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

   1 /*
   2  * Bit sliced AES using NEON instructions
   3  *
   4  * Copyright (C) 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 <crypto/aes.h>
  13 #include <crypto/cbc.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 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)");
  24 MODULE_ALIAS_CRYPTO("ctr(aes)");
  25 MODULE_ALIAS_CRYPTO("xts(aes)");
  26
  27 asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds);
  28
  29 asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
  30                                   int rounds, int blocks);
  31 asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
  32                                   int rounds, int blocks);
  33
  34 asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
  35                                   int rounds, int blocks, u8 iv[]);
  36
  37 asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
  38                                   int rounds, int blocks, u8 ctr[], u8 final[]);
  39
  40 asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
  41                                   int rounds, int blocks, u8 iv[]);
  42 asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
  43                                   int rounds, int blocks, u8 iv[]);
  44
  45 struct aesbs_ctx {
  46         int     rounds;
  47         u8      rk[13 * (8 * AES_BLOCK_SIZE) + 32] __aligned(AES_BLOCK_SIZE);
  48 };
  49
  50 struct aesbs_cbc_ctx {
  51         struct aesbs_ctx        key;
  52         struct crypto_cipher    *enc_tfm;
  53 };
  54
  55 struct aesbs_xts_ctx {
  56         struct aesbs_ctx        key;
  57         struct crypto_cipher    *tweak_tfm;
  58 };
  59
  60 static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
  61                         unsigned int key_len)
  62 {
  63         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
  64         struct crypto_aes_ctx rk;
  65         int err;
  66
  67         err = crypto_aes_expand_key(&rk, in_key, key_len);
  68         if (err)
  69                 return err;
  70
  71         ctx->rounds = 6 + key_len / 4;
  72
  73         kernel_neon_begin();
  74         aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
  75         kernel_neon_end();
  76
  77         return 0;
  78 }
  79
  80 static int __ecb_crypt(struct skcipher_request *req,
  81                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
  82                                   int rounds, int blocks))
  83 {
  84         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  85         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
  86         struct skcipher_walk walk;
  87         int err;
  88
  89         err = skcipher_walk_virt(&walk, req, true);
  90
  91         kernel_neon_begin();
  92         while (walk.nbytes >= AES_BLOCK_SIZE) {
  93                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
  94
  95                 if (walk.nbytes < walk.total)
  96                         blocks = round_down(blocks,
  97                                             walk.stride / AES_BLOCK_SIZE);
  98
  99                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
 100                    ctx->rounds, blocks);
 101                 err = skcipher_walk_done(&walk,
 102                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 103         }
 104         kernel_neon_end();
 105
 106         return err;
 107 }
 108
 109 static int ecb_encrypt(struct skcipher_request *req)
 110 {
 111         return __ecb_crypt(req, aesbs_ecb_encrypt);
 112 }
 113
 114 static int ecb_decrypt(struct skcipher_request *req)
 115 {
 116         return __ecb_crypt(req, aesbs_ecb_decrypt);
 117 }
 118
 119 static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 120                             unsigned int key_len)
 121 {
 122         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 123         struct crypto_aes_ctx rk;
 124         int err;
 125
 126         err = crypto_aes_expand_key(&rk, in_key, key_len);
 127         if (err)
 128                 return err;
 129
 130         ctx->key.rounds = 6 + key_len / 4;
 131
 132         kernel_neon_begin();
 133         aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
 134         kernel_neon_end();
 135
 136         return crypto_cipher_setkey(ctx->enc_tfm, in_key, key_len);
 137 }
 138
 139 static void cbc_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst)
 140 {
 141         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 142
 143         crypto_cipher_encrypt_one(ctx->enc_tfm, dst, src);
 144 }
 145
 146 static int cbc_encrypt(struct skcipher_request *req)
 147 {
 148         return crypto_cbc_encrypt_walk(req, cbc_encrypt_one);
 149 }
 150
 151 static int cbc_decrypt(struct skcipher_request *req)
 152 {
 153         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 154         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 155         struct skcipher_walk walk;
 156         int err;
 157
 158         err = skcipher_walk_virt(&walk, req, true);
 159
 160         kernel_neon_begin();
 161         while (walk.nbytes >= AES_BLOCK_SIZE) {
 162                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 163
