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

   1 /*
   2  * Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
   3  *
   4  * Copyright (C) 2015 - 2018 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     h[2];
  32         u64     h2[2];
  33         u64     h3[2];
  34         u64     h4[2];
  35 };
  36
  37 struct ghash_desc_ctx {
  38         u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
  39         u8 buf[GHASH_BLOCK_SIZE];
  40         u32 count;
  41 };
  42
  43 struct ghash_async_ctx {
  44         struct cryptd_ahash *cryptd_tfm;
  45 };
  46
  47 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
  48                                        struct ghash_key const *k,
  49                                        const char *head);
  50
  51 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
  52                                       struct ghash_key const *k,
  53                                       const char *head);
  54
  55 static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
  56                                   struct ghash_key const *k,
  57                                   const char *head);
  58
  59 static int ghash_init(struct shash_desc *desc)
  60 {
  61         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  62
  63         *ctx = (struct ghash_desc_ctx){};
  64         return 0;
  65 }
  66
  67 static int ghash_update(struct shash_desc *desc, const u8 *src,
  68                         unsigned int len)
  69 {
  70         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  71         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
  72
  73         ctx->count += len;
  74
  75         if ((partial + len) >= GHASH_BLOCK_SIZE) {
  76                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
  77                 int blocks;
  78
  79                 if (partial) {
  80                         int p = GHASH_BLOCK_SIZE - partial;
  81
  82                         memcpy(ctx->buf + partial, src, p);
  83                         src += p;
  84                         len -= p;
  85                 }
  86
  87                 blocks = len / GHASH_BLOCK_SIZE;
  88                 len %= GHASH_BLOCK_SIZE;
  89
  90                 kernel_neon_begin();
  91                 pmull_ghash_update(blocks, ctx->digest, src, key,
  92                                    partial ? ctx->buf : NULL);
  93                 kernel_neon_end();
  94                 src += blocks * GHASH_BLOCK_SIZE;
  95                 partial = 0;
  96         }
  97         if (len)
  98                 memcpy(ctx->buf + partial, src, len);
  99         return 0;
 100 }
 101
 102 static int ghash_final(struct shash_desc *desc, u8 *dst)
 103 {
 104         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
 105         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
 106
 107         if (partial) {
 108                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
 109
 110                 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
 111                 kernel_neon_begin();
 112                 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
 113                 kernel_neon_end();
 114         }
 115         put_unaligned_be64(ctx->digest[1], dst);
 116         put_unaligned_be64(ctx->digest[0], dst + 8);
 117
 118         *ctx = (struct ghash_desc_ctx){};
 119         return 0;
 120 }
 121
 122 static void ghash_reflect(u64 h[], const be128 *k)
 123 {
 124         u64 carry = be64_to_cpu(k->a) >> 63;
 125
 126         h[0] = (be64_to_cpu(k->b) << 1) | carry;
 127         h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
 128
 129         if (carry)
 130                 h[1] ^= 0xc200000000000000UL;
 131 }
 132
 133 static int ghash_setkey(struct crypto_shash *tfm,
 134                         const u8 *inkey, unsigned int keylen)
 135 {
 136         struct ghash_key *key = crypto_shash_ctx(tfm);
 137         be128 h, k;
 138
 139         if (keylen != GHASH_BLOCK_SIZE) {
 140                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 141                 return -EINVAL;
 142         }
 143
 144         memcpy(&k, inkey, GHASH_BLOCK_SIZE);
 145         ghash_reflect(key->h, &k);
 146
 147         h = k;
 148         gf128mul_lle(&h, &k);
 149         ghash_reflect(key->h2, &h);
 150
 151         gf128mul_lle(&h, &k);
 152         ghash_reflect(key->h3, &h);
 153
 154         gf128mul_lle(&h, &k);
 155         ghash_reflect(key->h4, &h);
 156
 157         return 0;
 158 }
 159
 160 static struct shash_alg ghash_alg = {
 161         .digestsize             = GHASH_DIGEST_SIZE,
 162         .init                   = ghash_init,
 163         .update                 = ghash_update,
 164         .final                  = ghash_final,
 165         .setkey                 = ghash_setkey,
 166         .descsize               = sizeof(struct ghash_desc_ctx),
 167         .base                   = {
 168                 .cra_name       = "__ghash",
 169                 .cra_driver_name = "__driver-ghash-ce",
 170                 .cra_priority   = 0,
 171                 .cra_flags      = CRYPTO_ALG_INTERNAL,
 172                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 173                 .cra_ctxsize    = sizeof(struct ghash_key),
 174                 .cra_module     = THIS_MODULE,
 175         },
 176 };
 177
 178 static int ghash_async_init(struct ahash_request *req)
 179 {
 180         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 181         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 182         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 183         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 184         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 185         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 186
 187         desc->tfm = child;
 188         desc->flags = req->base.flags;
 189         return crypto_shash_init(desc);
 190 }
 191
 192 static int ghash_async_update(struct ahash_request *req)
 193 {
 194         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 195         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 196         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 197         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 198
 199         if (!may_use_simd() ||
 200             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 201                 memcpy(cryptd_req, req, sizeof(*req));
 202                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 203                 return crypto_ahash_update(cryptd_req);
