lib/perl5/5.8.8/Digest/base.pm

   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>