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929 lines
31 KiB
C
929 lines
31 KiB
C
//-----------------------------------------------------------------------------
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// Borrowed initially from https://github.com/nfc-tools/libfreefare
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// Copyright (C) 2010, Romain Tartiere.
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// Copyright (C) Proxmark3 contributors. See AUTHORS.md for details.
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// See LICENSE.txt for the text of the license.
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//-----------------------------------------------------------------------------
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/*
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* This implementation was written based on information provided by the
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* following documents:
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*
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* NIST Special Publication 800-38B
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* Recommendation for Block Cipher Modes of Operation: The CMAC Mode for Authentication
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* May 2005
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*/
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#include "desfire_crypto.h"
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include "commonutil.h"
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#include "crc32.h"
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#include "crc.h"
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#include "crc16.h" // crc16 ccitt
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#include "nprintf.h"
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#include "iso14443a.h"
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#include "dbprint.h"
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#include "BigBuf.h"
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#ifndef AddCrc14A
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# define AddCrc14A(data, len) compute_crc(CRC_14443_A, (data), (len), (data)+(len), (data)+(len)+1)
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#endif
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static mbedtls_des_context ctx;
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static mbedtls_des3_context ctx3;
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static mbedtls_aes_context actx;
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static void update_key_schedules(desfirekey_t key);
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static void update_key_schedules(desfirekey_t key) {
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// DES_set_key ((DES_cblock *)key->data, &(key->ks1));
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// DES_set_key ((DES_cblock *)(key->data + 8), &(key->ks2));
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// if (T_3K3DES == key->type) {
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// DES_set_key ((DES_cblock *)(key->data + 16), &(key->ks3));
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// }
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}
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/******************************************************************************/
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void des_encrypt(void *out, const void *in, const void *key) {
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mbedtls_des_setkey_enc(&ctx, key);
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mbedtls_des_crypt_ecb(&ctx, in, out);
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}
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void des_decrypt(void *out, const void *in, const void *key) {
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mbedtls_des_setkey_dec(&ctx, key);
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mbedtls_des_crypt_ecb(&ctx, in, out);
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}
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void tdes_nxp_receive(const void *in, void *out, size_t length, const void *key, uint8_t *iv, int keymode) {
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// must be even blocks of 8 bytes.
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if (length % 8) {
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return;
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}
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if (keymode == 2) {
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mbedtls_des3_set2key_dec(&ctx3, key);
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} else {
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mbedtls_des3_set3key_dec(&ctx3, key);
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}
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unsigned char temp[8];
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uint8_t *tin = (uint8_t *) in;
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uint8_t *tout = (uint8_t *) out;
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while (length > 0) {
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memcpy(temp, tin, 8);
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mbedtls_des3_crypt_ecb(&ctx3, tin, tout);
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for (uint8_t i = 0; i < 8; i++) {
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tout[i] ^= iv[i];
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}
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memcpy(iv, temp, 8);
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tin += 8;
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tout += 8;
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length -= 8;
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}
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}
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void tdes_nxp_send(const void *in, void *out, size_t length, const void *key, uint8_t *iv, int keymode) {
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// must be even blocks of 8 bytes.
