7 use vars qw($VERSION @ISA @EXPORT @EXPORT_OK);
13 @ISA = qw(Exporter DynaLoader);
15 hmac_sha1 hmac_sha1_base64 hmac_sha1_hex
16 hmac_sha224 hmac_sha224_base64 hmac_sha224_hex
17 hmac_sha256 hmac_sha256_base64 hmac_sha256_hex
18 hmac_sha384 hmac_sha384_base64 hmac_sha384_hex
19 hmac_sha512 hmac_sha512_base64 hmac_sha512_hex
20 sha1 sha1_base64 sha1_hex
21 sha224 sha224_base64 sha224_hex
22 sha256 sha256_base64 sha256_hex
23 sha384 sha384_base64 sha384_hex
24 sha512 sha512_base64 sha512_hex);
26 # If possible, inherit from Digest::base (which depends on MIME::Base64)
33 push(@ISA, 'Digest::base');
36 *hexdigest = \&Hexdigest;
37 *b64digest = \&B64digest;
40 # The following routines aren't time-critical, so they can be left in Perl
43 my($class, $alg) = @_;
44 $alg =~ s/\D+//g if defined $alg;
45 if (ref($class)) { # instance method
46 unless (defined($alg) && ($alg != $class->algorithm)) {
50 shaclose($$class) if $$class;
51 $$class = shaopen($alg) || return;
54 $alg = 1 unless defined $alg;
55 my $state = shaopen($alg) || return;
63 shaclose($$self) if $$self;
68 my $state = shadup($$self) || return;
70 bless($copy, ref($self));
77 my($self, $data, $nbits) = @_;
78 unless (defined $nbits) {
79 $nbits = length($data);
80 $data = pack("B*", $data);
82 shawrite($data, $nbits, $$self);
90 Carp::croak("$msg: $!");
93 sub _addfile { # this is "addfile" from Digest::base 1.00
94 my ($self, $handle) = @_;
99 while (($n = read($handle, $buf, 4096))) {
102 _bail("Read failed") unless defined $n;
108 my ($self, $file, $mode) = @_;
110 return(_addfile($self, $file)) unless ref(\$file) eq 'SCALAR';
112 $mode = defined($mode) ? $mode : "";
113 my ($binary, $portable) = map { $_ eq $mode } ("b", "p");
117 # protect any leading or trailing whitespace in $file;
118 # otherwise, 2-arg "open" will ignore them
119 $file =~ s#^(\s)#./$1#;
120 open(FH, "< $file\0") or _bail("Open failed");
121 binmode(FH) if $binary || $portable;
123 unless ($portable && $text) {
124 $self->_addfile(*FH);
130 my ($buf1, $buf2) = ("", "");
132 while (($n1 = read(FH, $buf1, 4096))) {
133 while (substr($buf1, -1) eq "\015") {
134 $n2 = read(FH, $buf2, 4096);
135 _bail("Read failed") unless defined $n2;
139 $buf1 =~ s/\015?\015\012/\012/g; # DOS/Windows
140 $buf1 =~ s/\015/\012/g; # early MacOS
143 _bail("Read failed") unless defined $n1;
151 my $file = shift || "";
153 shadump($file, $$self) || return;
159 my $file = shift || "";
160 if (ref($class)) { # instance method
161 shaclose($$class) if $$class;
162 $$class = shaload($file) || return;
165 my $state = shaload($file) || return;
167 bless($self, $class);
171 Digest::SHA->bootstrap($VERSION);
178 Digest::SHA - Perl extension for SHA-1/224/256/384/512
184 # Functional interface
186 use Digest::SHA qw(sha1 sha1_hex sha1_base64 ...);
188 $digest = sha1($data);
189 $digest = sha1_hex($data);
190 $digest = sha1_base64($data);
192 $digest = sha256($data);
193 $digest = sha384_hex($data);
194 $digest = sha512_base64($data);
200 $sha = Digest::SHA->new($alg);
202 $sha->add($data); # feed data into stream
205 $sha->addfile($filename);
207 $sha->add_bits($bits);
208 $sha->add_bits($data, $nbits);
210 $sha_copy = $sha->clone; # if needed, make copy of
211 $sha->dump($file); # current digest state,
212 $sha->load($file); # or save it on disk
214 $digest = $sha->digest; # compute digest
215 $digest = $sha->hexdigest;
216 $digest = $sha->b64digest;
218 From the command line:
224 =head1 SYNOPSIS (HMAC-SHA)
226 # Functional interface only
228 use Digest::SHA qw(hmac_sha1 hmac_sha1_hex ...);
230 $digest = hmac_sha1($data, $key);
231 $digest = hmac_sha224_hex($data, $key);
232 $digest = hmac_sha256_base64($data, $key);
236 Digest::SHA is a complete implementation of the NIST Secure Hash
237 Standard. It gives Perl programmers a convenient way to calculate
238 SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512 message digests.
239 The module can handle all types of input, including partial-byte
244 Digest::SHA is written in C for speed. If your platform lacks a
245 C compiler, you can install the functionally equivalent (but much
246 slower) L<Digest::SHA::PurePerl> module.
