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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Accelerated GHASH implementation with Intel PCLMULQDQ-NI
   4  * instructions. This file contains glue code.
   5  *
   6  * Copyright (c) 2009 Intel Corp.
   7  *   Author: Huang Ying <ying.huang@intel.com>
   8  */
   9
  10 #include <linux/err.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/crypto.h>
  15 #include <crypto/algapi.h>
  16 #include <crypto/cryptd.h>
  17 #include <crypto/gf128mul.h>
  18 #include <crypto/internal/hash.h>
  19 #include <crypto/internal/simd.h>
  20 #include <asm/cpu_device_id.h>
  21 #include <asm/simd.h>
  22
  23 #define GHASH_BLOCK_SIZE        16
  24 #define GHASH_DIGEST_SIZE       16
  25
  26 void clmul_ghash_mul(char *dst, const u128 *shash);
  27
  28 void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
  29                         const u128 *shash);
  30
  31 struct ghash_async_ctx {
  32         struct cryptd_ahash *cryptd_tfm;
  33 };
  34
  35 struct ghash_ctx {
  36         u128 shash;
  37 };
  38
  39 struct ghash_desc_ctx {
  40         u8 buffer[GHASH_BLOCK_SIZE];
  41         u32 bytes;
  42 };
  43
  44 static int ghash_init(struct shash_desc *desc)
  45 {
  46         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
  47
  48         memset(dctx, 0, sizeof(*dctx));
  49
  50         return 0;
  51 }
  52
  53 static int ghash_setkey(struct crypto_shash *tfm,
  54                         const u8 *key, unsigned int keylen)
  55 {
  56         struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
  57         be128 *x = (be128 *)key;
  58         u64 a, b;
  59
  60         if (keylen != GHASH_BLOCK_SIZE)
  61                 return -EINVAL;
  62
  63         /* perform multiplication by 'x' in GF(2^128) */
  64         a = be64_to_cpu(x->a);
  65         b = be64_to_cpu(x->b);
  66
  67         ctx->shash.a = (b << 1) | (a >> 63);
  68         ctx->shash.b = (a << 1) | (b >> 63);
  69
  70         if (a >> 63)
  71                 ctx->shash.b ^= ((u64)0xc2) << 56;
  72
  73         return 0;
  74 }
  75
  76 static int ghash_update(struct shash_desc *desc,
  77                          const u8 *src, unsigned int srclen)
  78 {
  79         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
  80         struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
  81         u8 *dst = dctx->buffer;
  82
  83         kernel_fpu_begin();
  84         if (dctx->bytes) {
  85                 int n = min(srclen, dctx->bytes);
  86                 u8 *pos = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
  87
  88                 dctx->bytes -= n;
  89                 srclen -= n;
  90
  91                 while (n--)
  92                         *pos++ ^= *src++;
  93
  94                 if (!dctx->bytes)
  95                         clmul_ghash_mul(dst, &ctx->shash);
  96         }
  97
  98         clmul_ghash_update(dst, src, srclen, &ctx->shash);
  99         kernel_fpu_end();
 100
 101         if (srclen & 0xf) {
 102                 src += srclen - (srclen & 0xf);
 103                 srclen &= 0xf;
 104                 dctx->bytes = GHASH_BLOCK_SIZE - srclen;
 105                 while (srclen--)
 106                         *dst++ ^= *src++;
 107         }
 108
 109         return 0;
 110 }
 111
 112 static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
 113 {
 114         u8 *dst = dctx->buffer;
 115
 116         if (dctx->bytes) {
 117                 u8 *tmp = dst + (GHASH_BLOCK_SIZE - dctx->bytes);
 118
 119                 while (dctx->bytes--)
 120                         *tmp++ ^= 0;
 121
 122                 kernel_fpu_begin();
 123                 clmul_ghash_mul(dst, &ctx->shash);
 124                 kernel_fpu_end();
 125         }
 126
 127         dctx->bytes = 0;
 128 }
 129
 130 static int ghash_final(struct shash_desc *desc, u8 *dst)
 131 {
 132         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
 133         struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
 134         u8 *buf = dctx->buffer;
 135
 136         ghash_flush(ctx, dctx);
 137         memcpy(dst, buf, GHASH_BLOCK_SIZE);
 138
 139         return 0;
 140 }
 141
 142 static struct shash_alg ghash_alg = {
 143         .digestsize     = GHASH_DIGEST_SIZE,
 144         .init           = ghash_init,
 145         .update         = ghash_update,
 146         .final          = ghash_final,
 147         .setkey         = ghash_setkey,
 148         .descsize       = sizeof(struct ghash_desc_ctx),
 149         .base           = {
 150                 .cra_name               = "__ghash",
 151                 .cra_driver_name        = "__ghash-pclmulqdqni",
 152                 .cra_priority           = 0,
 153                 .cra_flags              = CRYPTO_ALG_INTERNAL,
 154                 .cra_blocksize          = GHASH_BLOCK_SIZE,
 155                 .cra_ctxsize            = sizeof(struct ghash_ctx),
 156                 .cra_module             = THIS_MODULE,
 157         },
 158 };
 159
 160 static int ghash_async_init(struct ahash_request *req)
 161 {
 162         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 163         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 164         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 165         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 166         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 167         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 168
 169         desc->tfm = child;
 170         return crypto_shash_init(desc);
 171 }
 172
 173 static int ghash_async_update(struct ahash_request *req)
 174 {
 175         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 176         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 177         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 178         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 179
 180         if (!crypto_simd_usable() ||
 181             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 182                 memcpy(cryptd_req, req, sizeof(*req));
 183                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 184                 return crypto_ahash_update(cryptd_req);
 185         } else {
 186                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 187                 return shash_ahash_update(req, desc);
 188         }
 189 }
 190
 191 static int ghash_async_final(struct ahash_request *req)
