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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
   4  *
   5  * Copyright (C) 2015 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
   6  */
   7
   8 #include <asm/hwcap.h>
   9 #include <asm/neon.h>
  10 #include <asm/simd.h>
  11 #include <asm/unaligned.h>
  12 #include <crypto/cryptd.h>
  13 #include <crypto/internal/hash.h>
  14 #include <crypto/internal/simd.h>
  15 #include <crypto/gf128mul.h>
  16 #include <linux/cpufeature.h>
  17 #include <linux/crypto.h>
  18 #include <linux/module.h>
  19
  20 MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
  21 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  22 MODULE_LICENSE("GPL v2");
  23 MODULE_ALIAS_CRYPTO("ghash");
  24
  25 #define GHASH_BLOCK_SIZE        16
  26 #define GHASH_DIGEST_SIZE       16
  27
  28 struct ghash_key {
  29         u64     h[2];
  30         u64     h2[2];
  31         u64     h3[2];
  32         u64     h4[2];
  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 void ghash_reflect(u64 h[], const be128 *k)
 121 {
 122         u64 carry = be64_to_cpu(k->a) >> 63;
 123
 124         h[0] = (be64_to_cpu(k->b) << 1) | carry;
 125         h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
 126
 127         if (carry)
 128                 h[1] ^= 0xc200000000000000UL;
 129 }
 130
 131 static int ghash_setkey(struct crypto_shash *tfm,
 132                         const u8 *inkey, unsigned int keylen)
 133 {
 134         struct ghash_key *key = crypto_shash_ctx(tfm);
 135         be128 h, k;
 136
 137         if (keylen != GHASH_BLOCK_SIZE) {
 138                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 139                 return -EINVAL;
 140         }
 141
 142         memcpy(&k, inkey, GHASH_BLOCK_SIZE);
 143         ghash_reflect(key->h, &k);
 144
 145         h = k;
 146         gf128mul_lle(&h, &k);
 147         ghash_reflect(key->h2, &h);
 148
 149         gf128mul_lle(&h, &k);
 150         ghash_reflect(key->h3, &h);
 151
 152         gf128mul_lle(&h, &k);
 153         ghash_reflect(key->h4, &h);
 154
 155         return 0;
 156 }
 157
 158 static struct shash_alg ghash_alg = {
 159         .digestsize             = GHASH_DIGEST_SIZE,
 160         .init                   = ghash_init,
 161         .update                 = ghash_update,
 162         .final                  = ghash_final,
 163         .setkey                 = ghash_setkey,
 164         .descsize               = sizeof(struct ghash_desc_ctx),
 165         .base                   = {
 166                 .cra_name       = "__ghash",
 167                 .cra_driver_name = "__driver-ghash-ce",
 168                 .cra_priority   = 0,
 169                 .cra_flags      = CRYPTO_ALG_INTERNAL,
 170                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 171                 .cra_ctxsize    = sizeof(struct ghash_key),
 172                 .cra_module     = THIS_MODULE,
 173         },
 174 };
 175
 176 static int ghash_async_init(struct ahash_request *req)
 177 {
 178         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 179         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 180         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 181         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 182         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 183         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 184
 185         desc->tfm = child;
 186         return crypto_shash_init(desc);
 187 }
 188
 189 static int ghash_async_update(struct ahash_request *req)
 190 {
 191         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 192         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 193         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 194         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 195
 196         if (!crypto_simd_usable() ||
 197             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 198                 memcpy(cryptd_req, req, sizeof(*req));
 199                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 200                 return crypto_ahash_update(cryptd_req);
 201         } else {
 202                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 203                 return shash_ahash_update(req, desc);
 204         }
 205 }
 206
 207 static int ghash_async_final(struct ahash_request *req)
 208 {
 209         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 210         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 211         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 212         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 213
 214         if (!crypto_simd_usable() ||
 215             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 216                 memcpy(cryptd_req, req, sizeof(*req));
 217                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 218                 return crypto_ahash_final(cryptd_req);
 219         } else {
 220                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 221                 return crypto_shash_final(desc, req->result);
 222         }
 223 }
 224
 225 static int ghash_async_digest(struct ahash_request *req)
 226 {