 164                 if (walk.nbytes < walk.total)
 165                         blocks = round_down(blocks,
 166                                             walk.stride / AES_BLOCK_SIZE);
 167
 168                 aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 169                                   ctx->key.rk, ctx->key.rounds, blocks,
 170                                   walk.iv);
 171                 err = skcipher_walk_done(&walk,
 172                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 173         }
 174         kernel_neon_end();
 175
 176         return err;
 177 }
 178
 179 static int cbc_init(struct crypto_tfm *tfm)
 180 {
 181         struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
 182
 183         ctx->enc_tfm = crypto_alloc_cipher("aes", 0, 0);
 184
 185         return PTR_ERR_OR_ZERO(ctx->enc_tfm);
 186 }
 187
 188 static void cbc_exit(struct crypto_tfm *tfm)
 189 {
 190         struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
 191
 192         crypto_free_cipher(ctx->enc_tfm);
 193 }
 194
 195 static int ctr_encrypt(struct skcipher_request *req)
 196 {
 197         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 198         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 199         struct skcipher_walk walk;
 200         u8 buf[AES_BLOCK_SIZE];
 201         int err;
 202
 203         err = skcipher_walk_virt(&walk, req, true);
 204
 205         kernel_neon_begin();
 206         while (walk.nbytes > 0) {
 207                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 208                 u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
 209
 210                 if (walk.nbytes < walk.total) {
 211                         blocks = round_down(blocks,
 212                                             walk.stride / AES_BLOCK_SIZE);
 213                         final = NULL;
 214                 }
 215
 216                 aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 217                                   ctx->rk, ctx->rounds, blocks, walk.iv, final);
 218
 219                 if (final) {
 220                         u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 221                         u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
 222
 223                         crypto_xor_cpy(dst, src, final,
 224                                        walk.total % AES_BLOCK_SIZE);
 225
 226                         err = skcipher_walk_done(&walk, 0);
 227                         break;
 228                 }
 229                 err = skcipher_walk_done(&walk,
 230                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 231         }
 232         kernel_neon_end();
 233
 234         return err;
 235 }
 236
 237 static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 238                             unsigned int key_len)
 239 {
 240         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 241         int err;
 242
 243         err = xts_verify_key(tfm, in_key, key_len);
 244         if (err)
 245                 return err;
 246
 247         key_len /= 2;
 248         err = crypto_cipher_setkey(ctx->tweak_tfm, in_key + key_len, key_len);
 249         if (err)
 250                 return err;
 251
 252         return aesbs_setkey(tfm, in_key, key_len);
 253 }
 254
 255 static int xts_init(struct crypto_tfm *tfm)
 256 {
 257         struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
 258
 259         ctx->tweak_tfm = crypto_alloc_cipher("aes", 0, 0);
 260
 261         return PTR_ERR_OR_ZERO(ctx->tweak_tfm);
 262 }
 263
 264 static void xts_exit(struct crypto_tfm *tfm)
 265 {
 266         struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
 267
 268         crypto_free_cipher(ctx->tweak_tfm);
 269 }
 270
 271 static int __xts_crypt(struct skcipher_request *req,
 272                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
 273                                   int rounds, int blocks, u8 iv[]))
 274 {
 275         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 276         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 277         struct skcipher_walk walk;
 278         int err;
 279
 280         err = skcipher_walk_virt(&walk, req, true);
 281
 282         crypto_cipher_encrypt_one(ctx->tweak_tfm, walk.iv, walk.iv);
 283
 284         kernel_neon_begin();
 285         while (walk.nbytes >= AES_BLOCK_SIZE) {
 286                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 287
 288                 if (walk.nbytes < walk.total)
 289                         blocks = round_down(blocks,
 290                                             walk.stride / AES_BLOCK_SIZE);
 291
 292                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
 293                    ctx->key.rounds, blocks, walk.iv);
 294                 err = skcipher_walk_done(&walk,
 295                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 296         }
 297         kernel_neon_end();
 298
 299         return err;
 300 }
 301
 302 static int xts_encrypt(struct skcipher_request *req)
 303 {
 304         return __xts_crypt(req, aesbs_xts_encrypt);
 305 }
 306
