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, int first);
  50 asmlinkage void neon_aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
  51                                      int rounds, int blocks, u8 iv[],
  52                                      int first);
  53
  54 struct aesbs_ctx {
  55         u8      rk[13 * (8 * AES_BLOCK_SIZE) + 32];
  56         int     rounds;
  57 } __aligned(AES_BLOCK_SIZE);
  58
  59 struct aesbs_cbc_ctx {
  60         struct aesbs_ctx        key;
  61         u32                     enc[AES_MAX_KEYLENGTH_U32];
  62 };
  63
  64 struct aesbs_ctr_ctx {
  65         struct aesbs_ctx        key;            /* must be first member */
  66         struct crypto_aes_ctx   fallback;
  67 };
  68
  69 struct aesbs_xts_ctx {
  70         struct aesbs_ctx        key;
  71         u32                     twkey[AES_MAX_KEYLENGTH_U32];
  72 };
  73
  74 static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
  75                         unsigned int key_len)
  76 {
  77         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
  78         struct crypto_aes_ctx rk;
  79         int err;
  80
  81         err = crypto_aes_expand_key(&rk, in_key, key_len);
  82         if (err)
  83                 return err;
  84
  85         ctx->rounds = 6 + key_len / 4;
  86
  87         kernel_neon_begin();
  88         aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
  89         kernel_neon_end();
  90
  91         return 0;
  92 }
  93
  94 static int __ecb_crypt(struct skcipher_request *req,
  95                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
  96                                   int rounds, int blocks))
  97 {
  98         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  99         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 100         struct skcipher_walk walk;
 101         int err;
 102
 103         err = skcipher_walk_virt(&walk, req, true);
 104
 105         kernel_neon_begin();
 106         while (walk.nbytes >= AES_BLOCK_SIZE) {
 107                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 108
 109                 if (walk.nbytes < walk.total)
 110                         blocks = round_down(blocks,
 111                                             walk.stride / AES_BLOCK_SIZE);
 112
 113                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
 114                    ctx->rounds, blocks);
 115                 err = skcipher_walk_done(&walk,
 116                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 117         }
 118         kernel_neon_end();
 119
 120         return err;
 121 }
 122
 123 static int ecb_encrypt(struct skcipher_request *req)
 124 {
 125         return __ecb_crypt(req, aesbs_ecb_encrypt);
 126 }
 127
 128 static int ecb_decrypt(struct skcipher_request *req)
 129 {
 130         return __ecb_crypt(req, aesbs_ecb_decrypt);
 131 }
 132
 133 static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 134                             unsigned int key_len)
 135 {
 136         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 137         struct crypto_aes_ctx rk;
 138         int err;
 139
 140         err = crypto_aes_expand_key(&rk, in_key, key_len);
 141         if (err)
 142                 return err;
 143
 144         ctx->key.rounds = 6 + key_len / 4;
 145
 146         memcpy(ctx->enc, rk.key_enc, sizeof(ctx->enc));
 147
 148         kernel_neon_begin();
 149         aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
 150         kernel_neon_end();
 151
 152         return 0;
 153 }
 154
 155 static int cbc_encrypt(struct skcipher_request *req)
 156 {
 157         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 158         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 159         struct skcipher_walk walk;
 160         int err, first = 1;
 161
 162         err = skcipher_walk_virt(&walk, req, true);
 163
 164         kernel_neon_begin();
 165         while (walk.nbytes >= AES_BLOCK_SIZE) {
 166                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 167
 168                 /* fall back to the non-bitsliced NEON implementation */
 169                 neon_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 170                                      ctx->enc, ctx->key.rounds, blocks, walk.iv,
 171                                      first);
 172                 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
 173                 first = 0;
 174         }
 175         kernel_neon_end();
 176         return err;
 177 }
 178
 179 static int cbc_decrypt(struct skcipher_request *req)
 180 {
 181         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 182         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 183         struct skcipher_walk walk;
 184         int err;
 185
 186         err = skcipher_walk_virt(&walk, req, true);
 187
 188         kernel_neon_begin();
 189         while (walk.nbytes >= AES_BLOCK_SIZE) {
 190                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 191
 192                 if (walk.nbytes < walk.total)
 193                         blocks = round_down(blocks,
 194                                             walk.stride / AES_BLOCK_SIZE);
 195
 196                 aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 197                                   ctx->key.rk, ctx->key.rounds, blocks,
 198                                   walk.iv);
