md5.h
1 /* md5.h - Declaration of functions and data types used for MD5 sum
2  computing library functions.
3  Copyright (C) 1995, 1996, 1999 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 LIBDVDREAD_MD5_H
22 #define LIBDVDREAD_MD5_H
23 
24 #include <stdio.h>
25 
26 #if defined HAVE_LIMITS_H || defined _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>
39 typedef u_int32_t md5_uint32;
40 #else
41 # if defined __STDC__ && __STDC__
42 # define UINT_MAX_32_BITS 4294967295U
43 # else
44 # define UINT_MAX_32_BITS 0xFFFFFFFF
45 # endif
46 
47 /* If UINT_MAX isn't defined, assume it's a 32-bit type.
48  This should be valid for all systems GNU cares about because
49  that doesn't include 16-bit systems, and only modern systems
50  (that certainly have <limits.h>) have 64+-bit integral types. */
51 
52 # ifndef UINT_MAX
53 # define UINT_MAX UINT_MAX_32_BITS
54 # endif
55 
56 # if UINT_MAX == UINT_MAX_32_BITS
57 typedef unsigned int md5_uint32;
58 # else
59 # if USHRT_MAX == UINT_MAX_32_BITS
60 typedef unsigned short md5_uint32;
61 # else
62 # if ULONG_MAX == UINT_MAX_32_BITS
63 typedef unsigned long md5_uint32;
64 # else
65 /* The following line is intended to evoke an error.
66  Using #error is not portable enough. */
67 "Cannot determine unsigned 32-bit data type."
68 # endif
69 # endif
70 # endif
71 #endif
72 
73 #undef __P
74 #if defined (__STDC__) && __STDC__
75 #define __P(x) x
76 #else
77 #define __P(x) ()
78 #endif
79 
80 /* Structure to save state of computation between the single steps. */
81 struct md5_ctx
82 {
83  md5_uint32 A;
84  md5_uint32 B;
85  md5_uint32 C;
86  md5_uint32 D;
87 
88  md5_uint32 total[2];
89  md5_uint32 buflen;
90  char buffer[128];
91 };
92 
93 /*
94  * The following three functions are build up the low level used in
95  * the functions `md5_stream' and `md5_buffer'.
96  */
97 
98 /* Initialize structure containing state of computation.
99  (RFC 1321, 3.3: Step 3) */
100 extern void md5_init_ctx __P ((struct md5_ctx *ctx));
101 
102 /* Starting with the result of former calls of this function (or the
103  initialization function update the context for the next LEN bytes
104  starting at BUFFER.
105  It is necessary that LEN is a multiple of 64!!! */
106 extern void md5_process_block __P ((const void *buffer, size_t len,
107  struct md5_ctx *ctx));
108 
109 /* Starting with the result of former calls of this function (or the
110  initialization function update the context for the next LEN bytes
111  starting at BUFFER.
112  It is NOT required that LEN is a multiple of 64. */
113 extern void md5_process_bytes __P ((const void *buffer, size_t len,
114  struct md5_ctx *ctx));
115 
116 /* Process the remaining bytes in the buffer and put result from CTX
117  in first 16 bytes following RESBUF. The result is always in little
118  endian byte order, so that a byte-wise output yields to the wanted
119  ASCII representation of the message digest.
120 
121  IMPORTANT: On some systems it is required that RESBUF be correctly
122  aligned for a 32 bits value. */
123 extern void *md5_finish_ctx __P ((struct md5_ctx *ctx, void *resbuf));
124 
125 
126 /* Put result from CTX in first 16 bytes following RESBUF. The result is
127  always in little endian byte order, so that a byte-wise output yields
128  to the wanted ASCII representation of the message digest.
129 
130  IMPORTANT: On some systems it is required that RESBUF is correctly
131  aligned for a 32 bits value. */
132 extern void *md5_read_ctx __P ((const struct md5_ctx *ctx, void *resbuf));
133 
134 
135 /* Compute MD5 message digest for bytes read from STREAM. The
136  resulting message digest number will be written into the 16 bytes
137  beginning at RESBLOCK. */
138 extern int md5_stream __P ((FILE *stream, void *resblock));
139 
140 /* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
141  result is always in little endian byte order, so that a byte-wise
142  output yields to the wanted ASCII representation of the message
143  digest. */
144 extern void *md5_buffer __P ((const char *buffer, size_t len, void *resblock));
145 
146 /* The following is from gnupg-1.0.2's cipher/bithelp.h. */
147 /* Rotate a 32 bit integer by n bytes */
148 #if defined __GNUC__ && defined __i386__
149 static inline md5_uint32
150 rol(md5_uint32 x, int n)
151 {
152  __asm__("roll %%cl,%0"
153  :"=r" (x)
154  :"0" (x),"c" (n));
155  return x;
156 }
157 #else
158 # define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) )
159 #endif
160 
161 #endif /* LIBDVDREAD_MD5_H */
Definition: md5.h:81