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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 | /* * Cryptographic API. * * TEA, XTEA, and XETA crypto alogrithms * * The TEA and Xtended TEA algorithms were developed by David Wheeler * and Roger Needham at the Computer Laboratory of Cambridge University. * * Due to the order of evaluation in XTEA many people have incorrectly * implemented it. XETA (XTEA in the wrong order), exists for * compatibility with these implementations. * * Copyright (c) 2004 Aaron Grothe ajgrothe@yahoo.com * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * */ #include <linux/init.h> #include <linux/module.h> #include <linux/mm.h> #include <asm/scatterlist.h> #include <linux/crypto.h> #define TEA_KEY_SIZE 16 #define TEA_BLOCK_SIZE 8 #define TEA_ROUNDS 32 #define TEA_DELTA 0x9e3779b9 #define XTEA_KEY_SIZE 16 #define XTEA_BLOCK_SIZE 8 #define XTEA_ROUNDS 32 #define XTEA_DELTA 0x9e3779b9 #define u32_in(x) le32_to_cpu(*(const __le32 *)(x)) #define u32_out(to, from) (*(__le32 *)(to) = cpu_to_le32(from)) struct tea_ctx { u32 KEY[4]; }; struct xtea_ctx { u32 KEY[4]; }; static int tea_setkey(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags) { struct tea_ctx *ctx = ctx_arg; if (key_len != 16) { *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; return -EINVAL; } ctx->KEY[0] = u32_in (in_key); ctx->KEY[1] = u32_in (in_key + 4); ctx->KEY[2] = u32_in (in_key + 8); ctx->KEY[3] = u32_in (in_key + 12); return 0; } static void tea_encrypt(void *ctx_arg, u8 *dst, const u8 *src) { u32 y, z, n, sum = 0; u32 k0, k1, k2, k3; struct tea_ctx *ctx = ctx_arg; y = u32_in (src); z = u32_in (src + 4); k0 = ctx->KEY[0]; k1 = ctx->KEY[1]; k2 = ctx->KEY[2]; k3 = ctx->KEY[3]; n = TEA_ROUNDS; while (n-- > 0) { sum += TEA_DELTA; y += ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1); z += ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3); } u32_out (dst, y); u32_out (dst + 4, z); } static void tea_decrypt(void *ctx_arg, u8 *dst, const u8 *src) { u32 y, z, n, sum; u32 k0, k1, k2, k3; struct tea_ctx *ctx = ctx_arg; y = u32_in (src); z = u32_in (src + 4); k0 = ctx->KEY[0]; k1 = ctx->KEY[1]; k2 = ctx->KEY[2]; k3 = ctx->KEY[3]; sum = TEA_DELTA << 5; n = TEA_ROUNDS; while (n-- > 0) { z -= ((y << 4) + k2) ^ (y + sum) ^ ((y >> 5) + k3); y -= ((z << 4) + k0) ^ (z + sum) ^ ((z >> 5) + k1); sum -= TEA_DELTA; } u32_out (dst, y); u32_out (dst + 4, z); } static int xtea_setkey(void *ctx_arg, const u8 *in_key, unsigned int key_len, u32 *flags) { struct xtea_ctx *ctx = ctx_arg; if (key_len != 16) { *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; return -EINVAL; } ctx->KEY[0] = u32_in (in_key); ctx->KEY[1] = u32_in (in_key + 4); ctx->KEY[2] = u32_in (in_key + 8); ctx->KEY[3] = u32_in (in_key + 12); return 0; } static void xtea_encrypt(void *ctx_arg, u8 *dst, const u8 *src) { u32 y, z, sum = 0; u32 limit = XTEA_DELTA * XTEA_ROUNDS; struct xtea_ctx *ctx = ctx_arg; y = u32_in (src); z = u32_in (src + 4); while (sum != limit) { y += ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum&3]); sum += XTEA_DELTA; z += ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 &3]); } u32_out (dst, y); u32_out (dst + 4, z); } static void xtea_decrypt(void *ctx_arg, u8 *dst, const u8 *src) { u32 y, z, sum; struct tea_ctx *ctx = ctx_arg; y = u32_in (src); z = u32_in (src + 4); sum = XTEA_DELTA * XTEA_ROUNDS; while (sum) { z -= ((y << 4 ^ y >> 5) + y) ^ (sum + ctx->KEY[sum>>11 & 3]); sum -= XTEA_DELTA; y -= ((z << 4 ^ z >> 5) + z) ^ (sum + ctx->KEY[sum & 3]); } u32_out (dst, y); u32_out (dst + 4, z); } static void xeta_encrypt(void *ctx_arg, u8 *dst, const u8 *src) { u32 y, z, sum = 0; u32 limit = XTEA_DELTA * XTEA_ROUNDS; struct xtea_ctx *ctx = ctx_arg; y = u32_in (src); z = u32_in (src + 4); while (sum != limit) { y += (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum&3]; sum += XTEA_DELTA; z += (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 &3]; } u32_out (dst, y); u32_out (dst + 4, z); } static void xeta_decrypt(void *ctx_arg, u8 *dst, const u8 *src) { u32 y, z, sum; struct tea_ctx *ctx = ctx_arg; y = u32_in (src); z = u32_in (src + 4); sum = XTEA_DELTA * XTEA_ROUNDS; while (sum) { z -= (y << 4 ^ y >> 5) + (y ^ sum) + ctx->KEY[sum>>11 & 3]; sum -= XTEA_DELTA; y -= (z << 4 ^ z >> 5) + (z ^ sum) + ctx->KEY[sum & 3]; } u32_out (dst, y); u32_out (dst + 4, z); } static struct crypto_alg tea_alg = { .cra_name = "tea", .cra_flags = CRYPTO_ALG_TYPE_CIPHER, .cra_blocksize = TEA_BLOCK_SIZE, .cra_ctxsize = sizeof (struct tea_ctx), .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT(tea_alg.cra_list), .cra_u = { .cipher = { .cia_min_keysize = TEA_KEY_SIZE, .cia_max_keysize = TEA_KEY_SIZE, .cia_setkey = tea_setkey, .cia_encrypt = tea_encrypt, .cia_decrypt = tea_decrypt } } }; static struct crypto_alg xtea_alg = { .cra_name = "xtea", .cra_flags = CRYPTO_ALG_TYPE_CIPHER, .cra_blocksize = XTEA_BLOCK_SIZE, .cra_ctxsize = sizeof (struct xtea_ctx), .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT(xtea_alg.cra_list), .cra_u = { .cipher = { .cia_min_keysize = XTEA_KEY_SIZE, .cia_max_keysize = XTEA_KEY_SIZE, .cia_setkey = xtea_setkey, .cia_encrypt = xtea_encrypt, .cia_decrypt = xtea_decrypt } } }; static struct crypto_alg xeta_alg = { .cra_name = "xeta", .cra_flags = CRYPTO_ALG_TYPE_CIPHER, .cra_blocksize = XTEA_BLOCK_SIZE, .cra_ctxsize = sizeof (struct xtea_ctx), .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT(xtea_alg.cra_list), .cra_u = { .cipher = { .cia_min_keysize = XTEA_KEY_SIZE, .cia_max_keysize = XTEA_KEY_SIZE, .cia_setkey = xtea_setkey, .cia_encrypt = xeta_encrypt, .cia_decrypt = xeta_decrypt } } }; static int __init init(void) { int ret = 0; ret = crypto_register_alg(&tea_alg); if (ret < 0) goto out; ret = crypto_register_alg(&xtea_alg); if (ret < 0) { crypto_unregister_alg(&tea_alg); goto out; } ret = crypto_register_alg(&xeta_alg); if (ret < 0) { crypto_unregister_alg(&tea_alg); crypto_unregister_alg(&xtea_alg); goto out; } out: return ret; } static void __exit fini(void) { crypto_unregister_alg(&tea_alg); crypto_unregister_alg(&xtea_alg); crypto_unregister_alg(&xeta_alg); } MODULE_ALIAS("xtea"); MODULE_ALIAS("xeta"); module_init(init); module_exit(fini); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("TEA, XTEA & XETA Cryptographic Algorithms"); |