 204         } else {
 205                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 206                 return shash_ahash_update(req, desc);
 207         }
 208 }
 209
 210 static int ghash_async_final(struct ahash_request *req)
 211 {
 212         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 213         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 214         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 215         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 216
 217         if (!may_use_simd() ||
 218             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 219                 memcpy(cryptd_req, req, sizeof(*req));
 220                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 221                 return crypto_ahash_final(cryptd_req);
 222         } else {
 223                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 224                 return crypto_shash_final(desc, req->result);
 225         }
 226 }
 227
 228 static int ghash_async_digest(struct ahash_request *req)
 229 {
 230         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 231         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 232         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 233         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 234
 235         if (!may_use_simd() ||
 236             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 237                 memcpy(cryptd_req, req, sizeof(*req));
 238                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 239                 return crypto_ahash_digest(cryptd_req);
 240         } else {
 241                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 242                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 243
 244                 desc->tfm = child;
 245                 desc->flags = req->base.flags;
 246                 return shash_ahash_digest(req, desc);
 247         }
 248 }
 249
 250 static int ghash_async_import(struct ahash_request *req, const void *in)
 251 {
 252         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 253         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 254         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 255         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 256
 257         desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
 258         desc->flags = req->base.flags;
 259
 260         return crypto_shash_import(desc, in);
 261 }
 262
 263 static int ghash_async_export(struct ahash_request *req, void *out)
 264 {
 265         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 266         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 267
 268         return crypto_shash_export(desc, out);
 269 }
 270
 271 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 272                               unsigned int keylen)
 273 {
 274         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 275         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 276         int err;
 277
 278         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 279         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 280                                & CRYPTO_TFM_REQ_MASK);
 281         err = crypto_ahash_setkey(child, key, keylen);
 282         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
 283                                & CRYPTO_TFM_RES_MASK);
 284
 285         return err;
 286 }
 287
 288 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 289 {
 290         struct cryptd_ahash *cryptd_tfm;
 291         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 292
 293         cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
 294                                         CRYPTO_ALG_INTERNAL,
 295                                         CRYPTO_ALG_INTERNAL);
 296         if (IS_ERR(cryptd_tfm))
 297                 return PTR_ERR(cryptd_tfm);
 298         ctx->cryptd_tfm = cryptd_tfm;
 299         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 300                                  sizeof(struct ahash_request) +
 301                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 302
 303         return 0;
 304 }
 305
 306 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 307 {
 308         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 309
 310         cryptd_free_ahash(ctx->cryptd_tfm);
 311 }
 312
 313 static struct ahash_alg ghash_async_alg = {
 314         .init                   = ghash_async_init,
 315         .update                 = ghash_async_update,
 316         .final                  = ghash_async_final,
 317         .setkey                 = ghash_async_setkey,
 318         .digest                 = ghash_async_digest,
 319         .import                 = ghash_async_import,
 320         .export                 = ghash_async_export,
 321         .halg.digestsize        = GHASH_DIGEST_SIZE,
 322         .halg.statesize         = sizeof(struct ghash_desc_ctx),
 323         .halg.base              = {
 324                 .cra_name       = "ghash",
 325                 .cra_driver_name = "ghash-ce",
 326                 .cra_priority   = 300,
 327                 .cra_flags      = CRYPTO_ALG_ASYNC,
 328                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 329                 .cra_ctxsize    = sizeof(struct ghash_async_ctx),
 330                 .cra_module     = THIS_MODULE,
 331                 .cra_init       = ghash_async_init_tfm,
 332                 .cra_exit       = ghash_async_exit_tfm,
 333         },
 334 };
 335
 336 static int __init ghash_ce_mod_init(void)
 337 {
 338         int err;
 339
 340         if (!(elf_hwcap & HWCAP_NEON))
 341                 return -ENODEV;
 342
 343         if (elf_hwcap2 & HWCAP2_PMULL)
 344                 pmull_ghash_update = pmull_ghash_update_p64;
 345         else
 346                 pmull_ghash_update = pmull_ghash_update_p8;
 347
 348         err = crypto_register_shash(&ghash_alg);
 349         if (err)
 350                 return err;
 351         err = crypto_register_ahash(&ghash_async_alg);
 352         if (err)
 353                 goto err_shash;
 354
 355         return 0;
 356
 357 err_shash:
 358         crypto_unregister_shash(&ghash_alg);
 359         return err;
 360 }
 361
 362 static void __exit ghash_ce_mod_exit(void)
 363 {
 364         crypto_unregister_ahash(&ghash_async_alg);
 365         crypto_unregister_shash(&ghash_alg);
 366 }
 367
 368 module_init(ghash_ce_mod_init);
 369 module_exit(ghash_ce_mod_exit);