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/b128ops.h>
  13 #include <crypto/cryptd.h>
  14 #include <crypto/internal/hash.h>
  15 #include <crypto/internal/simd.h>
  16 #include <crypto/gf128mul.h>
  17 #include <linux/cpufeature.h>
  18 #include <linux/crypto.h>
  19 #include <linux/module.h>
  20
  21 MODULE_DESCRIPTION("GHASH hash function using ARMv8 Crypto Extensions");
  22 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  23 MODULE_LICENSE("GPL v2");
  24 MODULE_ALIAS_CRYPTO("ghash");
  25
  26 #define GHASH_BLOCK_SIZE        16
  27 #define GHASH_DIGEST_SIZE       16
  28
  29 struct ghash_key {
  30         u64     h[2];
  31         u64     h2[2];
  32         u64     h3[2];
  33         u64     h4[2];
  34
  35         be128   k;
  36 };
  37
  38 struct ghash_desc_ctx {
  39         u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
  40         u8 buf[GHASH_BLOCK_SIZE];
  41         u32 count;
  42 };
  43
  44 struct ghash_async_ctx {
  45         struct cryptd_ahash *cryptd_tfm;
  46 };
  47
  48 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
  49                                        struct ghash_key const *k,
  50                                        const char *head);
  51
  52 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
  53                                       struct ghash_key const *k,
  54                                       const char *head);
  55
  56 static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
  57                                   struct ghash_key const *k,
  58                                   const char *head);
  59
  60 static int ghash_init(struct shash_desc *desc)
  61 {
  62         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  63
  64         *ctx = (struct ghash_desc_ctx){};
  65         return 0;
  66 }
  67
  68 static void ghash_do_update(int blocks, u64 dg[], const char *src,
  69                             struct ghash_key *key, const char *head)
  70 {
  71         if (likely(crypto_simd_usable())) {
  72                 kernel_neon_begin();
  73                 pmull_ghash_update(blocks, dg, src, key, head);
  74                 kernel_neon_end();
  75         } else {
  76                 be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) };
  77
  78                 do {
  79                         const u8 *in = src;
  80
  81                         if (head) {
  82                                 in = head;
  83                                 blocks++;
  84                                 head = NULL;
  85                         } else {
  86                                 src += GHASH_BLOCK_SIZE;
  87                         }
  88
  89                         crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE);
  90                         gf128mul_lle(&dst, &key->k);
  91                 } while (--blocks);
  92
  93                 dg[0] = be64_to_cpu(dst.b);
  94                 dg[1] = be64_to_cpu(dst.a);
  95         }
  96 }
  97
  98 static int ghash_update(struct shash_desc *desc, const u8 *src,
  99                         unsigned int len)
 100 {
 101         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
 102         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
 103
 104         ctx->count += len;
 105
 106         if ((partial + len) >= GHASH_BLOCK_SIZE) {
 107                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
 108                 int blocks;
 109
 110                 if (partial) {
 111                         int p = GHASH_BLOCK_SIZE - partial;
 112
 113                         memcpy(ctx->buf + partial, src, p);
 114                         src += p;
 115                         len -= p;
 116                 }
 117
 118                 blocks = len / GHASH_BLOCK_SIZE;
 119                 len %= GHASH_BLOCK_SIZE;
 120
 121                 ghash_do_update(blocks, ctx->digest, src, key,
 122                                 partial ? ctx->buf : NULL);
 123                 src += blocks * GHASH_BLOCK_SIZE;
 124                 partial = 0;
 125         }
 126         if (len)
 127                 memcpy(ctx->buf + partial, src, len);
 128         return 0;
 129 }
 130
 131 static int ghash_final(struct shash_desc *desc, u8 *dst)
 132 {
 133         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
 134         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
 135
 136         if (partial) {
 137                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
 138
 139                 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
 140                 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL);
 141         }
 142         put_unaligned_be64(ctx->digest[1], dst);
 143         put_unaligned_be64(ctx->digest[0], dst + 8);
 144
 145         *ctx = (struct ghash_desc_ctx){};
 146         return 0;
 147 }
 148
 149 static void ghash_reflect(u64 h[], const be128 *k)
 150 {
 151         u64 carry = be64_to_cpu(k->a) >> 63;
 152
 153         h[0] = (be64_to_cpu(k->b) << 1) | carry;
 154         h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
 155
 156         if (carry)
 157                 h[1] ^= 0xc200000000000000UL;
 158 }
 159
 160 static int ghash_setkey(struct crypto_shash *tfm,
 161                         const u8 *inkey, unsigned int keylen)
 162 {
 163         struct ghash_key *key = crypto_shash_ctx(tfm);
 164         be128 h;
 165
 166         if (keylen != GHASH_BLOCK_SIZE) {
 167                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 168                 return -EINVAL;
 169         }
 170
 171         /* needed for the fallback */
 172         memcpy(&key->k, inkey, GHASH_BLOCK_SIZE);
 173         ghash_reflect(key->h, &key->k);
 174
 175         h = key->k;
 176         gf128mul_lle(&h, &key->k);
 177         ghash_reflect(key->h2, &h);
 178
 179         gf128mul_lle(&h, &key->k);
 180         ghash_reflect(key->h3, &h);
 181
 182         gf128mul_lle(&h, &key->k);
 183         ghash_reflect(key->h4, &h);
 184
 185         return 0;
 186 }
 187
 188 static struct shash_alg ghash_alg = {
 189         .digestsize             = GHASH_DIGEST_SIZE,
 190         .init                   = ghash_init,
 191         .update                 = ghash_update,
 192         .final                  = ghash_final,
 193         .setkey                 = ghash_setkey,
 194         .descsize               = sizeof(struct ghash_desc_ctx),
 195
 196         .base.cra_name          = "ghash",
 197         .base.cra_driver_name   = "ghash-ce-sync",
 198         .base.cra_priority      = 300 - 1,
 199         .base.cra_blocksize     = GHASH_BLOCK_SIZE,
 200         .base.cra_ctxsize       = sizeof(struct ghash_key),
 201         .base.cra_module        = THIS_MODULE,
 202 };
 203
 204 static int ghash_async_init(struct ahash_request *req)
 205 {
 206         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 207         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 208         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 209         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 210         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 211         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 212
