include/crypto/sha1_base.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * sha1_base.h - core logic for SHA-1 implementations
   4  *
   5  * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
   6  */
   7
   8 #ifndef _CRYPTO_SHA1_BASE_H
   9 #define _CRYPTO_SHA1_BASE_H
  10
  11 #include <crypto/internal/hash.h>
  12 #include <crypto/sha1.h>
  13 #include <linux/crypto.h>
  14 #include <linux/module.h>
  15 #include <linux/string.h>
  16
  17 #include <asm/unaligned.h>
  18
  19 typedef void (sha1_block_fn)(struct sha1_state *sst, u8 const *src, int blocks);
  20
  21 static inline int sha1_base_init(struct shash_desc *desc)
  22 {
  23         struct sha1_state *sctx = shash_desc_ctx(desc);
  24
  25         sctx->state[0] = SHA1_H0;
  26         sctx->state[1] = SHA1_H1;
  27         sctx->state[2] = SHA1_H2;
  28         sctx->state[3] = SHA1_H3;
  29         sctx->state[4] = SHA1_H4;
  30         sctx->count = 0;
  31
  32         return 0;
  33 }
  34
  35 static inline int sha1_base_do_update(struct shash_desc *desc,
  36                                       const u8 *data,
  37                                       unsigned int len,
  38                                       sha1_block_fn *block_fn)
  39 {
  40         struct sha1_state *sctx = shash_desc_ctx(desc);
  41         unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
  42
  43         sctx->count += len;
  44
  45         if (unlikely((partial + len) >= SHA1_BLOCK_SIZE)) {
  46                 int blocks;
  47
  48                 if (partial) {
  49                         int p = SHA1_BLOCK_SIZE - partial;
  50
  51                         memcpy(sctx->buffer + partial, data, p);
  52                         data += p;
  53                         len -= p;
  54
  55                         block_fn(sctx, sctx->buffer, 1);
  56                 }
  57
  58                 blocks = len / SHA1_BLOCK_SIZE;
  59                 len %= SHA1_BLOCK_SIZE;
  60
  61                 if (blocks) {
  62                         block_fn(sctx, data, blocks);
  63                         data += blocks * SHA1_BLOCK_SIZE;
  64                 }
  65                 partial = 0;
  66         }
  67         if (len)
  68                 memcpy(sctx->buffer + partial, data, len);
  69
  70         return 0;
  71 }
  72
  73 static inline int sha1_base_do_finalize(struct shash_desc *desc,
  74                                         sha1_block_fn *block_fn)
  75 {
  76         const int bit_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
  77         struct sha1_state *sctx = shash_desc_ctx(desc);
  78         __be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
  79         unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
  80
  81         sctx->buffer[partial++] = 0x80;
  82         if (partial > bit_offset) {
  83                 memset(sctx->buffer + partial, 0x0, SHA1_BLOCK_SIZE - partial);
  84                 partial = 0;
  85
  86                 block_fn(sctx, sctx->buffer, 1);
  87         }
  88
  89         memset(sctx->buffer + partial, 0x0, bit_offset - partial);
  90         *bits = cpu_to_be64(sctx->count << 3);
  91         block_fn(sctx, sctx->buffer, 1);
  92
  93         return 0;
  94 }
  95
  96 static inline int sha1_base_finish(struct shash_desc *desc, u8 *out)
  97 {
  98         struct sha1_state *sctx = shash_desc_ctx(desc);
  99         __be32 *digest = (__be32 *)out;
 100         int i;
 101
 102         for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
 103                 put_unaligned_be32(sctx->state[i], digest++);
 104
 105         memzero_explicit(sctx, sizeof(*sctx));
 106         return 0;
 107 }
 108
 109 #endif /* _CRYPTO_SHA1_BASE_H */