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1 | package Digest::MD5; |
2 | |
3 | use strict; |
4 | use vars qw($VERSION @ISA @EXPORT_OK); |
5 | |
ac70dec1 |
6 | $VERSION = '2.25'; # $Date: 2003/07/05 05:25:37 $ |
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7 | |
8 | require Exporter; |
9 | *import = \&Exporter::import; |
10 | @EXPORT_OK = qw(md5 md5_hex md5_base64); |
11 | |
12 | require DynaLoader; |
13 | @ISA=qw(DynaLoader); |
14 | |
15 | eval { |
16 | Digest::MD5->bootstrap($VERSION); |
17 | }; |
18 | if ($@) { |
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19 | my $olderr = $@; |
20 | eval { |
21 | # Try to load the pure perl version |
22 | require Digest::Perl::MD5; |
23 | |
24 | Digest::Perl::MD5->import(qw(md5 md5_hex md5_base64)); |
25 | push(@ISA, "Digest::Perl::MD5"); # make OO interface work |
26 | }; |
27 | if ($@) { |
28 | # restore the original error |
29 | die $olderr; |
30 | } |
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31 | } |
32 | else { |
33 | *reset = \&new; |
34 | } |
35 | |
36 | 1; |
37 | __END__ |
38 | |
39 | =head1 NAME |
40 | |
41 | Digest::MD5 - Perl interface to the MD5 Algorithm |
42 | |
43 | =head1 SYNOPSIS |
44 | |
45 | # Functional style |
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46 | use Digest::MD5 qw(md5 md5_hex md5_base64); |
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47 | |
48 | $digest = md5($data); |
49 | $digest = md5_hex($data); |
50 | $digest = md5_base64($data); |
51 | |
52 | # OO style |
53 | use Digest::MD5; |
54 | |
55 | $ctx = Digest::MD5->new; |
56 | |
57 | $ctx->add($data); |
58 | $ctx->addfile(*FILE); |
59 | |
60 | $digest = $ctx->digest; |
61 | $digest = $ctx->hexdigest; |
62 | $digest = $ctx->b64digest; |
63 | |
64 | =head1 DESCRIPTION |
65 | |
66 | The C<Digest::MD5> module allows you to use the RSA Data Security |
67 | Inc. MD5 Message Digest algorithm from within Perl programs. The |
68 | algorithm takes as input a message of arbitrary length and produces as |
69 | output a 128-bit "fingerprint" or "message digest" of the input. |
70 | |
71 | The C<Digest::MD5> module provide a procedural interface for simple |
72 | use, as well as an object oriented interface that can handle messages |
73 | of arbitrary length and which can read files directly. |
74 | |
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75 | =head1 FUNCTIONS |
76 | |
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77 | The following functions are provided by the C<Digest::MD5> module. |
78 | None of these functions are exported by default. |
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79 | |
80 | =over 4 |
81 | |
82 | =item md5($data,...) |
83 | |
84 | This function will concatenate all arguments, calculate the MD5 digest |
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85 | of this "message", and return it in binary form. The returned string |
86 | will be 16 bytes long. |
87 | |
88 | The result of md5("a", "b", "c") will be exactly the same as the |
89 | result of md5("abc"). |
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90 | |
91 | =item md5_hex($data,...) |
92 | |
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93 | Same as md5(), but will return the digest in hexadecimal form. The |
94 | length of the returned string will be 32 and it will only contain |
95 | characters from this set: '0'..'9' and 'a'..'f'. |
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96 | |
97 | =item md5_base64($data,...) |
98 | |
99 | Same as md5(), but will return the digest as a base64 encoded string. |
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100 | The length of the returned string will be 22 and it will only contain |
101 | characters from this set: 'A'..'Z', 'a'..'z', '0'..'9', '+' and |
102 | '/'. |
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103 | |
ac70dec1 |
104 | Note that the base64 encoded string returned is not padded to be a |
105 | multiple of 4 bytes long. If you want interoperability with other |
106 | base64 encoded md5 digests you might want to append the redundant |
107 | string redundant "==" to the result. |
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108 | |
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109 | =back |
110 | |
111 | =head1 METHODS |
112 | |
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113 | The object oriented interface to C<Digest::MD5> is described in this |
114 | section. After a C<Digest::MD5> object has been created, you will add |
115 | data to it and finally ask for the digest in a suitable format. A |
116 | single object can be used to calculate multiple digests. |
117 | |
118 | The following methods are provided: |
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119 | |
120 | =over 4 |
121 | |
122 | =item $md5 = Digest::MD5->new |
123 | |
124 | The constructor returns a new C<Digest::MD5> object which encapsulate |