248 The programming interface is easy to use: it's the same one found
249 in CPAN's L<Digest> module. So, if your applications currently
250 use L<Digest::MD5> and you'd prefer the stronger security of SHA,
251 it's a simple matter to convert them.
253 The interface provides two ways to calculate digests: all-at-once,
254 or in stages. To illustrate, the following short program computes
255 the SHA-256 digest of "hello world" using each approach:
257 use Digest::SHA qw(sha256_hex);
259 $data = "hello world";
260 @frags = split(//, $data);
262 # all-at-once (Functional style)
263 $digest1 = sha256_hex($data);
265 # in-stages (OOP style)
266 $state = Digest::SHA->new(256);
267 for (@frags) { $state->add($_) }
268 $digest2 = $state->hexdigest;
270 print $digest1 eq $digest2 ?
271 "whew!\n" : "oops!\n";
273 To calculate the digest of an n-bit message where I<n> is not a
274 multiple of 8, use the I<add_bits()> method. For example, consider
275 the 446-bit message consisting of the bit-string "110" repeated
276 148 times, followed by "11". Here's how to display its SHA-1
280 $bits = "110" x 148 . "11";
281 $sha = Digest::SHA->new(1)->add_bits($bits);
282 print $sha->hexdigest, "\n";
284 Note that for larger bit-strings, it's more efficient to use the
285 two-argument version I<add_bits($data, $nbits)>, where I<$data> is
286 in the customary packed binary format used for Perl strings.
288 The module also lets you save intermediate SHA states to disk, or
289 display them on standard output. The I<dump()> method generates
290 portable, human-readable text describing the current state of
291 computation. You can subsequently retrieve the file with I<load()>
292 to resume where the calculation left off.
294 To see what a state description looks like, just run the following:
297 Digest::SHA->new->add("Shaw" x 1962)->dump;
299 As an added convenience, the Digest::SHA module offers routines to
300 calculate keyed hashes using the HMAC-SHA-1/224/256/384/512
301 algorithms. These services exist in functional form only, and
302 mimic the style and behavior of the I<sha()>, I<sha_hex()>, and
303 I<sha_base64()> functions.
305 # Test vector from draft-ietf-ipsec-ciph-sha-256-01.txt
307 use Digest::SHA qw(hmac_sha256_hex);
308 print hmac_sha256_hex("Hi There", chr(0x0b) x 32), "\n";
310 =head1 NIST STATEMENT ON SHA-1
312 I<NIST was recently informed that researchers had discovered a way
313 to "break" the current Federal Information Processing Standard SHA-1
314 algorithm, which has been in effect since 1994. The researchers
315 have not yet published their complete results, so NIST has not
316 confirmed these findings. However, the researchers are a reputable
317 research team with expertise in this area.>
319 I<Due to advances in computing power, NIST already planned to phase
320 out SHA-1 in favor of the larger and stronger hash functions (SHA-224,
321 SHA-256, SHA-384 and SHA-512) by 2010. New developments should use
322 the larger and stronger hash functions.>
324 ref. L<http://www.csrc.nist.gov/pki/HashWorkshop/NIST%20Statement/Burr_Mar2005.html>
326 =head1 PADDING OF BASE64 DIGESTS
328 By convention, CPAN Digest modules do B<not> pad their Base64 output.
329 Problems can occur when feeding such digests to other software that
330 expects properly padded Base64 encodings.
332 For the time being, any necessary padding must be done by the user.
333 Fortunately, this is a simple operation: if the length of a Base64-encoded
334 digest isn't a multiple of 4, simply append "=" characters to the end
335 of the digest until it is:
337 while (length($b64_digest) % 4) {
341 To illustrate, I<sha256_base64("abc")> is computed to be
343 ungWv48Bz+pBQUDeXa4iI7ADYaOWF3qctBD/YfIAFa0
345 which has a length of 43. So, the properly padded version is
347 ungWv48Bz+pBQUDeXa4iI7ADYaOWF3qctBD/YfIAFa0=
353 =head1 EXPORTABLE FUNCTIONS
355 Provided your C compiler supports a 64-bit type (e.g. the I<long
356 long> of C99, or I<__int64> used by Microsoft C/C++), all of these
357 functions will be available for use. Otherwise, you won't be able
358 to perform the SHA-384 and SHA-512 transforms, both of which require
365 =item B<sha1($data, ...)>
367 =item B<sha224($data, ...)>
369 =item B<sha256($data, ...)>
371 =item B<sha384($data, ...)>
373 =item B<sha512($data, ...)>
375 Logically joins the arguments into a single string, and returns
376 its SHA-1/224/256/384/512 digest encoded as a binary string.
