arch/x86/crypto/ghash-clmulni-intel_glue.c

   1 /*
   2  * Accelerated GHASH implementation with Intel PCLMULQDQ-NI
   3  * instructions. This file contains glue code.
   4  *
   5  * Copyright (c) 2009 Intel Corp.
   6  *   Author: Huang Ying <ying.huang@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published
  10  * by the Free Software Foundation.
  11  */
  12
  13 #include <linux/err.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/crypto.h>
  18 #include <crypto/algapi.h>
  19 #include <crypto/cryptd.h>
  20 #include <crypto/gf128mul.h>
  21 #include <crypto/internal/hash.h>
  22 #include <asm/i387.h>
  23 #include <asm/cpu_device_id.h>
  24
  25 #define GHASH_BLOCK_SIZE        16
  26 #define GHASH_DIGEST_SIZE       16
  27
  28 void clmul_ghash_mul(char *dst, const be128 *shash);
  29
  30 void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
  31                         const be128 *shash);
  32
  33 void clmul_ghash_setkey(be128 *shash, const u8 *key);
  34
  35 struct ghash_async_ctx {
  36         struct cryptd_ahash *cryptd_tfm;
  37 };
  38
  39 struct ghash_ctx {
  40         be128 shash;
  41 };
  42
  43 struct ghash_desc_ctx {
  44         u8 buffer[GHASH_BLOCK_SIZE];
  45         u32 bytes;
  46 };
  47
  48 static int ghash_init(struct shash_desc *desc)
  49 {
  50         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
  51
  52         memset(dctx, 0, sizeof(*dctx));
  53
  54         return 0;
  55 }
  56
  57 static int ghash_setkey(struct crypto_shash *tfm,
  58                         const u8 *key, unsigned int keylen)
  59 {
  60         struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
  61
  62         if (keylen != GHASH_BLOCK_SIZE) {
  63                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  64                 return -EINVAL;
  65         }
  66
  67         clmul_ghash_setkey(&ctx->shash, key);
  68
  69         return 0;
  70 }
  71
  72 static int ghash_update(struct shash_desc *desc,
  73                          const u8 *src, unsigned int srclen)
  74 {
  75         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
  76         struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
  77         u8 *dst = dctx->buffer;
  78
  79         kernel_fpu_begin();
  80         if (dctx->bytes) {
  81                 int n = min(srclen, dctx->bytes);
  82                 u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
  83
  84                 dctx->bytes -= n;
  85                 srclen -= n;
  86
  87                 while (n--)
  88                         *pos++ ^= *src++;
  89
  90                 if (!dctx->bytes)
  91                         clmul_ghash_mul(dst, &ctx->shash);
  92         }
  93
  94         clmul_ghash_update(dst, src, srclen, &ctx->shash);
  95         kernel_fpu_end();
  96
  97         if (srclen & 0xf) {
  98                 src += srclen - (srclen & 0xf);
  99                 srclen &= 0xf;
 100                 dctx->bytes = GHASH_BLOCK_SIZE - srclen;
 101                 while (srclen--)
 102                         *dst++ ^= *src++;
 103         }
 104
 105         return 0;
 106 }
 107
 108 static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
 109 {
 110         u8 *dst = dctx->buffer;
 111
 112         if (dctx->bytes) {
 113                 u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
 114
 115                 while (dctx->bytes--)
 116                         *tmp++ ^= 0;
 117
 118                 kernel_fpu_begin();
 119                 clmul_ghash_mul(dst, &ctx->shash);
 120                 kernel_fpu_end();
 121         }
 122
 123         dctx->bytes = 0;
 124 }
 125
 126 static int ghash_final(struct shash_desc *desc, u8 *dst)
 127 {
 128         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
 129         struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
 130         u8 *buf = dctx->buffer;
 131
 132         ghash_flush(ctx, dctx);
 133         memcpy(dst, buf, GHASH_BLOCK_SIZE);
 134
 135         return 0;
 136 }
 137
 138 static struct shash_alg ghash_alg = {
 139         .digestsize     = GHASH_DIGEST_SIZE,
 140         .init           = ghash_init,
 141         .update         = ghash_update,
 142         .final          = ghash_final,
 143         .setkey         = ghash_setkey,
 144         .descsize       = sizeof(struct ghash_desc_ctx),
 145         .base           = {
 146                 .cra_name               = "__ghash",
 147                 .cra_driver_name        = "__ghash-pclmulqdqni",
 148                 .cra_priority           = 0,
 149                 .cra_flags              = CRYPTO_ALG_TYPE_SHASH,
 150                 .cra_blocksize          = GHASH_BLOCK_SIZE,
 151                 .cra_ctxsize            = sizeof(struct ghash_ctx),
 152                 .cra_module             = THIS_MODULE,
 153                 .cra_list               = LIST_HEAD_INIT(ghash_alg.base.cra_list),
 154         },
 155 };
 156
 157 static int ghash_async_init(struct ahash_request *req)
 158 {
 159         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 160         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 161         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 162         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 163
 164         if (!irq_fpu_usable()) {
 165                 memcpy(cryptd_req, req, sizeof(*req));
 166                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 167                 return crypto_ahash_init(cryptd_req);
 168         } else {
 169                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 170                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 171
 172                 desc->tfm = child;
 173                 desc->flags = req->base.flags;
 174                 return crypto_shash_init(desc);
 175         }
 176 }
 177
 178 static int ghash_async_update(struct ahash_request *req)
 179 {
 180         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 181
 182         if (!irq_fpu_usable()) {
 183                 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 184                 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 185                 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 186
