pointer to the data to be sent.
* @param payload_len Length of the data to be sent.
* @param response Pointer to the buffer where the response will be stored.
* @param response_len Pointer to the variable where the length of the response will be stored.
* @param length Length of the data to be sent.
* @return Status code indicating success or failure of the operation.
*/
int sam_send_payload(
const uint8_t addr_src,
const uint8_t addr_dest,
const uint8_t addr_reply,
const uint8_t *const payload,
const uint16_t *payload_len,
uint8_t *response,
uint16_t *response_len
) {
int res = PM3_SUCCESS;
uint8_t *buf = response;
buf[0] = 0xA0; // CLA
buf[1] = 0xDA; // INS (PUT DATA)
buf[2] = 0x02; // P1 (TLV format?)
buf[3] = 0x63; // P2
buf[4] = SAM_TX_ASN1_PREFIX_LENGTH + (uint8_t) * payload_len; // LEN
buf[5] = addr_src;
buf[6] = addr_dest;
buf[7] = addr_reply;
buf[8] = 0x00;
buf[9] = 0x00;
buf[10] = 0x00;
memcpy(
&buf[11],
payload,
*payload_len
);
uint16_t length = SAM_TX_ASN1_PREFIX_LENGTH + SAM_TX_APDU_PREFIX_LENGTH + (uint8_t) * payload_len;
LogTrace(buf, length, 0, 0, NULL, true);
if (g_dbglevel >= DBG_INFO) {
DbpString("SAM REQUEST APDU: ");
Dbhexdump(length, buf, false);
}
if (sam_rxtx(buf, length, response, response_len) == false) {
if (g_dbglevel >= DBG_ERROR)
DbpString("SAM ERROR");
res = PM3_ECARDEXCHANGE;
goto out;
}
LogTrace(response, *response_len, 0, 0, NULL, false);
if (g_dbglevel >= DBG_INFO) {
DbpString("SAM RESPONSE APDU: ");
Dbhexdump(*response_len, response, false);
}
out:
return res;
}
/**
* @brief Retreives SAM firmware version.
*
* Used just as ping or sanity check here.
*
* @return Status code indicating success or failure of the operation.
*/
int sam_get_version(void) {
int res = PM3_SUCCESS;
if (g_dbglevel >= DBG_DEBUG)
DbpString("start sam_get_version");
uint8_t *response = BigBuf_malloc(ISO7816_MAX_FRAME);
uint16_t response_len = ISO7816_MAX_FRAME;
uint8_t payload[] = {
0xa0, 0x02, // <- SAM command
0x82, 0x00 // <- get version
};
uint16_t payload_len = sizeof(payload);
sam_send_payload(
0x44, 0x0a, 0x44,
payload,
&payload_len,
response,
&response_len
);
// resp:
// c1 64 00 00 00
// bd 11 <- SAM response
// 8a 0f <- get version response
// 80 02
// 01 29 <- version
// 81 06
// 68 3d 05 20 26 b6 <- build ID
// 82 01
// 01
// 90 00
if (g_dbglevel >= DBG_DEBUG)
DbpString("end sam_get_version");
if (response[5] != 0xbd) {
Dbprintf("Invalid SAM response");
goto error;
} else {
uint8_t *sam_response_an = sam_find_asn1_node(response + 5, 0x8a);
if (sam_response_an == NULL) {
if (g_dbglevel >= DBG_ERROR)
DbpString("SAM get response failed");
goto error;
}
uint8_t *sam_version_an = sam_find_asn1_node(sam_response_an, 0x80);
if (sam_version_an == NULL) {
if (g_dbglevel >= DBG_ERROR)
DbpString("SAM get version failed");
goto error;
}
uint8_t *sam_build_an = sam_find_asn1_node(sam_response_an, 0x81);
if (sam_build_an == NULL) {
if (g_dbglevel >= DBG_ERROR)
DbpString("SAM get firmware ID failed");
goto error;
}
if (g_dbglevel >= DBG_INFO) {
DbpString("SAM get version successful");
Dbprintf("Firmware version: %X.%X", sam_version_an[2], sam_version_an[3]);
Dbprintf("Firmware ID: ");
Dbhexdump(sam_build_an[1], sam_build_an + 2, false);
}
goto out;
}
error:
res = PM3_ESOFT;
out:
BigBuf_free();
if (g_dbglevel >= DBG_DEBUG)
DbpString("end sam_get_version");
return res;
}
/**
* @brief Finds an ASN.1 node of a specified type within a given root node.
*
* This function searches through a single level of the ASN.1 structure starting
* from the root node to find a node of the specified type.
*
* @param root Pointer to the root node of the ASN.1 structure.
* @param type The type of the ASN.1 node to find.
* @return Pointer to the ASN.1 node of the specified type if found, otherwise NULL.
*/
uint8_t *sam_find_asn1_node(const uint8_t *root, const uint8_t type) {
const uint8_t *end = (uint8_t *) root + *(root + 1);
uint8_t *current = (uint8_t *) root + 2;
while (current < end) {
if (*current == type) {
return current;
} else {
current += 2 + *(current + 1);
}
}
return NULL;
}
/**
* @brief Appends an ASN.1 node to the end of a given node.
*
* This function appends an ASN.1 node of a specified type and length to the end of
* the ASN.1 structure at specified node level.
*
* It is the most naive solution that does not handle the case where the node to append is
* not the last node at the same level. It also does not also care about proper
* order of the nodes.
*
* @param root Pointer to the root node of the ASN.1 structure.
* @param root Pointer to the node to be appended of the ASN.1 structure.
* @param type The type of the ASN.1 node to append.
* @param data Pointer to the data to be appended.
* @param len The length of the data to be appended.
*/
void sam_append_asn1_node(const uint8_t *root, const uint8_t *node, uint8_t type, const uint8_t *const data, uint8_t len) {
uint8_t *end = (uint8_t *) root + *(root + 1) + 2;
*(end) = type;
*(end + 1) = len;
memcpy(end + 2, data, len);
for (uint8_t *current = (uint8_t *) root; current <= node; current += 2) {
*(current + 1) += 2 + len;
};
return;
}
void sam_send_ack(void) {
uint8_t *response = BigBuf_malloc(ISO7816_MAX_FRAME);
uint16_t response_len = ISO7816_MAX_FRAME;
uint8_t payload[] = {
0xa0, 0
};
uint16_t payload_len = sizeof(payload);
sam_send_payload(
0x44, 0x0a, 0x00,
payload,
&payload_len,
response,
&response_len
);
BigBuf_free();
}