 227         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 228         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 229         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 230         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 231
 232         if (!crypto_simd_usable() ||
 233             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 234                 memcpy(cryptd_req, req, sizeof(*req));
 235                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 236                 return crypto_ahash_digest(cryptd_req);
 237         } else {
 238                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 239                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 240
 241                 desc->tfm = child;
 242                 return shash_ahash_digest(req, desc);
 243         }
 244 }
 245
 246 static int ghash_async_import(struct ahash_request *req, const void *in)
 247 {
 248         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 249         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 250         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 251         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 252
 253         desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
 254
 255         return crypto_shash_import(desc, in);
 256 }
 257
 258 static int ghash_async_export(struct ahash_request *req, void *out)
 259 {
 260         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 261         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 262
 263         return crypto_shash_export(desc, out);
 264 }
 265
 266 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 267                               unsigned int keylen)
 268 {
 269         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 270         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 271         int err;
 272
 273         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 274         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 275                                & CRYPTO_TFM_REQ_MASK);
 276         err = crypto_ahash_setkey(child, key, keylen);
 277         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
 278                                & CRYPTO_TFM_RES_MASK);
 279
 280         return err;
 281 }
 282
 283 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 284 {
 285         struct cryptd_ahash *cryptd_tfm;
 286         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 287
 288         cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
 289                                         CRYPTO_ALG_INTERNAL,
 290                                         CRYPTO_ALG_INTERNAL);
 291         if (IS_ERR(cryptd_tfm))
 292                 return PTR_ERR(cryptd_tfm);
 293         ctx->cryptd_tfm = cryptd_tfm;
 294         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 295                                  sizeof(struct ahash_request) +
 296                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 297
 298         return 0;
 299 }
 300
 301 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 302 {
 303         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 304
 305         cryptd_free_ahash(ctx->cryptd_tfm);
 306 }
 307
 308 static struct ahash_alg ghash_async_alg = {
 309         .init                   = ghash_async_init,
 310         .update                 = ghash_async_update,
 311         .final                  = ghash_async_final,
 312         .setkey                 = ghash_async_setkey,
 313         .digest                 = ghash_async_digest,
 314         .import                 = ghash_async_import,
 315         .export                 = ghash_async_export,
 316         .halg.digestsize        = GHASH_DIGEST_SIZE,
 317         .halg.statesize         = sizeof(struct ghash_desc_ctx),
 318         .halg.base              = {
 319                 .cra_name       = "ghash",
 320                 .cra_driver_name = "ghash-ce",
 321                 .cra_priority   = 300,
 322                 .cra_flags      = CRYPTO_ALG_ASYNC,
 323                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 324                 .cra_ctxsize    = sizeof(struct ghash_async_ctx),
 325                 .cra_module     = THIS_MODULE,
 326                 .cra_init       = ghash_async_init_tfm,
 327                 .cra_exit       = ghash_async_exit_tfm,
 328         },
 329 };
 330
 331 static int __init ghash_ce_mod_init(void)
 332 {
 333         int err;
 334
 335         if (!(elf_hwcap & HWCAP_NEON))
 336                 return -ENODEV;
 337
 338         if (elf_hwcap2 & HWCAP2_PMULL)
 339                 pmull_ghash_update = pmull_ghash_update_p64;
 340         else
 341                 pmull_ghash_update = pmull_ghash_update_p8;
 342
 343         err = crypto_register_shash(&ghash_alg);
 344         if (err)
 345                 return err;
 346         err = crypto_register_ahash(&ghash_async_alg);
 347         if (err)
 348                 goto err_shash;
 349
 350         return 0;
 351
 352 err_shash:
 353         crypto_unregister_shash(&ghash_alg);
 354         return err;
 355 }
 356
 357 static void __exit ghash_ce_mod_exit(void)
 358 {
 359         crypto_unregister_ahash(&ghash_async_alg);
 360         crypto_unregister_shash(&ghash_alg);
 361 }
 362
 363 module_init(ghash_ce_mod_init);
 364 module_exit(ghash_ce_mod_exit);