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/internal/simd.h>
  18 #include <crypto/gf128mul.h>
  19 #include <linux/cpufeature.h>
  20 #include <linux/crypto.h>
  21 #include <linux/module.h>
  22
  23 MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
  24 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  25 MODULE_LICENSE("GPL v2");
  26 MODULE_ALIAS_CRYPTO("ghash");
  27
  28 #define GHASH_BLOCK_SIZE        16
  29 #define GHASH_DIGEST_SIZE       16
  30
  31 struct ghash_key {
  32         u64     h[2];
  33         u64     h2[2];
  34         u64     h3[2];
  35         u64     h4[2];
  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 int ghash_update(struct shash_desc *desc, const u8 *src,
  69                         unsigned int len)
  70 {
  71         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  72         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
  73
  74         ctx->count += len;
  75
  76         if ((partial + len) >= GHASH_BLOCK_SIZE) {
  77                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
  78                 int blocks;
  79
  80                 if (partial) {
  81                         int p = GHASH_BLOCK_SIZE - partial;
  82
  83                         memcpy(ctx->buf + partial, src, p);
  84                         src += p;
  85                         len -= p;
  86                 }
  87
  88                 blocks = len / GHASH_BLOCK_SIZE;
  89                 len %= GHASH_BLOCK_SIZE;
  90
  91                 kernel_neon_begin();
  92                 pmull_ghash_update(blocks, ctx->digest, src, key,
  93                                    partial ? ctx->buf : NULL);
  94                 kernel_neon_end();
  95                 src += blocks * GHASH_BLOCK_SIZE;
  96                 partial = 0;
  97         }
  98         if (len)
  99                 memcpy(ctx->buf + partial, src, len);
 100         return 0;
 101 }
 102
 103 static int ghash_final(struct shash_desc *desc, u8 *dst)
 104 {
 105         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
 106         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
 107
 108         if (partial) {
 109                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
 110
 111                 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
 112                 kernel_neon_begin();
 113                 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
 114                 kernel_neon_end();
 115         }
 116         put_unaligned_be64(ctx->digest[1], dst);
 117         put_unaligned_be64(ctx->digest[0], dst + 8);
 118
 119         *ctx = (struct ghash_desc_ctx){};
 120         return 0;
 121 }
 122
 123 static void ghash_reflect(u64 h[], const be128 *k)
 124 {
 125         u64 carry = be64_to_cpu(k->a) >> 63;
 126
 127         h[0] = (be64_to_cpu(k->b) << 1) | carry;
 128         h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
 129
 130         if (carry)
 131                 h[1] ^= 0xc200000000000000UL;
 132 }
 133
 134 static int ghash_setkey(struct crypto_shash *tfm,
 135                         const u8 *inkey, unsigned int keylen)
 136 {
 137         struct ghash_key *key = crypto_shash_ctx(tfm);
 138         be128 h, k;
 139
 140         if (keylen != GHASH_BLOCK_SIZE) {
 141                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 142                 return -EINVAL;
 143         }
 144
 145         memcpy(&k, inkey, GHASH_BLOCK_SIZE);
 146         ghash_reflect(key->h, &k);
 147
 148         h = k;
 149         gf128mul_lle(&h, &k);
 150         ghash_reflect(key->h2, &h);
 151
 152         gf128mul_lle(&h, &k);
 153         ghash_reflect(key->h3, &h);
 154
 155         gf128mul_lle(&h, &k);
 156         ghash_reflect(key->h4, &h);
 157
 158         return 0;
 159 }
 160
 161 static struct shash_alg ghash_alg = {
 162         .digestsize             = GHASH_DIGEST_SIZE,
 163         .init                   = ghash_init,
 164         .update                 = ghash_update,
 165         .final                  = ghash_final,
 166         .setkey                 = ghash_setkey,
 167         .descsize               = sizeof(struct ghash_desc_ctx),
 168         .base                   = {
 169                 .cra_name       = "__ghash",
 170                 .cra_driver_name = "__driver-ghash-ce",
 171                 .cra_priority   = 0,
 172                 .cra_flags      = CRYPTO_ALG_INTERNAL,
 173                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 174                 .cra_ctxsize    = sizeof(struct ghash_key),
 175                 .cra_module     = THIS_MODULE,
 176         },
 177 };
 178
 179 static int ghash_async_init(struct ahash_request *req)
 180 {
 181         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 182         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 183         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 184         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 185         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 186         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 187
