1 /* 2 * Bit sliced AES using NEON instructions 3 * 4 * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <asm/neon.h> 12 #include <crypto/aes.h> 13 #include <crypto/cbc.h> 14 #include <crypto/internal/simd.h> 15 #include <crypto/internal/skcipher.h> 16 #include <crypto/xts.h> 17 #include <linux/module.h> 18 19 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); 20 MODULE_LICENSE("GPL v2"); 21 22 MODULE_ALIAS_CRYPTO("ecb(aes)"); 23 MODULE_ALIAS_CRYPTO("cbc(aes)"); 24 MODULE_ALIAS_CRYPTO("ctr(aes)"); 25 MODULE_ALIAS_CRYPTO("xts(aes)"); 26 27 asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds); 28 29 asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[], 30 int rounds, int blocks); 31 asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[], 32 int rounds, int blocks); 33 34 asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[], 35 int rounds, int blocks, u8 iv[]); 36 37 asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], 38 int rounds, int blocks, u8 ctr[], u8 final[]); 39 40 asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[], 41 int rounds, int blocks, u8 iv[]); 42 asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[], 43 int rounds, int blocks, u8 iv[]); 44 45 struct aesbs_ctx { 46 int rounds; 47 u8 rk[13 * (8 * AES_BLOCK_SIZE) + 32] __aligned(AES_BLOCK_SIZE); 48 }; 49 50 struct aesbs_cbc_ctx { 51 struct aesbs_ctx key; 52 struct crypto_cipher *enc_tfm; 53 }; 54 55 struct aesbs_xts_ctx { 56 struct aesbs_ctx key; 57 struct crypto_cipher *tweak_tfm; 58 }; 59 60 static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key, 61 unsigned int key_len) 62 { 63 struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm); 64 struct crypto_aes_ctx rk; 65 int err; 66 67 err = crypto_aes_expand_key(&rk, in_key, key_len); 68 if (err) 69 return err; 70 71 ctx->rounds = 6 + key_len / 4; 72 73 kernel_neon_begin(); 74 aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds); 75 kernel_neon_end(); 76 77 return 0; 78 } 79 80 static int __ecb_crypt(struct skcipher_request *req, 81 void (*fn)(u8 out[], u8 const in[], u8 const rk[], 82 int rounds, int blocks)) 83 { 84 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 85 struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm); 86 struct skcipher_walk walk; 87 int err; 88 89 err = skcipher_walk_virt(&walk, req, true); 90 91 kernel_neon_begin(); 92 while (walk.nbytes >= AES_BLOCK_SIZE) { 93 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE; 94 95 if (walk.nbytes < walk.total) 96 blocks = round_down(blocks, 97 walk.stride / AES_BLOCK_SIZE); 98 99 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk, 100 ctx->rounds, blocks); 101 err = skcipher_walk_done(&walk, 102 walk.nbytes - blocks * AES_BLOCK_SIZE); 103 } 104 kernel_neon_end(); 105 106 return err; 107 } 108 109 static int ecb_encrypt(struct skcipher_request *req) 110 { 111 return __ecb_crypt(req, aesbs_ecb_encrypt); 112 } 113 114 static int ecb_decrypt(struct skcipher_request *req) 115 { 116 return __ecb_crypt(req, aesbs_ecb_decrypt); 117 } 118 119 static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key, 120 unsigned int key_len) 121 { 122 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm); 123 struct crypto_aes_ctx rk; 124 int err; 125 126 err = crypto_aes_expand_key(&rk, in_key, key_len); 127 if (err) 128 return err; 129 130 ctx->key.rounds = 6 + key_len / 4; 131 132 kernel_neon_begin(); 133 aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds); 134 kernel_neon_end(); 135 136 return crypto_cipher_setkey(ctx->enc_tfm, in_key, key_len); 137 } 138 139 static void cbc_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst) 140 { 141 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm); 142 143 crypto_cipher_encrypt_one(ctx->enc_tfm, dst, src); 144 } 145 146 static int cbc_encrypt(struct skcipher_request *req) 147 { 148 return crypto_cbc_encrypt_walk(req, cbc_encrypt_one); 149 } 150 151 static int cbc_decrypt(struct