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if (length % 8) {
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return;
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}
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if (keymode == 2) {
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mbedtls_des3_set2key_enc(&ctx3, key);
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} else {
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mbedtls_des3_set3key_enc(&ctx3, key);
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}
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uint8_t *tin = (uint8_t *) in;
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uint8_t *tout = (uint8_t *) out;
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while (length > 0) {
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for (uint8_t i = 0; i < 8; i++) {
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tin[i] ^= iv[i];
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}
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mbedtls_des3_crypt_ecb(&ctx3, tin, tout);
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memcpy(iv, tout, 8);
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tin += 8;
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tout += 8;
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length -= 8;
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}
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}
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void aes128_nxp_receive(const void *in, void *out, size_t length, const void *key, unsigned char iv[16]) {
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if (length % 8) return;
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uint8_t *tin = (uint8_t *) in;
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uint8_t *tout = (uint8_t *) out;
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mbedtls_aes_setkey_dec(&actx, key, 128);
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mbedtls_aes_crypt_cbc(&actx, MBEDTLS_AES_DECRYPT, length, iv, tin, tout);
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}
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void aes128_nxp_send(const void *in, void *out, size_t length, const void *key, unsigned char iv[16]) {
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if (length % 8) return;
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uint8_t *tin = (uint8_t *) in;
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uint8_t *tout = (uint8_t *) out;
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mbedtls_aes_setkey_enc(&actx, key, 128);
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mbedtls_aes_crypt_cbc(&actx, MBEDTLS_AES_ENCRYPT, length, iv, tin, tout);
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}
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void Desfire_des_key_new(const uint8_t value[8], desfirekey_t key) {
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uint8_t data[8];
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memcpy(data, value, 8);
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for (int n = 0; n < 8; n++) {
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data[n] &= 0xFE;
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}
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Desfire_des_key_new_with_version(data, key);
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}
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void Desfire_des_key_new_with_version(const uint8_t value[8], desfirekey_t key) {
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if (key != NULL) {
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key->type = T_DES;
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memcpy(key->data, value, 8);
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memcpy(key->data + 8, value, 8);
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update_key_schedules(key);
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}
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}
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void Desfire_3des_key_new(const uint8_t value[16], desfirekey_t key) {
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uint8_t data[16];
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memcpy(data, value, 16);
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for (int n = 0; n < 8; n++) {
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data[n] &= 0xFE;
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}
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for (int n = 8; n < 16; n++) {
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data[n] |= 0x01;
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}
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Desfire_3des_key_new_with_version(data, key);
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}
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void Desfire_3des_key_new_with_version(const uint8_t value[16], desfirekey_t key) {
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if (key != NULL) {
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key->type = T_3DES;
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memcpy(key->data, value, 16);
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update_key_schedules(key);
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}
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}
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void Desfire_3k3des_key_new(const uint8_t value[24], desfirekey_t key) {
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uint8_t data[24];
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memcpy(data, value, 24);
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for (int n = 0; n < 8; n++) {
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data[n] &= 0xFE;
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}
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Desfire_3k3des_key_new_with_version(data, key);
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}
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void Desfire_3k3des_key_new_with_version(const uint8_t value[24], desfirekey_t key) {
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if (key != NULL) {
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key->type = T_3K3DES;
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memcpy(key->data, value, 24);
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update_key_schedules(key);
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}
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}
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void Desfire_aes_key_new(const uint8_t value[16], desfirekey_t key) {
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Desfire_aes_key_new_with_version(value, 0, key);
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}
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void Desfire_aes_key_new_with_version(const uint8_t value[16], uint8_t version, desfirekey_t key) {
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if (key != NULL) {
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memcpy(key->data, value, 16);
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key->type = T_AES;
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key->aes_version = version;
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}
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}
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uint8_t Desfire_key_get_version(desfirekey_t key) {
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uint8_t version = 0;
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for (int n = 0; n < 8; n++) {
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version |= ((key->data[n] & 1) << (7 - n));
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}
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return version;
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}
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void Desfire_key_set_version(desfirekey_t key, uint8_t version) {
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for (int n = 0; n < 8; n++) {
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uint8_t version_bit = ((version & (1 << (7 - n))) >> (7 - n));
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key->data[n] &= 0xFE;
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key->data[n] |= version_bit;
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if (key->type == T_DES) {
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key->data[n + 8] = key->data[n];
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} else {
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// Write ~version to avoid turning a 3DES key into a DES key
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key->data[n + 8] &= 0xFE;
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key->data[n + 8] |= ~version_bit;
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}
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}
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}
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void Desfire_session_key_new(const uint8_t rnda[], const uint8_t rndb[], desfirekey_t authkey, desfirekey_t key) {
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uint8_t buffer[24];
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switch (authkey->type) {
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case T_DES:
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memcpy(buffer, rnda, 4);
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memcpy(buffer + 4, rndb, 4);
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Desfire_des_key_new_with_version(buffer, key);
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break;
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case T_3DES:
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memcpy(buffer, rnda, 4);
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memcpy(buffer + 4, rndb, 4);
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memcpy(buffer + 8, rnda + 4, 4);
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memcpy(buffer + 12, rndb + 4, 4);
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Desfire_3des_key_new_with_version(buffer, key);
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break;
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case T_3K3DES:
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memcpy(buffer, rnda, 4);
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memcpy(buffer + 4, rndb, 4);
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memcpy(buffer + 8, rnda + 6, 4);
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memcpy(buffer + 12, rndb + 6, 4);
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memcpy(buffer + 16, rnda + 12, 4);
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memcpy(buffer + 20, rndb + 12, 4);
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Desfire_3k3des_key_new(buffer, key);
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break;
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case T_AES:
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memcpy(buffer, rnda, 4);
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memcpy(buffer + 4, rndb, 4);
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memcpy(buffer + 8, rnda + 12, 4);
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memcpy(buffer + 12, rndb + 12, 4);
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Desfire_aes_key_new(buffer, key);
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break;
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}
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}
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static size_t key_macing_length(desfirekey_t key);
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// iceman, see memxor inside string.c, dest/src swapped..