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125 | the state of the MD5 message-digest algorithm. |
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126 | |
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127 | If called as an instance method (i.e. $md5->new) it will just reset the |
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128 | state the object to the state of a newly created object. No new |
129 | object is created in this case. |
130 | |
131 | =item $md5->reset |
132 | |
133 | This is just an alias for $md5->new. |
134 | |
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135 | =item $md5->clone |
136 | |
137 | This a copy of the $md5 object. It is useful when you do not want to |
138 | destroy the digests state, but need an intermediate value of the |
139 | digest, e.g. when calculating digests iteratively on a continuous data |
140 | stream. Example: |
141 | |
142 | my $md5 = Digest::MD5->new; |
143 | while (<>) { |
144 | $md5->add($_); |
145 | print "Line $.: ", $md5->clone->hexdigest, "\n"; |
146 | } |
147 | |
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148 | =item $md5->add($data,...) |
149 | |
150 | The $data provided as argument are appended to the message we |
151 | calculate the digest for. The return value is the $md5 object itself. |
152 | |
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153 | All these lines will have the same effect on the state of the $md5 |
154 | object: |
155 | |
156 | $md5->add("a"); $md5->add("b"); $md5->add("c"); |
157 | $md5->add("a")->add("b")->add("c"); |
158 | $md5->add("a", "b", "c"); |
159 | $md5->add("abc"); |
160 | |
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161 | =item $md5->addfile($io_handle) |
162 | |
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163 | The $io_handle will be read until EOF and its content appended to the |
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164 | message we calculate the digest for. The return value is the $md5 |
165 | object itself. |
166 | |
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167 | The addfile() method will croak() if it fails reading data for some |
168 | reason. If it croaks it is unpredictable what the state of the $md5 |
169 | object will be in. The addfile() method might have been able to read |
170 | the file partially before it failed. It is probably wise to discard |
171 | or reset the $md5 object if this occurs. |
172 | |
173 | In most cases you want to make sure that the $io_handle is in |
174 | C<binmode> before you pass it as argument to the addfile() method. |
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175 | |
176 | =item $md5->digest |
177 | |
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178 | Return the binary digest for the message. The returned string will be |
179 | 16 bytes long. |
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180 | |
181 | Note that the C<digest> operation is effectively a destructive, |
182 | read-once operation. Once it has been performed, the C<Digest::MD5> |
183 | object is automatically C<reset> and can be used to calculate another |
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184 | digest value. Call $md5->clone->digest if you want to calculate the |
185 | digest without reseting the digest state. |
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186 | |
187 | =item $md5->hexdigest |
188 | |
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189 | Same as $md5->digest, but will return the digest in hexadecimal |
190 | form. The length of the returned string will be 32 and it will only |
191 | contain characters from this set: '0'..'9' and 'a'..'f'. |
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192 | |
193 | =item $md5->b64digest |
194 | |
195 | Same as $md5->digest, but will return the digest as a base64 encoded |
ac70dec1 |
196 | string. The length of the returned string will be 22 and it will only |
197 | contain characters from this set: 'A'..'Z', 'a'..'z', '0'..'9', '+' |
198 | and '/'. |
199 | |
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200 | |
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201 | The base64 encoded string returned is not padded to be a multiple of 4 |
202 | bytes long. If you want interoperability with other base64 encoded |
203 | md5 digests you might want to append the string "==" to the result. |
204 | |
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205 | =back |
206 | |
207 | |
208 | =head1 EXAMPLES |
209 | |
210 | The simplest way to use this library is to import the md5_hex() |
211 | function (or one of its cousins): |
212 | |
213 | use Digest::MD5 qw(md5_hex); |
214 | print "Digest is ", md5_hex("foobarbaz"), "\n"; |
215 | |
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216 | The above example would print out the message: |
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217 | |
