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., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, 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#include "ansidecl.h"
31
32/* The following contortions are an attempt to use the C preprocessor
33   to determine an unsigned integral type that is 32 bits wide.  An
34   alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
35   doing that would require that the configure script compile and *run*
36   the resulting executable.  Locally running cross-compiled executables
37   is usually not possible.  */
38
39#ifdef _LIBC
40# include <sys/types.h>
41typedef u_int32_t md5_uint32;
42typedef uintptr_t md5_uintptr;
43#else
44#  define INT_MAX_32_BITS 2147483647
45
46/* If UINT_MAX isn't defined, assume it's a 32-bit type.
47   This should be valid for all systems GNU cares about because
48   that doesn't include 16-bit systems, and only modern systems
49   (that certainly have <limits.h>) have 64+-bit integral types.  */
50
51# ifndef INT_MAX
52#  define INT_MAX INT_MAX_32_BITS
53# endif
54
55# if INT_MAX == INT_MAX_32_BITS
56   typedef unsigned int md5_uint32;
57# else
58#  if SHRT_MAX == INT_MAX_32_BITS
59    typedef unsigned short md5_uint32;
60#  else
61#   if LONG_MAX == INT_MAX_32_BITS
62     typedef unsigned long md5_uint32;
63#   else
64     /* The following line is intended to evoke an error.
65        Using #error is not portable enough.  */
66     "Cannot determine unsigned 32-bit data type."
67#   endif
68#  endif
69# endif
70/* We have to make a guess about the integer type equivalent in size
71   to pointers which should always be correct.  */
72typedef unsigned long int md5_uintptr;
73#endif
74
75/* Structure to save state of computation between the single steps.  */
76struct md5_ctx
77{
78  md5_uint32 A;
79  md5_uint32 B;
80  md5_uint32 C;
81  md5_uint32 D;
82
83  md5_uint32 total[2];
84  md5_uint32 buflen;
85  char buffer[128] ATTRIBUTE_ALIGNED_ALIGNOF(md5_uint32);
86};
87
88/*
89 * The following three functions are build up the low level used in
90 * the functions `md5_stream' and `md5_buffer'.
91 */
92
93/* Initialize structure containing state of computation.
94   (RFC 1321, 3.3: Step 3)  */
95extern void md5_init_ctx (struct md5_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!!! */
101extern void md5_process_block (const void *buffer, size_t len,
102                               struct md5_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.  */
108extern void md5_process_bytes (const void *buffer, size_t len,
109                               struct md5_ctx *ctx);
110
111/* Process the remaining bytes in the buffer and put result from CTX
112   in first 16 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 is correctly
117   aligned for a 32 bits value.  */
118extern void *md5_finish_ctx (struct md5_ctx *ctx, void *resbuf);
119
120
121/* Put result from CTX in first 16 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.  */
127extern void *md5_read_ctx (const struct md5_ctx *ctx, void *resbuf);
128
129
130/* Compute MD5 message digest for bytes read from STREAM.  The
131   resulting message digest number will be written into the 16 bytes
132   beginning at RESBLOCK.  */
133extern int md5_stream (FILE *stream, void *resblock);
134
135/* Compute MD5 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.  */
139extern void *md5_buffer (const char *buffer, size_t len, void *resblock);
140
141#endif
142