arch/arm/crypto/ghash-ce-glue.c

   1 /*
   2  * Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
   3  *
   4  * Copyright (C) 2015 Linaro Ltd. <ard.biesheuvel@linaro.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published
   8  * by the Free Software Foundation.
   9  */
  10
  11 #include <asm/hwcap.h>
  12 #include <asm/neon.h>
  13 #include <asm/simd.h>
  14 #include <asm/unaligned.h>
  15 #include <crypto/cryptd.h>
  16 #include <crypto/internal/hash.h>
  17 #include <crypto/gf128mul.h>
  18 #include <linux/cpufeature.h>
  19 #include <linux/crypto.h>
  20 #include <linux/module.h>
  21
  22 MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
  23 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  24 MODULE_LICENSE("GPL v2");
  25 MODULE_ALIAS_CRYPTO("ghash");
  26
  27 #define GHASH_BLOCK_SIZE        16
  28 #define GHASH_DIGEST_SIZE       16
  29
  30 struct ghash_key {
  31         u64     a;
  32         u64     b;
  33 };
  34
  35 struct ghash_desc_ctx {
  36         u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
  37         u8 buf[GHASH_BLOCK_SIZE];
  38         u32 count;
  39 };
  40
  41 struct ghash_async_ctx {
  42         struct cryptd_ahash *cryptd_tfm;
  43 };
  44
  45 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
  46                                        struct ghash_key const *k,
  47                                        const char *head);
  48
  49 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
  50                                       struct ghash_key const *k,
  51                                       const char *head);
  52
  53 static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
  54                                   struct ghash_key const *k,
  55                                   const char *head);
  56
  57 static int ghash_init(struct shash_desc *desc)
  58 {
  59         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  60
  61         *ctx = (struct ghash_desc_ctx){};
  62         return 0;
  63 }
  64
  65 static int ghash_update(struct shash_desc *desc, const u8 *src,
  66                         unsigned int len)
  67 {
  68         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  69         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
  70
  71         ctx->count += len;
  72
  73         if ((partial + len) >= GHASH_BLOCK_SIZE) {
  74                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
  75                 int blocks;
  76
  77                 if (partial) {
  78                         int p = GHASH_BLOCK_SIZE - partial;
  79
  80                         memcpy(ctx->buf + partial, src, p);
  81                         src += p;
  82                         len -= p;
  83                 }
  84
  85                 blocks = len / GHASH_BLOCK_SIZE;
  86                 len %= GHASH_BLOCK_SIZE;
  87
  88                 kernel_neon_begin();
  89                 pmull_ghash_update(blocks, ctx->digest, src, key,
  90                                    partial ? ctx->buf : NULL);
  91                 kernel_neon_end();
  92                 src += blocks * GHASH_BLOCK_SIZE;
  93                 partial = 0;
  94         }
  95         if (len)
  96                 memcpy(ctx->buf + partial, src, len);
  97         return 0;
  98 }
  99
 100 static int ghash_final(struct shash_desc *desc, u8 *dst)
 101 {
 102         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
 103         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
 104
 105         if (partial) {
 106                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
 107
 108                 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
 109                 kernel_neon_begin();
 110                 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
 111                 kernel_neon_end();
 112         }
 113         put_unaligned_be64(ctx->digest[1], dst);
 114         put_unaligned_be64(ctx->digest[0], dst + 8);
 115
 116         *ctx = (struct ghash_desc_ctx){};
 117         return 0;
 118 }
 119
 120 static int ghash_setkey(struct crypto_shash *tfm,
 121                         const u8 *inkey, unsigned int keylen)
 122 {
 123         struct ghash_key *key = crypto_shash_ctx(tfm);
 124         u64 a, b;
 125
 126         if (keylen != GHASH_BLOCK_SIZE) {
 127                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 128                 return -EINVAL;
 129         }
 130
 131         /* perform multiplication by 'x' in GF(2^128) */
 132         b = get_unaligned_be64(inkey);
 133         a = get_unaligned_be64(inkey + 8);
 134
 135         key->a = (a << 1) | (b >> 63);
 136         key->b = (b << 1) | (a >> 63);
 137
 138         if (b >> 63)
 139                 key->b ^= 0xc200000000000000UL;
 140
 141         return 0;
 142 }
 143
 144 static struct shash_alg ghash_alg = {
 145         .digestsize             = GHASH_DIGEST_SIZE,
 146         .init                   = ghash_init,
 147         .update                 = ghash_update,
 148         .final                  = ghash_final,
 149         .setkey                 = ghash_setkey,
 150         .descsize               = sizeof(struct ghash_desc_ctx),
 151         .base                   = {
 152                 .cra_name       = "__ghash",
 153                 .cra_driver_name = "__driver-ghash-ce",
 154                 .cra_priority   = 0,
 155                 .cra_flags      = CRYPTO_ALG_INTERNAL,
 156                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 157                 .cra_ctxsize    = sizeof(struct ghash_key),
 158                 .cra_module     = THIS_MODULE,
 159         },
 160 };
 161
 162 static int ghash_async_init(struct ahash_request *req)
 163 {
 164         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 165         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 166         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 167         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 168         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 169         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 170
 171         desc->tfm = child;
 172         desc->flags = req->base.flags;
 173         return crypto_shash_init(desc);
 174 }
 175
 176 static int ghash_async_update(struct ahash_request *req)
 177 {
 178         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 179         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 180         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 181         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 182
 183         if (!may_use_simd() ||
 184             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 185                 memcpy(cryptd_req, req, sizeof(*req));