 307 static int xts_decrypt(struct skcipher_request *req)
 308 {
 309         return __xts_crypt(req, aesbs_xts_decrypt);
 310 }
 311
 312 static struct skcipher_alg aes_algs[] = { {
 313         .base.cra_name          = "__ecb(aes)",
 314         .base.cra_driver_name   = "__ecb-aes-neonbs",
 315         .base.cra_priority      = 250,
 316         .base.cra_blocksize     = AES_BLOCK_SIZE,
 317         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 318         .base.cra_module        = THIS_MODULE,
 319         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 320
 321         .min_keysize            = AES_MIN_KEY_SIZE,
 322         .max_keysize            = AES_MAX_KEY_SIZE,
 323         .walksize               = 8 * AES_BLOCK_SIZE,
 324         .setkey                 = aesbs_setkey,
 325         .encrypt                = ecb_encrypt,
 326         .decrypt                = ecb_decrypt,
 327 }, {
 328         .base.cra_name          = "__cbc(aes)",
 329         .base.cra_driver_name   = "__cbc-aes-neonbs",
 330         .base.cra_priority      = 250,
 331         .base.cra_blocksize     = AES_BLOCK_SIZE,
 332         .base.cra_ctxsize       = sizeof(struct aesbs_cbc_ctx),
 333         .base.cra_module        = THIS_MODULE,
 334         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 335         .base.cra_init          = cbc_init,
 336         .base.cra_exit          = cbc_exit,
 337
 338         .min_keysize            = AES_MIN_KEY_SIZE,
 339         .max_keysize            = AES_MAX_KEY_SIZE,
 340         .walksize               = 8 * AES_BLOCK_SIZE,
 341         .ivsize                 = AES_BLOCK_SIZE,
 342         .setkey                 = aesbs_cbc_setkey,
 343         .encrypt                = cbc_encrypt,
 344         .decrypt                = cbc_decrypt,
 345 }, {
 346         .base.cra_name          = "__ctr(aes)",
 347         .base.cra_driver_name   = "__ctr-aes-neonbs",
 348         .base.cra_priority      = 250,
 349         .base.cra_blocksize     = 1,
 350         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 351         .base.cra_module        = THIS_MODULE,
 352         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 353
 354         .min_keysize            = AES_MIN_KEY_SIZE,
 355         .max_keysize            = AES_MAX_KEY_SIZE,
 356         .chunksize              = AES_BLOCK_SIZE,
 357         .walksize               = 8 * AES_BLOCK_SIZE,
 358         .ivsize                 = AES_BLOCK_SIZE,
 359         .setkey                 = aesbs_setkey,
 360         .encrypt                = ctr_encrypt,
 361         .decrypt                = ctr_encrypt,
 362 }, {
 363         .base.cra_name          = "__xts(aes)",
 364         .base.cra_driver_name   = "__xts-aes-neonbs",
 365         .base.cra_priority      = 250,
 366         .base.cra_blocksize     = AES_BLOCK_SIZE,
 367         .base.cra_ctxsize       = sizeof(struct aesbs_xts_ctx),
 368         .base.cra_module        = THIS_MODULE,
 369         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 370         .base.cra_init          = xts_init,
 371         .base.cra_exit          = xts_exit,
 372
 373         .min_keysize            = 2 * AES_MIN_KEY_SIZE,
 374         .max_keysize            = 2 * AES_MAX_KEY_SIZE,
 375         .walksize               = 8 * AES_BLOCK_SIZE,
 376         .ivsize                 = AES_BLOCK_SIZE,
 377         .setkey                 = aesbs_xts_setkey,
 378         .encrypt                = xts_encrypt,
 379         .decrypt                = xts_decrypt,
 380 } };
 381
 382 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
 383
 384 static void aes_exit(void)
 385 {
 386         int i;
 387
 388         for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
 389                 if (aes_simd_algs[i])
 390                         simd_skcipher_free(aes_simd_algs[i]);
 391
 392         crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 393 }
 394
 395 static int __init aes_init(void)
 396 {
 397         struct simd_skcipher_alg *simd;
 398         const char *basename;
 399         const char *algname;
 400         const char *drvname;
 401         int err;
 402         int i;
 403
 404         if (!(elf_hwcap & HWCAP_NEON))
 405                 return -ENODEV;
 406
 407         err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 408         if (err)
 409                 return err;
 410
 411         for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
 412                 if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
 413                         continue;
 414
 415                 algname = aes_algs[i].base.cra_name + 2;
 416                 drvname = aes_algs[i].base.cra_driver_name + 2;
 417                 basename = aes_algs[i].base.cra_driver_name;
 418                 simd = simd_skcipher_create_compat(algname, drvname, basename);
 419                 err = PTR_ERR(simd);
 420                 if (IS_ERR(simd))
 421                         goto unregister_simds;
 422
 423                 aes_simd_algs[i] = simd;
 424         }
 425         return 0;
 426
 427 unregister_simds:
 428         aes_exit();
 429         return err;
 430 }
 431
 432 late_initcall(aes_init);
 433 module_exit(aes_exit);