4 use vars qw($VERSION @ISA @EXPORT_OK);
6 $VERSION = '2.33_01'; # $Date: 2003/12/07 08:40:18 $
9 *import = \&Exporter::import;
10 @EXPORT_OK = qw(md5 md5_hex md5_base64);
17 push(@ISA, 'Digest::base');
21 *add_bits = sub { die $err };
26 Digest::MD5->bootstrap($VERSION);
31 # Try to load the pure perl version
32 require Digest::Perl::MD5;
34 Digest::Perl::MD5->import(qw(md5 md5_hex md5_base64));
35 push(@ISA, "Digest::Perl::MD5"); # make OO interface work
38 # restore the original error
51 Digest::MD5 - Perl interface to the MD5 Algorithm
56 use Digest::MD5 qw(md5 md5_hex md5_base64);
59 $digest = md5_hex($data);
60 $digest = md5_base64($data);
65 $ctx = Digest::MD5->new;
70 $digest = $ctx->digest;
71 $digest = $ctx->hexdigest;
72 $digest = $ctx->b64digest;
76 The C<Digest::MD5> module allows you to use the RSA Data Security
77 Inc. MD5 Message Digest algorithm from within Perl programs. The
78 algorithm takes as input a message of arbitrary length and produces as
79 output a 128-bit "fingerprint" or "message digest" of the input.
81 The C<Digest::MD5> module provide a procedural interface for simple
82 use, as well as an object oriented interface that can handle messages
83 of arbitrary length and which can read files directly.
87 The following functions are provided by the C<Digest::MD5> module.
88 None of these functions are exported by default.
94 This function will concatenate all arguments, calculate the MD5 digest
95 of this "message", and return it in binary form. The returned string
96 will be 16 bytes long.
98 The result of md5("a", "b", "c") will be exactly the same as the
101 =item md5_hex($data,...)
103 Same as md5(), but will return the digest in hexadecimal form. The
104 length of the returned string will be 32 and it will only contain
105 characters from this set: '0'..'9' and 'a'..'f'.
107 =item md5_base64($data,...)
109 Same as md5(), but will return the digest as a base64 encoded string.
110 The length of the returned string will be 22 and it will only contain
111 characters from this set: 'A'..'Z', 'a'..'z', '0'..'9', '+' and
114 Note that the base64 encoded string returned is not padded to be a
115 multiple of 4 bytes long. If you want interoperability with other
116 base64 encoded md5 digests you might want to append the redundant
117 string "==" to the result.
123 The object oriented interface to C<Digest::MD5> is described in this
124 section. After a C<Digest::MD5> object has been created, you will add
125 data to it and finally ask for the digest in a suitable format. A
126 single object can be used to calculate multiple digests.
128 The following methods are provided:
132 =item $md5 = Digest::MD5->new
134 The constructor returns a new C<Digest::MD5> object which encapsulate
135 the state of the MD5 message-digest algorithm.
137 If called as an instance method (i.e. $md5->new) it will just reset the
138 state the object to the state of a newly created object. No new
139 object is created in this case.
143 This is just an alias for $md5->new.
147 This a copy of the $md5 object. It is useful when you do not want to
148 destroy the digests state, but need an intermediate value of the
149 digest, e.g. when calculating digests iteratively on a continuous data
152 my $md5 = Digest::MD5->new;
155 print "Line $.: ", $md5->clone->hexdigest, "\n";
158 =item $md5->add($data,...)
160 The $data provided as argument are appended to the message we
161 calculate the digest for. The return value is the $md5 object itself.
163 All these lines will have the same effect on the state of the $md5
166 $md5->add("a"); $md5->add("b"); $md5->add("c");
167 $md5->add("a")->add("b")->add("c");
168 $md5->add("a", "b", "c");
171 =item $md5->addfile($io_handle)
173 The $io_handle will be read until EOF and its content appended to the
174 message we calculate the digest for. The return value is the $md5
177 The addfile() method will croak() if it fails reading data for some
178 reason. If it croaks it is unpredictable what the state of the $md5
179 object will be in. The addfile() method might have been able to read
180 the file partially before it failed. It is probably wise to discard
181 or reset the $md5 object if this occurs.
183 In most cases you want to make sure that the $io_handle is in
184 C<binmode> before you pass it as argument to the addfile() method.
186 =item $md5->add_bits($data, $nbits)
188 =item $md5->add_bits($bitstring)
190 Since the MD5 algorithm is byte oriented you might only add bits as
191 multiples of 8, so you probably want to just use add() instead. The
192 add_bits() method is provided for compatibility with other digest
193 implementations. See L<Digest> for description of the arguments
194 that add_bits() take.
