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Add XTEA encryption support in libavutil 

Signed-off-by: Martin Storsjö <martin@martin.st>
This commit is contained in:
Samuel Pitoiset 2012-07-03 15:53:16 +02:00 committed by Martin Storsjö
parent bc3dbcc8e5
commit 8c14f7a593
6 changed files with 235 additions and 1 deletions
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3
libavutil/Makefile
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@ -38,6 +38,7 @@ HEADERS = adler32.h \
samplefmt.h \
sha.h \
time.h \
xtea.h \
ARCH_HEADERS = bswap.h \
intmath.h \
@ -83,6 +84,7 @@ OBJS = adler32.o \
time.o \
tree.o \
utils.o \
xtea.o \
TESTPROGS = adler32 \
aes \
@ -101,3 +103,4 @@ TESTPROGS = adler32 \
parseutils \
sha \
tree \
xtea \

2
libavutil/avutil.h
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@ -152,7 +152,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 51
#define LIBAVUTIL_VERSION_MINOR 35
#define LIBAVUTIL_VERSION_MINOR 36
#define LIBAVUTIL_VERSION_MICRO 0
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \

165
libavutil/xtea.c Normal file
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@ -0,0 +1,165 @@
/*
* A 32-bit implementation of the XTEA algorithm
* Copyright (c) 2012 Samuel Pitoiset
*
* loosely based on the implementation of David Wheeler and Roger Needham
*
* This file is part of Libav.
*
* Libav 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 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/intreadwrite.h"
#include "avutil.h"
#include "common.h"
#include "xtea.h"
void av_xtea_init(AVXTEA *ctx, const uint8_t key[16])
{
int i;
for (i = 0; i < 4; i++)
ctx->key[i] = AV_RB32(key + (i << 2));
}
static void xtea_crypt_ecb(AVXTEA *ctx, uint8_t *dst, const uint8_t *src,
int decrypt)
{
uint32_t v0, v1;
int i;
v0 = AV_RB32(src);
v1 = AV_RB32(src + 4);
if (decrypt) {
uint32_t delta = 0x9E3779B9, sum = delta * 32;
for (i = 0; i < 32; i++) {
v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + ctx->key[(sum >> 11) & 3]);
sum -= delta;
v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + ctx->key[sum & 3]);
}
} else {
uint32_t sum = 0, delta = 0x9E3779B9;
for (i = 0; i < 32; i++) {
v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + ctx->key[sum & 3]);
sum += delta;
v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + ctx->key[(sum >> 11) & 3]);
}
}
AV_WB32(dst, v0);
AV_WB32(dst + 4, v1);
}
void av_xtea_crypt(AVXTEA *ctx, uint8_t *dst, const uint8_t *src, int count,
uint8_t *iv, int decrypt)
{
int i;
while (count > 0) {
if (decrypt) {
xtea_crypt_ecb(ctx, dst, src, decrypt);
if (iv) {
for (i = 0; i < 8; i++)
dst[i] = dst[i] ^ iv[i];
memcpy(iv, src, 8);
}
} else {
if (iv) {
for (i = 0; i < 8; i++)
dst[i] = src[i] ^ iv[i];
xtea_crypt_ecb(ctx, dst, dst, decrypt);
memcpy(iv, dst, 8);
} else {
xtea_crypt_ecb(ctx, dst, src, decrypt);
}
}
src += 8;
dst += 8;
count -= 8;
}
}
#ifdef TEST
#include <stdio.h>
#undef printf
#define XTEA_NUM_TESTS 6
static const uint8_t xtea_test_key[XTEA_NUM_TESTS][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 uint8_t xtea_test_pt[XTEA_NUM_TESTS][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 uint8_t xtea_test_ct[XTEA_NUM_TESTS][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 }
};
int main(void)
{
AVXTEA ctx;
uint8_t buf[8];
int i;
for (i = 0; i < XTEA_NUM_TESTS; i++) {
av_xtea_init(&ctx, xtea_test_key[i]);
av_xtea_crypt(&ctx, buf, xtea_test_pt[i], 1, NULL, 0);
if (memcmp(buf, xtea_test_ct[i], 8)) {
printf("Test encryption failed.\n");
return 1;
}
av_xtea_crypt(&ctx, buf, xtea_test_ct[i], 1, NULL, 1);
if (memcmp(buf, xtea_test_pt[i], 8)) {
printf("Test decryption failed.\n");
return 1;
}
}
printf("Test encryption/decryption success.\n");
return 0;
}
#endif

61
libavutil/xtea.h Normal file
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@ -0,0 +1,61 @@
/*
* A 32-bit implementation of the XTEA algorithm
*
* This file is part of Libav.
*
* Libav 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 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_XTEA_H
#define AVUTIL_XTEA_H
#include <stdint.h>
/**
* @defgroup lavu_xtea XTEA
* @ingroup lavu_crypto
* @{
*/
typedef struct AVXTEA {
uint32_t key[16];
} AVXTEA;
/**
* Initialize an AVXTEA context.
*
* @param x an AVXTEA context
* @param key a key of 16 bytes used for encryption/decryption
*/
void av_xtea_init(struct AVXTEA *ctx, const uint8_t key[16]);
/**
* Encrypt or decrypt a buffer using a previously initialized context.
*
* @param x an AVXTEA context
* @param dst destination array, can be equal to src
* @param src source array, can be equal to dst
* @param count number of 8 byte blocks
* @param iv initialization vector for CBC mode, if NULL then ECB will be used
* @param decrypt 0 for encryption, 1 for decryption
*/
void av_xtea_crypt(struct AVXTEA *ctx, uint8_t *dst, const uint8_t *src,
int count, uint8_t *iv, int decrypt);
/**
* @}
*/
#endif /* AVUTIL_XTEA_H */

4
tests/fate/libavutil.mak
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@ -41,4 +41,8 @@ FATE_LIBAVUTIL += fate-sha
fate-sha: libavutil/sha-test$(EXESUF)
fate-sha: CMD = run libavutil/sha-test
FATE_LIBAVUTIL += fate-xtea
fate-xtea: libavutil/xtea-test$(EXESUF)
fate-xtea: CMD = run libavutil/xtea-test
fate-libavutil: $(FATE_LIBAVUTIL)

1
tests/ref/fate/xtea Normal file
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@ -0,0 +1 @@
Test encryption/decryption success.