lib/sha256.h

   1 /* Declarations of functions and data types used for SHA256 and SHA224 sum
   2    library functions.
   3    Copyright (C) 2005-2006, 2008-2012 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef SHA256_H
  19 # define SHA256_H 1
  20
  21 # include <stdio.h>
  22 # include <stdint.h>
  23
  24 # ifdef __cplusplus
  25 extern "C" {
  26 # endif
  27
  28 /* Structure to save state of computation between the single steps.  */
  29 struct sha256_ctx
  30 {
  31   uint32_t state[8];
  32
  33   uint32_t total[2];
  34   size_t buflen;
  35   uint32_t buffer[32];
  36 };
  37
  38 enum { SHA224_DIGEST_SIZE = 224 / 8 };
  39 enum { SHA256_DIGEST_SIZE = 256 / 8 };
  40
  41 /* Initialize structure containing state of computation. */
  42 extern void sha256_init_ctx (struct sha256_ctx *ctx);
  43 extern void sha224_init_ctx (struct sha256_ctx *ctx);
  44
  45 /* Starting with the result of former calls of this function (or the
  46    initialization function update the context for the next LEN bytes
  47    starting at BUFFER.
  48    It is necessary that LEN is a multiple of 64!!! */
  49 extern void sha256_process_block (const void *buffer, size_t len,
  50                                   struct sha256_ctx *ctx);
  51
  52 /* Starting with the result of former calls of this function (or the
  53    initialization function update the context for the next LEN bytes
  54    starting at BUFFER.
  55    It is NOT required that LEN is a multiple of 64.  */
  56 extern void sha256_process_bytes (const void *buffer, size_t len,
  57                                   struct sha256_ctx *ctx);
  58
  59 /* Process the remaining bytes in the buffer and put result from CTX
  60    in first 32 (28) bytes following RESBUF.  The result is always in little
  61    endian byte order, so that a byte-wise output yields to the wanted
  62    ASCII representation of the message digest.  */
  63 extern void *sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf);
  64 extern void *sha224_finish_ctx (struct sha256_ctx *ctx, void *resbuf);
  65
  66
  67 /* Put result from CTX in first 32 (28) bytes following RESBUF.  The result is
  68    always in little endian byte order, so that a byte-wise output yields
  69    to the wanted ASCII representation of the message digest.  */
  70 extern void *sha256_read_ctx (const struct sha256_ctx *ctx, void *resbuf);
  71 extern void *sha224_read_ctx (const struct sha256_ctx *ctx, void *resbuf);
  72
  73
  74 /* Compute SHA256 (SHA224) message digest for bytes read from STREAM.  The
  75    resulting message digest number will be written into the 32 (28) bytes
  76    beginning at RESBLOCK.  */
  77 extern int sha256_stream (FILE *stream, void *resblock);
  78 extern int sha224_stream (FILE *stream, void *resblock);
  79
  80 /* Compute SHA256 (SHA224) message digest for LEN bytes beginning at BUFFER.  The
  81    result is always in little endian byte order, so that a byte-wise
  82    output yields to the wanted ASCII representation of the message
  83    digest.  */
  84 extern void *sha256_buffer (const char *buffer, size_t len, void *resblock);
  85 extern void *sha224_buffer (const char *buffer, size_t len, void *resblock);
  86
  87 # ifdef __cplusplus
  88 }
  89 # endif
  90
  91 #endif