198 Return the binary digest for the message. The returned string will be
201 Note that the C<digest> operation is effectively a destructive,
202 read-once operation. Once it has been performed, the C<Digest::MD5>
203 object is automatically C<reset> and can be used to calculate another
204 digest value. Call $md5->clone->digest if you want to calculate the
205 digest without resetting the digest state.
207 =item $md5->hexdigest
209 Same as $md5->digest, but will return the digest in hexadecimal
210 form. The length of the returned string will be 32 and it will only
211 contain characters from this set: '0'..'9' and 'a'..'f'.
213 =item $md5->b64digest
215 Same as $md5->digest, but will return the digest as a base64 encoded
216 string. The length of the returned string will be 22 and it will only
217 contain characters from this set: 'A'..'Z', 'a'..'z', '0'..'9', '+'
221 The base64 encoded string returned is not padded to be a multiple of 4
222 bytes long. If you want interoperability with other base64 encoded
223 md5 digests you might want to append the string "==" to the result.
230 The simplest way to use this library is to import the md5_hex()
231 function (or one of its cousins):
233 use Digest::MD5 qw(md5_hex);
234 print "Digest is ", md5_hex("foobarbaz"), "\n";
236 The above example would print out the message:
238 Digest is 6df23dc03f9b54cc38a0fc1483df6e21
240 The same checksum can also be calculated in OO style:
244 $md5 = Digest::MD5->new;
245 $md5->add('foo', 'bar');
247 $digest = $md5->hexdigest;
249 print "Digest is $digest\n";
251 With OO style you can break the message arbitrary. This means that we
252 are no longer limited to have space for the whole message in memory, i.e.
253 we can handle messages of any size.
255 This is useful when calculating checksum for files:
259 my $file = shift || "/etc/passwd";
260 open(FILE, $file) or die "Can't open '$file': $!";
263 $md5 = Digest::MD5->new;
268 print $md5->b64digest, " $file\n";
270 Or we can use the addfile method for more efficient reading of
275 my $file = shift || "/etc/passwd";
276 open(FILE, $file) or die "Can't open '$file': $!";
279 print Digest::MD5->new->addfile(*FILE)->hexdigest, " $file\n";
281 Perl 5.8 support Unicode characters in strings. Since the MD5
282 algorithm is only defined for strings of bytes, it can not be used on
283 strings that contains chars with ordinal number above 255. The MD5
284 functions and methods will croak if you try to feed them such input
287 use Digest::MD5 qw(md5_hex);
289 my $str = "abc\x{300}";
290 print md5_hex($str), "\n"; # croaks
291 # Wide character in subroutine entry
293 What you can do is calculate the MD5 checksum of the UTF-8
294 representation of such strings. This is achieved by filtering the
295 string through encode_utf8() function:
297 use Digest::MD5 qw(md5_hex);
298 use Encode qw(encode_utf8);
300 my $str = "abc\x{300}";
301 print md5_hex(encode_utf8($str)), "\n";
302 # 8c2d46911f3f5a326455f0ed7a8ed3b3
317 This library is free software; you can redistribute it and/or
318 modify it under the same terms as Perl itself.
320 Copyright 1998-2003 Gisle Aas.
321 Copyright 1995-1996 Neil Winton.
322 Copyright 1991-1992 RSA Data Security, Inc.
324 The MD5 algorithm is defined in RFC 1321. This implementation is
325 derived from the reference C code in RFC 1321 which is covered by
326 the following copyright statement:
332 Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
335 License to copy and use this software is granted provided that it
336 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
337 Algorithm" in all material mentioning or referencing this software
340 License is also granted to make and use derivative works provided
341 that such works are identified as "derived from the RSA Data
342 Security, Inc. MD5 Message-Digest Algorithm" in all material
343 mentioning or referencing the derived work.
345 RSA Data Security, Inc. makes no representations concerning either
346 the merchantability of this software or the suitability of this
347 software for any particular purpose. It is provided "as is"
348 without express or implied warranty of any kind.
350 These notices must be retained in any copies of any part of this
351 documentation and/or software.
355 This copyright does not prohibit distribution of any version of Perl
356 containing this extension under the terms of the GNU or Artistic
361 The original C<MD5> interface was written by Neil Winton
362 (C<N.Winton@axion.bt.co.uk>).
364 The C<Digest::MD5> module is written by Gisle Aas <gisle@ActiveState.com>.