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