arch/arm64/crypto/sha2-ce-glue.c

   1 /*
   2  * sha2-ce-glue.c - SHA-224/SHA-256 using ARMv8 Crypto Extensions
   3  *
   4  * Copyright (C) 2014 Linaro Ltd <ard.biesheuvel@linaro.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <asm/neon.h>
  12 #include <asm/unaligned.h>
  13 #include <crypto/internal/hash.h>
  14 #include <crypto/sha.h>
  15 #include <linux/cpufeature.h>
  16 #include <linux/crypto.h>
  17 #include <linux/module.h>
  18
  19 MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash using ARMv8 Crypto Extensions");
  20 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  21 MODULE_LICENSE("GPL v2");
  22
  23 asmlinkage int sha2_ce_transform(int blocks, u8 const *src, u32 *state,
  24                                  u8 *head, long bytes);
  25
  26 static int sha224_init(struct shash_desc *desc)
  27 {
  28         struct sha256_state *sctx = shash_desc_ctx(desc);
  29
  30         *sctx = (struct sha256_state){
  31                 .state = {
  32                         SHA224_H0, SHA224_H1, SHA224_H2, SHA224_H3,
  33                         SHA224_H4, SHA224_H5, SHA224_H6, SHA224_H7,
  34                 }
  35         };
  36         return 0;
  37 }
  38
  39 static int sha256_init(struct shash_desc *desc)
  40 {
  41         struct sha256_state *sctx = shash_desc_ctx(desc);
  42
  43         *sctx = (struct sha256_state){
  44                 .state = {
  45                         SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3,
  46                         SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7,
  47                 }
  48         };
  49         return 0;
  50 }
  51
  52 static int sha2_update(struct shash_desc *desc, const u8 *data,
  53                        unsigned int len)
  54 {
  55         struct sha256_state *sctx = shash_desc_ctx(desc);
  56         unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
  57
  58         sctx->count += len;
  59
  60         if ((partial + len) >= SHA256_BLOCK_SIZE) {
  61                 int blocks;
  62
  63                 if (partial) {
  64                         int p = SHA256_BLOCK_SIZE - partial;
  65
  66                         memcpy(sctx->buf + partial, data, p);
  67                         data += p;
  68                         len -= p;
  69                 }
  70
  71                 blocks = len / SHA256_BLOCK_SIZE;
  72                 len %= SHA256_BLOCK_SIZE;
  73
  74                 kernel_neon_begin_partial(28);
  75                 sha2_ce_transform(blocks, data, sctx->state,
  76                                   partial ? sctx->buf : NULL, 0);
  77                 kernel_neon_end();
  78
  79                 data += blocks * SHA256_BLOCK_SIZE;
  80                 partial = 0;
  81         }
  82         if (len)
  83                 memcpy(sctx->buf + partial, data, len);
  84         return 0;
  85 }
  86
  87 static void sha2_final(struct shash_desc *desc)
  88 {
  89         static const u8 padding[SHA256_BLOCK_SIZE] = { 0x80, };
  90
  91         struct sha256_state *sctx = shash_desc_ctx(desc);
  92         __be64 bits = cpu_to_be64(sctx->count << 3);
  93         u32 padlen = SHA256_BLOCK_SIZE
  94                      - ((sctx->count + sizeof(bits)) % SHA256_BLOCK_SIZE);
  95
  96         sha2_update(desc, padding, padlen);
  97         sha2_update(desc, (const u8 *)&bits, sizeof(bits));
  98 }
  99
 100 static int sha224_final(struct shash_desc *desc, u8 *out)
 101 {
 102         struct sha256_state *sctx = shash_desc_ctx(desc);
 103         __be32 *dst = (__be32 *)out;
 104         int i;
 105
 106         sha2_final(desc);
 107
 108         for (i = 0; i < SHA224_DIGEST_SIZE / sizeof(__be32); i++)
 109                 put_unaligned_be32(sctx->state[i], dst++);
 110
 111         *sctx = (struct sha256_state){};
 112         return 0;
 113 }
 114
 115 static int sha256_final(struct shash_desc *desc, u8 *out)
 116 {
 117         struct sha256_state *sctx = shash_desc_ctx(desc);
 118         __be32 *dst = (__be32 *)out;
 119         int i;
 120
 121         sha2_final(desc);
 122
 123         for (i = 0; i < SHA256_DIGEST_SIZE / sizeof(__be32); i++)
 124                 put_unaligned_be32(sctx->state[i], dst++);
 125
 126         *sctx = (struct sha256_state){};
 127         return 0;
 128 }
 129
 130 static void sha2_finup(struct shash_desc *desc, const u8 *data,
 131                        unsigned int len)
 132 {
 133         struct sha256_state *sctx = shash_desc_ctx(desc);
 134         int blocks;
 135
