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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Bit sliced AES using NEON instructions
   4  *
   5  * Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
   6  */
   7
   8 #include <asm/neon.h>
   9 #include <asm/simd.h>
  10 #include <crypto/aes.h>
  11 #include <crypto/ctr.h>
  12 #include <crypto/internal/simd.h>
  13 #include <crypto/internal/skcipher.h>
  14 #include <crypto/scatterwalk.h>
  15 #include <crypto/xts.h>
  16 #include <linux/module.h>
  17
  18 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  19 MODULE_LICENSE("GPL v2");
  20
  21 MODULE_ALIAS_CRYPTO("ecb(aes)");
  22 MODULE_ALIAS_CRYPTO("cbc(aes)");
  23 MODULE_ALIAS_CRYPTO("ctr(aes)");
  24 MODULE_ALIAS_CRYPTO("xts(aes)");
  25
  26 asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds);
  27
  28 asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
  29                                   int rounds, int blocks);
  30 asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
  31                                   int rounds, int blocks);
  32
  33 asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
  34                                   int rounds, int blocks, u8 iv[]);
  35
  36 asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
  37                                   int rounds, int blocks, u8 iv[], u8 final[]);
  38
  39 asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
  40                                   int rounds, int blocks, u8 iv[]);
  41 asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
  42                                   int rounds, int blocks, u8 iv[]);
  43
  44 /* borrowed from aes-neon-blk.ko */
  45 asmlinkage void neon_aes_ecb_encrypt(u8 out[], u8 const in[], u32 const rk[],
  46                                      int rounds, int blocks);
  47 asmlinkage void neon_aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
  48                                      int rounds, int blocks, u8 iv[]);
  49 asmlinkage void neon_aes_xts_encrypt(u8 out[], u8 const in[],
  50                                      u32 const rk1[], int rounds, int bytes,
  51                                      u32 const rk2[], u8 iv[], int first);
  52 asmlinkage void neon_aes_xts_decrypt(u8 out[], u8 const in[],
  53                                      u32 const rk1[], int rounds, int bytes,
  54                                      u32 const rk2[], u8 iv[], int first);
  55
  56 struct aesbs_ctx {
  57         u8      rk[13 * (8 * AES_BLOCK_SIZE) + 32];
  58         int     rounds;
  59 } __aligned(AES_BLOCK_SIZE);
  60
  61 struct aesbs_cbc_ctx {
  62         struct aesbs_ctx        key;
  63         u32                     enc[AES_MAX_KEYLENGTH_U32];
  64 };
  65
  66 struct aesbs_ctr_ctx {
  67         struct aesbs_ctx        key;            /* must be first member */
  68         struct crypto_aes_ctx   fallback;
  69 };
  70
  71 struct aesbs_xts_ctx {
  72         struct aesbs_ctx        key;
  73         u32                     twkey[AES_MAX_KEYLENGTH_U32];
  74         struct crypto_aes_ctx   cts;
  75 };
  76
  77 static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
  78                         unsigned int key_len)
  79 {
  80         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
  81         struct crypto_aes_ctx rk;
  82         int err;
  83
  84         err = aes_expandkey(&rk, in_key, key_len);
  85         if (err)
  86                 return err;
  87
  88         ctx->rounds = 6 + key_len / 4;
  89
  90         kernel_neon_begin();
  91         aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
  92         kernel_neon_end();
  93
  94         return 0;
  95 }
  96
  97 static int __ecb_crypt(struct skcipher_request *req,
  98                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
  99                                   int rounds, int blocks))
 100 {
 101         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 102         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 103         struct skcipher_walk walk;
 104         int err;
 105
 106         err = skcipher_walk_virt(&walk, req, false);
 107
 108         while (walk.nbytes >= AES_BLOCK_SIZE) {
 109                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 110
 111                 if (walk.nbytes < walk.total)
 112                         blocks = round_down(blocks,