 199                 err = skcipher_walk_done(&walk,
 200                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 201         }
 202         kernel_neon_end();
 203
 204         return err;
 205 }
 206
 207 static int aesbs_ctr_setkey_sync(struct crypto_skcipher *tfm, const u8 *in_key,
 208                                  unsigned int key_len)
 209 {
 210         struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
 211         int err;
 212
 213         err = crypto_aes_expand_key(&ctx->fallback, in_key, key_len);
 214         if (err)
 215                 return err;
 216
 217         ctx->key.rounds = 6 + key_len / 4;
 218
 219         kernel_neon_begin();
 220         aesbs_convert_key(ctx->key.rk, ctx->fallback.key_enc, ctx->key.rounds);
 221         kernel_neon_end();
 222
 223         return 0;
 224 }
 225
 226 static int ctr_encrypt(struct skcipher_request *req)
 227 {
 228         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 229         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 230         struct skcipher_walk walk;
 231         u8 buf[AES_BLOCK_SIZE];
 232         int err;
 233
 234         err = skcipher_walk_virt(&walk, req, true);
 235
 236         kernel_neon_begin();
 237         while (walk.nbytes > 0) {
 238                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 239                 u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
 240
 241                 if (walk.nbytes < walk.total) {
 242                         blocks = round_down(blocks,
 243                                             walk.stride / AES_BLOCK_SIZE);
 244                         final = NULL;
 245                 }
 246
 247                 aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 248                                   ctx->rk, ctx->rounds, blocks, walk.iv, final);
 249
 250                 if (final) {
 251                         u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 252                         u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
 253
 254                         crypto_xor_cpy(dst, src, final,
 255                                        walk.total % AES_BLOCK_SIZE);
 256
 257                         err = skcipher_walk_done(&walk, 0);
 258                         break;
 259                 }
 260                 err = skcipher_walk_done(&walk,
 261                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 262         }
 263         kernel_neon_end();
 264
 265         return err;
 266 }
 267
 268 static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 269                             unsigned int key_len)
 270 {
 271         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 272         struct crypto_aes_ctx rk;
 273         int err;
 274
 275         err = xts_verify_key(tfm, in_key, key_len);
 276         if (err)
 277                 return err;
 278
 279         key_len /= 2;
 280         err = crypto_aes_expand_key(&rk, in_key + key_len, key_len);
 281         if (err)
 282                 return err;
 283
 284         memcpy(ctx->twkey, rk.key_enc, sizeof(ctx->twkey));
 285
 286         return aesbs_setkey(tfm, in_key, key_len);
 287 }
 288
 289 static int ctr_encrypt_sync(struct skcipher_request *req)
 290 {
 291         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 292         struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
 293
 294         if (!may_use_simd())
 295                 return aes_ctr_encrypt_fallback(&ctx->fallback, req);
 296
 297         return ctr_encrypt(req);
 298 }
 299
 300 static int __xts_crypt(struct skcipher_request *req,
 301                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
 302                                   int rounds, int blocks, u8 iv[]))
 303 {
 304         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 305         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 306         struct skcipher_walk walk;
 307         int err;
 308
 309         err = skcipher_walk_virt(&walk, req, true);
 310
 311         kernel_neon_begin();
 312
 313         neon_aes_ecb_encrypt(walk.iv, walk.iv, ctx->twkey,
 314                              ctx->key.rounds, 1, 1);
 315
 316         while (walk.nbytes >= AES_BLOCK_SIZE) {
 317                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 318
 319                 if (walk.nbytes < walk.total)
 320                         blocks = round_down(blocks,
 321                                             walk.stride / AES_BLOCK_SIZE);
 322
 323                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
 324                    ctx->key.rounds, blocks, walk.iv);
 325                 err = skcipher_walk_done(&walk,
 326                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 327         }
 328         kernel_neon_end();
 329
 330         return err;
 331 }
 332
 333 static int xts_encrypt(struct skcipher_request *req)
 334 {
 335         return __xts_crypt(req, aesbs_xts_encrypt);
 336 }
 337
 338 static int xts_decrypt(struct skcipher_request *req)
 339 {
 340         return __xts_crypt(req, aesbs_xts_decrypt);
 341 }
 342
 343 static struct skcipher_alg aes_algs[] = { {
 344         .base.cra_name          = "__ecb(aes)",
 345         .base.cra_driver_name   = "__ecb-aes-neonbs",
 346         .base.cra_priority      = 250,
 347         .base.cra_blocksize     = AES_BLOCK_SIZE,
