| Digest-BubbleBabble documentation | Contained in the Digest-BubbleBabble distribution. |
Digest::BubbleBabble - Create bubble-babble fingerprints
# Create a fingerprint of a simple string.
use Digest::BubbleBabble qw( bubblebabble );
my $fingerprint = bubblebabble( Digest => "Pineapple" );
# Create a fingerprint of a SHA-1 hash.
use Digest::SHA1 qw( sha1 );
$fingerprint = bubblebabble( Digest => sha1("hello") );
Digest::BubbleBabble takes a message digest (often generated by either of the MD5 or SHA-1 message digest algorithms) and creates a fingerprint of that digest in "bubble babble" format. Bubble babble is a method of representing a message digest as a string of "real" words, to make the fingerprint easier to remember. The "words" are not necessarily real words, but they look more like words than a string of hex characters.
Bubble babble fingerprinting is used by the SSH2 suite (and, consequently, by Net::SSH::Perl, the Perl SSH implementation) to display easy-to-remember key fingerprints. The key (a DSA or RSA key) is converted into a textual form, digested using Digest::SHA1, and run through bubblebabble to create the key fingerprint.
Digest::BubbleBabble conditionally exports one function called bubblebabble; to import the function you must choose to import it, like this:
use Digest::BubbleBabble qw( bubblebabble );
Currently takes only one pair of arguments, the key of which must be Digest, the value of which is the actual message digest $digest. You should generate this message digest yourself using either Digest::MD5 of Digest::SHA1.
Returns the bubble babble form of the digest.
The BubbleBabble specification is available at: http://web.mit.edu/kenta/www/one/bubblebabble/spec/jrtrjwzi/draft-huima-01.txt
Digest::BubbleBabble is free software; you may redistribute it and/or modify it under the same terms as Perl itself.
Benjamin Trott, cpan@stupidfool.org
Except where otherwise noted, Digest::BubbleBabble is Copyright 2001 Benjamin Trott. All rights reserved.
| Digest-BubbleBabble documentation | Contained in the Digest-BubbleBabble distribution. |
package Digest::BubbleBabble; use strict; use 5.008_001; use Exporter; use vars qw( @EXPORT_OK @ISA $VERSION ); @ISA = qw( Exporter ); @EXPORT_OK = qw( bubblebabble ); $VERSION = '0.02'; use vars qw( @VOWELS @CONSONANTS ); @VOWELS = qw( a e i o u y ); @CONSONANTS = qw( b c d f g h k l m n p r s t v z x ); sub bubblebabble { my %param = @_; my @dgst = map ord, split //, $param{Digest}; my $dlen = length $param{Digest}; my $seed = 1; my $rounds = int($dlen / 2) + 1; my $retval = 'x'; for my $i (0..$rounds-1) { if ($i+1 < $rounds || $dlen % 2) { my $idx0 = ((($dgst[2 * $i] >> 6) & 3) + $seed) % 6; my $idx1 = ($dgst[2 * $i] >> 2) & 15; my $idx2 = (($dgst[2 * $i] & 3) + $seed / 6) % 6; $retval .= $VOWELS[$idx0] . $CONSONANTS[$idx1] . $VOWELS[$idx2]; if ($i+1 < $rounds) { my $idx3 = ($dgst[2 * $i + 1] >> 4) & 15; my $idx4 = $dgst[2 * $i + 1] & 15; $retval .= $CONSONANTS[$idx3] . '-' . $CONSONANTS[$idx4]; $seed = ($seed * 5 + $dgst[2 * $i] * 7 + $dgst[2 * $i + 1]) % 36; } } else { my $idx0 = $seed % 6; my $idx1 = 16; my $idx2 = $seed / 6; $retval .= $VOWELS[$idx0] . $CONSONANTS[$idx1] . $VOWELS[$idx2]; } } $retval .= 'x'; $retval; } 1; __END__