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static void xor(const uint8_t *ivect, uint8_t *data, const size_t len) {
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for (size_t i = 0; i < len; i++) {
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data[i] ^= ivect[i];
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}
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}
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void cmac_generate_subkeys(desfirekey_t key) {
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int kbs = key_block_size(key);
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const uint8_t R = (kbs == 8) ? 0x1B : 0x87;
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uint8_t l[kbs];
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memset(l, 0, kbs);
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uint8_t ivect[kbs];
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memset(ivect, 0, kbs);
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mifare_cypher_blocks_chained(NULL, key, ivect, l, kbs, MCD_RECEIVE, MCO_ENCYPHER);
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bool txor = false;
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// Used to compute CMAC on complete blocks
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memcpy(key->cmac_sk1, l, kbs);
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txor = l[0] & 0x80;
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lsl(key->cmac_sk1, kbs);
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if (txor) {
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key->cmac_sk1[kbs - 1] ^= R;
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}
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// Used to compute CMAC on the last block if non-complete
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memcpy(key->cmac_sk2, key->cmac_sk1, kbs);
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txor = key->cmac_sk1[0] & 0x80;
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lsl(key->cmac_sk2, kbs);
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if (txor) {
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key->cmac_sk2[kbs - 1] ^= R;
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}
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}
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void cmac(const desfirekey_t key, uint8_t *ivect, const uint8_t *data, size_t len, uint8_t *cmac) {
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int kbs = key_block_size(key);
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if (kbs == 0) {
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return;
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}
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uint8_t *buffer = BigBuf_malloc(padded_data_length(len, kbs));
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memcpy(buffer, data, len);
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if ((!len) || (len % kbs)) {
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buffer[len++] = 0x80;
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while (len % kbs) {
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buffer[len++] = 0x00;
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}
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xor(key->cmac_sk2, buffer + len - kbs, kbs);
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} else {
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xor(key->cmac_sk1, buffer + len - kbs, kbs);
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}
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mifare_cypher_blocks_chained(NULL, key, ivect, buffer, len, MCD_SEND, MCO_ENCYPHER);
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memcpy(cmac, ivect, kbs);
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//free(buffer);
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}
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size_t key_block_size(const desfirekey_t key) {
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if (key == NULL) {
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return 0;
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}
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size_t block_size = 8;
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switch (key->type) {
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case T_DES:
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case T_3DES:
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case T_3K3DES:
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block_size = 8;
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break;
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case T_AES:
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block_size = 16;
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break;
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}
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return block_size;
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}
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/*
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* Size of MACing produced with the key.
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*/
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static size_t key_macing_length(const desfirekey_t key) {
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size_t mac_length = DESFIRE_MAC_LENGTH;
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switch (key->type) {
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case T_DES:
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case T_3DES:
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mac_length = DESFIRE_MAC_LENGTH;
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break;
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case T_3K3DES:
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case T_AES:
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mac_length = DESFIRE_CMAC_LENGTH;
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break;
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}
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return mac_length;
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}
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/*
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* Size required to store nbytes of data in a buffer of size n*block_size.
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*/
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size_t padded_data_length(const size_t nbytes, const size_t block_size) {
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if ((!nbytes) || (nbytes % block_size))
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return ((nbytes / block_size) + 1) * block_size;
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else
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return nbytes;
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}
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/*
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* Buffer size required to MAC nbytes of data
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*/
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size_t maced_data_length(const desfirekey_t key, const size_t nbytes) {
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return nbytes + key_macing_length(key);
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}
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/*
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* Buffer size required to encipher nbytes of data and a two bytes CRC.
