include/sha1.h

   1 /* Declarations of functions and data types used for SHA1 sum
   2    library functions.
   3    Copyright (C) 2000-2021 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU General Public License as published by the
   7    Free Software Foundation; either version 3, or (at your option) any
   8    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, write to the Free Software Foundation,
  17    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 #ifndef SHA1_H
  20 # define SHA1_H 1
  21
  22 #include <stdio.h>
  23
  24 #if defined HAVE_LIMITS_H || _LIBC
  25 # include <limits.h>
  26 #endif
  27
  28 #include "ansidecl.h"
  29
  30 /* The following contortions are an attempt to use the C preprocessor
  31    to determine an unsigned integral type that is 32 bits wide.  An
  32    alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
  33    doing that would require that the configure script compile and *run*
  34    the resulting executable.  Locally running cross-compiled executables
  35    is usually not possible.  */
  36
  37 #ifdef _LIBC
  38 # include <sys/types.h>
  39 typedef u_int32_t sha1_uint32;
  40 typedef uintptr_t sha1_uintptr;
  41 #elif defined (HAVE_SYS_TYPES_H) && defined (HAVE_STDINT_H)
  42 #include <stdint.h>
  43 #include <sys/types.h>
  44 typedef uint32_t sha1_uint32;
  45 typedef uintptr_t sha1_uintptr;
  46 #else
  47 #  define INT_MAX_32_BITS 2147483647
  48
  49 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
  50    This should be valid for all systems GNU cares about because
  51    that doesn't include 16-bit systems, and only modern systems
  52    (that certainly have <limits.h>) have 64+-bit integral types.  */
  53
  54 # ifndef INT_MAX
  55 #  define INT_MAX INT_MAX_32_BITS
  56 # endif
  57
  58 # if INT_MAX == INT_MAX_32_BITS
  59    typedef unsigned int sha1_uint32;
  60 # else
  61 #  if SHRT_MAX == INT_MAX_32_BITS
  62     typedef unsigned short sha1_uint32;
  63 #  else
  64 #   if LONG_MAX == INT_MAX_32_BITS
  65      typedef unsigned long sha1_uint32;
  66 #   else
  67      /* The following line is intended to evoke an error.
  68         Using #error is not portable enough.  */
  69      "Cannot determine unsigned 32-bit data type."
  70 #   endif
  71 #  endif
  72 # endif
  73 #endif
  74
  75 #ifdef __cplusplus
  76 extern "C" {
  77 #endif
  78
  79 /* Structure to save state of computation between the single steps.  */
  80 struct sha1_ctx
  81 {
  82   sha1_uint32 A;
  83   sha1_uint32 B;
  84   sha1_uint32 C;
  85   sha1_uint32 D;
  86   sha1_uint32 E;
  87
  88   sha1_uint32 total[2];
  89   sha1_uint32 buflen;
  90   sha1_uint32 buffer[32];
  91 };
  92
  93
  94 /* Initialize structure containing state of computation. */
  95 extern void sha1_init_ctx (struct sha1_ctx *ctx);
  96
  97 /* Starting with the result of former calls of this function (or the
  98    initialization function update the context for the next LEN bytes
  99    starting at BUFFER.
 100    It is necessary that LEN is a multiple of 64!!! */
 101 extern void sha1_process_block (const void *buffer, size_t len,
 102                                 struct sha1_ctx *ctx);
 103
 104 /* Starting with the result of former calls of this function (or the
 105    initialization function update the context for the next LEN bytes
 106    starting at BUFFER.
 107    It is NOT required that LEN is a multiple of 64.  */
 108 extern void sha1_process_bytes (const void *buffer, size_t len,
 109                                 struct sha1_ctx *ctx);
 110
 111 /* Process the remaining bytes in the buffer and put result from CTX
 112    in first 20 bytes following RESBUF.  The result is always in little
 113    endian byte order, so that a byte-wise output yields to the wanted
 114    ASCII representation of the message digest.
 115
 116    IMPORTANT: On some systems it is required that RESBUF be correctly
 117    aligned for a 32 bits value.  */
 118 extern void *sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf);
 119
 120
 121 /* Put result from CTX in first 20 bytes following RESBUF.  The result is
 122    always in little endian byte order, so that a byte-wise output yields
 123    to the wanted ASCII representation of the message digest.
 124
 125    IMPORTANT: On some systems it is required that RESBUF is correctly
 126    aligned for a 32 bits value.  */
 127 extern void *sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf);
 128
 129
 130 /* Compute SHA1 message digest for bytes read from STREAM.  The
 131    resulting message digest number will be written into the 20 bytes
 132    beginning at RESBLOCK.  */
 133 extern int sha1_stream (FILE *stream, void *resblock);
 134
 135 /* Compute SHA1 message digest for LEN bytes beginning at BUFFER.  The
 136    result is always in little endian byte order, so that a byte-wise
 137    output yields to the wanted ASCII representation of the message
 138    digest.  */
 139 extern void *sha1_buffer (const char *buffer, size_t len, void *resblock);
 140
 141 #ifdef __cplusplus
 142 }
 143 #endif
 144
 145 #endif