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 <crypto/internal/simd.h>
  23 #include <asm/cpu_device_id.h>
  24 #include <asm/simd.h>
  25
  26 #define GHASH_BLOCK_SIZE        16
  27 #define GHASH_DIGEST_SIZE       16
  28
  29 void clmul_ghash_mul(char *dst, const u128 *shash);
  30
  31 void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
  32                         const u128 *shash);
  33
  34 struct ghash_async_ctx {
  35         struct cryptd_ahash *cryptd_tfm;
  36 };
  37
  38 struct ghash_ctx {
  39         u128 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         be128 *x = (be128 *)key;
  61         u64 a, b;
  62
  63         if (keylen != GHASH_BLOCK_SIZE) {
  64                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  65                 return -EINVAL;
  66         }
  67
  68         /* perform multiplication by 'x' in GF(2^128) */
  69         a = be64_to_cpu(x->a);
  70         b = be64_to_cpu(x->b);
  71
  72         ctx->shash.a = (b << 1) | (a >> 63);
  73         ctx->shash.b = (a << 1) | (b >> 63);
  74
  75         if (a >> 63)
  76                 ctx->shash.b ^= ((u64)0xc2) << 56;
  77
  78         return 0;
  79 }
  80
  81 static int ghash_update(struct shash_desc *desc,
  82                          const u8 *src, unsigned int srclen)
  83 {
  84         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
  85         struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
  86         u8 *dst = dctx->buffer;
  87
  88         kernel_fpu_begin();
  89         if (dctx->bytes) {
  90                 int n = min(srclen, dctx->bytes);
  91                 u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
  92
  93                 dctx->bytes -= n;
  94                 srclen -= n;
  95
  96                 while (n--)
  97                         *pos++ ^= *src++;
  98
  99                 if (!dctx->bytes)
 100                         clmul_ghash_mul(dst, &ctx->shash);
 101         }
 102
 103         clmul_ghash_update(dst, src, srclen, &ctx->shash);
 104         kernel_fpu_end();
 105
 106         if (srclen & 0xf) {
 107                 src += srclen - (srclen & 0xf);
 108                 srclen &= 0xf;
 109                 dctx->bytes = GHASH_BLOCK_SIZE - srclen;
 110                 while (srclen--)
 111                         *dst++ ^= *src++;
 112         }
 113
 114         return 0;
 115 }
 116
 117 static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
 118 {
 119         u8 *dst = dctx->buffer;
 120
 121         if (dctx->bytes) {
 122                 u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
 123
 124                 while (dctx->bytes--)
 125                         *tmp++ ^= 0;
 126
 127                 kernel_fpu_begin();
 128                 clmul_ghash_mul(dst, &ctx->shash);
 129                 kernel_fpu_end();
 130         }
 131
 132         dctx->bytes = 0;
 133 }
 134
 135 static int ghash_final(struct shash_desc *desc, u8 *dst)
 136 {
 137         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
 138         struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
 139         u8 *buf = dctx->buffer;
 140
 141         ghash_flush(ctx, dctx);
 142         memcpy(dst, buf, GHASH_BLOCK_SIZE);
 143
 144         return 0;
 145 }
 146
 147 static struct shash_alg ghash_alg = {
 148         .digestsize     = GHASH_DIGEST_SIZE,
 149         .init           = ghash_init,
 150         .update         = ghash_update,
 151         .final          = ghash_final,
 152         .setkey         = ghash_setkey,
 153         .descsize       = sizeof(struct ghash_desc_ctx),
 154         .base           = {
 155                 .cra_name               = "__ghash",
 156                 .cra_driver_name        = "__ghash-pclmulqdqni",
 157                 .cra_priority           = 0,
 158                 .cra_flags              = CRYPTO_ALG_INTERNAL,
 159                 .cra_blocksize          = GHASH_BLOCK_SIZE,
 160                 .cra_ctxsize            = sizeof(struct ghash_ctx),
 161                 .cra_module             = THIS_MODULE,
 162         },
 163 };
 164
 165 static int ghash_async_init(struct ahash_request *req)
 166 {
 167         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 168         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 169         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 170         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 171         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 172         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 173
 174         desc->tfm = child;
 175         return crypto_shash_init(desc);
 176 }
 177
 178 static int ghash_async_update(struct ahash_request *req)
 179 {
 180         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 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         if (!crypto_simd_usable() ||
 186             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 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         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         if (!crypto_simd_usable() ||
 204             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 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_import(struct ahash_request *req, const void *in)
 215 {
 216         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 217         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 218         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
 219
 220         ghash_async_init(req);