skcipher_request *req) 152 { 153 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 154 struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm); 155 struct skcipher_walk walk; 156 int err; 157 158 err = skcipher_walk_virt(&walk, req, true); 159 160 kernel_neon_begin(); 161 while (walk.nbytes >= AES_BLOCK_SIZE) { 162 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE; 163 164 if (walk.nbytes < walk.total) 165 blocks = round_down(blocks, 166 walk.stride / AES_BLOCK_SIZE); 167 168 aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr, 169 ctx->key.rk, ctx->key.rounds, blocks, 170 walk.iv); 171 err = skcipher_walk_done(&walk, 172 walk.nbytes - blocks * AES_BLOCK_SIZE); 173 } 174 kernel_neon_end(); 175 176 return err; 177 } 178 179 static int cbc_init(struct crypto_tfm *tfm) 180 { 181 struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm); 182 183 ctx->enc_tfm = crypto_alloc_cipher("aes", 0, 0); 184 185 return PTR_ERR_OR_ZERO(ctx->enc_tfm); 186 } 187 188 static void cbc_exit(struct crypto_tfm *tfm) 189 { 190 struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm); 191 192 crypto_free_cipher(ctx->enc_tfm); 193 } 194 195 static int ctr_encrypt(struct skcipher_request *req) 196 { 197 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 198 struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm); 199 struct skcipher_walk walk; 200 u8 buf[AES_BLOCK_SIZE]; 201 int err; 202 203 err = skcipher_walk_virt(&walk, req, true); 204 205 kernel_neon_begin(); 206 while (walk.nbytes > 0) { 207 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE; 208 u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL; 209 210 if (walk.nbytes < walk.total) { 211 blocks = round_down(blocks, 212 walk.stride / AES_BLOCK_SIZE); 213 final = NULL; 214 } 215 216 aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr, 217 ctx->rk, ctx->rounds, blocks, walk.iv, final); 218 219 if (final) { 220 u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE; 221 u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE; 222 223 crypto_xor_cpy(dst, src, final, 224 walk.total % AES_BLOCK_SIZE); 225 226 err = skcipher_walk_done(&walk, 0); 227 break; 228 } 229 err = skcipher_walk_done(&walk, 230 walk.nbytes - blocks * AES_BLOCK_SIZE); 231 } 232 kernel_neon_end(); 233 234 return err; 235 } 236 237 static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key, 238 unsigned int key_len) 239 { 240 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm); 241 int err; 242 243 err = xts_verify_key(tfm, in_key, key_len); 244 if (err) 245 return err; 246 247 key_len /= 2; 248 err = crypto_cipher_setkey(ctx->tweak_tfm, in_key + key_len, key_len); 249 if (err) 250 return err; 251 252 return aesbs_setkey(tfm, in_key, key_len); 253 } 254 255 static int xts_init(struct crypto_tfm *tfm) 256 { 257 struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm); 258 259 ctx->tweak_tfm = crypto_alloc_cipher("aes", 0, 0); 260 261 return PTR_ERR_OR_ZERO(ctx->tweak_tfm); 262 } 263 264 static void xts_exit(struct crypto_tfm *tfm) 265 { 266 struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm); 267 268 crypto_free_cipher(ctx->tweak_tfm); 269 } 270 271 static int __xts_crypt(struct skcipher_request *req, 272 void (*fn)(u8 out[], u8 const in[], u8 const rk[], 273 int rounds, int blocks, u8 iv[])) 274 { 275 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 276 struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm); 277 struct skcipher_walk walk; 278 int err; 279 280 err = skcipher_walk_virt(&walk, req, true); 281 282 crypto_cipher_encrypt_one(ctx->tweak_tfm, walk.iv, walk.iv); 283 284 kernel_neon_begin(); 285 while (walk.nbytes >= AES_BLOCK_SIZE) { 286 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE; 287 288 if (walk.nbytes < walk.total) 289 blocks = round_down(blocks, 290 walk.stride / AES_BLOCK_SIZE); 291 292 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk, 293 ctx->key.rounds, blocks, walk.iv); 