arch/arm64/crypto/aes-neonbs-glue.c

   1 /*
   2  * Bit sliced AES using NEON instructions
   3  *
   4  * Copyright (C) 2016 - 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 <asm/simd.h>
  13 #include <crypto/aes.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 #include "aes-ctr-fallback.h"
  20
  21 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  22 MODULE_LICENSE("GPL v2");
  23
  24 MODULE_ALIAS_CRYPTO("ecb(aes)");
  25 MODULE_ALIAS_CRYPTO("cbc(aes)");
  26 MODULE_ALIAS_CRYPTO("ctr(aes)");
  27 MODULE_ALIAS_CRYPTO("xts(aes)");
  28
  29 asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds);
  30
  31 asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
  32                                   int rounds, int blocks);
  33 asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
  34                                   int rounds, int blocks);
  35
  36 asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
  37                                   int rounds, int blocks, u8 iv[]);
  38
  39 asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
  40                                   int rounds, int blocks, u8 iv[], u8 final[]);
  41
  42 asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
  43                                   int rounds, int blocks, u8 iv[]);
  44 asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
  45                                   int rounds, int blocks, u8 iv[]);
  46
  47 /* borrowed from aes-neon-blk.ko */
  48 asmlinkage void neon_aes_ecb_encrypt(u8 out[], u8 const in[], u32 const rk[],
  49                                      int rounds, int blocks);
  50 asmlinkage void neon_aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
  51                                      int rounds, int blocks, u8 iv[]);
  52
  53 struct aesbs_ctx {
  54         u8      rk[13 * (8 * AES_BLOCK_SIZE) + 32];
  55         int     rounds;
  56 } __aligned(AES_BLOCK_SIZE);
  57
  58 struct aesbs_cbc_ctx {
  59         struct aesbs_ctx        key;
  60         u32                     enc[AES_MAX_KEYLENGTH_U32];
  61 };
  62
  63 struct aesbs_ctr_ctx {
  64         struct aesbs_ctx        key;            /* must be first member */
  65         struct crypto_aes_ctx   fallback;
  66 };
  67
  68 struct aesbs_xts_ctx {
  69         struct aesbs_ctx        key;
  70         u32                     twkey[AES_MAX_KEYLENGTH_U32];
  71 };
  72
  73 static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
  74                         unsigned int key_len)
  75 {
  76         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
  77         struct crypto_aes_ctx rk;
  78         int err;
  79
  80         err = crypto_aes_expand_key(&rk, in_key, key_len);
  81         if (err)
  82                 return err;
  83
  84         ctx->rounds = 6 + key_len / 4;
  85
  86         kernel_neon_begin();
  87         aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
  88         kernel_neon_end();
  89
  90         return 0;
  91 }
  92
  93 static int __ecb_crypt(struct skcipher_request *req,
  94                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
  95                                   int rounds, int blocks))
  96 {
  97         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  98         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
  99         struct skcipher_walk walk;
 100         int err;
 101
 102         err = skcipher_walk_virt(&walk, req, false);
 103
 104         while (walk.nbytes >= AES_BLOCK_SIZE) {
 105                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 106
 107                 if (walk.nbytes < walk.total)
 108                         blocks = round_down(blocks,
 109                                             walk.stride / AES_BLOCK_SIZE);
 110
 111                 kernel_neon_begin();
 112                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
 113                    ctx->rounds, blocks);
 114                 kernel_neon_end();
 115                 err = skcipher_walk_done(&walk,
 116                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 117         }
 118
 119         return err;
 120 }
 121
 122 static int ecb_encrypt(struct skcipher_request *req)
 123 {
 124         return __ecb_crypt(req, aesbs_ecb_encrypt);
 125 }
 126
 127 static int ecb_decrypt(struct skcipher_request *req)
 128 {
 129         return __ecb_crypt(req, aesbs_ecb_decrypt);
 130 }
 131