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*/
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size_t enciphered_data_length(const desfiretag_t tag, const size_t nbytes, int communication_settings) {
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size_t crc_length = 0;
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if (!(communication_settings & NO_CRC)) {
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switch (DESFIRE(tag)->authentication_scheme) {
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case AS_LEGACY:
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crc_length = 2;
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break;
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case AS_NEW:
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crc_length = 4;
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break;
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}
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}
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size_t block_size = DESFIRE(tag)->session_key ? key_block_size(DESFIRE(tag)->session_key) : 1;
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return padded_data_length(nbytes + crc_length, block_size);
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}
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void *mifare_cryto_preprocess_data(desfiretag_t tag, void *data, size_t *nbytes, size_t offset, int communication_settings) {
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uint8_t *res = data;
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uint8_t mac[4];
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size_t edl;
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bool append_mac = true;
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desfirekey_t key = DESFIRE(tag)->session_key;
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if (!key)
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return data;
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switch (communication_settings & MDCM_MASK) {
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case MDCM_PLAIN:
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if (AS_LEGACY == DESFIRE(tag)->authentication_scheme)
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break;
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/*
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* When using new authentication methods, PLAIN data transmission from
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* the PICC to the PCD are CMACed, so we have to maintain the
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* cryptographic initialisation vector up-to-date to check data
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* integrity later.
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*
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* The only difference with CMACed data transmission is that the CMAC
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* is not appended to the data send by the PCD to the PICC.
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*/
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append_mac = false;
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/* pass through */
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case MDCM_MACED:
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switch (DESFIRE(tag)->authentication_scheme) {
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case AS_LEGACY:
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if (!(communication_settings & MAC_COMMAND))
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break;
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/* pass through */
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edl = padded_data_length(*nbytes - offset, key_block_size(DESFIRE(tag)->session_key)) + offset;
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// Fill in the crypto buffer with data ...
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memcpy(res, data, *nbytes);
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// ... and 0 padding
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memset(res + *nbytes, 0, edl - *nbytes);
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mifare_cypher_blocks_chained(tag, NULL, NULL, res + offset, edl - offset, MCD_SEND, MCO_ENCYPHER);
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memcpy(mac, res + edl - 8, 4);
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// Copy again provided data (was overwritten by mifare_cypher_blocks_chained)
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memcpy(res, data, *nbytes);
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if (!(communication_settings & MAC_COMMAND))
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break;
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// Append MAC
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size_t bla = maced_data_length(DESFIRE(tag)->session_key, *nbytes - offset) + offset;
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(void)bla++;
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memcpy(res + *nbytes, mac, 4);
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*nbytes += 4;
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break;
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case AS_NEW:
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if (!(communication_settings & CMAC_COMMAND))
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break;
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cmac(key, DESFIRE(tag)->ivect, res, *nbytes, DESFIRE(tag)->cmac);
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if (append_mac) {
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size_t len = maced_data_length(key, *nbytes);
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(void)++len;
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memcpy(res, data, *nbytes);
|
|
memcpy(res + *nbytes, DESFIRE(tag)->cmac, DESFIRE_CMAC_LENGTH);
|
|
*nbytes += DESFIRE_CMAC_LENGTH;
|
|
}
|
|
break;
|
|
}
|
|
|
|
break;
|
|
case MDCM_ENCIPHERED:
|
|
/* |<-------------- data -------------->|
|
|
* |<--- offset -->| |
|
|
* +---------------+--------------------+-----+---------+
|
|
* | CMD + HEADERS | DATA TO BE SECURED | CRC | PADDING |
|
|
* +---------------+--------------------+-----+---------+ ----------------
|
|
* | |<~~~~v~~~~~~~~~~~~~>| ^ | | (DES / 3DES)
|
|
* | | `---- crc16() ----' | |
|
|
* | | | ^ | | ----- *or* -----
|
|
* |<~~~~~~~~~~~~~~~~~~~~v~~~~~~~~~~~~~>| ^ | | (3K3DES / AES)
|
|
* | `---- crc32() ----' | |
|
|
* | | ---- *then* ----
|
|
* |<---------------------------------->|
|
|
* encypher()/decypher()
|
|
*/
|
|
|
|
if (!(communication_settings & ENC_COMMAND))
|
|
break;
|
|
edl = enciphered_data_length(tag, *nbytes - offset, communication_settings) + offset;
|
|
|
|
// Fill in the crypto buffer with data ...
