1package Digest::MD5; 2 3use strict; 4use vars qw($VERSION @ISA @EXPORT_OK); 5 6$VERSION = '2.33'; # $Date: 2003/12/07 08:40:18 $ 7 8require Exporter; 9*import = \&Exporter::import; 10@EXPORT_OK = qw(md5 md5_hex md5_base64); 11 12require DynaLoader; 13@ISA=qw(DynaLoader); 14 15eval { 16 require Digest::base; 17 push(@ISA, 'Digest::base'); 18}; 19if ($@) { 20 my $err = $@; 21 *add_bits = sub { die $err }; 22} 23 24 25eval { 26 Digest::MD5->bootstrap($VERSION); 27}; 28if ($@) { 29 my $olderr = $@; 30 eval { 31 # Try to load the pure perl version 32 require Digest::Perl::MD5; 33 34 Digest::Perl::MD5->import(qw(md5 md5_hex md5_base64)); 35 push(@ISA, "Digest::Perl::MD5"); # make OO interface work 36 }; 37 if ($@) { 38 # restore the original error 39 die $olderr; 40 } 41} 42else { 43 *reset = \&new; 44} 45 461; 47__END__ 48 49=head1 NAME 50 51Digest::MD5 - Perl interface to the MD5 Algorithm 52 53=head1 SYNOPSIS 54 55 # Functional style 56 use Digest::MD5 qw(md5 md5_hex md5_base64); 57 58 $digest = md5($data); 59 $digest = md5_hex($data); 60 $digest = md5_base64($data); 61 62 # OO style 63 use Digest::MD5; 64 65 $ctx = Digest::MD5->new; 66 67 $ctx->add($data); 68 $ctx->addfile(*FILE); 69 70 $digest = $ctx->digest; 71 $digest = $ctx->hexdigest; 72 $digest = $ctx->b64digest; 73 74=head1 DESCRIPTION 75 76The C<Digest::MD5> module allows you to use the RSA Data Security 77Inc. MD5 Message Digest algorithm from within Perl programs. The 78algorithm takes as input a message of arbitrary length and produces as 79output a 128-bit "fingerprint" or "message digest" of the input. 80 81The C<Digest::MD5> module provide a procedural interface for simple 82use, as well as an object oriented interface that can handle messages 83of arbitrary length and which can read files directly. 84 85=head1 FUNCTIONS 86 87The following functions are provided by the C<Digest::MD5> module. 88None of these functions are exported by default. 89 90=over 4 91 92=item md5($data,...) 93 94This function will concatenate all arguments, calculate the MD5 digest 95of this "message", and return it in binary form. The returned string 96will be 16 bytes long. 97 98The result of md5("a", "b", "c") will be exactly the same as the 99result of md5("abc"). 100 101=item md5_hex($data,...) 102 103Same as md5(), but will return the digest in hexadecimal form. The 104length of the returned string will be 32 and it will only contain 105characters from this set: '0'..'9' and 'a'..'f'. 106 107=item md5_base64($data,...) 108 109Same as md5(), but will return the digest as a base64 encoded string. 110The length of the returned string will be 22 and it will only contain 111characters from this set: 'A'..'Z', 'a'..'z', '0'..'9', '+' and 112'/'. 113 114Note that the base64 encoded string returned is not padded to be a 115multiple of 4 bytes long. If you want interoperability with other 116base64 encoded md5 digests you might want to append the redundant 117string "==" to the result. 118 119=back 120 121=head1 METHODS 122 123The object oriented interface to C<Digest::MD5> is described in this 124section. After a C<Digest::MD5> object has been created, you will add 125data to it and finally ask for the digest in a suitable format. A 126single object can be used to calculate multiple digests. 127 128The following methods are provided: 129 130=over 4 131 132=item $md5 = Digest::MD5->new 133 134The constructor returns a new C<Digest::MD5> object which encapsulate 135the state of the MD5 message-digest algorithm. 136 137If called as an instance method (i.e. $md5->new) it will just reset the 138state the object to the state of a newly created object. No new 139object is created in this case. 140 141=item $md5->reset 142 143This is just an alias for $md5->new. 144 145=item $md5->clone 146 147This a copy of the $md5 object. It is useful when you do not want to 148destroy the digests state, but need an intermediate value of the 149digest, e.g. when calculating digests iteratively on a continuous data 150stream. Example: 151 152 my $md5 = Digest::MD5->new; 153 while (<>) { 154 $md5->add($_); 155 print "Line $.: ", $md5->clone->hexdigest, "\n"; 156 } 157 158=item $md5->add($data,...) 159 160The $data provided as argument are appended to the message we 161calculate the digest for. The return value is the $md5 object itself. 162 163All these lines will have the same effect on the state of the $md5 164object: 165 166 $md5->add("a"); $md5->add("b"); $md5->add("c"); 167 $md5->add("a")->add("b")->add("c"); 168 $md5->add("a", "b", "c"); 169 $md5->add("abc"); 170 171=item $md5->addfile($io_handle) 172 173The $io_handle will be read until EOF and its content appended to the 174message we calculate the digest for. The return value is the $md5 175object itself. 176 177The addfile() method will croak() if it fails reading data for some 178reason. If it croaks it is unpredictable what the state of the $md5 179object will be in. The addfile() method might have been able to read 180the file partially before it failed. It is probably wise to discard 181or reset the $md5 object if this occurs. 182 183In most cases you want to make sure that the $io_handle is in 184C<binmode> before you pass it as argument to the addfile() method. 