 132 static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 133                             unsigned int key_len)
 134 {
 135         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 136         struct crypto_aes_ctx rk;
 137         int err;
 138
 139         err = crypto_aes_expand_key(&rk, in_key, key_len);
 140         if (err)
 141                 return err;
 142
 143         ctx->key.rounds = 6 + key_len / 4;
 144
 145         memcpy(ctx->enc, rk.key_enc, sizeof(ctx->enc));
 146
 147         kernel_neon_begin();
 148         aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
 149         kernel_neon_end();
 150
 151         return 0;
 152 }
 153
 154 static int cbc_encrypt(struct skcipher_request *req)
 155 {
 156         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 157         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 158         struct skcipher_walk walk;
 159         int err;
 160
 161         err = skcipher_walk_virt(&walk, req, false);
 162
 163         while (walk.nbytes >= AES_BLOCK_SIZE) {
 164                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 165
 166                 /* fall back to the non-bitsliced NEON implementation */
 167                 kernel_neon_begin();
 168                 neon_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 169                                      ctx->enc, ctx->key.rounds, blocks,
 170                                      walk.iv);
 171                 kernel_neon_end();
 172                 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
 173         }
 174         return err;
 175 }
 176
 177 static int cbc_decrypt(struct skcipher_request *req)
 178 {
 179         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 180         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 181         struct skcipher_walk walk;
 182         int err;
 183
 184         err = skcipher_walk_virt(&walk, req, false);
 185
 186         while (walk.nbytes >= AES_BLOCK_SIZE) {
 187                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 188
 189                 if (walk.nbytes < walk.total)
 190                         blocks = round_down(blocks,
 191                                             walk.stride / AES_BLOCK_SIZE);
 192
 193                 kernel_neon_begin();
 194                 aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 195                                   ctx->key.rk, ctx->key.rounds, blocks,
 196                                   walk.iv);
 197                 kernel_neon_end();
 198                 err = skcipher_walk_done(&walk,
 199                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 200         }
 201
 202         return err;
 203 }
 204
 205 static int aesbs_ctr_setkey_sync(struct crypto_skcipher *tfm, const u8 *in_key,
 206                                  unsigned int key_len)
 207 {
 208         struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
 209         int err;
 210
 211         err = crypto_aes_expand_key(&ctx->fallback, in_key, key_len);
 212         if (err)
 213                 return err;
 214
 215         ctx->key.rounds = 6 + key_len / 4;
 216
 217         kernel_neon_begin();
 218         aesbs_convert_key(ctx->key.rk, ctx->fallback.key_enc, ctx->key.rounds);
 219         kernel_neon_end();
 220
 221         return 0;
 222 }
 223
 224 static int ctr_encrypt(struct skcipher_request *req)
 225 {
 226         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 227         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 228         struct skcipher_walk walk;
 229         u8 buf[AES_BLOCK_SIZE];
 230         int err;
 231
 232         err = skcipher_walk_virt(&walk, req, false);
 233
 234         while (walk.nbytes > 0) {
 235                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 236                 u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
 237
 238                 if (walk.nbytes < walk.total) {
 239                         blocks = round_down(blocks,
 240                                             walk.stride / AES_BLOCK_SIZE);
 241                         final = NULL;
 242                 }
 243
 244                 kernel_neon_begin();
 245                 aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 246                                   ctx->rk, ctx->rounds, blocks, walk.iv, final);
 247                 kernel_neon_end();
 248
 249                 if (final) {
