libfreefare/libfreefare/mad.c
2017-06-29 12:25:53 +02:00

447 lines
10 KiB
C

/*
* This implementation was written based on information provided by the
* following document:
*
* AN10787
* MIFARE Application Directory (MAD)
* Rev. 04 - 5 March 2009
*
* NXP Type MF1K/4K Tag Operation
* Storing NFC Forum data in Mifare Standard 1k/4k
* Rev. 1.1 - 21 August 2007
*/
#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif
#include <sys/types.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <freefare.h>
/*
* The documentation says the preset is 0xE3 but the bits have to be mirrored:
* 0xe3 = 1110 0011 <=> 1100 0111 = 0xc7
*/
#define CRC_PRESET 0xc7
#define SECTOR_0X00_AIDS 15
#define SECTOR_0X10_AIDS 23
struct mad_sector_0x00 {
uint8_t crc;
uint8_t info;
MadAid aids[SECTOR_0X00_AIDS];
};
struct mad_sector_0x10 {
uint8_t crc;
uint8_t info;
MadAid aids[SECTOR_0X10_AIDS];
};
struct mad {
struct mad_sector_0x00 sector_0x00;
struct mad_sector_0x10 sector_0x10;
uint8_t version;
};
/* Public Key A value of MAD sector(s) */
const MifareClassicKey mad_public_key_a = {
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5
};
/* AID - Administration codes: */
/* if sector is free */
const MadAid mad_free_aid = {
.function_cluster_code = 0x00,
.application_code = 0x00,
};
/* if sector is defect, e.g. access keys are destroyed or unknown */
const MadAid mad_defect_aid = {
.function_cluster_code = 0x00,
.application_code = 0x01,
};
/* if sector is reserved */
const MadAid mad_reserved_aid = {
.function_cluster_code = 0x00,
.application_code = 0x02,
};
/* if sector contains card holder information in ASCII format. */
const MadAid mad_card_holder_aid = {
.function_cluster_code = 0x00,
.application_code = 0x04,
};
/* if sector not applicable (above memory size) */
const MadAid mad_not_applicable_aid = {
.function_cluster_code = 0x00,
.application_code = 0x05,
};
/* NFC Forum AID */
const MadAid mad_nfcforum_aid = {
.function_cluster_code = 0xe1,
.application_code = 0x03,
};
/*
* Allocate an empty new MAD.
*/
Mad
mad_new(uint8_t version)
{
Mad mad = malloc(sizeof(*mad));
if (!mad)
return NULL;
mad->version = version;
memset(&(mad->sector_0x00), 0, sizeof(mad->sector_0x00));
memset(&(mad->sector_0x10), 0, sizeof(mad->sector_0x10));
return mad;
}
/*
* Compute CRC.
*/
void
nxp_crc(uint8_t *crc, const uint8_t value)
{
/* x^8 + x^4 + x^3 + x^2 + 1 => 0x11d */
const uint8_t poly = 0x1d;
*crc ^= value;
for (int current_bit = 7; current_bit >= 0; current_bit--) {
int bit_out = (*crc) & 0x80;
*crc <<= 1;
if (bit_out)
*crc ^= poly;
}
}
uint8_t
sector_0x00_crc8(Mad mad)
{
uint8_t crc = CRC_PRESET;
nxp_crc(&crc, mad->sector_0x00.info);
for (int n = 0; n < SECTOR_0X00_AIDS; n++) {
nxp_crc(&crc, mad->sector_0x00.aids[n].application_code);
nxp_crc(&crc, mad->sector_0x00.aids[n].function_cluster_code);
}
return crc;
}
uint8_t
sector_0x10_crc8(Mad mad)
{
uint8_t crc = CRC_PRESET;
nxp_crc(&crc, mad->sector_0x10.info);
for (int n = 0; n < SECTOR_0X10_AIDS; n++) {
nxp_crc(&crc, mad->sector_0x10.aids[n].application_code);
nxp_crc(&crc, mad->sector_0x10.aids[n].function_cluster_code);
}
return crc;
}
/*
* Read a MAD from the provided MIFARE tag.
