1/* md5.h - Declaration of functions and data types used for MD5 sum
2   computing library functions.
3   Copyright (C) 1995, 1996 Free Software Foundation, Inc.
4   NOTE: The canonical source of this file is maintained with the GNU C
5   Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
6
7   This program is free software; you can redistribute it and/or modify it
8   under the terms of the GNU General Public License as published by the
9   Free Software Foundation; either version 2, or (at your option) any
10   later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software Foundation,
19   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
20
21#ifndef _MD5_H
22#define _MD5_H 1
23
24#ifdef HAVE_CONFIG_H
25# include <config.h>
26#endif
27
28#ifdef USE_MD5
29
30#define PARAMS(args) args
31
32#include <stdio.h>
33
34#if defined HAVE_LIMITS_H || _LIBC
35# include <limits.h>
36#endif
37
38/* The following contortions are an attempt to use the C preprocessor
39   to determine an unsigned integral type that is 32 bits wide.  An
40   alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
41   doing that would require that the configure script compile and *run*
42   the resulting executable.  Locally running cross-compiled executables
43   is usually not possible.  */
44
45#ifdef _LIBC
46# include <sys/types.h>
47typedef u_int32_t md5_uint32;
48#else
49# if defined __STDC__ && __STDC__
50#  define UINT_MAX_32_BITS 4294967295U
51# else
52#  define UINT_MAX_32_BITS 0xFFFFFFFF
53# endif
54
55/* If UINT_MAX isn't defined, assume it's a 32-bit type.
56   This should be valid for all systems GNU cares about because
57   that doesn't include 16-bit systems, and only modern systems
58   (that certainly have <limits.h>) have 64+-bit integral types.  */
59
60# ifndef UINT_MAX
61#  define UINT_MAX UINT_MAX_32_BITS
62# endif
63
64# if UINT_MAX == UINT_MAX_32_BITS
65   typedef unsigned int md5_uint32;
66# else
67#  if USHRT_MAX == UINT_MAX_32_BITS
68    typedef unsigned short md5_uint32;
69#  else
70#   if ULONG_MAX == UINT_MAX_32_BITS
71     typedef unsigned long md5_uint32;
72#   else
73     /* The following line is intended to evoke an error.
74        Using #error is not portable enough.  */
75     "Cannot determine unsigned 32-bit data type."
76#   endif
77#  endif
78# endif
79#endif
80
81/* Structure to save state of computation between the single steps.  */
82struct md5_ctx
83{
84  md5_uint32 A;
85  md5_uint32 B;
86  md5_uint32 C;
87  md5_uint32 D;
88
89  md5_uint32 total[2];
90  md5_uint32 buflen;
91  char buffer[128];
92};
93
94/*
95 * The following three functions are build up the low level used in
96 * the functions `md5_stream' and `md5_buffer'.
97 */
98
99/* Initialize structure containing state of computation.
100   (RFC 1321, 3.3: Step 3)  */
101extern void md5_init_ctx PARAMS ((struct md5_ctx *ctx));
102
103/* Starting with the result of former calls of this function (or the
104   initialization function update the context for the next LEN bytes
105   starting at BUFFER.
106   It is necessary that LEN is a multiple of 64!!! */
107extern void md5_process_block PARAMS ((const void *buffer, size_t len,
108				       struct md5_ctx *ctx));
109
110/* Starting with the result of former calls of this function (or the
111   initialization function update the context for the next LEN bytes
112   starting at BUFFER.
113   It is NOT required that LEN is a multiple of 64.  */
114extern void md5_process_bytes PARAMS ((const void *buffer, size_t len,
115				       struct md5_ctx *ctx));
116
117/* Process the remaining bytes in the buffer and put result from CTX
118   in first 16 bytes following RESBUF.  The result is always in little
119   endian byte order, so that a byte-wise output yields to the wanted
120   ASCII representation of the message digest.
121
122   IMPORTANT: On some systems it is required that RESBUF is correctly
123   aligned for a 32 bits value.  */
124extern void *md5_finish_ctx PARAMS ((struct md5_ctx *ctx, void *resbuf));
125
126
127/* Put result from CTX in first 16 bytes following RESBUF.  The result is
128   always in little endian byte order, so that a byte-wise output yields
129   to the wanted ASCII representation of the message digest.
130
131   IMPORTANT: On some systems it is required that RESBUF is correctly
132   aligned for a 32 bits value.  */
133extern void *md5_read_ctx PARAMS ((const struct md5_ctx *ctx, void *resbuf));
134
135
136/* Compute MD5 message digest for bytes read from STREAM.  The
137   resulting message digest number will be written into the 16 bytes
138   beginning at RESBLOCK.  */
139extern int md5_stream PARAMS ((FILE *stream, void *resblock));
140
141/* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
142   result is always in little endian byte order, so that a byte-wise
143   output yields to the wanted ASCII representation of the message
144   digest.  */
145extern void *md5_buffer PARAMS ((const char *buffer, size_t len,
146				 void *resblock));
147
148#endif
149#endif
150