 113                                             walk.stride / AES_BLOCK_SIZE);
 114
 115                 kernel_neon_begin();
 116                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
 117                    ctx->rounds, blocks);
 118                 kernel_neon_end();
 119                 err = skcipher_walk_done(&walk,
 120                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 121         }
 122
 123         return err;
 124 }
 125
 126 static int ecb_encrypt(struct skcipher_request *req)
 127 {
 128         return __ecb_crypt(req, aesbs_ecb_encrypt);
 129 }
 130
 131 static int ecb_decrypt(struct skcipher_request *req)
 132 {
 133         return __ecb_crypt(req, aesbs_ecb_decrypt);
 134 }
 135
 136 static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 137                             unsigned int key_len)
 138 {
 139         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 140         struct crypto_aes_ctx rk;
 141         int err;
 142
 143         err = aes_expandkey(&rk, in_key, key_len);
 144         if (err)
 145                 return err;
 146
 147         ctx->key.rounds = 6 + key_len / 4;
 148
 149         memcpy(ctx->enc, rk.key_enc, sizeof(ctx->enc));
 150
 151         kernel_neon_begin();
 152         aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
 153         kernel_neon_end();
 154
 155         return 0;
 156 }
 157
 158 static int cbc_encrypt(struct skcipher_request *req)
 159 {
 160         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 161         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 162         struct skcipher_walk walk;
 163         int err;
 164
 165         err = skcipher_walk_virt(&walk, req, false);
 166
 167         while (walk.nbytes >= AES_BLOCK_SIZE) {
 168                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 169
 170                 /* fall back to the non-bitsliced NEON implementation */
 171                 kernel_neon_begin();
 172                 neon_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 173                                      ctx->enc, ctx->key.rounds, blocks,
 174                                      walk.iv);
 175                 kernel_neon_end();
 176                 err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
 177         }
 178         return err;
 179 }
 180
 181 static int cbc_decrypt(struct skcipher_request *req)
 182 {
 183         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 184         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 185         struct skcipher_walk walk;
 186         int err;
 187
 188         err = skcipher_walk_virt(&walk, req, false);
 189
 190         while (walk.nbytes >= AES_BLOCK_SIZE) {
 191                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 192
 193                 if (walk.nbytes < walk.total)
 194                         blocks = round_down(blocks,
 195                                             walk.stride / AES_BLOCK_SIZE);
 196
 197                 kernel_neon_begin();
 198                 aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 199                                   ctx->key.rk, ctx->key.rounds, blocks,
 200                                   walk.iv);
 201                 kernel_neon_end();
 202                 err = skcipher_walk_done(&walk,
 203                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 204         }
 205
 206         return err;
 207 }
 208
 209 static int aesbs_ctr_setkey_sync(struct crypto_skcipher *tfm, const u8 *in_key,
 210                                  unsigned int key_len)
 211 {
 212         struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
 213         int err;
 214
 215         err = aes_expandkey(&ctx->fallback, in_key, key_len);
 216         if (err)
 217                 return err;
 218
 219         ctx->key.rounds = 6 + key_len / 4;
 220
 221         kernel_neon_begin();
 222         aesbs_convert_key(ctx->key.rk, ctx->fallback.key_enc, ctx->key.rounds);
 223         kernel_neon_end();
 224
 225         return 0;
 226 }
 227
 228 static int ctr_encrypt(struct skcipher_request *req)
 229 {
 230         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 231         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 232         struct skcipher_walk walk;
 233         u8 buf[AES_BLOCK_SIZE];
 234         int err;
 235
 236         err = skcipher_walk_virt(&walk, req, false);
 237
 238         while (walk.nbytes > 0) {