*/
Mad
mad_read(FreefareTag tag)
{
Mad mad = malloc(sizeof(*mad));
if (!mad)
goto error;
/* Authenticate using MAD key A */
if (mifare_classic_authenticate(tag, 0x03, mad_public_key_a, MFC_KEY_A) < 0) {
goto error;
}
/* Read first sector trailer block */
MifareClassicBlock data;
if (mifare_classic_read(tag, 0x03, &data) < 0) {
goto error;
}
uint8_t gpb = data[9];
/* Check MAD availability (DA bit) */
if (!(gpb & 0x80)) {
goto error;
}
/* Get MAD version (ADV bits) */
switch (gpb & 0x03) {
case 0x01:
mad->version = 1;
break;
case 0x02:
mad->version = 2;
break;
default:
/* MAD enabled but version not supported */
errno = ENOTSUP;
goto error;
}
/* Read MAD data at 0x00 (MAD1, MAD2) */
if (mifare_classic_read(tag, 0x01, &data) < 0)
goto error;
uint8_t *p = (uint8_t *) & (mad->sector_0x00);
memcpy(p, data, sizeof(data));
p += sizeof(data);
if (mifare_classic_read(tag, 0x02, &data) < 0)
goto error;
memcpy(p, data, sizeof(data));
uint8_t crc = mad->sector_0x00.crc;
uint8_t computed_crc = sector_0x00_crc8(mad);
if (crc != computed_crc)
goto error;
/* Read MAD data at 0x10 (MAD2) */
if (mad->version == 2) {
/* Authenticate using MAD key A */
if (mifare_classic_authenticate(tag, 0x43, mad_public_key_a, MFC_KEY_A) < 0) {
goto error;
}
p = (uint8_t *) & (mad->sector_0x10);
if (mifare_classic_read(tag, 0x40, &data) < 0)
goto error;
memcpy(p, data, sizeof(data));
p += sizeof(data);
if (mifare_classic_read(tag, 0x41, &data) < 0)
goto error;
memcpy(p, data, sizeof(data));
p += sizeof(data);
if (mifare_classic_read(tag, 0x42, &data) < 0)
goto error;
memcpy(p, data, sizeof(data));
crc = mad->sector_0x10.crc;
computed_crc = sector_0x10_crc8(mad);
if (crc != computed_crc)
goto error;
}
return mad;
error:
free(mad);
return NULL;
}
/*
* Write the mad to the provided MIFARE tad using the provided Key-B keys.
*/
int
mad_write(FreefareTag tag, Mad mad, const MifareClassicKey key_b_sector_00, const MifareClassicKey key_b_sector_10)
{
MifareClassicBlock data;
if (mifare_classic_authenticate(tag, 0x00, key_b_sector_00, MFC_KEY_B) < 0)
return -1;
if ((1 != mifare_classic_get_data_block_permission(tag, 0x01, MCAB_W, MFC_KEY_B)) ||
(1 != mifare_classic_get_data_block_permission(tag, 0x02, MCAB_W, MFC_KEY_B)) ||
(1 != mifare_classic_get_trailer_block_permission(tag, 0x03, MCAB_WRITE_KEYA, MFC_KEY_B)) ||
(1 != mifare_classic_get_trailer_block_permission(tag, 0x03, MCAB_WRITE_ACCESS_BITS, MFC_KEY_B))) {
errno = EPERM;
return -1;
}
uint8_t gpb = 0x80;
/*
* FIXME Handle mono-application cards
*/
gpb |= 0x40;
/* Write MAD version */
switch (mad->version) {
case 1:
gpb |= 0x01;
break;
case 2:
gpb |= 0x02;
break;
}
if (2 == mad->version) {
if (mifare_classic_authenticate(tag, 0x40, key_b_sector_10, MFC_KEY_B) < 0)
return -1;
if ((1 != mifare_classic_get_data_block_permission(tag, 0x40, MCAB_W, MFC_KEY_B)) ||
(1 != mifare_classic_get_data_block_permission(tag, 0x41, MCAB_W, MFC_KEY_B)) ||
(1 != mifare_classic_get_data_block_permission(tag, 0x42, MCAB_W, MFC_KEY_B)) ||
(1 != mifare_classic_get_trailer_block_permission(tag, 0x43, MCAB_WRITE_KEYA, MFC_KEY_B)) ||
(1 != mifare_classic_get_trailer_block_permission(tag, 0x43, MCAB_WRITE_ACCESS_BITS, MFC_KEY_B))) {
errno = EPERM;
return -1;
}
mad->sector_0x10.crc = sector_0x10_crc8(mad);
memcpy(data, (uint8_t *) & (mad->sector_0x10), sizeof(data));
