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