 250                         u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 251                         u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
 252
 253                         crypto_xor_cpy(dst, src, final,
 254                                        walk.total % AES_BLOCK_SIZE);
 255
 256                         err = skcipher_walk_done(&walk, 0);
 257                         break;
 258                 }
 259                 err = skcipher_walk_done(&walk,
 260                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 261         }
 262         return err;
 263 }
 264
 265 static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 266                             unsigned int key_len)
 267 {
 268         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 269         struct crypto_aes_ctx rk;
 270         int err;
 271
 272         err = xts_verify_key(tfm, in_key, key_len);
 273         if (err)
 274                 return err;
 275
 276         key_len /= 2;
 277         err = crypto_aes_expand_key(&rk, in_key + key_len, key_len);
 278         if (err)
 279                 return err;
 280
 281         memcpy(ctx->twkey, rk.key_enc, sizeof(ctx->twkey));
 282
 283         return aesbs_setkey(tfm, in_key, key_len);
 284 }
 285
 286 static int ctr_encrypt_sync(struct skcipher_request *req)
 287 {
 288         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 289         struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
 290
 291         if (!may_use_simd())
 292                 return aes_ctr_encrypt_fallback(&ctx->fallback, req);
 293
 294         return ctr_encrypt(req);
 295 }
 296
 297 static int __xts_crypt(struct skcipher_request *req,
 298                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
 299                                   int rounds, int blocks, u8 iv[]))
 300 {
 301         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 302         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 303         struct skcipher_walk walk;
 304         int err;
 305
 306         err = skcipher_walk_virt(&walk, req, false);
 307
 308         kernel_neon_begin();
 309         neon_aes_ecb_encrypt(walk.iv, walk.iv, ctx->twkey, ctx->key.rounds, 1);
 310         kernel_neon_end();
 311
 312         while (walk.nbytes >= AES_BLOCK_SIZE) {
 313                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 314
 315                 if (walk.nbytes < walk.total)
 316                         blocks = round_down(blocks,
 317                                             walk.stride / AES_BLOCK_SIZE);
 318
 319                 kernel_neon_begin();
 320                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
 321                    ctx->key.rounds, blocks, walk.iv);
 322                 kernel_neon_end();
 323                 err = skcipher_walk_done(&walk,
 324                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 325         }
 326         return err;
 327 }
 328
 329 static int xts_encrypt(struct skcipher_request *req)
 330 {
 331         return __xts_crypt(req, aesbs_xts_encrypt);
 332 }
 333
 334 static int xts_decrypt(struct skcipher_request *req)
 335 {
 336         return __xts_crypt(req, aesbs_xts_decrypt);
 337 }
 338
 339 static struct skcipher_alg aes_algs[] = { {
 340         .base.cra_name          = "__ecb(aes)",
 341         .base.cra_driver_name   = "__ecb-aes-neonbs",
 342         .base.cra_priority      = 250,
 343         .base.cra_blocksize     = AES_BLOCK_SIZE,
 344         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 345         .base.cra_module        = THIS_MODULE,
 346         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 347
 348         .min_keysize            = AES_MIN_KEY_SIZE,
 349         .max_keysize            = AES_MAX_KEY_SIZE,
 350         .walksize               = 8 * AES_BLOCK_SIZE,
 351         .setkey                 = aesbs_setkey,
 352         .encrypt                = ecb_encrypt,
 353         .decrypt                = ecb_decrypt,
 354 }, {
 355         .base.cra_name          = "__cbc(aes)",
 356         .base.cra_driver_name   = "__cbc-aes-neonbs",
 357         .base.cra_priority      = 250,
 358         .base.cra_blocksize     = AES_BLOCK_SIZE,
 359         .base.cra_ctxsize       = sizeof(struct aesbs_cbc_ctx),
 360         .base.cra_module        = THIS_MODULE,
 361         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 362
 363         .min_keysize            = AES_MIN_KEY_SIZE,