 239                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 240                 u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
 241
 242                 if (walk.nbytes < walk.total) {
 243                         blocks = round_down(blocks,
 244                                             walk.stride / AES_BLOCK_SIZE);
 245                         final = NULL;
 246                 }
 247
 248                 kernel_neon_begin();
 249                 aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 250                                   ctx->rk, ctx->rounds, blocks, walk.iv, final);
 251                 kernel_neon_end();
 252
 253                 if (final) {
 254                         u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 255                         u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
 256
 257                         crypto_xor_cpy(dst, src, final,
 258                                        walk.total % AES_BLOCK_SIZE);
 259
 260                         err = skcipher_walk_done(&walk, 0);
 261                         break;
 262                 }
 263                 err = skcipher_walk_done(&walk,
 264                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 265         }
 266         return err;
 267 }
 268
 269 static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 270                             unsigned int key_len)
 271 {
 272         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 273         struct crypto_aes_ctx rk;
 274         int err;
 275
 276         err = xts_verify_key(tfm, in_key, key_len);
 277         if (err)
 278                 return err;
 279
 280         key_len /= 2;
 281         err = aes_expandkey(&ctx->cts, in_key, key_len);
 282         if (err)
 283                 return err;
 284
 285         err = aes_expandkey(&rk, in_key + key_len, key_len);
 286         if (err)
 287                 return err;
 288
 289         memcpy(ctx->twkey, rk.key_enc, sizeof(ctx->twkey));
 290
 291         return aesbs_setkey(tfm, in_key, key_len);
 292 }
 293
 294 static void ctr_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst)
 295 {
 296         struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
 297         unsigned long flags;
 298
 299         /*
 300          * Temporarily disable interrupts to avoid races where
 301          * cachelines are evicted when the CPU is interrupted
 302          * to do something else.
 303          */
 304         local_irq_save(flags);
 305         aes_encrypt(&ctx->fallback, dst, src);
 306         local_irq_restore(flags);
 307 }
 308
 309 static int ctr_encrypt_sync(struct skcipher_request *req)
 310 {
 311         if (!crypto_simd_usable())
 312                 return crypto_ctr_encrypt_walk(req, ctr_encrypt_one);
 313
 314         return ctr_encrypt(req);
 315 }
 316
 317 static int __xts_crypt(struct skcipher_request *req, bool encrypt,
 318                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
 319                                   int rounds, int blocks, u8 iv[]))
 320 {
 321         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 322         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 323         int tail = req->cryptlen % (8 * AES_BLOCK_SIZE);
 324         struct scatterlist sg_src[2], sg_dst[2];
 325         struct skcipher_request subreq;
 326         struct scatterlist *src, *dst;
 327         struct skcipher_walk walk;
 328         int nbytes, err;
 329         int first = 1;
 330         u8 *out, *in;
 331
 332         if (req->cryptlen < AES_BLOCK_SIZE)
 333                 return -EINVAL;
 334
 335         /* ensure that the cts tail is covered by a single step */
 336         if (unlikely(tail > 0 && tail < AES_BLOCK_SIZE)) {
 337                 int xts_blocks = DIV_ROUND_UP(req->cryptlen,
 338                                               AES_BLOCK_SIZE) - 2;
 339
 340                 skcipher_request_set_tfm(&subreq, tfm);
 341                 skcipher_request_set_callback(&subreq,
 342                                               skcipher_request_flags(req),
 343                                               NULL, NULL);
 344                 skcipher_request_set_crypt(&subreq, req->src, req->dst,
 345                                            xts_blocks * AES_BLOCK_SIZE,
 346                                            req->iv);
 347                 req = &subreq;
