arch/arm64/crypto/polyval-ce-glue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Glue code for POLYVAL using ARMv8 Crypto Extensions
   4  *
   5  * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
   6  * Copyright (c) 2009 Intel Corp.
   7  *   Author: Huang Ying <ying.huang@intel.com>
   8  * Copyright 2021 Google LLC
   9  */
  10
  11 /*
  12  * Glue code based on ghash-clmulni-intel_glue.c.
  13  *
  14  * This implementation of POLYVAL uses montgomery multiplication accelerated by
  15  * ARMv8 Crypto Extensions instructions to implement the finite field operations.
  16  */
  17
  18 #include <crypto/algapi.h>
  19 #include <crypto/internal/hash.h>
  20 #include <crypto/internal/simd.h>
  21 #include <crypto/polyval.h>
  22 #include <linux/crypto.h>
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/cpufeature.h>
  27 #include <asm/neon.h>
  28 #include <asm/simd.h>
  29
  30 #define NUM_KEY_POWERS  8
  31
  32 struct polyval_tfm_ctx {
  33         /*
  34          * These powers must be in the order h^8, ..., h^1.
  35          */
  36         u8 key_powers[NUM_KEY_POWERS][POLYVAL_BLOCK_SIZE];
  37 };
  38
  39 struct polyval_desc_ctx {
  40         u8 buffer[POLYVAL_BLOCK_SIZE];
  41         u32 bytes;
  42 };
  43
  44 asmlinkage void pmull_polyval_update(const struct polyval_tfm_ctx *keys,
  45         const u8 *in, size_t nblocks, u8 *accumulator);
  46 asmlinkage void pmull_polyval_mul(u8 *op1, const u8 *op2);
  47
  48 static void internal_polyval_update(const struct polyval_tfm_ctx *keys,
  49         const u8 *in, size_t nblocks, u8 *accumulator)
  50 {
  51         if (likely(crypto_simd_usable())) {
  52                 kernel_neon_begin();
  53                 pmull_polyval_update(keys, in, nblocks, accumulator);
  54                 kernel_neon_end();
  55         } else {
  56                 polyval_update_non4k(keys->key_powers[NUM_KEY_POWERS-1], in,
  57                         nblocks, accumulator);
  58         }
  59 }
  60
  61 static void internal_polyval_mul(u8 *op1, const u8 *op2)
  62 {
  63         if (likely(crypto_simd_usable())) {
  64                 kernel_neon_begin();
  65                 pmull_polyval_mul(op1, op2);
  66                 kernel_neon_end();
  67         } else {
  68                 polyval_mul_non4k(op1, op2);
  69         }
  70 }
  71
  72 static int polyval_arm64_setkey(struct crypto_shash *tfm,
  73                         const u8 *key, unsigned int keylen)
  74 {
  75         struct polyval_tfm_ctx *tctx = crypto_shash_ctx(tfm);
  76         int i;
  77
  78         if (keylen != POLYVAL_BLOCK_SIZE)
  79                 return -EINVAL;
  80
  81         memcpy(tctx->key_powers[NUM_KEY_POWERS-1], key, POLYVAL_BLOCK_SIZE);
  82
  83         for (i = NUM_KEY_POWERS-2; i >= 0; i--) {
  84                 memcpy(tctx->key_powers[i], key, POLYVAL_BLOCK_SIZE);
  85                 internal_polyval_mul(tctx->key_powers[i],
  86                                      tctx->key_powers[i+1]);
  87         }
  88
  89         return 0;
  90 }
  91
  92 static int polyval_arm64_init(struct shash_desc *desc)
  93 {
  94         struct polyval_desc_ctx *dctx = shash_desc_ctx(desc);
  95
  96         memset(dctx, 0, sizeof(*dctx));
  97
  98         return 0;
  99 }
 100
 101 static int polyval_arm64_update(struct shash_desc *desc,
 102                          const u8 *src, unsigned int srclen)
 103 {
 104         struct polyval_desc_ctx *dctx = shash_desc_ctx(desc);
 105         const struct polyval_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
 106         u8 *pos;
 107         unsigned int nblocks;
 108         unsigned int n;
 109
 110         if (dctx->bytes) {
 111                 n = min(srclen, dctx->bytes);
 112                 pos = dctx->buffer + POLYVAL_BLOCK_SIZE - dctx->bytes;
 113
 114                 dctx->bytes -= n;
 115                 srclen -= n;
 116
 117                 while (n--)
 118                         *pos++ ^= *src++;
 119
 120                 if (!dctx->bytes)
 121                         internal_polyval_mul(dctx->buffer,
 122                                             tctx->key_powers[NUM_KEY_POWERS-1]);
 123         }
 124
 125         while (srclen >= POLYVAL_BLOCK_SIZE) {
 126                 /* allow rescheduling every 4K bytes */
 127                 nblocks = min(srclen, 4096U) / POLYVAL_BLOCK_SIZE;
 128                 internal_polyval_update(tctx, src, nblocks, dctx->buffer);
 129                 srclen -= nblocks * POLYVAL_BLOCK_SIZE;
 130                 src += nblocks * POLYVAL_BLOCK_SIZE;
 131         }
 132
 133         if (srclen) {
 134                 dctx->bytes = POLYVAL_BLOCK_SIZE - srclen;
 135                 pos = dctx->buffer;
 136                 while (srclen--)
 137                         *pos++ ^= *src++;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int polyval_arm64_final(struct shash_desc *desc, u8 *dst)
 144 {
 145         struct polyval_desc_ctx *dctx = shash_desc_ctx(desc);
 146         const struct polyval_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
 147
 148         if (dctx->bytes) {
 149                 internal_polyval_mul(dctx->buffer,
 150                                      tctx->key_powers[NUM_KEY_POWERS-1]);
 151         }
 152
 153         memcpy(dst, dctx->buffer, POLYVAL_BLOCK_SIZE);
 154
 155         return 0;
 156 }
 157
 158 static struct shash_alg polyval_alg = {
 159         .digestsize     = POLYVAL_DIGEST_SIZE,
 160         .init           = polyval_arm64_init,
 161         .update         = polyval_arm64_update,
 162         .final          = polyval_arm64_final,
 163         .setkey         = polyval_arm64_setkey,
 164         .descsize       = sizeof(struct polyval_desc_ctx),
 165         .base           = {
 166                 .cra_name               = "polyval",
 167                 .cra_driver_name        = "polyval-ce",
 168                 .cra_priority           = 200,
 169                 .cra_blocksize          = POLYVAL_BLOCK_SIZE,
 170                 .cra_ctxsize            = sizeof(struct polyval_tfm_ctx),
 171                 .cra_module             = THIS_MODULE,
 172         },
 173 };
 174
 175 static int __init polyval_ce_mod_init(void)
 176 {
 177         return crypto_register_shash(&polyval_alg);
 178 }
 179
 180 static void __exit polyval_ce_mod_exit(void)
 181 {
 182         crypto_unregister_shash(&polyval_alg);
 183 }
 184
 185 module_cpu_feature_match(PMULL, polyval_ce_mod_init)
 186 module_exit(polyval_ce_mod_exit);
 187
 188 MODULE_LICENSE("GPL");
 189 MODULE_DESCRIPTION("POLYVAL hash function accelerated by ARMv8 Crypto Extensions");
 190 MODULE_ALIAS_CRYPTO("polyval");
 191 MODULE_ALIAS_CRYPTO("polyval-ce");