294 err = skcipher_walk_done(&walk, 295 walk.nbytes - blocks * AES_BLOCK_SIZE); 296 } 297 kernel_neon_end(); 298 299 return err; 300 } 301 302 static int xts_encrypt(struct skcipher_request *req) 303 { 304 return __xts_crypt(req, aesbs_xts_encrypt); 305 } 306 307 static int xts_decrypt(struct skcipher_request *req) 308 { 309 return __xts_crypt(req, aesbs_xts_decrypt); 310 } 311 312 static struct skcipher_alg aes_algs[] = { { 313 .base.cra_name = "__ecb(aes)", 314 .base.cra_driver_name = "__ecb-aes-neonbs", 315 .base.cra_priority = 250, 316 .base.cra_blocksize = AES_BLOCK_SIZE, 317 .base.cra_ctxsize = sizeof(struct aesbs_ctx), 318 .base.cra_module = THIS_MODULE, 319 .base.cra_flags = CRYPTO_ALG_INTERNAL, 320 321 .min_keysize = AES_MIN_KEY_SIZE, 322 .max_keysize = AES_MAX_KEY_SIZE, 323 .walksize = 8 * AES_BLOCK_SIZE, 324 .setkey = aesbs_setkey, 325 .encrypt = ecb_encrypt, 326 .decrypt = ecb_decrypt, 327 }, { 328 .base.cra_name = "__cbc(aes)", 329 .base.cra_driver_name = "__cbc-aes-neonbs", 330 .base.cra_priority = 250, 331 .base.cra_blocksize = AES_BLOCK_SIZE, 332 .base.cra_ctxsize = sizeof(struct aesbs_cbc_ctx), 333 .base.cra_module = THIS_MODULE, 334 .base.cra_flags = CRYPTO_ALG_INTERNAL, 335 .base.cra_init = cbc_init, 336 .base.cra_exit = cbc_exit, 337 338 .min_keysize = AES_MIN_KEY_SIZE, 339 .max_keysize = AES_MAX_KEY_SIZE, 340 .walksize = 8 * AES_BLOCK_SIZE, 341 .ivsize = AES_BLOCK_SIZE, 342 .setkey = aesbs_cbc_setkey, 343 .encrypt = cbc_encrypt, 344 .decrypt = cbc_decrypt, 345 }, { 346 .base.cra_name = "__ctr(aes)", 347 .base.cra_driver_name = "__ctr-aes-neonbs", 348 .base.cra_priority = 250, 349 .base.cra_blocksize = 1, 350 .base.cra_ctxsize = sizeof(struct aesbs_ctx), 351 .base.cra_module = THIS_MODULE, 352 .base.cra_flags = CRYPTO_ALG_INTERNAL, 353 354 .min_keysize = AES_MIN_KEY_SIZE, 355 .max_keysize = AES_MAX_KEY_SIZE, 356 .chunksize = AES_BLOCK_SIZE, 357 .walksize = 8 * AES_BLOCK_SIZE, 358 .ivsize = AES_BLOCK_SIZE, 359 .setkey = aesbs_setkey, 360 .encrypt = ctr_encrypt, 361 .decrypt = ctr_encrypt, 362 }, { 363 .base.cra_name = "__xts(aes)", 364 .base.cra_driver_name = "__xts-aes-neonbs", 365 .base.cra_priority = 250, 366 .base.cra_blocksize = AES_BLOCK_SIZE, 367 .base.cra_ctxsize = sizeof(struct aesbs_xts_ctx), 368 .base.cra_module = THIS_MODULE, 369 .base.cra_flags = CRYPTO_ALG_INTERNAL, 370 .base.cra_init = xts_init, 371 .base.cra_exit = xts_exit, 372 373 .min_keysize = 2 * AES_MIN_KEY_SIZE, 374 .max_keysize = 2 * AES_MAX_KEY_SIZE, 375 .walksize = 8 * AES_BLOCK_SIZE, 376 .ivsize = AES_BLOCK_SIZE, 377 .setkey = aesbs_xts_setkey, 378 .encrypt = xts_encrypt, 379 .decrypt = xts_decrypt, 380 } }; 381 382 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)]; 383 384 static void aes_exit(void) 385 { 386 int i; 387 388 for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++) 389 if (aes_simd_algs[i]) 390 simd_skcipher_free(aes_simd_algs[i]); 391 392 crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs)); 393 } 394 395 static int __init aes_init(void) 396 { 397 struct simd_skcipher_alg *simd; 398 const char *basename; 399 const char *algname; 400 const char *drvname; 401 int err; 402 int i; 403 404 if (!(elf_hwcap & HWCAP_NEON)) 405 return -ENODEV; 406 407 err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs)); 408 if (err) 409 return err; 410 411 for (i = 0; i < ARRAY_SIZE(aes_algs); i++) { 412 if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL)) 413 continue; 414 415 algname = aes_algs[i].base.cra_name + 2; 416 drvname = aes_algs[i].base.cra_driver_name + 2; 417 basename = aes_algs[i].base.cra_driver_name; 418 simd = simd_skcipher_create_compat(algname, drvname, basename); 419 err = PTR_ERR(simd); 420 if (IS_ERR(simd)) 421 goto unregister_simds; 422 423 aes_simd_algs[i] = simd; 424 } 425 return 0; 426 427 unregister_simds: 428 aes_exit(); 429 return err; 430 } 431 432 late_initcall(aes_init); 433 module_exit(aes_exit); 434