 348         } else {
 349                 tail = 0;
 350         }
 351
 352         err = skcipher_walk_virt(&walk, req, false);
 353         if (err)
 354                 return err;
 355
 356         while (walk.nbytes >= AES_BLOCK_SIZE) {
 357                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 358
 359                 if (walk.nbytes < walk.total || walk.nbytes % AES_BLOCK_SIZE)
 360                         blocks = round_down(blocks,
 361                                             walk.stride / AES_BLOCK_SIZE);
 362
 363                 out = walk.dst.virt.addr;
 364                 in = walk.src.virt.addr;
 365                 nbytes = walk.nbytes;
 366
 367                 kernel_neon_begin();
 368                 if (likely(blocks > 6)) { /* plain NEON is faster otherwise */
 369                         if (first)
 370                                 neon_aes_ecb_encrypt(walk.iv, walk.iv,
 371                                                      ctx->twkey,
 372                                                      ctx->key.rounds, 1);
 373                         first = 0;
 374
 375                         fn(out, in, ctx->key.rk, ctx->key.rounds, blocks,
 376                            walk.iv);
 377
 378                         out += blocks * AES_BLOCK_SIZE;
 379                         in += blocks * AES_BLOCK_SIZE;
 380                         nbytes -= blocks * AES_BLOCK_SIZE;
 381                 }
 382
 383                 if (walk.nbytes == walk.total && nbytes > 0)
 384                         goto xts_tail;
 385
 386                 kernel_neon_end();
 387                 err = skcipher_walk_done(&walk, nbytes);
 388         }
 389
 390         if (err || likely(!tail))
 391                 return err;
 392
 393         /* handle ciphertext stealing */
 394         dst = src = scatterwalk_ffwd(sg_src, req->src, req->cryptlen);
 395         if (req->dst != req->src)
 396                 dst = scatterwalk_ffwd(sg_dst, req->dst, req->cryptlen);
 397
 398         skcipher_request_set_crypt(req, src, dst, AES_BLOCK_SIZE + tail,
 399                                    req->iv);
 400
 401         err = skcipher_walk_virt(&walk, req, false);
 402         if (err)
 403                 return err;
 404
 405         out = walk.dst.virt.addr;
 406         in = walk.src.virt.addr;
 407         nbytes = walk.nbytes;
 408
 409         kernel_neon_begin();
 410 xts_tail:
 411         if (encrypt)
 412                 neon_aes_xts_encrypt(out, in, ctx->cts.key_enc, ctx->key.rounds,
 413                                      nbytes, ctx->twkey, walk.iv, first ?: 2);
 414         else
 415                 neon_aes_xts_decrypt(out, in, ctx->cts.key_dec, ctx->key.rounds,
 416                                      nbytes, ctx->twkey, walk.iv, first ?: 2);
 417         kernel_neon_end();
 418
 419         return skcipher_walk_done(&walk, 0);
 420 }
 421
 422 static int xts_encrypt(struct skcipher_request *req)
 423 {
 424         return __xts_crypt(req, true, aesbs_xts_encrypt);
 425 }
 426
 427 static int xts_decrypt(struct skcipher_request *req)
 428 {
 429         return __xts_crypt(req, false, aesbs_xts_decrypt);
 430 }
 431
 432 static struct skcipher_alg aes_algs[] = { {
 433         .base.cra_name          = "__ecb(aes)",
 434         .base.cra_driver_name   = "__ecb-aes-neonbs",
 435         .base.cra_priority      = 250,
 436         .base.cra_blocksize     = AES_BLOCK_SIZE,
 437         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 438         .base.cra_module        = THIS_MODULE,
 439         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 440
 441         .min_keysize            = AES_MIN_KEY_SIZE,
 442         .max_keysize            = AES_MAX_KEY_SIZE,
 443         .walksize               = 8 * AES_BLOCK_SIZE,
 444         .setkey                 = aesbs_setkey,
 445         .encrypt                = ecb_encrypt,
 446         .decrypt                = ecb_decrypt,
 447 }, {
 448         .base.cra_name          = "__cbc(aes)",
 449         .base.cra_driver_name   = "__cbc-aes-neonbs",
 450         .base.cra_priority      = 250,
 451         .base.cra_blocksize     = AES_BLOCK_SIZE,
 452         .base.cra_ctxsize       = sizeof(struct aesbs_cbc_ctx),
 453         .base.cra_module        = THIS_MODULE,
 454         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 455
 456         .min_keysize            = AES_MIN_KEY_SIZE,