 192 {
 193         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 194         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 195         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 196         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 197
 198         if (!crypto_simd_usable() ||
 199             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 200                 memcpy(cryptd_req, req, sizeof(*req));
 201                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 202                 return crypto_ahash_final(cryptd_req);
 203         } else {
 204                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 205                 return crypto_shash_final(desc, req->result);
 206         }
 207 }
 208
 209 static int ghash_async_import(struct ahash_request *req, const void *in)
 210 {
 211         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 212         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 213         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
 214
 215         ghash_async_init(req);
 216         memcpy(dctx, in, sizeof(*dctx));
 217         return 0;
 218
 219 }
 220
 221 static int ghash_async_export(struct ahash_request *req, void *out)
 222 {
 223         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 224         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 225         struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
 226
 227         memcpy(out, dctx, sizeof(*dctx));
 228         return 0;
 229
 230 }
 231
 232 static int ghash_async_digest(struct ahash_request *req)
 233 {
 234         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 235         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 236         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 237         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 238
 239         if (!crypto_simd_usable() ||
 240             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 241                 memcpy(cryptd_req, req, sizeof(*req));
 242                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 243                 return crypto_ahash_digest(cryptd_req);
 244         } else {
 245                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 246                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 247
 248                 desc->tfm = child;
 249                 return shash_ahash_digest(req, desc);
 250         }
 251 }
 252
 253 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 254                               unsigned int keylen)
 255 {
 256         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 257         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 258
 259         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 260         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 261                                & CRYPTO_TFM_REQ_MASK);
 262         return crypto_ahash_setkey(child, key, keylen);
 263 }
 264
 265 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 266 {
 267         struct cryptd_ahash *cryptd_tfm;
 268         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 269
 270         cryptd_tfm = cryptd_alloc_ahash("__ghash-pclmulqdqni",
 271                                         CRYPTO_ALG_INTERNAL,
 272                                         CRYPTO_ALG_INTERNAL);
 273         if (IS_ERR(cryptd_tfm))
 274                 return PTR_ERR(cryptd_tfm);
 275         ctx->cryptd_tfm = cryptd_tfm;
 276         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 277                                  sizeof(struct ahash_request) +
 278                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 279
 280         return 0;
 281 }
 282
 283 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 284 {
 285         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 286
 287         cryptd_free_ahash(ctx->cryptd_tfm);
 288 }
 289
 290 static struct ahash_alg ghash_async_alg = {
 291         .init           = ghash_async_init,
 292         .update         = ghash_async_update,
 293         .final          = ghash_async_final,
 294         .setkey         = ghash_async_setkey,
 295         .digest         = ghash_async_digest,
 296         .export         = ghash_async_export,
 297         .import         = ghash_async_import,
 298         .halg = {
 299                 .digestsize     = GHASH_DIGEST_SIZE,
 300                 .statesize = sizeof(struct ghash_desc_ctx),
 301                 .base = {
 302                         .cra_name               = "ghash",
 303                         .cra_driver_name        = "ghash-clmulni",
 304                         .cra_priority           = 400,
 305                         .cra_ctxsize            = sizeof(struct ghash_async_ctx),
 306                         .cra_flags              = CRYPTO_ALG_ASYNC,
 307                         .cra_blocksize          = GHASH_BLOCK_SIZE,
 308                         .cra_module             = THIS_MODULE,
 309                         .cra_init               = ghash_async_init_tfm,
 310                         .cra_exit               = ghash_async_exit_tfm,
 311                 },
 312         },
 313 };
 314
 315 static const struct x86_cpu_id pcmul_cpu_id[] = {
 316         X86_MATCH_FEATURE(X86_FEATURE_PCLMULQDQ, NULL), /* Pickle-Mickle-Duck */
 317         {}
 318 };
 319 MODULE_DEVICE_TABLE(x86cpu, pcmul_cpu_id);
 320
 321 static int __init ghash_pclmulqdqni_mod_init(void)
 322 {
 323         int err;
 324
 325         if (!x86_match_cpu(pcmul_cpu_id))
 326                 return -ENODEV;
 327
 328         err = crypto_register_shash(&ghash_alg);
 329         if (err)
 330                 goto err_out;
 331         err = crypto_register_ahash(&ghash_async_alg);
 332         if (err)
 333                 goto err_shash;
 334
 335         return 0;
 336
 337 err_shash:
 338         crypto_unregister_shash(&ghash_alg);
 339 err_out:
 340         return err;
 341 }
 342
 343 static void __exit ghash_pclmulqdqni_mod_exit(void)
 344 {
 345         crypto_unregister_ahash(&ghash_async_alg);
 346         crypto_unregister_shash(&ghash_alg);
 347 }
 348
 349 module_init(ghash_pclmulqdqni_mod_init);
 350 module_exit(ghash_pclmulqdqni_mod_exit);
 351
 352 MODULE_LICENSE("GPL");
 353 MODULE_DESCRIPTION("GHASH hash function, accelerated by PCLMULQDQ-NI");
 354 MODULE_ALIAS_CRYPTO("ghash");