proxmark3/common/mbedtls/xtea.c
2021-05-14 14:07:59 +02:00

261 lines
7 KiB
C

/*
* An 32-bit implementation of the XTEA algorithm
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_XTEA_C)
#include "mbedtls/xtea.h"
#include "mbedtls/platform_util.h"
#include <string.h>
#if defined(MBEDTLS_SELF_TEST)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdio.h>
#define mbedtls_printf printf
#endif /* MBEDTLS_PLATFORM_C */
#endif /* MBEDTLS_SELF_TEST */
#if !defined(MBEDTLS_XTEA_ALT)
/*
* 32-bit integer manipulation macros (big endian)
*/
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n,b,i) \
{ \
(n) = ( (uint32_t) (b)[(i) ] << 24 ) \
| ( (uint32_t) (b)[(i) + 1] << 16 ) \
| ( (uint32_t) (b)[(i) + 2] << 8 ) \
| ( (uint32_t) (b)[(i) + 3] ); \
}
#endif
#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n,b,i) \
{ \
(b)[(i) ] = (unsigned char) ( (n) >> 24 ); \
(b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \
(b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \
(b)[(i) + 3] = (unsigned char) ( (n) ); \
}
#endif
void mbedtls_xtea_init(mbedtls_xtea_context *ctx) {
memset(ctx, 0, sizeof(mbedtls_xtea_context));
}
void mbedtls_xtea_free(mbedtls_xtea_context *ctx) {
if (ctx == NULL)
return;
mbedtls_platform_zeroize(ctx, sizeof(mbedtls_xtea_context));
}
/*
* XTEA key schedule
*/
void mbedtls_xtea_setup(mbedtls_xtea_context *ctx, const unsigned char key[16]) {
int i;
memset(ctx, 0, sizeof(mbedtls_xtea_context));
for (i = 0; i < 4; i++) {
GET_UINT32_BE(ctx->k[i], key, i << 2);
}
}
/*
* XTEA encrypt function
*/
int mbedtls_xtea_crypt_ecb(mbedtls_xtea_context *ctx, int mode,
const unsigned char input[8], unsigned char output[8]) {
uint32_t *k, v0, v1, i;
k = ctx->k;
GET_UINT32_BE(v0, input, 0);
GET_UINT32_BE(v1, input, 4);
if (mode == MBEDTLS_XTEA_ENCRYPT) {
uint32_t sum = 0, delta = 0x9E3779B9;
for (i = 0; i < 32; i++) {
v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
sum += delta;
v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum >> 11) & 3]);
}
} else { /* MBEDTLS_XTEA_DECRYPT */
uint32_t delta = 0x9E3779B9, sum = delta * 32;
for (i = 0; i < 32; i++) {
v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + k[(sum >> 11) & 3]);
sum -= delta;
v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + k[sum & 3]);
}
}
PUT_UINT32_BE(v0, output, 0);
PUT_UINT32_BE(v1, output, 4);
return (0);
}
#if defined(MBEDTLS_CIPHER_MODE_CBC)
/*
* XTEA-CBC buffer encryption/decryption
*/
int mbedtls_xtea_crypt_cbc(mbedtls_xtea_context *ctx, int mode, size_t length,
unsigned char iv[8], const unsigned char *input,
unsigned char *output) {
int i;
unsigned char temp[8];
if (length % 8)
return (MBEDTLS_ERR_XTEA_INVALID_INPUT_LENGTH);
if (mode == MBEDTLS_XTEA_DECRYPT) {
while (length > 0) {
memcpy(temp, input, 8);
mbedtls_xtea_crypt_ecb(ctx, mode, input, output);
for (i = 0; i < 8; i++)
output[i] = (unsigned char)(output[i] ^ iv[i]);
memcpy(iv, temp, 8);
input += 8;
output += 8;
length -= 8;
}
} else {
while (length > 0) {
for (i = 0; i < 8; i++)
output[i] = (unsigned char)(input[i] ^ iv[i]);
mbedtls_xtea_crypt_ecb(ctx, mode, output, output);
memcpy(iv, output, 8);
input += 8;
output += 8;
length -= 8;
}
}
return (0);
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */
#endif /* !MBEDTLS_XTEA_ALT */
#if defined(MBEDTLS_SELF_TEST)
/*
* XTEA tests vectors (non-official)
*/
static const unsigned char xtea_test_key[6][16] = {
{
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
0x0c, 0x0d, 0x0e, 0x0f
},
{
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
0x0c, 0x0d, 0x0e, 0x0f
},
{
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
0x0c, 0x0d, 0x0e, 0x0f
},
{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00
},
{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00
},
{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00
}
};
static const unsigned char xtea_test_pt[6][8] = {
{ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
{ 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f },
{ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
{ 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 }
};
static const unsigned char xtea_test_ct[6][8] = {
{ 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 },
{ 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 },
{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
{ 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 },
{ 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d },
{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
};
/*
* Checkup routine
*/
int mbedtls_xtea_self_test(int verbose) {
int i, ret = 0;
unsigned char buf[8];
mbedtls_xtea_context ctx;
mbedtls_xtea_init(&ctx);
for (i = 0; i < 6; i++) {
if (verbose != 0)
mbedtls_printf(" XTEA test #%d: ", i + 1);
memcpy(buf, xtea_test_pt[i], 8);
mbedtls_xtea_setup(&ctx, xtea_test_key[i]);
mbedtls_xtea_crypt_ecb(&ctx, MBEDTLS_XTEA_ENCRYPT, buf, buf);
if (memcmp(buf, xtea_test_ct[i], 8) != 0) {
if (verbose != 0)
mbedtls_printf("failed\n");
ret = 1;
goto exit;
}
if (verbose != 0)
mbedtls_printf("passed\n");
}
if (verbose != 0)
mbedtls_printf("\n");
exit:
mbedtls_xtea_free(&ctx);
return (ret);
}
#endif /* MBEDTLS_SELF_TEST */
#endif /* MBEDTLS_XTEA_C */