crypt/sha256.h

   1 /* Declaration of functions and data types used for SHA256 sum computing
   2    library functions.
   3    Copyright (C) 2007-2020 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _SHA256_H
  21 #define _SHA256_H 1
  22
  23 #include <limits.h>
  24 #include <stdint.h>
  25 #include <stdio.h>
  26 #include <endian.h>
  27
  28
  29 /* Structure to save state of computation between the single steps.  */
  30 struct sha256_ctx
  31 {
  32   uint32_t H[8];
  33
  34   union
  35   {
  36     uint64_t total64;
  37 #define TOTAL64_low (1 - (BYTE_ORDER == LITTLE_ENDIAN))
  38 #define TOTAL64_high (BYTE_ORDER == LITTLE_ENDIAN)
  39     uint32_t total[2];
  40   };
  41   uint32_t buflen;
  42   union
  43   {
  44     char buffer[128];
  45     uint32_t buffer32[32];
  46     uint64_t buffer64[16];
  47   };
  48 };
  49
  50 /* Initialize structure containing state of computation.
  51    (FIPS 180-2: 5.3.2)  */
  52 extern void __sha256_init_ctx (struct sha256_ctx *ctx) __THROW;
  53
  54 /* Starting with the result of former calls of this function (or the
  55    initialization function update the context for the next LEN bytes
  56    starting at BUFFER.
  57    It is NOT required that LEN is a multiple of 64.  */
  58 extern void __sha256_process_bytes (const void *buffer, size_t len,
  59                                     struct sha256_ctx *ctx) __THROW;
  60
  61 /* Process the remaining bytes in the buffer and put result from CTX
  62    in first 32 bytes following RESBUF.
  63
  64    IMPORTANT: On some systems it is required that RESBUF is correctly
  65    aligned for a 32 bits value.  */
  66 extern void *__sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
  67   __THROW;
  68
  69 #endif /* sha256.h */