arch/arm/crypto/ghash-ce-glue.c

   1 /*
   2  * Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
   3  *
   4  * Copyright (C) 2015 Linaro Ltd. <ard.biesheuvel@linaro.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published
   8  * by the Free Software Foundation.
   9  */
  10
  11 #include <asm/hwcap.h>
  12 #include <asm/neon.h>
  13 #include <asm/simd.h>
  14 #include <asm/unaligned.h>
  15 #include <crypto/cryptd.h>
  16 #include <crypto/internal/hash.h>
  17 #include <crypto/gf128mul.h>
  18 #include <linux/cpufeature.h>
  19 #include <linux/crypto.h>
  20 #include <linux/module.h>
  21
  22 MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
  23 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  24 MODULE_LICENSE("GPL v2");
  25
  26 #define GHASH_BLOCK_SIZE        16
  27 #define GHASH_DIGEST_SIZE       16
  28
  29 struct ghash_key {
  30         u64     a;
  31         u64     b;
  32 };
  33
  34 struct ghash_desc_ctx {
  35         u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
  36         u8 buf[GHASH_BLOCK_SIZE];
  37         u32 count;
  38 };
  39
  40 struct ghash_async_ctx {
  41         struct cryptd_ahash *cryptd_tfm;
  42 };
  43
  44 asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src,
  45                                    struct ghash_key const *k, const char *head);
  46
  47 static int ghash_init(struct shash_desc *desc)
  48 {
  49         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  50
  51         *ctx = (struct ghash_desc_ctx){};
  52         return 0;
  53 }
  54
  55 static int ghash_update(struct shash_desc *desc, const u8 *src,
  56                         unsigned int len)
  57 {
  58         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  59         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
  60
  61         ctx->count += len;
  62
  63         if ((partial + len) >= GHASH_BLOCK_SIZE) {
  64                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
  65                 int blocks;
  66
  67                 if (partial) {
  68                         int p = GHASH_BLOCK_SIZE - partial;
  69
  70                         memcpy(ctx->buf + partial, src, p);
  71                         src += p;
  72                         len -= p;
  73                 }
  74
  75                 blocks = len / GHASH_BLOCK_SIZE;
  76                 len %= GHASH_BLOCK_SIZE;
  77
  78                 kernel_neon_begin();
  79                 pmull_ghash_update(blocks, ctx->digest, src, key,
  80                                    partial ? ctx->buf : NULL);
  81                 kernel_neon_end();
  82                 src += blocks * GHASH_BLOCK_SIZE;
  83                 partial = 0;
  84         }
  85         if (len)
  86                 memcpy(ctx->buf + partial, src, len);
  87         return 0;
  88 }
  89
  90 static int ghash_final(struct shash_desc *desc, u8 *dst)
  91 {
  92         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  93         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
  94
  95         if (partial) {
  96                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
  97
  98                 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
  99                 kernel_neon_begin();
 100                 pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
 101                 kernel_neon_end();
 102         }
 103         put_unaligned_be64(ctx->digest[1], dst);
 104         put_unaligned_be64(ctx->digest[0], dst + 8);
 105
 106         *ctx = (struct ghash_desc_ctx){};
 107         return 0;
 108 }
 109
 110 static int ghash_setkey(struct crypto_shash *tfm,
 111                         const u8 *inkey, unsigned int keylen)
 112 {
 113         struct ghash_key *key = crypto_shash_ctx(tfm);
 114         u64 a, b;
 115
 116         if (keylen != GHASH_BLOCK_SIZE) {
 117                 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 118                 return -EINVAL;
 119         }
 120
 121         /* perform multiplication by 'x' in GF(2^128) */
 122         b = get_unaligned_be64(inkey);
 123         a = get_unaligned_be64(inkey + 8);
 124
 125         key->a = (a << 1) | (b >> 63);
 126         key->b = (b << 1) | (a >> 63);
 127
 128         if (b >> 63)
 129                 key->b ^= 0xc200000000000000UL;
 130
 131         return 0;
 132 }
 133
 134 static struct shash_alg ghash_alg = {
 135         .digestsize             = GHASH_DIGEST_SIZE,
 136         .init                   = ghash_init,
 137         .update                 = ghash_update,
 138         .final                  = ghash_final,
 139         .setkey                 = ghash_setkey,
 140         .descsize               = sizeof(struct ghash_desc_ctx),
 141         .base                   = {
 142                 .cra_name       = "__ghash",
 143                 .cra_driver_name = "__driver-ghash-ce",
 144                 .cra_priority   = 0,
 145                 .cra_flags      = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_INTERNAL,
 146                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 147                 .cra_ctxsize    = sizeof(struct ghash_key),
 148                 .cra_module     = THIS_MODULE,
 149         },
 150 };
 151
 152 static int ghash_async_init(struct ahash_request *req)
 153 {
 154         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 155         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 156         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 157         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 158         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 159         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 160
 161         desc->tfm = child;
 162         desc->flags = req->base.flags;
 163         return crypto_shash_init(desc);
 164 }
 165
 166 static int ghash_async_update(struct ahash_request *req)
 167 {
 168         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 169         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 170         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 171         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 172
 173         if (!may_use_simd() ||
 174             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 175                 memcpy(cryptd_req, req, sizeof(*req));
 176                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 177                 return crypto_ahash_update(cryptd_req);