218 | Digest is 6df23dc03f9b54cc38a0fc1483df6e21 |
219 | |
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220 | The same checksum can also be calculated in OO style: |
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221 | |
222 | use Digest::MD5; |
223 | |
224 | $md5 = Digest::MD5->new; |
225 | $md5->add('foo', 'bar'); |
226 | $md5->add('baz'); |
227 | $digest = $md5->hexdigest; |
228 | |
229 | print "Digest is $digest\n"; |
230 | |
231 | With OO style you can break the message arbitrary. This means that we |
232 | are no longer limited to have space for the whole message in memory, i.e. |
233 | we can handle messages of any size. |
234 | |
235 | This is useful when calculating checksum for files: |
236 | |
237 | use Digest::MD5; |
238 | |
239 | my $file = shift || "/etc/passwd"; |
240 | open(FILE, $file) or die "Can't open '$file': $!"; |
241 | binmode(FILE); |
242 | |
243 | $md5 = Digest::MD5->new; |
244 | while (<FILE>) { |
245 | $md5->add($_); |
246 | } |
247 | close(FILE); |
248 | print $md5->b64digest, " $file\n"; |
249 | |
250 | Or we can use the builtin addfile method for more efficient reading of |
251 | the file: |
252 | |
253 | use Digest::MD5; |
254 | |
255 | my $file = shift || "/etc/passwd"; |
256 | open(FILE, $file) or die "Can't open '$file': $!"; |
257 | binmode(FILE); |
258 | |
259 | print Digest::MD5->new->addfile(*FILE)->hexdigest, " $file\n"; |
260 | |
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261 | Perl 5.8 support Unicode characters in strings. Since the MD5 |
262 | algorithm is only defined for strings of bytes, it can not be used on |
263 | strings that contains chars with ordinal number above 255. The MD5 |
264 | functions and methods will croak if you try to feed them such input |
265 | data: |
266 | |
267 | use Digest::MD5 qw(md5_hex); |
268 | |
269 | my $str = "abc\x{300}"; |
270 | print md5_hex($str), "\n"; # croaks |
271 | # Wide character in subroutine entry |
272 | |
273 | What you can do is calculate the MD5 checksum of the UTF-8 |
274 | representation of such strings. This is achieved by filtering the |
275 | string through encode_utf8() function: |
276 | |
277 | use Digest::MD5 qw(md5_hex); |
278 | use Encode qw(encode_utf8); |
279 | |
280 | my $str = "abc\x{300}"; |
281 | print md5_hex(encode_utf8($str)), "\n"; |
282 | # 8c2d46911f3f5a326455f0ed7a8ed3b3 |
283 | |
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284 | =head1 SEE ALSO |
285 | |
286 | L<Digest>, |
287 | L<Digest::MD2>, |
288 | L<Digest::SHA1>, |
289 | L<Digest::HMAC> |
290 | |
291 | L<md5sum(1)> |
292 | |
293 | RFC 1321 |
294 | |
295 | =head1 COPYRIGHT |
296 | |
297 | This library is free software; you can redistribute it and/or |
298 | modify it under the same terms as Perl itself. |
299 | |
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300 | Copyright 1998-2003 Gisle Aas. |
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301 | Copyright 1995-1996 Neil Winton. |
302 | Copyright 1991-1992 RSA Data Security, Inc. |
303 | |
ac70dec1 |
304 | The MD5 algorithm is defined in RFC 1321. This implementation is |
305 | derived from the reference C code in RFC 1321 which is covered by |
306 | the following copyright statement: |
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307 | |
308 | =over 4 |
309 | |
310 | =item |
311 | |
312 | Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All |
313 | rights reserved. |
314 | |
315 | License to copy and use this software is granted provided that it |
316 | is identified as the "RSA Data Security, Inc. MD5 Message-Digest |
317 | Algorithm" in all material mentioning or referencing this software |
318 | or this function. |
319 | |
320 | License is also granted to make and use derivative works provided |
321 | that such works are identified as "derived from the RSA Data |
322 | Security, Inc. MD5 Message-Digest Algorithm" in all material |
323 | mentioning or referencing the derived work. |
324 | |
325 | RSA Data Security, Inc. makes no representations concerning either |
326 | the merchantability of this software or the suitability of this |
327 | software for any particular purpose. It is provided "as is" |
328 | without express or implied warranty of any kind. |
329 | |
330 | These notices must be retained in any copies of any part of this |
331 | documentation and/or software. |
332 | |
333 | =back |
334 | |
335 | This copyright does not prohibit distribution of any version of Perl |
336 | containing this extension under the terms of the GNU or Artistic |
337 | licenses. |
338 | |
339 | =head1 AUTHORS |
340 | |
ac70dec1 |
341 | The original C<MD5> interface was written by Neil Winton |
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342 | (C<N.Winton@axion.bt.co.uk>). |
343 | |
ac70dec1 |
344 | The C<Digest::MD5> module is written by Gisle Aas <gisle@ActiveState.com>. |
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345 | |
346 | =cut |