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 asmlinkage void __aes_arm_encrypt(const u32 rk[], int rounds, const u8 in[],
  46                                   u8 out[]);
  47
  48 struct aesbs_ctx {
  49         int     rounds;
  50         u8      rk[13 * (8 * AES_BLOCK_SIZE) + 32] __aligned(AES_BLOCK_SIZE);
  51 };
  52
  53 struct aesbs_cbc_ctx {
  54         struct aesbs_ctx        key;
  55         u32                     enc[AES_MAX_KEYLENGTH_U32];
  56 };
  57
  58 struct aesbs_xts_ctx {
  59         struct aesbs_ctx        key;
  60         u32                     twkey[AES_MAX_KEYLENGTH_U32];
  61 };
  62
  63 static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
  64                         unsigned int key_len)
  65 {
  66         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
  67         struct crypto_aes_ctx rk;
  68         int err;
  69
  70         err = crypto_aes_expand_key(&rk, in_key, key_len);
  71         if (err)
  72                 return err;
  73
  74         ctx->rounds = 6 + key_len / 4;
  75
  76         kernel_neon_begin();
  77         aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
  78         kernel_neon_end();
  79
  80         return 0;
  81 }
  82
  83 static int __ecb_crypt(struct skcipher_request *req,
  84                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
  85                                   int rounds, int blocks))
  86 {
  87         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  88         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
  89         struct skcipher_walk walk;
  90         int err;
  91
  92         err = skcipher_walk_virt(&walk, req, true);
  93
  94         kernel_neon_begin();
  95         while (walk.nbytes >= AES_BLOCK_SIZE) {
  96                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
  97
  98                 if (walk.nbytes < walk.total)
  99                         blocks = round_down(blocks,
 100                                             walk.stride / AES_BLOCK_SIZE);
 101
 102                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
 103                    ctx->rounds, blocks);
 104                 err = skcipher_walk_done(&walk,
 105                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 106         }
 107         kernel_neon_end();
 108
 109         return err;
 110 }
 111
 112 static int ecb_encrypt(struct skcipher_request *req)
 113 {
 114         return __ecb_crypt(req, aesbs_ecb_encrypt);
 115 }
 116
 117 static int ecb_decrypt(struct skcipher_request *req)
 118 {
 119         return __ecb_crypt(req, aesbs_ecb_decrypt);
 120 }
 121
 122 static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 123                             unsigned int key_len)
 124 {
 125         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 126         struct crypto_aes_ctx rk;
 127         int err;
 128
 129         err = crypto_aes_expand_key(&rk, in_key, key_len);
 130         if (err)
 131                 return err;
 132
 133         ctx->key.rounds = 6 + key_len / 4;
 134
 135         memcpy(ctx->enc, rk.key_enc, sizeof(ctx->enc));
 136
 137         kernel_neon_begin();
 138         aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
 139         kernel_neon_end();
 140
 141         return 0;
 142 }
 143
 144 static void cbc_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst)
 145 {
 146         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 147
 148         __aes_arm_encrypt(ctx->enc, ctx->key.rounds, src, dst);
 149 }
 150
 151 static int cbc_encrypt(struct skcipher_request *req)
 152 {
 153         return crypto_cbc_encrypt_walk(req, cbc_encrypt_one);
 154 }
 155
 156 static int cbc_decrypt(struct skcipher_request *req)
 157 {
 158         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 159         struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
 160         struct skcipher_walk walk;
 161         int err;
 162
 163         err = skcipher_walk_virt(&walk, req, true);
 164
 165         kernel_neon_begin();
 166         while (walk.nbytes >= AES_BLOCK_SIZE) {
 167                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 168
 169                 if (walk.nbytes < walk.total)
 170                         blocks = round_down(blocks,
 171                                             walk.stride / AES_BLOCK_SIZE);
 172
 173                 aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
 174                                   ctx->key.rk, ctx->key.rounds, blocks,
 175                                   walk.iv);