 187                 memcpy(cryptd_req, req, sizeof(*req));
 188                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 189                 return crypto_ahash_update(cryptd_req);
 190         } else {
 191                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 192                 return shash_ahash_update(req, desc);
 193         }
 194 }
 195
 196 static int ghash_async_final(struct ahash_request *req)
 197 {
 198         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 199
 200         if (!irq_fpu_usable()) {
 201                 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 202                 struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 203                 struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 204
 205                 memcpy(cryptd_req, req, sizeof(*req));
 206                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 207                 return crypto_ahash_final(cryptd_req);
 208         } else {
 209                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 210                 return crypto_shash_final(desc, req->result);
 211         }
 212 }
 213
 214 static int ghash_async_digest(struct ahash_request *req)
 215 {
 216         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 217         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 218         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 219         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 220
 221         if (!irq_fpu_usable()) {
 222                 memcpy(cryptd_req, req, sizeof(*req));
 223                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 224                 return crypto_ahash_digest(cryptd_req);
 225         } else {
 226                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 227                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 228
 229                 desc->tfm = child;
 230                 desc->flags = req->base.flags;
 231                 return shash_ahash_digest(req, desc);
 232         }
 233 }
 234
 235 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 236                               unsigned int keylen)
 237 {
 238         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 239         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 240         int err;
 241
 242         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 243         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 244                                & CRYPTO_TFM_REQ_MASK);
 245         err = crypto_ahash_setkey(child, key, keylen);
 246         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
 247                                & CRYPTO_TFM_RES_MASK);
 248
 249         return err;
 250 }
 251
 252 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 253 {
 254         struct cryptd_ahash *cryptd_tfm;
 255         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 256
 257         cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni", 0, 0);
 258         if (IS_ERR(cryptd_tfm))
 259                 return PTR_ERR(cryptd_tfm);
 260         ctx->cryptd_tfm = cryptd_tfm;
 261         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 262                                  sizeof(struct ahash_request) +
 263                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 264
 265         return 0;
 266 }
 267
 268 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 269 {
 270         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 271
 272         cryptd_free_ahash(ctx->cryptd_tfm);
 273 }
 274
 275 static struct ahash_alg ghash_async_alg = {
 276         .init           = ghash_async_init,
 277         .update         = ghash_async_update,
 278         .final          = ghash_async_final,
 279         .setkey         = ghash_async_setkey,
 280         .digest         = ghash_async_digest,
 281         .halg = {
 282                 .digestsize     = GHASH_DIGEST_SIZE,
 283                 .base = {
 284                         .cra_name               = "ghash",
 285                         .cra_driver_name        = "ghash-clmulni",
 286                         .cra_priority           = 400,
 287                         .cra_flags              = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
 288                         .cra_blocksize          = GHASH_BLOCK_SIZE,
 289                         .cra_type               = &crypto_ahash_type,
 290                         .cra_module             = THIS_MODULE,
 291                         .cra_list               = LIST_HEAD_INIT(ghash_async_alg.halg.base.cra_list),
 292                         .cra_init               = ghash_async_init_tfm,
 293                         .cra_exit               = ghash_async_exit_tfm,
 294                 },
 295         },
 296 };
 297
 298 static const struct x86_cpu_id pcmul_cpu_id[] = {
 299         X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), /* Pickle-Mickle-Duck */
 300         {}
 301 };
 302 MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
 303
 304 static int __init ghash_pclmulqdqni_mod_init(void)
 305 {
 306         int err;
 307
 308         if (!x86_match_cpu(pcmul_cpu_id))
 309                 return -ENODEV;
 310
 311         err = crypto_register_shash(&ghash_alg);
 312         if (err)
 313                 goto err_out;
 314         err = crypto_register_ahash(&ghash_async_alg);
 315         if (err)
 316                 goto err_shash;
 317
 318         return 0;
 319
 320 err_shash:
 321         crypto_unregister_shash(&ghash_alg);
 322 err_out:
 323         return err;
 324 }
 325
 326 static void __exit ghash_pclmulqdqni_mod_exit(void)
 327 {
 328         crypto_unregister_ahash(&ghash_async_alg);
 329         crypto_unregister_shash(&ghash_alg);
 330 }
 331
 332 module_init(ghash_pclmulqdqni_mod_init);
 333 module_exit(ghash_pclmulqdqni_mod_exit);
 334
 335 MODULE_LICENSE("GPL");
 336 MODULE_DESCRIPTION("GHASH Message Digest Algorithm, "
 337                    "acclerated by PCLMULQDQ-NI");
 338 MODULE_ALIAS("ghash");