if (mifare_classic_write(tag, 0x40, data) < 0) return -1;
memcpy(data, (uint8_t *) & (mad->sector_0x10) + sizeof(data), sizeof(data));
if (mifare_classic_write(tag, 0x41, data) < 0) return -1;
memcpy(data, (uint8_t *) & (mad->sector_0x10) + sizeof(data) * 2, sizeof(data));
if (mifare_classic_write(tag, 0x42, data) < 0) return -1;
mifare_classic_trailer_block(&data, mad_public_key_a, 0x0, 0x1, 0x1, 0x6, 0x00, key_b_sector_10);
if (mifare_classic_write(tag, 0x43, data) < 0) return -1;
}
mad->sector_0x00.crc = sector_0x00_crc8(mad);
if (mifare_classic_authenticate(tag, 0x00, key_b_sector_00, MFC_KEY_B) < 0) return -1;
memcpy(data, (uint8_t *) & (mad->sector_0x00), sizeof(data));
if (mifare_classic_write(tag, 0x01, data) < 0) return -1;
memcpy(data, (uint8_t *) & (mad->sector_0x00) + sizeof(data), sizeof(data));
if (mifare_classic_write(tag, 0x02, data) < 0) return -1;
mifare_classic_trailer_block(&data, mad_public_key_a, 0x0, 0x1, 0x1, 0x6, gpb, key_b_sector_00);
if (mifare_classic_write(tag, 0x03, data) < 0) return -1;
return 0;
}
/*
* Return a MAD version.
*/
int
mad_get_version(Mad mad)
{
return mad->version;
}
/*
* Set a MAD version.
*/
void
mad_set_version(Mad mad, const uint8_t version)
{
if ((version == 2) && (mad->version == 1)) {
/* We use a larger MAD so initialise the new blocks */
memset(&(mad->sector_0x10), 0, sizeof(mad->sector_0x10));
}
mad->version = version;
}
/*
* Return the MAD card publisher sector.
*/
MifareClassicSectorNumber
mad_get_card_publisher_sector(Mad mad)
{
return (mad->sector_0x00.info & 0x3f);
}
/*
* Set the MAD card publisher sector.
*/
int
mad_set_card_publisher_sector(Mad mad, const MifareClassicSectorNumber cps)
{
if (((mad->version == 2) && (cps > 0x27)) | (mad->version == 1) && (cps > 0x0f)) {
errno = EINVAL;
return -1;
}
mad->sector_0x00.info = (cps & 0x3f);
return 0;
}
/*
* Get the provided sector's application identifier.
*/
int
mad_get_aid(Mad mad, const MifareClassicSectorNumber sector, MadAid *aid)
{
if ((sector < 1) || (sector == 0x10) || (sector > 0x27)) {
errno = EINVAL;
return -1;
}
if (sector > 0x0f) {
if (mad->version != 2) {
errno = EINVAL;
return -1;
}
aid->function_cluster_code = mad->sector_0x10.aids[sector - 0x0f - 2].function_cluster_code;
aid->application_code = mad->sector_0x10.aids[sector - 0x0f - 2].application_code;
} else {
aid->function_cluster_code = mad->sector_0x00.aids[sector - 1].function_cluster_code;
aid->application_code = mad->sector_0x00.aids[sector - 1].application_code;
}
return 0;
}
/*
* Set the provided sector's application identifier.
*/
int
mad_set_aid(Mad mad, const MifareClassicSectorNumber sector, MadAid aid)
{
if ((sector < 1) || (sector == 0x10) || (sector > 0x27)) {
errno = EINVAL;
return -1;
}
if (sector > 0x0f) {
if (mad->version != 2) {
errno = EINVAL;
return -1;
}
mad->sector_0x10.aids[sector - 0x0f - 2].function_cluster_code = aid.function_cluster_code;
mad->sector_0x10.aids[sector - 0x0f - 2].application_code = aid.application_code;
} else {
mad->sector_0x00.aids[sector - 1].function_cluster_code = aid.function_cluster_code;
mad->sector_0x00.aids[sector - 1].application_code = aid.application_code;
}
return 0;
}
bool
mad_sector_reserved(const MifareClassicSectorNumber sector)
{
return ((0x00 == sector) || (0x10 == sector));
}
/*
* Free memory allocated by mad_new() and mad_read().
*/
void
mad_free(Mad mad)
{
free(mad);
}