 364         .max_keysize            = AES_MAX_KEY_SIZE,
 365         .walksize               = 8 * AES_BLOCK_SIZE,
 366         .ivsize                 = AES_BLOCK_SIZE,
 367         .setkey                 = aesbs_cbc_setkey,
 368         .encrypt                = cbc_encrypt,
 369         .decrypt                = cbc_decrypt,
 370 }, {
 371         .base.cra_name          = "__ctr(aes)",
 372         .base.cra_driver_name   = "__ctr-aes-neonbs",
 373         .base.cra_priority      = 250,
 374         .base.cra_blocksize     = 1,
 375         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 376         .base.cra_module        = THIS_MODULE,
 377         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 378
 379         .min_keysize            = AES_MIN_KEY_SIZE,
 380         .max_keysize            = AES_MAX_KEY_SIZE,
 381         .chunksize              = AES_BLOCK_SIZE,
 382         .walksize               = 8 * AES_BLOCK_SIZE,
 383         .ivsize                 = AES_BLOCK_SIZE,
 384         .setkey                 = aesbs_setkey,
 385         .encrypt                = ctr_encrypt,
 386         .decrypt                = ctr_encrypt,
 387 }, {
 388         .base.cra_name          = "ctr(aes)",
 389         .base.cra_driver_name   = "ctr-aes-neonbs",
 390         .base.cra_priority      = 250 - 1,
 391         .base.cra_blocksize     = 1,
 392         .base.cra_ctxsize       = sizeof(struct aesbs_ctr_ctx),
 393         .base.cra_module        = THIS_MODULE,
 394
 395         .min_keysize            = AES_MIN_KEY_SIZE,
 396         .max_keysize            = AES_MAX_KEY_SIZE,
 397         .chunksize              = AES_BLOCK_SIZE,
 398         .walksize               = 8 * AES_BLOCK_SIZE,
 399         .ivsize                 = AES_BLOCK_SIZE,
 400         .setkey                 = aesbs_ctr_setkey_sync,
 401         .encrypt                = ctr_encrypt_sync,
 402         .decrypt                = ctr_encrypt_sync,
 403 }, {
 404         .base.cra_name          = "__xts(aes)",
 405         .base.cra_driver_name   = "__xts-aes-neonbs",
 406         .base.cra_priority      = 250,
 407         .base.cra_blocksize     = AES_BLOCK_SIZE,
 408         .base.cra_ctxsize       = sizeof(struct aesbs_xts_ctx),
 409         .base.cra_module        = THIS_MODULE,
 410         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 411
 412         .min_keysize            = 2 * AES_MIN_KEY_SIZE,
 413         .max_keysize            = 2 * AES_MAX_KEY_SIZE,
 414         .walksize               = 8 * AES_BLOCK_SIZE,
 415         .ivsize                 = AES_BLOCK_SIZE,
 416         .setkey                 = aesbs_xts_setkey,
 417         .encrypt                = xts_encrypt,
 418         .decrypt                = xts_decrypt,
 419 } };
 420
 421 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
 422
 423 static void aes_exit(void)
 424 {
 425         int i;
 426
 427         for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
 428                 if (aes_simd_algs[i])
 429                         simd_skcipher_free(aes_simd_algs[i]);
 430
 431         crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 432 }
 433
 434 static int __init aes_init(void)
 435 {
 436         struct simd_skcipher_alg *simd;
 437         const char *basename;
 438         const char *algname;
 439         const char *drvname;
 440         int err;
 441         int i;
 442
 443         if (!(elf_hwcap & HWCAP_ASIMD))
 444                 return -ENODEV;
 445
 446         err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 447         if (err)
 448                 return err;
 449
 450         for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
 451                 if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
 452                         continue;
 453
 454                 algname = aes_algs[i].base.cra_name + 2;
 455                 drvname = aes_algs[i].base.cra_driver_name + 2;
 456                 basename = aes_algs[i].base.cra_driver_name;
 457                 simd = simd_skcipher_create_compat(algname, drvname, basename);
 458                 err = PTR_ERR(simd);
 459                 if (IS_ERR(simd))
 460                         goto unregister_simds;
 461
 462                 aes_simd_algs[i] = simd;
 463         }
 464         return 0;
 465
 466 unregister_simds:
 467         aes_exit();
 468         return err;
 469 }
 470
 471 module_init(aes_init);
 472 module_exit(aes_exit);