378 =item B<sha1_hex($data, ...)>
380 =item B<sha224_hex($data, ...)>
382 =item B<sha256_hex($data, ...)>
384 =item B<sha384_hex($data, ...)>
386 =item B<sha512_hex($data, ...)>
388 Logically joins the arguments into a single string, and returns
389 its SHA-1/224/256/384/512 digest encoded as a hexadecimal string.
391 =item B<sha1_base64($data, ...)>
393 =item B<sha224_base64($data, ...)>
395 =item B<sha256_base64($data, ...)>
397 =item B<sha384_base64($data, ...)>
399 =item B<sha512_base64($data, ...)>
401 Logically joins the arguments into a single string, and returns
402 its SHA-1/224/256/384/512 digest encoded as a Base64 string.
404 It's important to note that the resulting string does B<not> contain
405 the padding characters typical of Base64 encodings. This omission is
406 deliberate, and is done to maintain compatibility with the family of
407 CPAN Digest modules. See L</"PADDING OF BASE64 DIGESTS"> for details.
417 Returns a new Digest::SHA object. Allowed values for I<$alg> are
418 1, 224, 256, 384, or 512. It's also possible to use common string
419 representations of the algorithm (e.g. "sha256", "SHA-384"). If
420 the argument is missing, SHA-1 will be used by default.
422 Invoking I<new> as an instance method will not create a new object;
423 instead, it will simply reset the object to the initial state
424 associated with I<$alg>. If the argument is missing, the object
425 will continue using the same algorithm that was selected at creation.
429 This method has exactly the same effect as I<new($alg)>. In fact,
430 I<reset> is just an alias for I<new>.
434 Returns the number of digest bits for this object. The values are
435 160, 224, 256, 384, and 512 for SHA-1, SHA-224, SHA-256, SHA-384,
436 and SHA-512, respectively.
440 Returns the digest algorithm for this object. The values are 1,
441 224, 256, 384, and 512 for SHA-1, SHA-224, SHA-256, SHA-384, and
442 SHA-512, respectively.
446 Returns a duplicate copy of the object.
448 =item B<add($data, ...)>
450 Logically joins the arguments into a single string, and uses it to
451 update the current digest state. In other words, the following
452 statements have the same effect:
454 $sha->add("a"); $sha->add("b"); $sha->add("c");
455 $sha->add("a")->add("b")->add("c");
456 $sha->add("a", "b", "c");
459 The return value is the updated object itself.
461 =item B<add_bits($data, $nbits)>
463 =item B<add_bits($bits)>
465 Updates the current digest state by appending bits to it. The
466 return value is the updated object itself.
468 The first form causes the most-significant I<$nbits> of I<$data>
469 to be appended to the stream. The I<$data> argument is in the
470 customary binary format used for Perl strings.
472 The second form takes an ASCII string of "0" and "1" characters as
473 its argument. It's equivalent to
475 $sha->add_bits(pack("B*", $bits), length($bits));
477 So, the following two statements do the same thing:
479 $sha->add_bits("111100001010");
480 $sha->add_bits("\xF0\xA0", 12);
482 =item B<addfile(*FILE)>
484 Reads from I<FILE> until EOF, and appends that data to the current
485 state. The return value is the updated object itself.
487 =item B<addfile($filename [, $mode])>
489 Reads the contents of I<$filename>, and appends that data to the current
490 state. The return value is the updated object itself.
492 By default, I<$filename> is simply opened and read; no special modes
493 or I/O disciplines are used. To change this, set the optional I<$mode>
494 argument to one of the following values:
496 "b" read file in binary mode
498 "p" use portable mode
500 The "p" mode is handy since it ensures that the digest value of
501 I<$filename> will be the same when computed on different operating
502 systems. It accomplishes this by internally translating all newlines in
503 text files to UNIX format before calculating the digest. Binary files
504 are read in raw mode with no translation whatsoever.
506 For a fuller discussion of newline formats, refer to CPAN module
507 L<File::LocalizeNewlines>. Its "universal line separator" regex forms
508 the basis of I<addfile>'s portable mode processing.