 186                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 187                 return crypto_ahash_update(cryptd_req);
 188         } else {
 189                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 190                 return shash_ahash_update(req, desc);
 191         }
 192 }
 193
 194 static int ghash_async_final(struct ahash_request *req)
 195 {
 196         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 197         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 198         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 199         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 200
 201         if (!may_use_simd() ||
 202             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 203                 memcpy(cryptd_req, req, sizeof(*req));
 204                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 205                 return crypto_ahash_final(cryptd_req);
 206         } else {
 207                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 208                 return crypto_shash_final(desc, req->result);
 209         }
 210 }
 211
 212 static int ghash_async_digest(struct ahash_request *req)
 213 {
 214         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 215         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 216         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 217         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 218
 219         if (!may_use_simd() ||
 220             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 221                 memcpy(cryptd_req, req, sizeof(*req));
 222                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 223                 return crypto_ahash_digest(cryptd_req);
 224         } else {
 225                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 226                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 227
 228                 desc->tfm = child;
 229                 desc->flags = req->base.flags;
 230                 return shash_ahash_digest(req, desc);
 231         }
 232 }
 233
 234 static int ghash_async_import(struct ahash_request *req, const void *in)
 235 {
 236         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 237         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 238         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 239         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 240
 241         desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
 242         desc->flags = req->base.flags;
 243
 244         return crypto_shash_import(desc, in);
 245 }
 246
 247 static int ghash_async_export(struct ahash_request *req, void *out)
 248 {
 249         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 250         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 251
 252         return crypto_shash_export(desc, out);
 253 }
 254
 255 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 256                               unsigned int keylen)
 257 {
 258         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 259         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 260         int err;
 261
 262         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 263         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 264                                & CRYPTO_TFM_REQ_MASK);
 265         err = crypto_ahash_setkey(child, key, keylen);
 266         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
 267                                & CRYPTO_TFM_RES_MASK);
 268
 269         return err;
 270 }
 271
 272 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 273 {
 274         struct cryptd_ahash *cryptd_tfm;
 275         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 276
 277         cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
 278                                         CRYPTO_ALG_INTERNAL,
 279                                         CRYPTO_ALG_INTERNAL);
 280         if (IS_ERR(cryptd_tfm))
 281                 return PTR_ERR(cryptd_tfm);
 282         ctx->cryptd_tfm = cryptd_tfm;
 283         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 284                                  sizeof(struct ahash_request) +
 285                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 286
 287         return 0;
 288 }
 289
 290 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 291 {
 292         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 293
 294         cryptd_free_ahash(ctx->cryptd_tfm);
 295 }
 296
 297 static struct ahash_alg ghash_async_alg = {
 298         .init                   = ghash_async_init,
 299         .update                 = ghash_async_update,
 300         .final                  = ghash_async_final,
 301         .setkey                 = ghash_async_setkey,
 302         .digest                 = ghash_async_digest,
 303         .import                 = ghash_async_import,
 304         .export                 = ghash_async_export,
 305         .halg.digestsize        = GHASH_DIGEST_SIZE,
 306         .halg.statesize         = sizeof(struct ghash_desc_ctx),
 307         .halg.base              = {
 308                 .cra_name       = "ghash",
 309                 .cra_driver_name = "ghash-ce",
 310                 .cra_priority   = 300,
 311                 .cra_flags      = CRYPTO_ALG_ASYNC,
 312                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 313                 .cra_ctxsize    = sizeof(struct ghash_async_ctx),
 314                 .cra_module     = THIS_MODULE,
 315                 .cra_init       = ghash_async_init_tfm,
 316                 .cra_exit       = ghash_async_exit_tfm,
 317         },
 318 };
 319
 320 static int __init ghash_ce_mod_init(void)
 321 {
 322         int err;
 323
 324         if (!(elf_hwcap & HWCAP_NEON))
 325                 return -ENODEV;
 326
 327         if (elf_hwcap2 & HWCAP2_PMULL)
 328                 pmull_ghash_update = pmull_ghash_update_p64;
 329         else
 330                 pmull_ghash_update = pmull_ghash_update_p8;
 331
 332         err = crypto_register_shash(&ghash_alg);
 333         if (err)
 334                 return err;
 335         err = crypto_register_ahash(&ghash_async_alg);
 336         if (err)
 337                 goto err_shash;
 338
 339         return 0;
 340
 341 err_shash:
 342         crypto_unregister_shash(&ghash_alg);
 343         return err;
 344 }
 345
 346 static void __exit ghash_ce_mod_exit(void)
 347 {
 348         crypto_unregister_ahash(&ghash_async_alg);
 349         crypto_unregister_shash(&ghash_alg);
 350 }
 351
 352 module_init(ghash_ce_mod_init);
 353 module_exit(ghash_ce_mod_exit);