2 * A 32-bit implementation of the XTEA algorithm
3 * Copyright (c) 2012 Samuel Pitoiset
5 * loosely based on the implementation of David Wheeler and Roger Needham
7 * This file is part of FFmpeg.
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 * @brief XTEA 32-bit implementation
27 * @author Samuel Pitoiset
33 #include "intreadwrite.h"
37 AVXTEA *av_xtea_alloc(void)
39 return av_mallocz(sizeof(struct AVXTEA));
42 void av_xtea_init(AVXTEA *ctx, const uint8_t key[16])
46 for (i = 0; i < 4; i++)
47 ctx->key[i] = AV_RB32(key + (i << 2));
50 void av_xtea_le_init(AVXTEA *ctx, const uint8_t key[16])
54 for (i = 0; i < 4; i++)
55 ctx->key[i] = AV_RL32(key + (i << 2));
58 static void xtea_crypt_ecb(AVXTEA *ctx, uint8_t *dst, const uint8_t *src,
59 int decrypt, uint8_t *iv)
63 uint32_t k0 = ctx->key[0];
64 uint32_t k1 = ctx->key[1];
65 uint32_t k2 = ctx->key[2];
66 uint32_t k3 = ctx->key[3];
70 v1 = AV_RB32(src + 4);
75 uint32_t delta = 0x9E3779B9U, sum = delta * 32;
77 for (i = 0; i < 32; i++) {
78 v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + ctx->key[(sum >> 11) & 3]);
80 v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + ctx->key[sum & 3]);
83 #define DSTEP(SUM, K0, K1) \
84 v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (SUM + K0); \
85 v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (SUM - 0x9E3779B9U + K1)
87 DSTEP(0xC6EF3720U, k2, k3);
88 DSTEP(0x28B7BD67U, k3, k2);
89 DSTEP(0x8A8043AEU, k0, k1);
90 DSTEP(0xEC48C9F5U, k1, k0);
91 DSTEP(0x4E11503CU, k2, k3);
92 DSTEP(0xAFD9D683U, k2, k2);
93 DSTEP(0x11A25CCAU, k3, k1);
94 DSTEP(0x736AE311U, k0, k0);
95 DSTEP(0xD5336958U, k1, k3);
96 DSTEP(0x36FBEF9FU, k1, k2);
97 DSTEP(0x98C475E6U, k2, k1);
98 DSTEP(0xFA8CFC2DU, k3, k0);
99 DSTEP(0x5C558274U, k0, k3);
100 DSTEP(0xBE1E08BBU, k1, k2);
101 DSTEP(0x1FE68F02U, k1, k1);
102 DSTEP(0x81AF1549U, k2, k0);
103 DSTEP(0xE3779B90U, k3, k3);
104 DSTEP(0x454021D7U, k0, k2);
105 DSTEP(0xA708A81EU, k1, k1);
106 DSTEP(0x08D12E65U, k1, k0);
107 DSTEP(0x6A99B4ACU, k2, k3);
108 DSTEP(0xCC623AF3U, k3, k2);
109 DSTEP(0x2E2AC13AU, k0, k1);
110 DSTEP(0x8FF34781U, k0, k0);
111 DSTEP(0xF1BBCDC8U, k1, k3);
112 DSTEP(0x5384540FU, k2, k2);
113 DSTEP(0xB54CDA56U, k3, k1);
114 DSTEP(0x1715609DU, k0, k0);
115 DSTEP(0x78DDE6E4U, k0, k3);
116 DSTEP(0xDAA66D2BU, k1, k2);
117 DSTEP(0x3C6EF372U, k2, k1);
118 DSTEP(0x9E3779B9U, k3, k0);
122 v1 ^= AV_RB32(iv + 4);
128 uint32_t sum = 0, delta = 0x9E3779B9U;
130 for (i = 0; i < 32; i++) {
131 v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + ctx->key[sum & 3]);
133 v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + ctx->key[(sum >> 11) & 3]);
136 #define ESTEP(SUM, K0, K1) \
137 v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (SUM + K0);\
138 v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (SUM + 0x9E3779B9U + K1)
139 ESTEP(0x00000000U, k0, k3);
140 ESTEP(0x9E3779B9U, k1, k2);
141 ESTEP(0x3C6EF372U, k2, k1);
142 ESTEP(0xDAA66D2BU, k3, k0);
143 ESTEP(0x78DDE6E4U, k0, k0);
144 ESTEP(0x1715609DU, k1, k3);
145 ESTEP(0xB54CDA56U, k2, k2);
146 ESTEP(0x5384540FU, k3, k1);
147 ESTEP(0xF1BBCDC8U, k0, k0);
148 ESTEP(0x8FF34781U, k1, k0);
149 ESTEP(0x2E2AC13AU, k2, k3);
150 ESTEP(0xCC623AF3U, k3, k2);
151 ESTEP(0x6A99B4ACU, k0, k1);
152 ESTEP(0x08D12E65U, k1, k1);
153 ESTEP(0xA708A81EU, k2, k0);
154 ESTEP(0x454021D7U, k3, k3);
155 ESTEP(0xE3779B90U, k0, k2);
156 ESTEP(0x81AF1549U, k1, k1);
157 ESTEP(0x1FE68F02U, k2, k1);
158 ESTEP(0xBE1E08BBU, k3, k0);
159 ESTEP(0x5C558274U, k0, k3);
160 ESTEP(0xFA8CFC2DU, k1, k2);
161 ESTEP(0x98C475E6U, k2, k1);
162 ESTEP(0x36FBEF9FU, k3, k1);
163 ESTEP(0xD5336958U, k0, k0);
164 ESTEP(0x736AE311U, k1, k3);
165 ESTEP(0x11A25CCAU, k2, k2);
166 ESTEP(0xAFD9D683U, k3, k2);
167 ESTEP(0x4E11503CU, k0, k1);
168 ESTEP(0xEC48C9F5U, k1, k0);
169 ESTEP(0x8A8043AEU, k2, k3);
170 ESTEP(0x28B7BD67U, k3, k2);
175 AV_WB32(dst + 4, v1);
178 static void xtea_le_crypt_ecb(AVXTEA *ctx, uint8_t *dst, const uint8_t *src,
179 int decrypt, uint8_t *iv)
185 v1 = AV_RL32(src + 4);
188 uint32_t delta = 0x9E3779B9, sum = delta * 32;
190 for (i = 0; i < 32; i++) {
191 v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + ctx->key[(sum >> 11) & 3]);
193 v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + ctx->key[sum & 3]);
197 v1 ^= AV_RL32(iv + 4);