|
|
memcpy(res, data, *nbytes);
|
|
if (!(communication_settings & NO_CRC)) {
|
|
// ... CRC ...
|
|
switch (DESFIRE(tag)->authentication_scheme) {
|
|
case AS_LEGACY:
|
|
AddCrc14A(res + offset, *nbytes - offset);
|
|
*nbytes += 2;
|
|
break;
|
|
case AS_NEW:
|
|
crc32_append(res, *nbytes);
|
|
*nbytes += 4;
|
|
break;
|
|
}
|
|
}
|
|
// ... and padding
|
|
memset(res + *nbytes, 0, edl - *nbytes);
|
|
|
|
*nbytes = edl;
|
|
|
|
mifare_cypher_blocks_chained(tag, NULL, NULL, res + offset, *nbytes - offset, MCD_SEND, (AS_NEW == DESFIRE(tag)->authentication_scheme) ? MCO_ENCYPHER : MCO_DECYPHER);
|
|
break;
|
|
default:
|
|
|
|
*nbytes = -1;
|
|
res = NULL;
|
|
break;
|
|
}
|
|
|
|
return res;
|
|
|
|
}
|
|
|
|
void *mifare_cryto_postprocess_data(desfiretag_t tag, void *data, size_t *nbytes, int communication_settings) {
|
|
void *res = data;
|
|
uint8_t first_cmac_byte = 0x00;
|
|
|
|
desfirekey_t key = DESFIRE(tag)->session_key;
|
|
|
|
if (!key) {
|
|
return data;
|
|
}
|
|
|
|
// Return directly if we just have a status code.
|
|
if (1 == *nbytes) {
|
|
return res;
|
|
}
|
|
|
|
switch (communication_settings & MDCM_MASK) {
|
|
case MDCM_PLAIN: {
|
|
|
|
if (AS_LEGACY == DESFIRE(tag)->authentication_scheme) {
|
|
break;
|
|
}
|
|
}
|
|
/* pass through */
|
|
case MDCM_MACED: {
|
|
switch (DESFIRE(tag)->authentication_scheme) {
|
|
case AS_LEGACY: {
|
|
|
|
if ((communication_settings & MAC_VERIFY) == MAC_VERIFY) {
|
|
|
|
*nbytes -= key_macing_length(key);
|
|
|
|
if (*nbytes == 0) {
|
|
*nbytes = -1;
|
|
res = NULL;
|
|
#ifdef WITH_DEBUG
|
|
Dbprintf("No room for MAC!");
|
|
#endif
|
|
break;
|
|
}
|
|
|
|
size_t edl = enciphered_data_length(tag, *nbytes - 1, communication_settings);
|
|
uint8_t edata[edl];
|
|
memset(edata, 0, sizeof(edata));
|
|
memcpy(edata, data, *nbytes - 1);
|
|
|
|
mifare_cypher_blocks_chained(tag, NULL, NULL, edata, edl, MCD_SEND, MCO_ENCYPHER);
|
|
|
|
if (0 != memcmp((uint8_t *)data + *nbytes - 1, edata + edl - 8, 4)) {
|
|
#ifdef WITH_DEBUG
|
|
Dbprintf("MACing not verified");
|
|
hexdump((uint8_t *)data + *nbytes - 1, key_macing_length(key), "Expect ", 0);
|
|
hexdump(edata + edl - 8, key_macing_length(key), "Actual ", 0);
|
|
#endif
|
|
DESFIRE(tag)->last_pcd_error = CRYPTO_ERROR;
|
|
*nbytes = -1;
|
|
res = NULL;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case AS_NEW: {
|
|
|
|
if ((communication_settings & CMAC_COMMAND) != CMAC_COMMAND) {