 136         if (sctx->count || !len || (len % SHA256_BLOCK_SIZE)) {
 137                 sha2_update(desc, data, len);
 138                 sha2_final(desc);
 139                 return;
 140         }
 141
 142         /*
 143          * Use a fast path if the input is a multiple of 64 bytes. In
 144          * this case, there is no need to copy data around, and we can
 145          * perform the entire digest calculation in a single invocation
 146          * of sha2_ce_transform()
 147          */
 148         blocks = len / SHA256_BLOCK_SIZE;
 149
 150         kernel_neon_begin_partial(28);
 151         sha2_ce_transform(blocks, data, sctx->state, NULL, len);
 152         kernel_neon_end();
 153 }
 154
 155 static int sha224_finup(struct shash_desc *desc, const u8 *data,
 156                         unsigned int len, u8 *out)
 157 {
 158         struct sha256_state *sctx = shash_desc_ctx(desc);
 159         __be32 *dst = (__be32 *)out;
 160         int i;
 161
 162         sha2_finup(desc, data, len);
 163
 164         for (i = 0; i < SHA224_DIGEST_SIZE / sizeof(__be32); i++)
 165                 put_unaligned_be32(sctx->state[i], dst++);
 166
 167         *sctx = (struct sha256_state){};
 168         return 0;
 169 }
 170
 171 static int sha256_finup(struct shash_desc *desc, const u8 *data,
 172                         unsigned int len, u8 *out)
 173 {
 174         struct sha256_state *sctx = shash_desc_ctx(desc);
 175         __be32 *dst = (__be32 *)out;
 176         int i;
 177
 178         sha2_finup(desc, data, len);
 179
 180         for (i = 0; i < SHA256_DIGEST_SIZE / sizeof(__be32); i++)
 181                 put_unaligned_be32(sctx->state[i], dst++);
 182
 183         *sctx = (struct sha256_state){};
 184         return 0;
 185 }
 186
 187 static int sha2_export(struct shash_desc *desc, void *out)
 188 {
 189         struct sha256_state *sctx = shash_desc_ctx(desc);
 190         struct sha256_state *dst = out;
 191
 192         *dst = *sctx;
 193         return 0;
 194 }
 195
 196 static int sha2_import(struct shash_desc *desc, const void *in)
 197 {
 198         struct sha256_state *sctx = shash_desc_ctx(desc);
 199         struct sha256_state const *src = in;
 200
 201         *sctx = *src;
 202         return 0;
 203 }
 204
 205 static struct shash_alg algs[] = { {
 206         .init                   = sha224_init,
 207         .update                 = sha2_update,
 208         .final                  = sha224_final,
 209         .finup                  = sha224_finup,
 210         .export                 = sha2_export,
 211         .import                 = sha2_import,
 212         .descsize               = sizeof(struct sha256_state),
 213         .digestsize             = SHA224_DIGEST_SIZE,
 214         .statesize              = sizeof(struct sha256_state),
 215         .base                   = {
 216                 .cra_name               = "sha224",
 217                 .cra_driver_name        = "sha224-ce",
 218                 .cra_priority           = 200,
 219                 .cra_flags              = CRYPTO_ALG_TYPE_SHASH,
 220                 .cra_blocksize          = SHA256_BLOCK_SIZE,
 221                 .cra_module             = THIS_MODULE,
 222         }
 223 }, {
 224         .init                   = sha256_init,
 225         .update                 = sha2_update,
 226         .final                  = sha256_final,
 227         .finup                  = sha256_finup,
 228         .export                 = sha2_export,
 229         .import                 = sha2_import,
 230         .descsize               = sizeof(struct sha256_state),
 231         .digestsize             = SHA256_DIGEST_SIZE,
 232         .statesize              = sizeof(struct sha256_state),
 233         .base                   = {
 234                 .cra_name               = "sha256",
 235                 .cra_driver_name        = "sha256-ce",
 236                 .cra_priority           = 200,
 237                 .cra_flags              = CRYPTO_ALG_TYPE_SHASH,
 238                 .cra_blocksize          = SHA256_BLOCK_SIZE,
 239                 .cra_module             = THIS_MODULE,
 240         }
 241 } };
 242
 243 static int __init sha2_ce_mod_init(void)
 244 {
 245         return crypto_register_shashes(algs, ARRAY_SIZE(algs));
 246 }
 247
 248 static void __exit sha2_ce_mod_fini(void)
 249 {
 250         crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
 251 }
 252
 253 module_cpu_feature_match(SHA2, sha2_ce_mod_init);
 254 module_exit(sha2_ce_mod_fini);