185 186=item $md5->add_bits($data, $nbits) 187 188=item $md5->add_bits($bitstring) 189 190Since the MD5 algorithm is byte oriented you might only add bits as 191multiples of 8, so you probably want to just use add() instead. The 192add_bits() method is provided for compatibility with other digest 193implementations. See L<Digest> for description of the arguments 194that add_bits() take. 195 196=item $md5->digest 197 198Return the binary digest for the message. The returned string will be 19916 bytes long. 200 201Note that the C<digest> operation is effectively a destructive, 202read-once operation. Once it has been performed, the C<Digest::MD5> 203object is automatically C<reset> and can be used to calculate another 204digest value. Call $md5->clone->digest if you want to calculate the 205digest without reseting the digest state. 206 207=item $md5->hexdigest 208 209Same as $md5->digest, but will return the digest in hexadecimal 210form. The length of the returned string will be 32 and it will only 211contain characters from this set: '0'..'9' and 'a'..'f'. 212 213=item $md5->b64digest 214 215Same as $md5->digest, but will return the digest as a base64 encoded 216string. The length of the returned string will be 22 and it will only 217contain characters from this set: 'A'..'Z', 'a'..'z', '0'..'9', '+' 218and '/'. 219 220 221The base64 encoded string returned is not padded to be a multiple of 4 222bytes long. If you want interoperability with other base64 encoded 223md5 digests you might want to append the string "==" to the result. 224 225=back 226 227 228=head1 EXAMPLES 229 230The simplest way to use this library is to import the md5_hex() 231function (or one of its cousins): 232 233 use Digest::MD5 qw(md5_hex); 234 print "Digest is ", md5_hex("foobarbaz"), "\n"; 235 236The above example would print out the message: 237 238 Digest is 6df23dc03f9b54cc38a0fc1483df6e21 239 240The same checksum can also be calculated in OO style: 241 242 use Digest::MD5; 243 244 $md5 = Digest::MD5->new; 245 $md5->add('foo', 'bar'); 246 $md5->add('baz'); 247 $digest = $md5->hexdigest; 248 249 print "Digest is $digest\n"; 250 251With OO style you can break the message arbitrary. This means that we 252are no longer limited to have space for the whole message in memory, i.e. 253we can handle messages of any size. 254 255This is useful when calculating checksum for files: 256 257 use Digest::MD5; 258 259 my $file = shift || "/etc/passwd"; 260 open(FILE, $file) or die "Can't open '$file': $!"; 261 binmode(FILE); 262 263 $md5 = Digest::MD5->new; 264 while (<FILE>) { 265 $md5->add($_); 266 } 267 close(FILE); 268 print $md5->b64digest, " $file\n"; 269 270Or we can use the addfile method for more efficient reading of 271the file: 272 273 use Digest::MD5; 274 275 my $file = shift || "/etc/passwd"; 276 open(FILE, $file) or die "Can't open '$file': $!"; 277 binmode(FILE); 278 279 print Digest::MD5->new->addfile(*FILE)->hexdigest, " $file\n"; 280 281Perl 5.8 support Unicode characters in strings. Since the MD5 282algorithm is only defined for strings of bytes, it can not be used on 283strings that contains chars with ordinal number above 255. The MD5 284functions and methods will croak if you try to feed them such input 285data: 286 287 use Digest::MD5 qw(md5_hex); 288 289 my $str = "abc\x{300}"; 290 print md5_hex($str), "\n"; # croaks 291 # Wide character in subroutine entry 292 293What you can do is calculate the MD5 checksum of the UTF-8 294representation of such strings. This is achieved by filtering the 295string through encode_utf8() function: 296 297 use Digest::MD5 qw(md5_hex); 298 use Encode qw(encode_utf8); 299 300 my $str = "abc\x{300}"; 301 print md5_hex(encode_utf8($str)), "\n"; 302 # 8c2d46911f3f5a326455f0ed7a8ed3b3 303 304=head1 SEE ALSO 305 306L<Digest>, 307L<Digest::MD2>, 308L<Digest::SHA1>, 309L<Digest::HMAC> 310 311L<md5sum(1)> 312 313RFC 1321 314 315=head1 COPYRIGHT 316 317This library is free software; you can redistribute it and/or 318modify it under the same terms as Perl itself. 319 320 Copyright 1998-2003 Gisle Aas. 321 Copyright 1995-1996 Neil Winton. 322 Copyright 1991-1992 RSA Data Security, Inc. 323 324The MD5 algorithm is defined in RFC 1321. This implementation is 325derived from the reference C code in RFC 1321 which is covered by 326the following copyright statement: 327 328=over 4 329 330=item 331 332Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All 333rights reserved. 334 335License to copy and use this software is granted provided that it 336is identified as the "RSA Data Security, Inc. MD5 Message-Digest 337Algorithm" in all material mentioning or referencing this software 338or this function. 339 340License is also granted to make and use derivative works provided 341that such works are identified as "derived from the RSA Data 342Security, Inc. MD5 Message-Digest Algorithm" in all material 343mentioning or referencing the derived work. 344 345RSA Data Security, Inc. makes no representations concerning either 346the merchantability of this software or the suitability of this 347software for any particular purpose. It is provided "as is" 348without express or implied warranty of any kind. 349 350These notices must be retained in any copies of any part of this 351documentation and/or software. 352 353=back 354 355This copyright does not prohibit distribution of any version of Perl 356containing this extension under the terms of the GNU or Artistic 357licenses. 358 359=head1 AUTHORS 360 361The original C<MD5> interface was written by Neil Winton 362(C<N.Winton@axion.bt.co.uk>). 363 364The C<Digest::MD5> module is written by Gisle Aas <gisle@ActiveState.com>. 365 366=cut 367