lib/sha256.h

   1 /* Declarations of functions and data types used for SHA256 and SHA224 sum
   2    library functions.
   3    Copyright (C) 2005-2006, 2008-2024 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 /* This file uses HAVE_OPENSSL_SHA256.  */
  22 # if !_GL_CONFIG_H_INCLUDED
  23 #  error "Please include config.h first."
  24 # endif
  25
  26 # include <stdio.h>
  27 # include <stdint.h>
  28
  29 # if HAVE_OPENSSL_SHA256
  30 #  ifndef OPENSSL_API_COMPAT
  31 #   define OPENSSL_API_COMPAT 0x10101000L /* FIXME: Use OpenSSL 1.1+ API.  */
  32 #  endif
  33 /* If <openssl/macros.h> would give a compile-time error, don't use OpenSSL.  */
  34 #  include <openssl/opensslv.h>
  35 #  if OPENSSL_VERSION_MAJOR >= 3
  36 #   include <openssl/configuration.h>
  37 #   if (OPENSSL_CONFIGURED_API \
  38         < (OPENSSL_API_COMPAT < 0x900000L ? OPENSSL_API_COMPAT : \
  39            ((OPENSSL_API_COMPAT >> 28) & 0xF) * 10000 \
  40            + ((OPENSSL_API_COMPAT >> 20) & 0xFF) * 100 \
  41            + ((OPENSSL_API_COMPAT >> 12) & 0xFF)))
  42 #    undef HAVE_OPENSSL_SHA256
  43 #   endif
  44 #  endif
  45 #  if HAVE_OPENSSL_SHA256
  46 #   include <openssl/sha.h>
  47 #  endif
  48 # endif
  49
  50 # ifdef __cplusplus
  51 extern "C" {
  52 # endif
  53
  54 enum { SHA224_DIGEST_SIZE = 224 / 8 };
  55 enum { SHA256_DIGEST_SIZE = 256 / 8 };
  56
  57 # if HAVE_OPENSSL_SHA256
  58 #  define GL_OPENSSL_NAME 224
  59 #  include "gl_openssl.h"
  60 #  define GL_OPENSSL_NAME 256
  61 #  include "gl_openssl.h"
  62 # else
  63 /* Structure to save state of computation between the single steps.  */
  64 struct sha256_ctx
  65 {
  66   uint32_t state[8];
  67
  68   uint32_t total[2];
  69   size_t buflen;       /* ≥ 0, ≤ 128 */
  70   uint32_t buffer[32]; /* 128 bytes; the first buflen bytes are in use */
  71 };
  72
  73 /* Initialize structure containing state of computation. */
  74 extern void sha256_init_ctx (struct sha256_ctx *ctx);
  75 extern void sha224_init_ctx (struct sha256_ctx *ctx);
  76
  77 /* Starting with the result of former calls of this function (or the
  78    initialization function update the context for the next LEN bytes
  79    starting at BUFFER.
  80    It is necessary that LEN is a multiple of 64!!! */
  81 extern void sha256_process_block (const void *buffer, size_t len,
  82                                   struct sha256_ctx *ctx);
  83
  84 /* Starting with the result of former calls of this function (or the
  85    initialization function update the context for the next LEN bytes
  86    starting at BUFFER.
  87    It is NOT required that LEN is a multiple of 64.  */
  88 extern void sha256_process_bytes (const void *buffer, size_t len,
  89                                   struct sha256_ctx *ctx);
  90
  91 /* Process the remaining bytes in the buffer and put result from CTX
  92    in first 32 (28) bytes following RESBUF.  The result is always in little
  93    endian byte order, so that a byte-wise output yields to the wanted
  94    ASCII representation of the message digest.  */
  95 extern void *sha256_finish_ctx (struct sha256_ctx *ctx, void *restrict resbuf);
  96 extern void *sha224_finish_ctx (struct sha256_ctx *ctx, void *restrict resbuf);
  97
  98
  99 /* Put result from CTX in first 32 (28) bytes following RESBUF.  The result is
 100    always in little endian byte order, so that a byte-wise output yields
 101    to the wanted ASCII representation of the message digest.  */
 102 extern void *sha256_read_ctx (const struct sha256_ctx *ctx,
 103                               void *restrict resbuf);
 104 extern void *sha224_read_ctx (const struct sha256_ctx *ctx,
 105                               void *restrict resbuf);
 106
 107
 108 /* Compute SHA256 (SHA224) message digest for LEN bytes beginning at BUFFER.
 109    The result is always in little endian byte order, so that a byte-wise
 110    output yields to the wanted ASCII representation of the message
 111    digest.  */
 112 extern void *sha256_buffer (const char *buffer, size_t len,
 113                             void *restrict resblock);
 114 extern void *sha224_buffer (const char *buffer, size_t len,
 115                             void *restrict resblock);
 116
 117 # endif
 118
 119 /* Compute SHA256 (SHA224) message digest for bytes read from STREAM.
 120    STREAM is an open file stream.  Regular files are handled more efficiently.
 121    The contents of STREAM from its current position to its end will be read.
 122    The case that the last operation on STREAM was an 'ungetc' is not supported.
 123    The resulting message digest number will be written into the 32 (28) bytes
 124    beginning at RESBLOCK.  */
 125 extern int sha256_stream (FILE *stream, void *resblock);
 126 extern int sha224_stream (FILE *stream, void *resblock);
 127
 128
 129 # ifdef __cplusplus
 130 }
 131 # endif
 132
 133 #endif
 134
 135 /*
 136  * Hey Emacs!
 137  * Local Variables:
 138  * coding: utf-8
 139  * End:
 140  */