 188         desc->tfm = child;
 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 (!crypto_simd_usable() ||
 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 (!crypto_simd_usable() ||
 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 (!crypto_simd_usable() ||
 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                 return shash_ahash_digest(req, desc);
 246         }
 247 }
 248
 249 static int ghash_async_import(struct ahash_request *req, const void *in)
 250 {
 251         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 252         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 253         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 254         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 255
 256         desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
 257
 258         return crypto_shash_import(desc, in);
 259 }
 260
 261 static int ghash_async_export(struct ahash_request *req, void *out)
 262 {
 263         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 264         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 265
 266         return crypto_shash_export(desc, out);
 267 }
 268
 269 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 270                               unsigned int keylen)
 271 {
 272         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 273         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 274         int err;
 275
 276         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 277         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 278                                & CRYPTO_TFM_REQ_MASK);
 279         err = crypto_ahash_setkey(child, key, keylen);
 280         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
 281                                & CRYPTO_TFM_RES_MASK);
 282
 283         return err;
 284 }
 285
 286 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 287 {
 288         struct cryptd_ahash *cryptd_tfm;
 289         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 290
 291         cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
 292                                         CRYPTO_ALG_INTERNAL,
 293                                         CRYPTO_ALG_INTERNAL);
 294         if (IS_ERR(cryptd_tfm))
 295                 return PTR_ERR(cryptd_tfm);
 296         ctx->cryptd_tfm = cryptd_tfm;
 297         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 298                                  sizeof(struct ahash_request) +
 299                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 300
 301         return 0;
 302 }
 303
 304 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 305 {
 306         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 307
 308         cryptd_free_ahash(ctx->cryptd_tfm);
 309 }
 310
 311 static struct ahash_alg ghash_async_alg = {
 312         .init                   = ghash_async_init,
 313         .update                 = ghash_async_update,
 314         .final                  = ghash_async_final,
 315         .setkey                 = ghash_async_setkey,
 316         .digest                 = ghash_async_digest,
 317         .import                 = ghash_async_import,
 318         .export                 = ghash_async_export,
 319         .halg.digestsize        = GHASH_DIGEST_SIZE,
 320         .halg.statesize         = sizeof(struct ghash_desc_ctx),
 321         .halg.base              = {
 322                 .cra_name       = "ghash",
 323                 .cra_driver_name = "ghash-ce",
 324                 .cra_priority   = 300,
 325                 .cra_flags      = CRYPTO_ALG_ASYNC,
 326                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 327                 .cra_ctxsize    = sizeof(struct ghash_async_ctx),
 328                 .cra_module     = THIS_MODULE,
 329                 .cra_init       = ghash_async_init_tfm,
 330                 .cra_exit       = ghash_async_exit_tfm,
 331         },
 332 };
 333
 334 static int __init ghash_ce_mod_init(void)
 335 {
 336         int err;
 337
 338         if (!(elf_hwcap & HWCAP_NEON))
 339                 return -ENODEV;
 340
 341         if (elf_hwcap2 & HWCAP2_PMULL)
 342                 pmull_ghash_update = pmull_ghash_update_p64;
 343         else
 344                 pmull_ghash_update = pmull_ghash_update_p8;
 345
 346         err = crypto_register_shash(&ghash_alg);
 347         if (err)
 348                 return err;
 349         err = crypto_register_ahash(&ghash_async_alg);
 350         if (err)
 351                 goto err_shash;
 352
 353         return 0;
 354
 355 err_shash:
 356         crypto_unregister_shash(&ghash_alg);
 357         return err;
 358 }
 359
 360 static void __exit ghash_ce_mod_exit(void)
 361 {
 362         crypto_unregister_ahash(&ghash_async_alg);
 363         crypto_unregister_shash(&ghash_alg);
 364 }
 365
 366 module_init(ghash_ce_mod_init);
 367 module_exit(ghash_ce_mod_exit);