libfreefare/libfreefare/mifare_application.c
2010-08-24 10:51:58 +00:00

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/*-
* Copyright (C) 2009, Romain Tartiere, Romuald Conty.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser 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.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
* $Id$
*/
/*
* This implementation was written based on information provided by the
* following document:
*
* /dev/brain
*/
#include "config.h"
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <freefare.h>
#include "freefare_internal.h"
#define FIRST_SECTOR 1
int aidcmp (const MadAid left, const MadAid right);
size_t count_aids (const Mad mad, const MadAid aid);
/*
* Get the number of sectors allocated in the MAD for the provided application.
*/
size_t
count_aids (const Mad mad, const MadAid aid)
{
size_t result = 0;
MifareClassicSectorNumber s_max = (mad_get_version (mad) == 1) ? 0x0f : 0x27;
/* Count application sectors */
MadAid c_aid;
for (MifareClassicSectorNumber s = FIRST_SECTOR; s <= s_max; s++) {
mad_get_aid (mad, s, &c_aid);
if (0 == aidcmp (aid, c_aid)) {
result++;
}
}
return result;
}
/*
* Compare two application identifiers.
*/
inline int
aidcmp (const MadAid left, const MadAid right)
{
return ((left.function_cluster_code - right.function_cluster_code) << 8) | (left.application_code - right.application_code);
}
/*
* Card publisher functions (MAD owner).
*/
/*
* Allocates a new application into a MAD.
*/
MifareClassicSectorNumber *
mifare_application_alloc (Mad mad, MadAid aid, size_t size)
{
uint8_t sector_map[40];
MifareClassicSectorNumber sector;
MadAid sector_aid;
MifareClassicSectorNumber *res = NULL;
ssize_t s = size;
/*
* Ensure the card does not already have the application registered.
*/
MifareClassicSectorNumber *found;
if ((found = mifare_application_find (mad, aid))) {
free (found);
return NULL;
}
for (size_t i = 0; i < sizeof (sector_map); i++)
sector_map[i] = 0;
/*
* Try to minimize lost space and allocate as many large pages as possible
* when the target is a Mifare Classic 4k.
*/
MadAid free_aid = { 0x00, 0x00 };
if (mad_get_version (mad) == 2) {
sector = 32;
while ((s >= 12*16) && sector < 40) {
mad_get_aid (mad, sector, &sector_aid);
if (0 == aidcmp (sector_aid, free_aid)) {
sector_map[sector] = 1;
s -= 15*16;
}
sector++;
}
}
sector = FIRST_SECTOR;
MifareClassicSectorNumber s_max = (mad_get_version (mad) == 1) ? 15 : 31;
while ((s > 0) && (sector <= s_max)) {
if (mad_sector_reserved (sector))
continue;
mad_get_aid (mad, sector, &sector_aid);
if (0 == aidcmp (sector_aid, free_aid)) {
sector_map[sector] = 1;
s -= 3*16;
}
sector++;
}
/*
* Ensure the remaining free space is suficient before destroying the MAD.
*/
if (s > 0)
return NULL;
int n = 0;
for (size_t i = FIRST_SECTOR; i < sizeof (sector_map); i++)
if (sector_map[i])
n++;
if (!(res = malloc (sizeof (*res) * (n+1))))
return NULL;
n = 0;
for (size_t i = FIRST_SECTOR; i < sizeof (sector_map); i++)
if (sector_map[i]) {
res[n] = i;
mad_set_aid (mad, i, aid);
n++;
}
res[n] = 0;
/* Return the list of allocated sectors */
return res;
}
/*
* Remove an application from a MAD.
*/
void
mifare_application_free (Mad mad, MadAid aid)
{
MifareClassicSectorNumber *sectors = mifare_application_find (mad, aid);
MifareClassicSectorNumber *p = sectors;
MadAid free_aid = { 0x00, 0x00 };
while (*p) {
mad_set_aid (mad, *p, free_aid);
p++;
}
free (sectors);
}
/*
* Application owner functions.
*/
/*
* Get all sector numbers of an application from the provided MAD.
*/
MifareClassicSectorNumber *
mifare_application_find (Mad mad, MadAid aid)
{
MifareClassicSectorNumber *res = NULL;
size_t res_count = count_aids (mad, aid);
if (res_count)
res = malloc (sizeof (*res) * (res_count + 1));
size_t r = FIRST_SECTOR, w = 0;
if (res) {
/* Fill in the result */
MadAid c_aid;
while (w < res_count) {
mad_get_aid (mad, r, &c_aid);
if (0 == aidcmp (c_aid, aid)) {
res[w++] = r;
}
r++;
}
res[w] = 0;
}
return res;
}
ssize_t
mifare_application_read (MifareTag tag, Mad mad, const MadAid aid, void *buf, size_t nbytes, const MifareClassicKey key, const MifareClassicKeyType key_type)
{
ssize_t res = 0;
MifareClassicSectorNumber *sectors = mifare_application_find (mad, aid);
MifareClassicSectorNumber *s = sectors;
if (!sectors)
return errno = EBADF, -1;
while (*s && nbytes && (res >= 0)) {
MifareClassicBlockNumber first_block = mifare_classic_sector_first_block (*s);
MifareClassicBlockNumber last_block = mifare_classic_sector_last_block (*s);
MifareClassicBlockNumber b = first_block;
MifareClassicBlock block;
if (mifare_classic_authenticate (tag, first_block, key, key_type) < 0) {
res = -1;
break;
}
while ((b < last_block) && nbytes) {
size_t n = MIN (nbytes, 16);
if (mifare_classic_read (tag, b, &block) < 0) {
res = -1;
break;
}
memcpy ((uint8_t *)buf + res, &block, n);
nbytes -= n;
res += n;
b++;
}
s++;
}
free (sectors);
return res;
}
ssize_t
mifare_application_write (MifareTag tag, Mad mad, const MadAid aid, const void *buf, size_t nbytes, const MifareClassicKey key, const MifareClassicKeyType key_type)
{
ssize_t res = 0;
MifareClassicSectorNumber *sectors = mifare_application_find (mad, aid);
MifareClassicSectorNumber *s = sectors;
if (!sectors)
return errno = EBADF, -1;
while (*s && nbytes && (res >= 0)) {
MifareClassicBlockNumber first_block = mifare_classic_sector_first_block (*s);
MifareClassicBlockNumber last_block = mifare_classic_sector_last_block (*s);
MifareClassicBlockNumber b = first_block;
MifareClassicBlock block;
if (mifare_classic_authenticate (tag, first_block, key, key_type) < 0) {
res = -1;
break;
}
while ((b < last_block) && nbytes) {
size_t n = MIN (nbytes, 16);
// Avoid overwriting existing data with uninitialized memory.
if (n < 16) {
if (mifare_classic_read (tag, b, &block) < 0) {
res = -1;
break;
}
}
memcpy (&block, (uint8_t *)buf + res, n);
if (mifare_classic_write (tag, b, block) < 0) {
res = -1;
break;
}
nbytes -= n;
res += n;
b++;
}
s++;
}
free (sectors);
return res;
}