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