 348         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 349         .base.cra_module        = THIS_MODULE,
 350         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 351
 352         .min_keysize            = AES_MIN_KEY_SIZE,
 353         .max_keysize            = AES_MAX_KEY_SIZE,
 354         .walksize               = 8 * AES_BLOCK_SIZE,
 355         .setkey                 = aesbs_setkey,
 356         .encrypt                = ecb_encrypt,
 357         .decrypt                = ecb_decrypt,
 358 }, {
 359         .base.cra_name          = "__cbc(aes)",
 360         .base.cra_driver_name   = "__cbc-aes-neonbs",
 361         .base.cra_priority      = 250,
 362         .base.cra_blocksize     = AES_BLOCK_SIZE,
 363         .base.cra_ctxsize       = sizeof(struct aesbs_cbc_ctx),
 364         .base.cra_module        = THIS_MODULE,
 365         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 366
 367         .min_keysize            = AES_MIN_KEY_SIZE,
 368         .max_keysize            = AES_MAX_KEY_SIZE,
 369         .walksize               = 8 * AES_BLOCK_SIZE,
 370         .ivsize                 = AES_BLOCK_SIZE,
 371         .setkey                 = aesbs_cbc_setkey,
 372         .encrypt                = cbc_encrypt,
 373         .decrypt                = cbc_decrypt,
 374 }, {
 375         .base.cra_name          = "__ctr(aes)",
 376         .base.cra_driver_name   = "__ctr-aes-neonbs",
 377         .base.cra_priority      = 250,
 378         .base.cra_blocksize     = 1,
 379         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 380         .base.cra_module        = THIS_MODULE,
 381         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 382
 383         .min_keysize            = AES_MIN_KEY_SIZE,
 384         .max_keysize            = AES_MAX_KEY_SIZE,
 385         .chunksize              = AES_BLOCK_SIZE,
 386         .walksize               = 8 * AES_BLOCK_SIZE,
 387         .ivsize                 = AES_BLOCK_SIZE,
 388         .setkey                 = aesbs_setkey,
 389         .encrypt                = ctr_encrypt,
 390         .decrypt                = ctr_encrypt,
 391 }, {
 392         .base.cra_name          = "ctr(aes)",
 393         .base.cra_driver_name   = "ctr-aes-neonbs",
 394         .base.cra_priority      = 250 - 1,
 395         .base.cra_blocksize     = 1,
 396         .base.cra_ctxsize       = sizeof(struct aesbs_ctr_ctx),
 397         .base.cra_module        = THIS_MODULE,
 398
 399         .min_keysize            = AES_MIN_KEY_SIZE,
 400         .max_keysize            = AES_MAX_KEY_SIZE,
 401         .chunksize              = AES_BLOCK_SIZE,
 402         .walksize               = 8 * AES_BLOCK_SIZE,
 403         .ivsize                 = AES_BLOCK_SIZE,
 404         .setkey                 = aesbs_ctr_setkey_sync,
 405         .encrypt                = ctr_encrypt_sync,
 406         .decrypt                = ctr_encrypt_sync,
 407 }, {
 408         .base.cra_name          = "__xts(aes)",
 409         .base.cra_driver_name   = "__xts-aes-neonbs",
 410         .base.cra_priority      = 250,
 411         .base.cra_blocksize     = AES_BLOCK_SIZE,
 412         .base.cra_ctxsize       = sizeof(struct aesbs_xts_ctx),
 413         .base.cra_module        = THIS_MODULE,
 414         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 415
 416         .min_keysize            = 2 * AES_MIN_KEY_SIZE,
 417         .max_keysize            = 2 * AES_MAX_KEY_SIZE,
 418         .walksize               = 8 * AES_BLOCK_SIZE,
 419         .ivsize                 = AES_BLOCK_SIZE,
 420         .setkey                 = aesbs_xts_setkey,
 421         .encrypt                = xts_encrypt,
 422         .decrypt                = xts_decrypt,
 423 } };
 424
 425 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
 426
 427 static void aes_exit(void)
 428 {
 429         int i;
 430
 431         for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
 432                 if (aes_simd_algs[i])
 433                         simd_skcipher_free(aes_simd_algs[i]);
 434
 435         crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 436 }
 437
 438 static int __init aes_init(void)
 439 {
 440         struct simd_skcipher_alg *simd;
 441         const char *basename;
 442         const char *algname;
 443         const char *drvname;
 444         int err;
 445         int i;
 446
 447         if (!(elf_hwcap & HWCAP_ASIMD))
 448                 return -ENODEV;
 449
 450         err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 451         if (err)
 452                 return err;
 453
 454         for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
 455                 if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
 456                         continue;
 457
 458                 algname = aes_algs[i].base.cra_name + 2;
 459                 drvname = aes_algs[i].base.cra_driver_name + 2;
 460                 basename = aes_algs[i].base.cra_driver_name;
 461                 simd = simd_skcipher_create_compat(algname, drvname, basename);
 462                 err = PTR_ERR(simd);
 463                 if (IS_ERR(simd))
 464                         goto unregister_simds;
 465
 466                 aes_simd_algs[i] = simd;
 467         }
 468         return 0;
 469
 470 unregister_simds:
 471         aes_exit();
 472         return err;
 473 }
 474
 475 module_init(aes_init);
 476 module_exit(aes_exit);