1/* Declaration of functions and data types used for MD5 sum computing
2 library functions.
3 Copyright (C) 1995-2021 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library 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 GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#ifndef _MD5_H
21#define _MD5_H 1
22
23#include <stdio.h>
24
25#if defined HAVE_LIMITS_H || defined _LIBC
26# include <limits.h>
27#endif
28
29#define MD5_DIGEST_SIZE 16
30#define MD5_BLOCK_SIZE 64
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 <stdint.h>
41typedef uint32_t md5_uint32;
42typedef uintptr_t md5_uintptr;
43#else
44# define UINT_MAX_32_BITS 4294967295U
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 UINT_MAX
52# define UINT_MAX UINT_MAX_32_BITS
53# endif
54
55# if UINT_MAX == UINT_MAX_32_BITS
56 typedef unsigned int md5_uint32;
57# else
58# if USHRT_MAX == UINT_MAX_32_BITS
59 typedef unsigned short md5_uint32;
60# else
61# if ULONG_MAX == UINT_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 union
86 {
87 char buffer[128];
88 md5_uint32 buffer32[32];
89 };
90};
91
92/*
93 * The following three functions are build up the low level used in
94 * the functions `md5_stream' and `md5_buffer'.
95 */
96
97/* Initialize structure containing state of computation.
98 (RFC 1321, 3.3: Step 3) */
99extern void __md5_init_ctx (struct md5_ctx *ctx) __THROW;
100
101/* Starting with the result of former calls of this function (or the
102 initialization function update the context for the next LEN bytes
103 starting at BUFFER.
104 It is necessary that LEN is a multiple of 64!!! */
105extern void __md5_process_block (const void *buffer, size_t len,
106 struct md5_ctx *ctx) __THROW;
107
108/* Starting with the result of former calls of this function (or the
109 initialization function update the context for the next LEN bytes
110 starting at BUFFER.
111 It is NOT required that LEN is a multiple of 64. */
112extern void __md5_process_bytes (const void *buffer, size_t len,
113 struct md5_ctx *ctx) __THROW;
114
115/* Process the remaining bytes in the buffer and put result from CTX
116 in first 16 bytes following RESBUF. The result is always in little
117 endian byte order, so that a byte-wise output yields to the wanted
118 ASCII representation of the message digest.
119
120 IMPORTANT: On some systems it is required that RESBUF is correctly
121 aligned for a 32 bits value. */
122extern void *__md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) __THROW;
123
124
125/* Put result from CTX in first 16 bytes following RESBUF. The result is
126 always in little endian byte order, so that a byte-wise output yields
127 to the wanted ASCII representation of the message digest.
128
129 IMPORTANT: On some systems it is required that RESBUF is correctly
130 aligned for a 32 bits value. */
131extern void *__md5_read_ctx (const struct md5_ctx *ctx, void *resbuf) __THROW;
132
133
134/* Compute MD5 message digest for bytes read from STREAM. The
135 resulting message digest number will be written into the 16 bytes
136 beginning at RESBLOCK. */
137extern int __md5_stream (FILE *stream, void *resblock) __THROW;
138
139/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
140 result is always in little endian byte order, so that a byte-wise
141 output yields to the wanted ASCII representation of the message
142 digest. */
143extern void *__md5_buffer (const char *buffer, size_t len,
144 void *resblock) __THROW;
145
146#endif /* md5.h */
147