include/crypto/sha256_base.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * sha256_base.h - core logic for SHA-256 implementations
   4  *
   5  * Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
   6  */
   7
   8 #ifndef _CRYPTO_SHA256_BASE_H
   9 #define _CRYPTO_SHA256_BASE_H
  10
  11 #include <asm/byteorder.h>
  12 #include <linux/unaligned.h>
  13 #include <crypto/internal/hash.h>
  14 #include <crypto/sha2.h>
  15 #include <linux/string.h>
  16 #include <linux/types.h>
  17
  18 typedef void (sha256_block_fn)(struct sha256_state *sst, u8 const *src,
  19                                int blocks);
  20
  21 static inline int sha224_base_init(struct shash_desc *desc)
  22 {
  23         struct sha256_state *sctx = shash_desc_ctx(desc);
  24
  25         sha224_init(sctx);
  26         return 0;
  27 }
  28
  29 static inline int sha256_base_init(struct shash_desc *desc)
  30 {
  31         struct sha256_state *sctx = shash_desc_ctx(desc);
  32
  33         sha256_init(sctx);
  34         return 0;
  35 }
  36
  37 static inline int lib_sha256_base_do_update(struct sha256_state *sctx,
  38                                             const u8 *data,
  39                                             unsigned int len,
  40                                             sha256_block_fn *block_fn)
  41 {
  42         unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
  43
  44         sctx->count += len;
  45
  46         if (unlikely((partial + len) >= SHA256_BLOCK_SIZE)) {
  47                 int blocks;
  48
  49                 if (partial) {
  50                         int p = SHA256_BLOCK_SIZE - partial;
  51
  52                         memcpy(sctx->buf + partial, data, p);
  53                         data += p;
  54                         len -= p;
  55
  56                         block_fn(sctx, sctx->buf, 1);
  57                 }
  58
  59                 blocks = len / SHA256_BLOCK_SIZE;
  60                 len %= SHA256_BLOCK_SIZE;
  61
  62                 if (blocks) {
  63                         block_fn(sctx, data, blocks);
  64                         data += blocks * SHA256_BLOCK_SIZE;
  65                 }
  66                 partial = 0;
  67         }
  68         if (len)
  69                 memcpy(sctx->buf + partial, data, len);
  70
  71         return 0;
  72 }
  73
  74 static inline int sha256_base_do_update(struct shash_desc *desc,
  75                                         const u8 *data,
  76                                         unsigned int len,
  77                                         sha256_block_fn *block_fn)
  78 {
  79         struct sha256_state *sctx = shash_desc_ctx(desc);
  80
  81         return lib_sha256_base_do_update(sctx, data, len, block_fn);
  82 }
  83
  84 static inline int lib_sha256_base_do_finalize(struct sha256_state *sctx,
  85                                               sha256_block_fn *block_fn)
  86 {
  87         const int bit_offset = SHA256_BLOCK_SIZE - sizeof(__be64);
  88         __be64 *bits = (__be64 *)(sctx->buf + bit_offset);
  89         unsigned int partial = sctx->count % SHA256_BLOCK_SIZE;
  90
  91         sctx->buf[partial++] = 0x80;
  92         if (partial > bit_offset) {
  93                 memset(sctx->buf + partial, 0x0, SHA256_BLOCK_SIZE - partial);
  94                 partial = 0;
  95
  96                 block_fn(sctx, sctx->buf, 1);
  97         }
  98
  99         memset(sctx->buf + partial, 0x0, bit_offset - partial);
 100         *bits = cpu_to_be64(sctx->count << 3);
 101         block_fn(sctx, sctx->buf, 1);
 102
 103         return 0;
 104 }
 105
 106 static inline int sha256_base_do_finalize(struct shash_desc *desc,
 107                                           sha256_block_fn *block_fn)
 108 {
 109         struct sha256_state *sctx = shash_desc_ctx(desc);
 110
 111         return lib_sha256_base_do_finalize(sctx, block_fn);
 112 }
 113
 114 static inline int lib_sha256_base_finish(struct sha256_state *sctx, u8 *out,
 115                                          unsigned int digest_size)
 116 {
 117         __be32 *digest = (__be32 *)out;
 118         int i;
 119
 120         for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
 121                 put_unaligned_be32(sctx->state[i], digest++);
 122
 123         memzero_explicit(sctx, sizeof(*sctx));
 124         return 0;
 125 }
 126
 127 static inline int sha256_base_finish(struct shash_desc *desc, u8 *out)
 128 {
 129         unsigned int digest_size = crypto_shash_digestsize(desc->tfm);
 130         struct sha256_state *sctx = shash_desc_ctx(desc);
 131
 132         return lib_sha256_base_finish(sctx, out, digest_size);
 133 }
 134
 135 #endif /* _CRYPTO_SHA256_BASE_H */