 176                 err = skcipher_walk_done(&walk,
 177                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 178         }
 179         kernel_neon_end();
 180
 181         return err;
 182 }
 183
 184 static int ctr_encrypt(struct skcipher_request *req)
 185 {
 186         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 187         struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
 188         struct skcipher_walk walk;
 189         u8 buf[AES_BLOCK_SIZE];
 190         int err;
 191
 192         err = skcipher_walk_virt(&walk, req, true);
 193
 194         kernel_neon_begin();
 195         while (walk.nbytes > 0) {
 196                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 197                 u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
 198
 199                 if (walk.nbytes < walk.total) {
 200                         blocks = round_down(blocks,
 201                                             walk.stride / AES_BLOCK_SIZE);
 202                         final = NULL;
 203                 }
 204
 205                 aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
 206                                   ctx->rk, ctx->rounds, blocks, walk.iv, final);
 207
 208                 if (final) {
 209                         u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 210                         u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
 211
 212                         if (dst != src)
 213                                 memcpy(dst, src, walk.total % AES_BLOCK_SIZE);
 214                         crypto_xor(dst, final, walk.total % AES_BLOCK_SIZE);
 215
 216                         err = skcipher_walk_done(&walk, 0);
 217                         break;
 218                 }
 219                 err = skcipher_walk_done(&walk,
 220                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 221         }
 222         kernel_neon_end();
 223
 224         return err;
 225 }
 226
 227 static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
 228                             unsigned int key_len)
 229 {
 230         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 231         struct crypto_aes_ctx rk;
 232         int err;
 233
 234         err = xts_verify_key(tfm, in_key, key_len);
 235         if (err)
 236                 return err;
 237
 238         key_len /= 2;
 239         err = crypto_aes_expand_key(&rk, in_key + key_len, key_len);
 240         if (err)
 241                 return err;
 242
 243         memcpy(ctx->twkey, rk.key_enc, sizeof(ctx->twkey));
 244
 245         return aesbs_setkey(tfm, in_key, key_len);
 246 }
 247
 248 static int __xts_crypt(struct skcipher_request *req,
 249                        void (*fn)(u8 out[], u8 const in[], u8 const rk[],
 250                                   int rounds, int blocks, u8 iv[]))
 251 {
 252         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 253         struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
 254         struct skcipher_walk walk;
 255         int err;
 256
 257         err = skcipher_walk_virt(&walk, req, true);
 258
 259         __aes_arm_encrypt(ctx->twkey, ctx->key.rounds, walk.iv, walk.iv);
 260
 261         kernel_neon_begin();
 262         while (walk.nbytes >= AES_BLOCK_SIZE) {
 263                 unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
 264
 265                 if (walk.nbytes < walk.total)
 266                         blocks = round_down(blocks,
 267                                             walk.stride / AES_BLOCK_SIZE);
 268
 269                 fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
 270                    ctx->key.rounds, blocks, walk.iv);
 271                 err = skcipher_walk_done(&walk,
 272                                          walk.nbytes - blocks * AES_BLOCK_SIZE);
 273         }
 274         kernel_neon_end();
 275
 276         return err;
 277 }
 278
 279 static int xts_encrypt(struct skcipher_request *req)
 280 {
 281         return __xts_crypt(req, aesbs_xts_encrypt);
 282 }
 283
 284 static int xts_decrypt(struct skcipher_request *req)
 285 {
 286         return __xts_crypt(req, aesbs_xts_decrypt);
 287 }
 288
 289 static struct skcipher_alg aes_algs[] = { {
 290         .base.cra_name          = "__ecb(aes)",
 291         .base.cra_driver_name   = "__ecb-aes-neonbs",
 292         .base.cra_priority      = 250,
 293         .base.cra_blocksize     = AES_BLOCK_SIZE,
 294         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 295         .base.cra_module        = THIS_MODULE,
