| 1 | package Digest::base; |
| 2 | |
| 3 | use strict; |
| 4 | use vars qw($VERSION); |
| 5 | $VERSION = "1.00"; |
| 6 | |
| 7 | # subclass is supposed to implement at least these |
| 8 | sub new; |
| 9 | sub clone; |
| 10 | sub add; |
| 11 | sub digest; |
| 12 | |
| 13 | sub reset { |
| 14 | my $self = shift; |
| 15 | $self->new(@_); # ugly |
| 16 | } |
| 17 | |
| 18 | sub addfile { |
| 19 | my ($self, $handle) = @_; |
| 20 | |
| 21 | my $n; |
| 22 | my $buf = ""; |
| 23 | |
| 24 | while (($n = read($handle, $buf, 4*1024))) { |
| 25 | $self->add($buf); |
| 26 | } |
| 27 | unless (defined $n) { |
| 28 | require Carp; |
| 29 | Carp::croak("Read failed: $!"); |
| 30 | } |
| 31 | |
| 32 | $self; |
| 33 | } |
| 34 | |
| 35 | sub add_bits { |
| 36 | my $self = shift; |
| 37 | my $bits; |
| 38 | my $nbits; |
| 39 | if (@_ == 1) { |
| 40 | my $arg = shift; |
| 41 | $bits = pack("B*", $arg); |
| 42 | $nbits = length($arg); |
| 43 | } |
| 44 | else { |
| 45 | ($bits, $nbits) = @_; |
| 46 | } |
| 47 | if (($nbits % 8) != 0) { |
| 48 | require Carp; |
| 49 | Carp::croak("Number of bits must be multiple of 8 for this algorithm"); |
| 50 | } |
| 51 | return $self->add(substr($bits, 0, $nbits/8)); |
| 52 | } |
| 53 | |
| 54 | sub hexdigest { |
| 55 | my $self = shift; |
| 56 | return unpack("H*", $self->digest(@_)); |
| 57 | } |
| 58 | |
| 59 | sub b64digest { |
| 60 | my $self = shift; |
| 61 | require MIME::Base64; |
| 62 | my $b64 = MIME::Base64::encode($self->digest(@_), ""); |
| 63 | $b64 =~ s/=+$//; |
| 64 | return $b64; |
| 65 | } |
| 66 | |
| 67 | 1; |
| 68 | |
| 69 | __END__ |
| 70 | |
| 71 | =head1 NAME |
| 72 | |
| 73 | Digest::base - Digest base class |
| 74 | |
| 75 | =head1 SYNOPSIS |
| 76 | |
| 77 | package Digest::Foo; |
| 78 | use base 'Digest::base'; |
| 79 | |
| 80 | =head1 DESCRIPTION |
| 81 | |
| 82 | The C<Digest::base> class provide implementations of the methods |
| 83 | C<addfile> and C<add_bits> in terms of C<add>, and of the methods |
| 84 | C<hexdigest> and C<b64digest> in terms of C<digest>. |
| 85 | |
| 86 | Digest implementations might want to inherit from this class to get |
| 87 | this implementations of the alternative I<add> and I<digest> methods. |
| 88 | A minimal subclass needs to implement the following methods by itself: |
| 89 | |
| 90 | new |
| 91 | clone |
| 92 | add |
| 93 | digest |
| 94 | |
| 95 | The arguments and expected behaviour of these methods are described in |
| 96 | L<Digest>. |
| 97 | |
| 98 | =head1 SEE ALSO |
| 99 | |
| 100 | L<Digest> |