include/sha1.h

   1 /* Declarations of functions and data types used for SHA1 sum
   2    library functions.
   3    Copyright (C) 2000, 2001, 2003, 2005, 2006, 2008, 2010
   4    Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 3, or (at your option) any
   9    later version.
  10
  11    This program 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
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 #ifndef SHA1_H
  21 # define SHA1_H 1
  22
  23 #include <stdio.h>
  24
  25 #if defined HAVE_LIMITS_H || _LIBC
  26 # include <limits.h>
  27 #endif
  28
  29 #include "ansidecl.h"
  30
  31 /* The following contortions are an attempt to use the C preprocessor
  32    to determine an unsigned integral type that is 32 bits wide.  An
  33    alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
  34    doing that would require that the configure script compile and *run*
  35    the resulting executable.  Locally running cross-compiled executables
  36    is usually not possible.  */
  37
  38 #ifdef _LIBC
  39 # include <sys/types.h>
  40 typedef u_int32_t sha1_uint32;
  41 typedef uintptr_t sha1_uintptr;
  42 #else
  43 #  define INT_MAX_32_BITS 2147483647
  44
  45 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
  46    This should be valid for all systems GNU cares about because
  47    that doesn't include 16-bit systems, and only modern systems
  48    (that certainly have <limits.h>) have 64+-bit integral types.  */
  49
  50 # ifndef INT_MAX
  51 #  define INT_MAX INT_MAX_32_BITS
  52 # endif
  53
  54 # if INT_MAX == INT_MAX_32_BITS
  55    typedef unsigned int sha1_uint32;
  56 # else
  57 #  if SHRT_MAX == INT_MAX_32_BITS
  58     typedef unsigned short sha1_uint32;
  59 #  else
  60 #   if LONG_MAX == INT_MAX_32_BITS
  61      typedef unsigned long sha1_uint32;
  62 #   else
  63      /* The following line is intended to evoke an error.
  64         Using #error is not portable enough.  */
  65      "Cannot determine unsigned 32-bit data type."
  66 #   endif
  67 #  endif
  68 # endif
  69 #endif
  70
  71 #ifdef __cplusplus
  72 extern "C" {
  73 #endif
  74
  75 /* Structure to save state of computation between the single steps.  */
  76 struct sha1_ctx
  77 {
  78   sha1_uint32 A;
  79   sha1_uint32 B;
  80   sha1_uint32 C;
  81   sha1_uint32 D;
  82   sha1_uint32 E;
  83
  84   sha1_uint32 total[2];
  85   sha1_uint32 buflen;
  86   sha1_uint32 buffer[32];
  87 };
  88
  89
  90 /* Initialize structure containing state of computation. */
  91 extern void sha1_init_ctx (struct sha1_ctx *ctx);
  92
  93 /* Starting with the result of former calls of this function (or the
  94    initialization function update the context for the next LEN bytes
  95    starting at BUFFER.
  96    It is necessary that LEN is a multiple of 64!!! */
  97 extern void sha1_process_block (const void *buffer, size_t len,
  98                                 struct sha1_ctx *ctx);
  99
 100 /* Starting with the result of former calls of this function (or the
 101    initialization function update the context for the next LEN bytes
 102    starting at BUFFER.
 103    It is NOT required that LEN is a multiple of 64.  */
 104 extern void sha1_process_bytes (const void *buffer, size_t len,
 105                                 struct sha1_ctx *ctx);
 106
 107 /* Process the remaining bytes in the buffer and put result from CTX
 108    in first 20 bytes following RESBUF.  The result is always in little
 109    endian byte order, so that a byte-wise output yields to the wanted
 110    ASCII representation of the message digest.
 111
 112    IMPORTANT: On some systems it is required that RESBUF be correctly
 113    aligned for a 32 bits value.  */
 114 extern void *sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf);
 115
 116
 117 /* Put result from CTX in first 20 bytes following RESBUF.  The result is
 118    always in little endian byte order, so that a byte-wise output yields
 119    to the wanted ASCII representation of the message digest.
 120
 121    IMPORTANT: On some systems it is required that RESBUF is correctly
 122    aligned for a 32 bits value.  */
 123 extern void *sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf);
 124
 125
 126 /* Compute SHA1 message digest for bytes read from STREAM.  The
 127    resulting message digest number will be written into the 20 bytes
 128    beginning at RESBLOCK.  */
 129 extern int sha1_stream (FILE *stream, void *resblock);
 130
 131 /* Compute SHA1 message digest for LEN bytes beginning at BUFFER.  The
 132    result is always in little endian byte order, so that a byte-wise
 133    output yields to the wanted ASCII representation of the message
 134    digest.  */
 135 extern void *sha1_buffer (const char *buffer, size_t len, void *resblock);
 136
 137 #ifdef __cplusplus
 138 }
 139 #endif
 140
 141 #endif