 213         desc->tfm = child;
 214         return crypto_shash_init(desc);
 215 }
 216
 217 static int ghash_async_update(struct ahash_request *req)
 218 {
 219         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 220         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 221         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 222         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 223
 224         if (!crypto_simd_usable() ||
 225             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 226                 memcpy(cryptd_req, req, sizeof(*req));
 227                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 228                 return crypto_ahash_update(cryptd_req);
 229         } else {
 230                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 231                 return shash_ahash_update(req, desc);
 232         }
 233 }
 234
 235 static int ghash_async_final(struct ahash_request *req)
 236 {
 237         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 238         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 239         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 240         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 241
 242         if (!crypto_simd_usable() ||
 243             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 244                 memcpy(cryptd_req, req, sizeof(*req));
 245                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 246                 return crypto_ahash_final(cryptd_req);
 247         } else {
 248                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 249                 return crypto_shash_final(desc, req->result);
 250         }
 251 }
 252
 253 static int ghash_async_digest(struct ahash_request *req)
 254 {
 255         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 256         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 257         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 258         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 259
 260         if (!crypto_simd_usable() ||
 261             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 262                 memcpy(cryptd_req, req, sizeof(*req));
 263                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 264                 return crypto_ahash_digest(cryptd_req);
 265         } else {
 266                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 267                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 268
 269                 desc->tfm = child;
 270                 return shash_ahash_digest(req, desc);
 271         }
 272 }
 273
 274 static int ghash_async_import(struct ahash_request *req, const void *in)
 275 {
 276         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 277         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 278         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 279         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 280
 281         desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
 282
 283         return crypto_shash_import(desc, in);
 284 }
 285
 286 static int ghash_async_export(struct ahash_request *req, void *out)
 287 {
 288         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 289         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 290
 291         return crypto_shash_export(desc, out);
 292 }
 293
 294 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 295                               unsigned int keylen)
 296 {
 297         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 298         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 299         int err;
 300
 301         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 302         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 303                                & CRYPTO_TFM_REQ_MASK);
 304         err = crypto_ahash_setkey(child, key, keylen);
 305         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
 306                                & CRYPTO_TFM_RES_MASK);
 307
 308         return err;
 309 }
 310
 311 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 312 {
 313         struct cryptd_ahash *cryptd_tfm;
 314         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 315
 316         cryptd_tfm = cryptd_alloc_ahash("ghash-ce-sync", 0, 0);
 317         if (IS_ERR(cryptd_tfm))
 318                 return PTR_ERR(cryptd_tfm);
 319         ctx->cryptd_tfm = cryptd_tfm;
 320         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 321                                  sizeof(struct ahash_request) +
 322                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 323
 324         return 0;
 325 }
 326
 327 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 328 {
 329         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 330
 331         cryptd_free_ahash(ctx->cryptd_tfm);
 332 }
 333
 334 static struct ahash_alg ghash_async_alg = {
 335         .init                   = ghash_async_init,
 336         .update                 = ghash_async_update,
 337         .final                  = ghash_async_final,
 338         .setkey                 = ghash_async_setkey,
 339         .digest                 = ghash_async_digest,
 340         .import                 = ghash_async_import,
 341         .export                 = ghash_async_export,
 342         .halg.digestsize        = GHASH_DIGEST_SIZE,
 343         .halg.statesize         = sizeof(struct ghash_desc_ctx),
 344         .halg.base              = {
 345                 .cra_name       = "ghash",
 346                 .cra_driver_name = "ghash-ce",
 347                 .cra_priority   = 300,
 348                 .cra_flags      = CRYPTO_ALG_ASYNC,
 349                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 350                 .cra_ctxsize    = sizeof(struct ghash_async_ctx),
 351                 .cra_module     = THIS_MODULE,
 352                 .cra_init       = ghash_async_init_tfm,
 353                 .cra_exit       = ghash_async_exit_tfm,
 354         },
 355 };
 356
 357 static int __init ghash_ce_mod_init(void)
 358 {
 359         int err;
 360
 361         if (!(elf_hwcap & HWCAP_NEON))
 362                 return -ENODEV;
 363
 364         if (elf_hwcap2 & HWCAP2_PMULL)
 365                 pmull_ghash_update = pmull_ghash_update_p64;
 366         else
 367                 pmull_ghash_update = pmull_ghash_update_p8;
 368
 369         err = crypto_register_shash(&ghash_alg);
 370         if (err)
 371                 return err;
 372         err = crypto_register_ahash(&ghash_async_alg);
 373         if (err)
 374                 goto err_shash;
 375
 376         return 0;
 377
 378 err_shash:
 379         crypto_unregister_shash(&ghash_alg);
 380         return err;
 381 }
 382
 383 static void __exit ghash_ce_mod_exit(void)
 384 {
 385         crypto_unregister_ahash(&ghash_async_alg);
 386         crypto_unregister_shash(&ghash_alg);
 387 }
 388
 389 module_init(ghash_ce_mod_init);
 390 module_exit(ghash_ce_mod_exit);