gl/sha256.h

   1 /* Declarations of functions and data types used for SHA256 and SHA224 sum
   2    library functions.
   3    Copyright (C) 2005-2006, 2008-2023 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://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 # if HAVE_OPENSSL_SHA256
  25 #  ifndef OPENSSL_API_COMPAT
  26 #   define OPENSSL_API_COMPAT 0x10101000L /* FIXME: Use OpenSSL 1.1+ API.  */
  27 #  endif
  28 #  include <openssl/sha.h>
  29 # endif
  30
  31 # ifdef __cplusplus
  32 extern "C" {
  33 # endif
  34
  35 enum { SHA224_DIGEST_SIZE = 224 / 8 };
  36 enum { SHA256_DIGEST_SIZE = 256 / 8 };
  37
  38 # if HAVE_OPENSSL_SHA256
  39 #  define GL_OPENSSL_NAME 224
  40 #  include "gl_openssl.h"
  41 #  define GL_OPENSSL_NAME 256
  42 #  include "gl_openssl.h"
  43 # else
  44 /* Structure to save state of computation between the single steps.  */
  45 struct sha256_ctx
  46 {
  47   uint32_t state[8];
  48
  49   uint32_t total[2];
  50   size_t buflen;       /* ≥ 0, ≤ 128 */
  51   uint32_t buffer[32]; /* 128 bytes; the first buflen bytes are in use */
  52 };
  53
  54 /* Initialize structure containing state of computation. */
  55 extern void sha256_init_ctx (struct sha256_ctx *ctx);
  56 extern void sha224_init_ctx (struct sha256_ctx *ctx);
  57
  58 /* Starting with the result of former calls of this function (or the
  59    initialization function update the context for the next LEN bytes
  60    starting at BUFFER.
  61    It is necessary that LEN is a multiple of 64!!! */
  62 extern void sha256_process_block (const void *buffer, size_t len,
  63                                   struct sha256_ctx *ctx);
  64
  65 /* Starting with the result of former calls of this function (or the
  66    initialization function update the context for the next LEN bytes
  67    starting at BUFFER.
  68    It is NOT required that LEN is a multiple of 64.  */
  69 extern void sha256_process_bytes (const void *buffer, size_t len,
  70                                   struct sha256_ctx *ctx);
  71
  72 /* Process the remaining bytes in the buffer and put result from CTX
  73    in first 32 (28) bytes following RESBUF.  The result is always in little
  74    endian byte order, so that a byte-wise output yields to the wanted
  75    ASCII representation of the message digest.  */
  76 extern void *sha256_finish_ctx (struct sha256_ctx *ctx, void *restrict resbuf);
  77 extern void *sha224_finish_ctx (struct sha256_ctx *ctx, void *restrict resbuf);
  78
  79
  80 /* Put result from CTX in first 32 (28) bytes following RESBUF.  The result is
  81    always in little endian byte order, so that a byte-wise output yields
  82    to the wanted ASCII representation of the message digest.  */
  83 extern void *sha256_read_ctx (const struct sha256_ctx *ctx,
  84                               void *restrict resbuf);
  85 extern void *sha224_read_ctx (const struct sha256_ctx *ctx,
  86                               void *restrict resbuf);
  87
  88
  89 /* Compute SHA256 (SHA224) message digest for LEN bytes beginning at BUFFER.
  90    The result is always in little endian byte order, so that a byte-wise
  91    output yields to the wanted ASCII representation of the message
  92    digest.  */
  93 extern void *sha256_buffer (const char *buffer, size_t len,
  94                             void *restrict resblock);
  95 extern void *sha224_buffer (const char *buffer, size_t len,
  96                             void *restrict resblock);
  97
  98 # endif
  99
 100 /* Compute SHA256 (SHA224) message digest for bytes read from STREAM.
 101    STREAM is an open file stream.  Regular files are handled more efficiently.
 102    The contents of STREAM from its current position to its end will be read.
 103    The case that the last operation on STREAM was an 'ungetc' is not supported.
 104    The resulting message digest number will be written into the 32 (28) bytes
 105    beginning at RESBLOCK.  */
 106 extern int sha256_stream (FILE *stream, void *resblock);
 107 extern int sha224_stream (FILE *stream, void *resblock);
 108
 109
 110 # ifdef __cplusplus
 111 }
 112 # endif
 113
 114 #endif
 115
 116 /*
 117  * Hey Emacs!
 118  * Local Variables:
 119  * coding: utf-8
 120  * End:
 121  */