|
|
break;
|
|
}
|
|
|
|
int n = 0;
|
|
|
|
if ((communication_settings & CMAC_VERIFY) == CMAC_VERIFY) {
|
|
if (*nbytes < 9) {
|
|
*nbytes = -1;
|
|
res = NULL;
|
|
break;
|
|
}
|
|
first_cmac_byte = ((uint8_t *)data)[*nbytes - 9];
|
|
((uint8_t *)data)[*nbytes - 9] = ((uint8_t *)data)[*nbytes - 1];
|
|
|
|
n = 8;
|
|
}
|
|
|
|
cmac(key, DESFIRE(tag)->ivect, ((uint8_t *)data), *nbytes - n, DESFIRE(tag)->cmac);
|
|
|
|
if ((communication_settings & CMAC_VERIFY) == CMAC_VERIFY) {
|
|
|
|
((uint8_t *)data)[*nbytes - 9] = first_cmac_byte;
|
|
|
|
if (0 != memcmp(DESFIRE(tag)->cmac, (uint8_t *)data + *nbytes - 9, 8)) {
|
|
#ifdef WITH_DEBUG
|
|
Dbprintf("CMAC NOT verified :-(");
|
|
hexdump((uint8_t *)data + *nbytes - 9, 8, "Expect ", 0);
|
|
hexdump(DESFIRE(tag)->cmac, 8, "Actual ", 0);
|
|
#endif
|
|
DESFIRE(tag)->last_pcd_error = CRYPTO_ERROR;
|
|
*nbytes = -1;
|
|
res = NULL;
|
|
} else {
|
|
*nbytes -= 8;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case MDCM_ENCIPHERED: {
|
|
(*nbytes)--;
|
|
bool verified = false;
|
|
int crc_pos = 0x00;
|
|
int end_crc_pos = 0x00;
|
|
uint8_t x;
|
|
|
|
/*
|
|
* AS_LEGACY:
|
|
* ,-----------------+-------------------------------+--------+
|
|
* \ BLOCK n-1 | BLOCK n | STATUS |
|
|
* / PAYLOAD | CRC0 | CRC1 | 0x80? | 0x000000000000 | 0x9100 |
|
|
* `-----------------+-------------------------------+--------+
|
|
*
|
|
* <------------ DATA ------------>
|
|
* FRAME = PAYLOAD + CRC(PAYLOAD) + PADDING
|
|
*
|
|
* AS_NEW:
|
|
* ,-------------------------------+-----------------------------------------------+--------+
|
|
* \ BLOCK n-1 | BLOCK n | STATUS |
|
|
* / PAYLOAD | CRC0 | CRC1 | CRC2 | CRC3 | 0x80? | 0x0000000000000000000000000000 | 0x9100 |
|
|
* `-------------------------------+-----------------------------------------------+--------+
|
|
* <----------------------------------- DATA ------------------------------------->|
|
|
*
|
|
* <----------------- DATA ---------------->
|
|
* FRAME = PAYLOAD + CRC(PAYLOAD + STATUS) + PADDING + STATUS
|
|
* `------------------'
|
|
*/
|
|
|
|
mifare_cypher_blocks_chained(tag, NULL, NULL, res, *nbytes, MCD_RECEIVE, MCO_DECYPHER);
|
|
|
|
/*
|
|
* Look for the CRC and ensure it is followed by NULL padding. We
|
|
* can't start by the end because the CRC is supposed to be 0 when
|
|
* verified, and accumulating 0's in it should not change it.