201 uint32_t sum = 0, delta = 0x9E3779B9;
203 for (i = 0; i < 32; i++) {
204 v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + ctx->key[sum & 3]);
206 v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + ctx->key[(sum >> 11) & 3]);
211 AV_WL32(dst + 4, v1);
214 static void xtea_crypt(AVXTEA *ctx, uint8_t *dst, const uint8_t *src, int count,
215 uint8_t *iv, int decrypt,
216 void (*crypt)(AVXTEA *, uint8_t *, const uint8_t *, int, uint8_t *))
222 crypt(ctx, dst, src, decrypt, iv);
230 for (i = 0; i < 8; i++)
231 dst[i] = src[i] ^ iv[i];
232 crypt(ctx, dst, dst, decrypt, NULL);
235 crypt(ctx, dst, src, decrypt, NULL);
243 void av_xtea_crypt(AVXTEA *ctx, uint8_t *dst, const uint8_t *src, int count,
244 uint8_t *iv, int decrypt)
246 xtea_crypt(ctx, dst, src, count, iv, decrypt, xtea_crypt_ecb);
249 void av_xtea_le_crypt(AVXTEA *ctx, uint8_t *dst, const uint8_t *src, int count,
250 uint8_t *iv, int decrypt)
252 xtea_crypt(ctx, dst, src, count, iv, decrypt, xtea_le_crypt_ecb);
258 #define XTEA_NUM_TESTS 6
260 static const uint8_t xtea_test_key[XTEA_NUM_TESTS][16] = {
261 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
262 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
263 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
264 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
265 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
266 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
267 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
268 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
269 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
270 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
271 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
272 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
275 static const uint8_t xtea_test_pt[XTEA_NUM_TESTS][8] = {
276 { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
277 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
278 { 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f },
279 { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
280 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
281 { 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 }
284 static const uint8_t xtea_test_ct[XTEA_NUM_TESTS][8] = {
285 { 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 },
286 { 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 },
287 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
288 { 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 },
289 { 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d },
290 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
293 static void test_xtea(AVXTEA *ctx, uint8_t *dst, const uint8_t *src,
294 const uint8_t *ref, int len, uint8_t *iv, int dir,
296 void (*crypt)(AVXTEA *, uint8_t *, const uint8_t *, int, uint8_t *, int))
298 crypt(ctx, dst, src, len, iv, dir);
299 if (memcmp(dst, ref, 8*len)) {
301 printf("%s failed\ngot ", test);
302 for (i = 0; i < 8*len; i++)
303 printf("%02x ", dst[i]);
304 printf("\nexpected ");
305 for (i = 0; i < 8*len; i++)
306 printf("%02x ", ref[i]);
315 uint8_t buf[16], iv[8];
317 static const uint8_t src[32] = "HelloWorldHelloWorldHelloWorld";
321 for (i = 0; i < XTEA_NUM_TESTS; i++) {
322 av_xtea_init(&ctx, xtea_test_key[i]);
324 test_xtea(&ctx, buf, xtea_test_pt[i], xtea_test_ct[i], 1, NULL, 0, "encryption", av_xtea_crypt);
325 test_xtea(&ctx, buf, xtea_test_ct[i], xtea_test_pt[i], 1, NULL, 1, "decryption", av_xtea_crypt);
327 for (j = 0; j < 4; j++)
328 AV_WL32(&buf[4*j], AV_RB32(&xtea_test_key[i][4*j]));
329 av_xtea_le_init(&ctx, buf);
330 for (j = 0; j < 2; j++) {
331 AV_WL32(&ct[4*j], AV_RB32(&xtea_test_ct[i][4*j]));
332 AV_WL32(&pl[4*j], AV_RB32(&xtea_test_pt[i][4*j]));
334 test_xtea(&ctx, buf, pl, ct, 1, NULL, 0, "encryption", av_xtea_le_crypt);
335 test_xtea(&ctx, buf, ct, pl, 1, NULL, 1, "decryption", av_xtea_le_crypt);
338 memcpy(iv, "HALLO123", 8);
339 av_xtea_crypt(&ctx, ct, src, 4, iv, 0);
341 /* decrypt into pl */
342 memcpy(iv, "HALLO123", 8);
343 test_xtea(&ctx, pl, ct, src, 4, iv, 1, "CBC decryption", av_xtea_crypt);
345 memcpy(iv, "HALLO123", 8);
346 test_xtea(&ctx, ct, ct, src, 4, iv, 1, "CBC inplace decryption", av_xtea_crypt);
349 printf("Test encryption/decryption success.\n");