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

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