|
|
*/
|
|
switch (DESFIRE(tag)->authentication_scheme) {
|
|
case AS_LEGACY: {
|
|
crc_pos = *nbytes - 8 - 1; // The CRC can be over two blocks
|
|
if (crc_pos < 0) {
|
|
crc_pos = 0; // Single block
|
|
}
|
|
break;
|
|
}
|
|
case AS_NEW: {
|
|
/* Move status between payload and CRC */
|
|
res = DESFIRE(tag)->crypto_buffer;
|
|
memcpy(res, data, *nbytes);
|
|
|
|
crc_pos = (*nbytes) - 16 - 3;
|
|
if (crc_pos < 0) {
|
|
crc_pos = 0; // Single block
|
|
}
|
|
|
|
memcpy((uint8_t *)res + crc_pos + 1, (uint8_t *)res + crc_pos, *nbytes - crc_pos);
|
|
((uint8_t *)res)[crc_pos] = 0x00;
|
|
crc_pos++;
|
|
*nbytes += 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
do {
|
|
uint16_t crc_16 = 0x00;
|
|
uint32_t crc = 0x00;
|
|
|
|
switch (DESFIRE(tag)->authentication_scheme) {
|
|
case AS_LEGACY: {
|
|
AddCrc14A((uint8_t *)res, end_crc_pos);
|
|
end_crc_pos = crc_pos + 2;
|
|
crc = crc_16;
|
|
break;
|
|
}
|
|
case AS_NEW: {
|
|
end_crc_pos = crc_pos + 4;
|
|
crc32_ex(res, end_crc_pos, (uint8_t *)&crc);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (crc == 0) {
|
|
verified = true;
|
|
for (int n = end_crc_pos; n < *nbytes - 1; n++) {
|
|
uint8_t byte = ((uint8_t *)res)[n];
|
|
if (!((0x00 == byte) || ((0x80 == byte) && (n == end_crc_pos))))
|
|
verified = false;
|
|
}
|
|
}
|
|
|
|
if (verified) {
|
|
|
|
*nbytes = crc_pos;
|
|
|
|
switch (DESFIRE(tag)->authentication_scheme) {
|
|
case AS_LEGACY: {
|
|
((uint8_t *)data)[(*nbytes)++] = 0x00;
|
|
break;
|
|
}
|
|
case AS_NEW: {
|
|
/* The status byte was already before the CRC */
|
|
break;
|
|
}
|
|
}
|
|
|
|
} else {
|
|
switch (DESFIRE(tag)->authentication_scheme) {
|
|
case AS_LEGACY: {
|
|
break;
|
|
}
|
|
case AS_NEW: {
|
|
x = ((uint8_t *)res)[crc_pos - 1];
|
|
((uint8_t *)res)[crc_pos - 1] = ((uint8_t *)res)[crc_pos];
|
|
((uint8_t *)res)[crc_pos] = x;
|
|
break;
|
|
}
|
|
}
|
|
crc_pos++;
|
|
}
|
|
|
|
} while (verified == false && (end_crc_pos < *nbytes));
|
|
|
|
if (verified == false) {
|
|
#ifdef WITH_DEBUG
|
|
/* FIXME In some configurations, the file is transmitted PLAIN */
|
|
Dbprintf("CRC not verified in decyphered stream");
|
|
#endif
|
|
DESFIRE(tag)->last_pcd_error = CRYPTO_ERROR;
|
|
*nbytes = -1;
|
|
res = NULL;
|
|
}
|
|
break;
|
|
}
|
|
default: {
|
|
Dbprintf("Unknown communication settings");
|
|
*nbytes = -1;
|
|
res = NULL;
|
|
break;
|
|
}
|
|
}
|
|
return res;
|
|
}
|
|
|
|
|
|
void mifare_cypher_single_block(desfirekey_t key, uint8_t *data, uint8_t *ivect, MifareCryptoDirection direction, MifareCryptoOperation operation, size_t block_size) {
|
|
uint8_t ovect[DESFIRE_MAX_CRYPTO_BLOCK_SIZE];
|
|
if (direction == MCD_SEND) {
|
|
xor(ivect, data, block_size);
|
|
} else {
|
|
memcpy(ovect, data, block_size);
|
|
}
|
|
|
|
uint8_t edata[DESFIRE_MAX_CRYPTO_BLOCK_SIZE] = {0};
|
|
|
|
switch (key->type) {
|
|
case T_DES:
|
|
switch (operation) {
|
|
case MCO_ENCYPHER:
|
|
//DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks1), DES_ENCRYPT);
|
|
des_encrypt(edata, data, key->data);
|
|
break;
|
|
case MCO_DECYPHER:
|
|
//DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks1), DES_DECRYPT);
|
|
des_decrypt(edata, data, key->data);
|
|
break;
|
|
}
|
|
break;
|
|
case T_3DES:
|
|
switch (operation) {
|
|
case MCO_ENCYPHER:
|
|
mbedtls_des3_set2key_enc(&ctx3, key->data);
|
|
mbedtls_des3_crypt_ecb(&ctx3, data, edata);
|
|
// DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks1), DES_ENCRYPT);
|
|
// DES_ecb_encrypt ((DES_cblock *) edata, (DES_cblock *) data, &(key->ks2), DES_DECRYPT);
|
|
// DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks1), DES_ENCRYPT);
|
|
break;
|
|
case MCO_DECYPHER:
|
|
mbedtls_des3_set2key_dec(&ctx3, key->data);
|
|
mbedtls_des3_crypt_ecb(&ctx3, data, edata);
|
|
// DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks1), DES_DECRYPT);
|
|
// DES_ecb_encrypt ((DES_cblock *) edata, (DES_cblock *) data, &(key->ks2), DES_ENCRYPT);
|
|
// DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks1), DES_DECRYPT);
|
|
break;
|
|
}
|
|
break;
|
|
case T_3K3DES:
|
|
switch (operation) {
|
|
case MCO_ENCYPHER:
|
|
mbedtls_des3_set3key_enc(&ctx3, key->data);
|
|
mbedtls_des3_crypt_ecb(&ctx3, data, edata);
|
|
// DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks1), DES_ENCRYPT);
|
|
// DES_ecb_encrypt ((DES_cblock *) edata, (DES_cblock *) data, &(key->ks2), DES_DECRYPT);
|
|
// DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks3), DES_ENCRYPT);
|
|
break;
|
|
case MCO_DECYPHER:
|
|
mbedtls_des3_set3key_dec(&ctx3, key->data);
|
|
mbedtls_des3_crypt_ecb(&ctx3, data, edata);
|
|
// DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks3), DES_DECRYPT);
|
|
// DES_ecb_encrypt ((DES_cblock *) edata, (DES_cblock *) data, &(key->ks2), DES_ENCRYPT);
|
|
// DES_ecb_encrypt ((DES_cblock *) data, (DES_cblock *) edata, &(key->ks1), DES_DECRYPT);
|
|
break;
|
|
}
|
|
break;
|
|
case T_AES:
|
|
switch (operation) {
|
|
case MCO_ENCYPHER: {
|
|
mbedtls_aes_init(&actx);
|
|
mbedtls_aes_setkey_enc(&actx, key->data, 128);
|
|
mbedtls_aes_crypt_cbc(&actx, MBEDTLS_AES_ENCRYPT, sizeof(edata), ivect, data, edata);
|
|
break;
|
|
}
|
|
case MCO_DECYPHER: {
|
|
mbedtls_aes_init(&actx);
|
|
mbedtls_aes_setkey_dec(&actx, key->data, 128);
|
|
mbedtls_aes_crypt_cbc(&actx, MBEDTLS_AES_DECRYPT, sizeof(edata), ivect, edata, data);
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
memcpy(data, edata, block_size);
|
|
|
|
if (direction == MCD_SEND) {
|
|
memcpy(ivect, data, block_size);
|
|
} else {
|
|
xor(ivect, data, block_size);
|
|
memcpy(ivect, ovect, block_size);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function performs all CBC cyphering / deciphering.
|
|
*
|
|
* The tag argument may be NULL, in which case both key and ivect shall be set.
|
|
* When using the tag session_key and ivect for processing data, these
|
|
* arguments should be set to NULL.
|
|
*
|
|
* Because the tag may contain additional data, one may need to call this
|
|
* function with tag, key and ivect defined.
|
|
*/
|
|
void mifare_cypher_blocks_chained(desfiretag_t tag, desfirekey_t key, uint8_t *ivect, uint8_t *data, size_t data_size, MifareCryptoDirection direction, MifareCryptoOperation operation) {
|
|
size_t block_size;
|
|
|
|
if (tag) {
|
|
if (key == NULL) {
|
|
key = DESFIRE(tag)->session_key;
|
|
}
|
|
if (ivect == NULL) {
|
|
ivect = DESFIRE(tag)->ivect;
|
|
}
|
|
|
|
switch (DESFIRE(tag)->authentication_scheme) {
|
|
case AS_LEGACY:
|
|
memset(ivect, 0, DESFIRE_MAX_CRYPTO_BLOCK_SIZE);
|
|
break;
|
|
case AS_NEW:
|
|
break;
|
|
}
|
|
}
|
|
|
|
block_size = key_block_size(key);
|
|
|
|
size_t offset = 0;
|
|
while (offset < data_size) {
|
|
mifare_cypher_single_block(key, data + offset, ivect, direction, operation, block_size);
|
|
offset += block_size;
|
|
}
|
|
}
|