4 use vars qw($VERSION @ISA @EXPORT_OK);
6 $VERSION = '2.24'; # $Date: 2003/03/09 15:23:10 $
9 *import = \&Exporter::import;
10 @EXPORT_OK = qw(md5 md5_hex md5_base64);
16 Digest::MD5->bootstrap($VERSION);
21 # Try to load the pure perl version
22 require Digest::Perl::MD5;
24 Digest::Perl::MD5->import(qw(md5 md5_hex md5_base64));
25 push(@ISA, "Digest::Perl::MD5"); # make OO interface work
28 # restore the original error
41 Digest::MD5 - Perl interface to the MD5 Algorithm
46 use Digest::MD5 qw(md5 md5_hex md5_base64);
49 $digest = md5_hex($data);
50 $digest = md5_base64($data);
55 $ctx = Digest::MD5->new;
60 $digest = $ctx->digest;
61 $digest = $ctx->hexdigest;
62 $digest = $ctx->b64digest;
66 The C<Digest::MD5> module allows you to use the RSA Data Security
67 Inc. MD5 Message Digest algorithm from within Perl programs. The
68 algorithm takes as input a message of arbitrary length and produces as
69 output a 128-bit "fingerprint" or "message digest" of the input.
71 The C<Digest::MD5> module provide a procedural interface for simple
72 use, as well as an object oriented interface that can handle messages
73 of arbitrary length and which can read files directly.
75 A binary digest will be 16 bytes long. A hex digest will be 32
76 characters long. A base64 digest will be 22 characters long.
80 The following functions can be exported from the C<Digest::MD5>
81 module. No functions are exported by default.
87 This function will concatenate all arguments, calculate the MD5 digest
88 of this "message", and return it in binary form.
90 =item md5_hex($data,...)
92 Same as md5(), but will return the digest in hexadecimal form.
94 =item md5_base64($data,...)
96 Same as md5(), but will return the digest as a base64 encoded string.
98 The base64 encoded string returned is not padded to be a multiple of 4
99 bytes long. If you want interoperability with other base64 encoded
100 md5 digests you might want to append the string "==" to the result.
106 The following methods are available:
110 =item $md5 = Digest::MD5->new
112 The constructor returns a new C<Digest::MD5> object which encapsulate
113 the state of the MD5 message-digest algorithm. You can add data to
114 the object and finally ask for the digest.
116 If called as an instance method (i.e. $md5->new) it will just reset the
117 state the object to the state of a newly created object. No new
118 object is created in this case.
122 This is a copy constructor returning a clone of the $md5 object. It is
123 useful when you do not want to destroy the digests state, but need an
124 intermediate value of the digest, e.g. when calculating digests
125 iteratively on a continuous data stream in order to obtain a copy which
130 This is just an alias for $md5->new.
132 =item $md5->add($data,...)
134 The $data provided as argument are appended to the message we
135 calculate the digest for. The return value is the $md5 object itself.
137 =item $md5->addfile($io_handle)
139 The $io_handle is read until EOF and the content is appended to the
140 message we calculate the digest for. The return value is the $md5
143 In most cases you want to make sure that the $io_handle is set up to
148 Return the binary digest for the message.
150 Note that the C<digest> operation is effectively a destructive,
151 read-once operation. Once it has been performed, the C<Digest::MD5>
152 object is automatically C<reset> and can be used to calculate another
153 digest value. Call $md5->clone->digest if you want to calculate the
154 digest without reseting the digest state.
156 =item $md5->hexdigest
158 Same as $md5->digest, but will return the digest in hexadecimal form.
160 =item $md5->b64digest
162 Same as $md5->digest, but will return the digest as a base64 encoded
165 The base64 encoded string returned is not padded to be a multiple of 4
166 bytes long. If you want interoperability with other base64 encoded
167 md5 digests you might want to append the string "==" to the result.
174 The simplest way to use this library is to import the md5_hex()
175 function (or one of its cousins):
177 use Digest::MD5 qw(md5_hex);
178 print "Digest is ", md5_hex("foobarbaz"), "\n";
180 The above example would print out the message
182 Digest is 6df23dc03f9b54cc38a0fc1483df6e21
184 provided that the implementation is working correctly. The same
185 checksum can also be calculated in OO style:
189 $md5 = Digest::MD5->new;
190 $md5->add('foo', 'bar');
192 $digest = $md5->hexdigest;
194 print "Digest is $digest\n";
196 With OO style you can break the message arbitrary. This means that we
197 are no longer limited to have space for the whole message in memory, i.e.
198 we can handle messages of any size.
200 This is useful when calculating checksum for files:
204 my $file = shift || "/etc/passwd";
205 open(FILE, $file) or die "Can't open '$file': $!";
208 $md5 = Digest::MD5->new;
213 print $md5->b64digest, " $file\n";
215 Or we can use the builtin addfile method for more efficient reading of
220 my $file = shift || "/etc/passwd";
221 open(FILE, $file) or die "Can't open '$file': $!";
224 print Digest::MD5->new->addfile(*FILE)->hexdigest, " $file\n";
226 Perl 5.8 support Unicode characters in strings. Since the MD5
227 algorithm is only defined for strings of bytes, it can not be used on
228 strings that contains chars with ordinal number above 255. The MD5
229 functions and methods will croak if you try to feed them such input
232 use Digest::MD5 qw(md5_hex);
234 my $str = "abc\x{300}";
235 print md5_hex($str), "\n"; # croaks
236 # Wide character in subroutine entry
238 What you can do is calculate the MD5 checksum of the UTF-8
239 representation of such strings. This is achieved by filtering the
240 string through encode_utf8() function:
242 use Digest::MD5 qw(md5_hex);
243 use Encode qw(encode_utf8);
245 my $str = "abc\x{300}";
246 print md5_hex(encode_utf8($str)), "\n";
247 # 8c2d46911f3f5a326455f0ed7a8ed3b3
262 This library is free software; you can redistribute it and/or
263 modify it under the same terms as Perl itself.
265 Copyright 1998-2003 Gisle Aas.
266 Copyright 1995-1996 Neil Winton.
267 Copyright 1991-1992 RSA Data Security, Inc.
269 The MD5 algorithm is defined in RFC 1321. The basic C code
270 implementing the algorithm is derived from that in the RFC and is
271 covered by the following copyright:
277 Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
280 License to copy and use this software is granted provided that it
281 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
282 Algorithm" in all material mentioning or referencing this software
285 License is also granted to make and use derivative works provided
286 that such works are identified as "derived from the RSA Data
287 Security, Inc. MD5 Message-Digest Algorithm" in all material
288 mentioning or referencing the derived work.
290 RSA Data Security, Inc. makes no representations concerning either
291 the merchantability of this software or the suitability of this
292 software for any particular purpose. It is provided "as is"
293 without express or implied warranty of any kind.
295 These notices must be retained in any copies of any part of this
296 documentation and/or software.
300 This copyright does not prohibit distribution of any version of Perl
301 containing this extension under the terms of the GNU or Artistic
306 The original MD5 interface was written by Neil Winton
307 (C<N.Winton@axion.bt.co.uk>).
309 This release was made by Gisle Aas <gisle@ActiveState.com>