 296         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 297
 298         .min_keysize            = AES_MIN_KEY_SIZE,
 299         .max_keysize            = AES_MAX_KEY_SIZE,
 300         .walksize               = 8 * AES_BLOCK_SIZE,
 301         .setkey                 = aesbs_setkey,
 302         .encrypt                = ecb_encrypt,
 303         .decrypt                = ecb_decrypt,
 304 }, {
 305         .base.cra_name          = "__cbc(aes)",
 306         .base.cra_driver_name   = "__cbc-aes-neonbs",
 307         .base.cra_priority      = 250,
 308         .base.cra_blocksize     = AES_BLOCK_SIZE,
 309         .base.cra_ctxsize       = sizeof(struct aesbs_cbc_ctx),
 310         .base.cra_module        = THIS_MODULE,
 311         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 312
 313         .min_keysize            = AES_MIN_KEY_SIZE,
 314         .max_keysize            = AES_MAX_KEY_SIZE,
 315         .walksize               = 8 * AES_BLOCK_SIZE,
 316         .ivsize                 = AES_BLOCK_SIZE,
 317         .setkey                 = aesbs_cbc_setkey,
 318         .encrypt                = cbc_encrypt,
 319         .decrypt                = cbc_decrypt,
 320 }, {
 321         .base.cra_name          = "__ctr(aes)",
 322         .base.cra_driver_name   = "__ctr-aes-neonbs",
 323         .base.cra_priority      = 250,
 324         .base.cra_blocksize     = 1,
 325         .base.cra_ctxsize       = sizeof(struct aesbs_ctx),
 326         .base.cra_module        = THIS_MODULE,
 327         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 328
 329         .min_keysize            = AES_MIN_KEY_SIZE,
 330         .max_keysize            = AES_MAX_KEY_SIZE,
 331         .chunksize              = AES_BLOCK_SIZE,
 332         .walksize               = 8 * AES_BLOCK_SIZE,
 333         .ivsize                 = AES_BLOCK_SIZE,
 334         .setkey                 = aesbs_setkey,
 335         .encrypt                = ctr_encrypt,
 336         .decrypt                = ctr_encrypt,
 337 }, {
 338         .base.cra_name          = "__xts(aes)",
 339         .base.cra_driver_name   = "__xts-aes-neonbs",
 340         .base.cra_priority      = 250,
 341         .base.cra_blocksize     = AES_BLOCK_SIZE,
 342         .base.cra_ctxsize       = sizeof(struct aesbs_xts_ctx),
 343         .base.cra_module        = THIS_MODULE,
 344         .base.cra_flags         = CRYPTO_ALG_INTERNAL,
 345
 346         .min_keysize            = 2 * AES_MIN_KEY_SIZE,
 347         .max_keysize            = 2 * AES_MAX_KEY_SIZE,
 348         .walksize               = 8 * AES_BLOCK_SIZE,
 349         .ivsize                 = AES_BLOCK_SIZE,
 350         .setkey                 = aesbs_xts_setkey,
 351         .encrypt                = xts_encrypt,
 352         .decrypt                = xts_decrypt,
 353 } };
 354
 355 static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
 356
 357 static void aes_exit(void)
 358 {
 359         int i;
 360
 361         for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
 362                 if (aes_simd_algs[i])
 363                         simd_skcipher_free(aes_simd_algs[i]);
 364
 365         crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 366 }
 367
 368 static int __init aes_init(void)
 369 {
 370         struct simd_skcipher_alg *simd;
 371         const char *basename;
 372         const char *algname;
 373         const char *drvname;
 374         int err;
 375         int i;
 376
 377         if (!(elf_hwcap & HWCAP_NEON))
 378                 return -ENODEV;
 379
 380         err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
 381         if (err)
 382                 return err;
 383
 384         for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
 385                 if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
 386                         continue;
 387
 388                 algname = aes_algs[i].base.cra_name + 2;
 389                 drvname = aes_algs[i].base.cra_driver_name + 2;
 390                 basename = aes_algs[i].base.cra_driver_name;
 391                 simd = simd_skcipher_create_compat(algname, drvname, basename);
 392                 err = PTR_ERR(simd);
 393                 if (IS_ERR(simd))
 394                         goto unregister_simds;
 395
 396                 aes_simd_algs[i] = simd;
 397         }
 398         return 0;
 399
 400 unregister_simds:
 401         aes_exit();
 402         return err;
 403 }
 404
 405 module_init(aes_init);
 406 module_exit(aes_exit);