 457         .max_keysize            = AES_MAX_KEY_SIZE,
 458         .walksize               = 8 * AES_BLOCK_SIZE,
 459         .ivsize                 = AES_BLOCK_SIZE,
 460         .setkey                 = aesbs_cbc_setkey,
 461         .encrypt                = cbc_encrypt,
 462         .decrypt                = cbc_decrypt,
 463 }, {
 464         .base.cra_name          = "__ctr(aes)",
 465         .base.cra_driver_name   = "__ctr-aes-neonbs",
 466         .base.cra_priority      = 250,
 467         .base.cra_blocksize     = 1,
 468         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 469         .base.cra_module        = THIS_MODULE,
 470         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 471
 472         .min_keysize            = AES_MIN_KEY_SIZE,
 473         .max_keysize            = AES_MAX_KEY_SIZE,
 474         .chunksize              = AES_BLOCK_SIZE,
 475         .walksize               = 8 * AES_BLOCK_SIZE,
 476         .ivsize                 = AES_BLOCK_SIZE,
 477         .setkey                 = aesbs_setkey,
 478         .encrypt                = ctr_encrypt,
 479         .decrypt                = ctr_encrypt,
 480 }, {
 481         .base.cra_name          = "ctr(aes)",
 482         .base.cra_driver_name   = "ctr-aes-neonbs",
 483         .base.cra_priority      = 250 - 1,
 484         .base.cra_blocksize     = 1,
 485         .base.cra_ctxsize       = sizeof(struct aesbs_ctr_ctx),
 486         .base.cra_module        = THIS_MODULE,
 487
 488         .min_keysize            = AES_MIN_KEY_SIZE,
 489         .max_keysize            = AES_MAX_KEY_SIZE,
 490         .chunksize              = AES_BLOCK_SIZE,
 491         .walksize               = 8 * AES_BLOCK_SIZE,
 492         .ivsize                 = AES_BLOCK_SIZE,
 493         .setkey                 = aesbs_ctr_setkey_sync,
 494         .encrypt                = ctr_encrypt_sync,
 495         .decrypt                = ctr_encrypt_sync,
 496 }, {
 497         .base.cra_name          = "__xts(aes)",
 498         .base.cra_driver_name   = "__xts-aes-neonbs",
 499         .base.cra_priority      = 250,
 500         .base.cra_blocksize     = AES_BLOCK_SIZE,
 501         .base.cra_ctxsize       = sizeof(struct aesbs_xts_ctx),
 502         .base.cra_module        = THIS_MODULE,
 503         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 504
 505         .min_keysize            = 2 * AES_MIN_KEY_SIZE,
 506         .max_keysize            = 2 * AES_MAX_KEY_SIZE,
 507         .walksize               = 8 * AES_BLOCK_SIZE,
 508         .ivsize                 = AES_BLOCK_SIZE,
 509         .setkey                 = aesbs_xts_setkey,
 510         .encrypt                = xts_encrypt,
 511         .decrypt                = xts_decrypt,
 512 } };
 513
 514 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
 515
 516 static void aes_exit(void)
 517 {
 518         int i;
 519
 520         for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
 521                 if (aes_simd_algs[i])
 522                         simd_skcipher_free(aes_simd_algs[i]);
 523
 524         crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 525 }
 526
 527 static int __init aes_init(void)
 528 {
 529         struct simd_skcipher_alg *simd;
 530         const char *basename;
 531         const char *algname;
 532         const char *drvname;
 533         int err;
 534         int i;
 535
 536         if (!cpu_have_named_feature(ASIMD))
 537                 return -ENODEV;
 538
 539         err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 540         if (err)
 541                 return err;
 542
 543         for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
 544                 if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
 545                         continue;
 546
 547                 algname = aes_algs[i].base.cra_name + 2;
 548                 drvname = aes_algs[i].base.cra_driver_name + 2;
 549                 basename = aes_algs[i].base.cra_driver_name;
 550                 simd = simd_skcipher_create_compat(algname, drvname, basename);
 551                 err = PTR_ERR(simd);
 552                 if (IS_ERR(simd))
 553                         goto unregister_simds;
 554
 555                 aes_simd_algs[i] = simd;
 556         }
 557         return 0;
 558
 559 unregister_simds:
 560         aes_exit();
 561         return err;
 562 }
 563
 564 module_init(aes_init);
 565 module_exit(aes_exit);