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