1/* md5.h - Declaration of functions and data types used for MD5 sum
2   computing library functions.
3   Copyright 1995, 1996, 2000 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#include <stdio.h>
25
26#if defined HAVE_LIMITS_H || _LIBC
27# include <limits.h>
28#endif
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>
39typedef u_int32_t md5_uint32;
40#else
41#  define INT_MAX_32_BITS 2147483647
42
43/* If UINT_MAX isn't defined, assume it's a 32-bit type.
44   This should be valid for all systems GNU cares about because
45   that doesn't include 16-bit systems, and only modern systems
46   (that certainly have <limits.h>) have 64+-bit integral types.  */
47
48# ifndef INT_MAX
49#  define INT_MAX INT_MAX_32_BITS
50# endif
51
52# if INT_MAX == INT_MAX_32_BITS
53   typedef unsigned int md5_uint32;
54# else
55#  if SHRT_MAX == INT_MAX_32_BITS
56    typedef unsigned short md5_uint32;
57#  else
58#   if LONG_MAX == INT_MAX_32_BITS
59     typedef unsigned long md5_uint32;
60#   else
61     /* The following line is intended to evoke an error.
62        Using #error is not portable enough.  */
63     "Cannot determine unsigned 32-bit data type."
64#   endif
65#  endif
66# endif
67#endif
68
69#undef __P
70#if defined (__STDC__) && __STDC__
71#define	__P(x) x
72#else
73#define	__P(x) ()
74#endif
75
76/* Structure to save state of computation between the single steps.  */
77struct md5_ctx
78{
79  md5_uint32 A;
80  md5_uint32 B;
81  md5_uint32 C;
82  md5_uint32 D;
83
84  md5_uint32 total[2];
85  md5_uint32 buflen;
86  char buffer[128];
87};
88
89/*
90 * The following three functions are build up the low level used in
91 * the functions `md5_stream' and `md5_buffer'.
92 */
93
94/* Initialize structure containing state of computation.
95   (RFC 1321, 3.3: Step 3)  */
96extern void md5_init_ctx __P ((struct md5_ctx *ctx));
97
98/* Starting with the result of former calls of this function (or the
99   initialization function update the context for the next LEN bytes
100   starting at BUFFER.
101   It is necessary that LEN is a multiple of 64!!! */
102extern void md5_process_block __P ((const void *buffer, size_t len,
103				    struct md5_ctx *ctx));
104
105/* Starting with the result of former calls of this function (or the
106   initialization function update the context for the next LEN bytes
107   starting at BUFFER.
108   It is NOT required that LEN is a multiple of 64.  */
109extern void md5_process_bytes __P ((const void *buffer, size_t len,
110				    struct md5_ctx *ctx));
111
112/* Process the remaining bytes in the buffer and put result from CTX
113   in first 16 bytes following RESBUF.  The result is always in little
114   endian byte order, so that a byte-wise output yields to the wanted
115   ASCII representation of the message digest.
116
117   IMPORTANT: On some systems it is required that RESBUF is correctly
118   aligned for a 32 bits value.  */
119extern void *md5_finish_ctx __P ((struct md5_ctx *ctx, void *resbuf));
120
121
122/* Put result from CTX in first 16 bytes following RESBUF.  The result is
123   always in little endian byte order, so that a byte-wise output yields
124   to the wanted ASCII representation of the message digest.
125
126   IMPORTANT: On some systems it is required that RESBUF is correctly
127   aligned for a 32 bits value.  */
128extern void *md5_read_ctx __P ((const struct md5_ctx *ctx, void *resbuf));
129
130
131/* Compute MD5 message digest for bytes read from STREAM.  The
132   resulting message digest number will be written into the 16 bytes
133   beginning at RESBLOCK.  */
134extern int md5_stream __P ((FILE *stream, void *resblock));
135
136/* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
137   result is always in little endian byte order, so that a byte-wise
138   output yields to the wanted ASCII representation of the message
139   digest.  */
140extern void *md5_buffer __P ((const char *buffer, size_t len, void *resblock));
141
142#endif
143