510 =item B<dump($filename)>
512 Provides persistent storage of intermediate SHA states by writing
513 a portable, human-readable representation of the current state to
514 I<$filename>. If the argument is missing, or equal to the empty
515 string, the state information will be written to STDOUT.
517 =item B<load($filename)>
519 Returns a Digest::SHA object representing the intermediate SHA
520 state that was previously dumped to I<$filename>. If called as a
521 class method, a new object is created; if called as an instance
522 method, the object is reset to the state contained in I<$filename>.
523 If the argument is missing, or equal to the empty string, the state
524 information will be read from STDIN.
528 Returns the digest encoded as a binary string.
530 Note that the I<digest> method is a read-once operation. Once it
531 has been performed, the Digest::SHA object is automatically reset
532 in preparation for calculating another digest value. Call
533 I<$sha-E<gt>clone-E<gt>digest> if it's necessary to preserve the
534 original digest state.
538 Returns the digest encoded as a hexadecimal string.
540 Like I<digest>, this method is a read-once operation. Call
541 I<$sha-E<gt>clone-E<gt>hexdigest> if it's necessary to preserve
542 the original digest state.
544 This method is inherited if L<Digest::base> is installed on your
545 system. Otherwise, a functionally equivalent substitute is used.
549 Returns the digest encoded as a Base64 string.
551 Like I<digest>, this method is a read-once operation. Call
552 I<$sha-E<gt>clone-E<gt>b64digest> if it's necessary to preserve
553 the original digest state.
555 This method is inherited if L<Digest::base> is installed on your
556 system. Otherwise, a functionally equivalent substitute is used.
558 It's important to note that the resulting string does B<not> contain
559 the padding characters typical of Base64 encodings. This omission is
560 deliberate, and is done to maintain compatibility with the family of
561 CPAN Digest modules. See L</"PADDING OF BASE64 DIGESTS"> for details.
565 I<HMAC-SHA-1/224/256/384/512>
569 =item B<hmac_sha1($data, $key)>
571 =item B<hmac_sha224($data, $key)>
573 =item B<hmac_sha256($data, $key)>
575 =item B<hmac_sha384($data, $key)>
577 =item B<hmac_sha512($data, $key)>
579 Returns the HMAC-SHA-1/224/256/384/512 digest of I<$data>/I<$key>,
580 with the result encoded as a binary string. Multiple I<$data>
581 arguments are allowed, provided that I<$key> is the last argument
584 =item B<hmac_sha1_hex($data, $key)>
586 =item B<hmac_sha224_hex($data, $key)>
588 =item B<hmac_sha256_hex($data, $key)>
590 =item B<hmac_sha384_hex($data, $key)>
592 =item B<hmac_sha512_hex($data, $key)>
594 Returns the HMAC-SHA-1/224/256/384/512 digest of I<$data>/I<$key>,
595 with the result encoded as a hexadecimal string. Multiple I<$data>
596 arguments are allowed, provided that I<$key> is the last argument
599 =item B<hmac_sha1_base64($data, $key)>
601 =item B<hmac_sha224_base64($data, $key)>
603 =item B<hmac_sha256_base64($data, $key)>
605 =item B<hmac_sha384_base64($data, $key)>
607 =item B<hmac_sha512_base64($data, $key)>
609 Returns the HMAC-SHA-1/224/256/384/512 digest of I<$data>/I<$key>,
610 with the result encoded as a Base64 string. Multiple I<$data>
611 arguments are allowed, provided that I<$key> is the last argument
614 It's important to note that the resulting string does B<not> contain
615 the padding characters typical of Base64 encodings. This omission is
616 deliberate, and is done to maintain compatibility with the family of
617 CPAN Digest modules. See L</"PADDING OF BASE64 DIGESTS"> for details.
623 L<Digest>, L<Digest::SHA::PurePerl>
625 The Secure Hash Standard (FIPS PUB 180-2) can be found at:
627 L<http://csrc.nist.gov/publications/fips/fips180-2/fips180-2withchangenotice.pdf>
629 The Keyed-Hash Message Authentication Code (HMAC):
631 L<http://csrc.nist.gov/publications/fips/fips198/fips-198a.pdf>
635 Mark Shelor <mshelor@cpan.org>
637 =head1 ACKNOWLEDGMENTS
639 The author is particularly grateful to
658 for their valuable comments and suggestions.
660 =head1 COPYRIGHT AND LICENSE
662 Copyright (C) 2003-2010 Mark Shelor
664 This library is free software; you can redistribute it and/or modify
665 it under the same terms as Perl itself.