Drop pointless directory name prefixes from #includes in the current dir
[libav.git] / libavutil / xtea.c
1 /*
2 * A 32-bit implementation of the XTEA algorithm
3 * Copyright (c) 2012 Samuel Pitoiset
4 *
5 * loosely based on the implementation of David Wheeler and Roger Needham
6 *
7 * This file is part of Libav.
8 *
9 * Libav 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.
13 *
14 * Libav 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.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with Libav; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 #include "avutil.h"
25 #include "common.h"
26 #include "intreadwrite.h"
27 #include "xtea.h"
28
29 void av_xtea_init(AVXTEA *ctx, const uint8_t key[16])
30 {
31 int i;
32
33 for (i = 0; i < 4; i++)
34 ctx->key[i] = AV_RB32(key + (i << 2));
35 }
36
37 static void xtea_crypt_ecb(AVXTEA *ctx, uint8_t *dst, const uint8_t *src,
38 int decrypt, uint8_t *iv)
39 {
40 uint32_t v0, v1;
41 int i;
42
43 v0 = AV_RB32(src);
44 v1 = AV_RB32(src + 4);
45
46 if (decrypt) {
47 uint32_t delta = 0x9E3779B9, sum = delta * 32;
48
49 for (i = 0; i < 32; i++) {
50 v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + ctx->key[(sum >> 11) & 3]);
51 sum -= delta;
52 v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + ctx->key[sum & 3]);
53 }
54 if (iv) {
55 v0 ^= AV_RB32(iv);
56 v1 ^= AV_RB32(iv + 4);
57 memcpy(iv, src, 8);
58 }
59 } else {
60 uint32_t sum = 0, delta = 0x9E3779B9;
61
62 for (i = 0; i < 32; i++) {
63 v0 += (((v1 << 4) ^ (v1 >> 5)) + v1) ^ (sum + ctx->key[sum & 3]);
64 sum += delta;
65 v1 += (((v0 << 4) ^ (v0 >> 5)) + v0) ^ (sum + ctx->key[(sum >> 11) & 3]);
66 }
67 }
68
69 AV_WB32(dst, v0);
70 AV_WB32(dst + 4, v1);
71 }
72
73 void av_xtea_crypt(AVXTEA *ctx, uint8_t *dst, const uint8_t *src, int count,
74 uint8_t *iv, int decrypt)
75 {
76 int i;
77
78 if (decrypt) {
79 while (count--) {
80 xtea_crypt_ecb(ctx, dst, src, decrypt, iv);
81
82 src += 8;
83 dst += 8;
84 }
85 } else {
86 while (count--) {
87 if (iv) {
88 for (i = 0; i < 8; i++)
89 dst[i] = src[i] ^ iv[i];
90 xtea_crypt_ecb(ctx, dst, dst, decrypt, NULL);
91 memcpy(iv, dst, 8);
92 } else {
93 xtea_crypt_ecb(ctx, dst, src, decrypt, NULL);
94 }
95 src += 8;
96 dst += 8;
97 }
98 }
99 }
100
101 #ifdef TEST
102 #include <stdio.h>
103
104 #define XTEA_NUM_TESTS 6
105
106 static const uint8_t xtea_test_key[XTEA_NUM_TESTS][16] = {
107 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
108 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
109 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
110 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
111 { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
112 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
113 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
114 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
115 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
116 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
117 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
118 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
119 };
120
121 static const uint8_t xtea_test_pt[XTEA_NUM_TESTS][8] = {
122 { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
123 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
124 { 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f },
125 { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
126 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
127 { 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 }
128 };
129
130 static const uint8_t xtea_test_ct[XTEA_NUM_TESTS][8] = {
131 { 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 },
132 { 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 },
133 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
134 { 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 },
135 { 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d },
136 { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
137 };
138
139 static void test_xtea(AVXTEA *ctx, uint8_t *dst, const uint8_t *src,
140 const uint8_t *ref, int len, uint8_t *iv, int dir,
141 const char *test)
142 {
143 av_xtea_crypt(ctx, dst, src, len, iv, dir);
144 if (memcmp(dst, ref, 8*len)) {
145 int i;
146 printf("%s failed\ngot ", test);
147 for (i = 0; i < 8*len; i++)
148 printf("%02x ", dst[i]);
149 printf("\nexpected ");
150 for (i = 0; i < 8*len; i++)
151 printf("%02x ", ref[i]);
152 printf("\n");
153 exit(1);
154 }
155 }
156
157 int main(void)
158 {
159 AVXTEA ctx;
160 uint8_t buf[8], iv[8];
161 int i;
162 const uint8_t src[32] = "HelloWorldHelloWorldHelloWorld";
163 uint8_t ct[32];
164 uint8_t pl[32];
165
166 for (i = 0; i < XTEA_NUM_TESTS; i++) {
167 av_xtea_init(&ctx, xtea_test_key[i]);
168
169 test_xtea(&ctx, buf, xtea_test_pt[i], xtea_test_ct[i], 1, NULL, 0, "encryption");
170 test_xtea(&ctx, buf, xtea_test_ct[i], xtea_test_pt[i], 1, NULL, 1, "decryption");
171
172 /* encrypt */
173 memcpy(iv, "HALLO123", 8);
174 av_xtea_crypt(&ctx, ct, src, 4, iv, 0);
175
176 /* decrypt into pl */
177 memcpy(iv, "HALLO123", 8);
178 test_xtea(&ctx, pl, ct, src, 4, iv, 1, "CBC decryption");
179
180 memcpy(iv, "HALLO123", 8);
181 test_xtea(&ctx, ct, ct, src, 4, iv, 1, "CBC inplace decryption");
182 }
183 printf("Test encryption/decryption success.\n");
184
185 return 0;
186 }
187
188 #endif