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