 221         memcpy(dctx, in, sizeof(*dctx));
 222         return 0;
 223
 224 }
 225
 226 static int ghash_async_export(struct ahash_request *req, void *out)
 227 {
 228         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 229         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 230         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
 231
 232         memcpy(out, dctx, sizeof(*dctx));
 233         return 0;
 234
 235 }
 236
 237 static int ghash_async_digest(struct ahash_request *req)
 238 {
 239         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 240         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 241         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 242         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 243
 244         if (!crypto_simd_usable() ||
 245             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 246                 memcpy(cryptd_req, req, sizeof(*req));
 247                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 248                 return crypto_ahash_digest(cryptd_req);
 249         } else {
 250                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 251                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 252
 253                 desc->tfm = child;
 254                 return shash_ahash_digest(req, desc);
 255         }
 256 }
 257
 258 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 259                               unsigned int keylen)
 260 {
 261         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 262         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 263         int err;
 264
 265         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 266         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 267                                & CRYPTO_TFM_REQ_MASK);
 268         err = crypto_ahash_setkey(child, key, keylen);
 269         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
 270                                & CRYPTO_TFM_RES_MASK);
 271
 272         return err;
 273 }
 274
 275 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 276 {
 277         struct cryptd_ahash *cryptd_tfm;
 278         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 279
 280         cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni",
 281                                         CRYPTO_ALG_INTERNAL,
 282                                         CRYPTO_ALG_INTERNAL);
 283         if (IS_ERR(cryptd_tfm))
 284                 return PTR_ERR(cryptd_tfm);
 285         ctx->cryptd_tfm = cryptd_tfm;
 286         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 287                                  sizeof(struct ahash_request) +
 288                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 289
 290         return 0;
 291 }
 292
 293 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 294 {
 295         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 296
 297         cryptd_free_ahash(ctx->cryptd_tfm);
 298 }
 299
 300 static struct ahash_alg ghash_async_alg = {
 301         .init           = ghash_async_init,
 302         .update         = ghash_async_update,
 303         .final          = ghash_async_final,
 304         .setkey         = ghash_async_setkey,
 305         .digest         = ghash_async_digest,
 306         .export         = ghash_async_export,
 307         .import         = ghash_async_import,
 308         .halg = {
 309                 .digestsize     = GHASH_DIGEST_SIZE,
 310                 .statesize = sizeof(struct ghash_desc_ctx),
 311                 .base = {
 312                         .cra_name               = "ghash",
 313                         .cra_driver_name        = "ghash-clmulni",
 314                         .cra_priority           = 400,
 315                         .cra_ctxsize            = sizeof(struct ghash_async_ctx),
 316                         .cra_flags              = CRYPTO_ALG_ASYNC,
 317                         .cra_blocksize          = GHASH_BLOCK_SIZE,
 318                         .cra_module             = THIS_MODULE,
 319                         .cra_init               = ghash_async_init_tfm,
 320                         .cra_exit               = ghash_async_exit_tfm,
 321                 },
 322         },
 323 };
 324
 325 static const struct x86_cpu_id pcmul_cpu_id[] = {
 326         X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), /* Pickle-Mickle-Duck */
 327         {}
 328 };
 329 MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
 330
 331 static int __init ghash_pclmulqdqni_mod_init(void)
 332 {
 333         int err;
 334
 335         if (!x86_match_cpu(pcmul_cpu_id))
 336                 return -ENODEV;
 337
 338         err = crypto_register_shash(&ghash_alg);
 339         if (err)
 340                 goto err_out;
 341         err = crypto_register_ahash(&ghash_async_alg);
 342         if (err)
 343                 goto err_shash;
 344
 345         return 0;
 346
 347 err_shash:
 348         crypto_unregister_shash(&ghash_alg);
 349 err_out:
 350         return err;
 351 }
 352
 353 static void __exit ghash_pclmulqdqni_mod_exit(void)
 354 {
 355         crypto_unregister_ahash(&ghash_async_alg);
 356         crypto_unregister_shash(&ghash_alg);
 357 }
 358
 359 module_init(ghash_pclmulqdqni_mod_init);
 360 module_exit(ghash_pclmulqdqni_mod_exit);
 361
 362 MODULE_LICENSE("GPL");
 363 MODULE_DESCRIPTION("GHASH Message Digest Algorithm, "
 364                    "accelerated by PCLMULQDQ-NI");
 365 MODULE_ALIAS_CRYPTO("ghash");