 178         } else {
 179                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 180                 return shash_ahash_update(req, desc);
 181         }
 182 }
 183
 184 static int ghash_async_final(struct ahash_request *req)
 185 {
 186         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 187         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 188         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 189         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 190
 191         if (!may_use_simd() ||
 192             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 193                 memcpy(cryptd_req, req, sizeof(*req));
 194                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 195                 return crypto_ahash_final(cryptd_req);
 196         } else {
 197                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 198                 return crypto_shash_final(desc, req->result);
 199         }
 200 }
 201
 202 static int ghash_async_digest(struct ahash_request *req)
 203 {
 204         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 205         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 206         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 207         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 208
 209         if (!may_use_simd() ||
 210             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 211                 memcpy(cryptd_req, req, sizeof(*req));
 212                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 213                 return crypto_ahash_digest(cryptd_req);
 214         } else {
 215                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 216                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 217
 218                 desc->tfm = child;
 219                 desc->flags = req->base.flags;
 220                 return shash_ahash_digest(req, desc);
 221         }
 222 }
 223
 224 static int ghash_async_import(struct ahash_request *req, const void *in)
 225 {
 226         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 227         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 228         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 229         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 230
 231         desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
 232         desc->flags = req->base.flags;
 233
 234         return crypto_shash_import(desc, in);
 235 }
 236
 237 static int ghash_async_export(struct ahash_request *req, void *out)
 238 {
 239         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 240         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 241
 242         return crypto_shash_export(desc, out);
 243 }
 244
 245 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 246                               unsigned int keylen)
 247 {
 248         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 249         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 250         int err;
 251
 252         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 253         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 254                                & CRYPTO_TFM_REQ_MASK);
 255         err = crypto_ahash_setkey(child, key, keylen);
 256         crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
 257                                & CRYPTO_TFM_RES_MASK);
 258
 259         return err;
 260 }
 261
 262 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 263 {
 264         struct cryptd_ahash *cryptd_tfm;
 265         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 266
 267         cryptd_tfm = cryptd_alloc_ahash("__driver-ghash-ce",
 268                                         CRYPTO_ALG_INTERNAL,
 269                                         CRYPTO_ALG_INTERNAL);
 270         if (IS_ERR(cryptd_tfm))
 271                 return PTR_ERR(cryptd_tfm);
 272         ctx->cryptd_tfm = cryptd_tfm;
 273         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 274                                  sizeof(struct ahash_request) +
 275                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 276
 277         return 0;
 278 }
 279
 280 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 281 {
 282         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 283
 284         cryptd_free_ahash(ctx->cryptd_tfm);
 285 }
 286
 287 static struct ahash_alg ghash_async_alg = {
 288         .init                   = ghash_async_init,
 289         .update                 = ghash_async_update,
 290         .final                  = ghash_async_final,
 291         .setkey                 = ghash_async_setkey,
 292         .digest                 = ghash_async_digest,
 293         .import                 = ghash_async_import,
 294         .export                 = ghash_async_export,
 295         .halg.digestsize        = GHASH_DIGEST_SIZE,
 296         .halg.statesize         = sizeof(struct ghash_desc_ctx),
 297         .halg.base              = {
 298                 .cra_name       = "ghash",
 299                 .cra_driver_name = "ghash-ce",
 300                 .cra_priority   = 300,
 301                 .cra_flags      = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC,
 302                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 303                 .cra_type       = &crypto_ahash_type,
 304                 .cra_ctxsize    = sizeof(struct ghash_async_ctx),
 305                 .cra_module     = THIS_MODULE,
 306                 .cra_init       = ghash_async_init_tfm,
 307                 .cra_exit       = ghash_async_exit_tfm,
 308         },
 309 };
 310
 311 static int __init ghash_ce_mod_init(void)
 312 {
 313         int err;
 314
 315         err = crypto_register_shash(&ghash_alg);
 316         if (err)
 317                 return err;
 318         err = crypto_register_ahash(&ghash_async_alg);
 319         if (err)
 320                 goto err_shash;
 321
 322         return 0;
 323
 324 err_shash:
 325         crypto_unregister_shash(&ghash_alg);
 326         return err;
 327 }
 328
 329 static void __exit ghash_ce_mod_exit(void)
 330 {
 331         crypto_unregister_ahash(&ghash_async_alg);
 332         crypto_unregister_shash(&ghash_alg);
 333 }
 334
 335 module_cpu_feature_match(PMULL, ghash_ce_mod_init);
 336 module_exit(ghash_ce_mod_exit);