Initial Commit

database/perl/vendor/lib/Crypt/RSA/Errorhandler.pm

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+package Crypt::RSA::Errorhandler; 
+use strict;
+use warnings;
+
+## Crypt::RSA::Errorhandler -- Base class that provides error 
+##                             handling functionality.
+##
+## Copyright (c) 2001, Vipul Ved Prakash.  All rights reserved.
+## This code is free software; you can redistribute it and/or modify
+## it under the same terms as Perl itself.
+
+sub new { 
+    bless {}, shift
+}
+
+
+sub error { 
+    my ($self, $errstr, @towipe) = @_;
+    $$self{errstr} = "$errstr\n";
+    for (@towipe) { 
+        my $var = $_;
+        if (ref($var) =~ /Crypt::RSA/) { 
+            $var->DESTROY();
+        } elsif (ref($var) eq "SCALAR") { 
+            $$var = ""; 
+        } elsif (ref($var) eq "ARRAY") { 
+            @$var = ();
+        } elsif (ref($var) eq "HASH") { 
+            %$var = ();
+        }
+    }
+    return;    
+} 
+
+
+sub errstr { 
+    my $self = shift;
+    return $$self{errstr};
+}
+
+sub errstrrst { 
+    my $self = shift;
+    $$self{errstr} = "";
+}
+
+1;
+
+
+=head1 NAME
+
+Crypt::RSA::Errorhandler - Error handling mechanism for Crypt::RSA.
+
+=head1 SYNOPSIS
+
+    package Foo;
+
+    use Crypt::RSA::Errorhandler;
+    @ISA = qw(Crypt::RSA::Errorhandler);
+    
+    sub alive { 
+        ..
+        ..
+        return 
+        $self->error ("Awake, awake! Ring the alarum bell. \
+                       Murther and treason!", $dagger) 
+            if $self->murdered($king);
+    }
+
+
+    package main; 
+
+    use Foo;
+    my $foo = new Foo;
+    $foo->alive($king) or print $foo->errstr(); 
+        # prints "Awake, awake! ... "
+
+=head1 DESCRIPTION 
+
+Crypt::RSA::Errorhandler encapsulates the error handling mechanism used
+by the modules in Crypt::RSA bundle. Crypt::RSA::Errorhandler doesn't
+have a constructor and is meant to be inherited. The derived modules use
+its two methods, error() and errstr(), to communicate error messages to
+the caller.
+
+When a method of the derived module fails, it calls $self->error() and
+returns undef to the caller. The error message passed to error() is made
+available to the caller through the errstr() accessor. error() also
+accepts a list of sensitive data that it wipes out (undef'es) before
+returning.
+
+The caller should B<never> call errstr() to check for errors. errstr()
+should be called only when a method indicates (usually through an undef
+return value) that an error has occurred. This is because errstr() is
+never overwritten and will always contain a value after the occurence of
+first error.
+
+=head1 METHODS
+
+=over 4
+
+=item B<new()>
+
+Barebones constructor.
+
+=item B<error($mesage, ($wipeme, $wipemetoo))>
+
+The first argument to error() is $message which is placed in $self-
+>{errstr} and the remaining arguments are interpreted as
+variables containing sensitive data that are wiped out from the
+memory. error() always returns undef.
+
+=item B<errstr()> 
+
+errstr() is an accessor method for $self->{errstr}.
+
+=item B<errstrrst()>
+
+This method sets $self->{errstr} to an empty string.
+
+=back
+
+=head1 AUTHOR
+
+Vipul Ved Prakash, E<lt>mail@vipul.netE<gt>
+
+=head1 SEE ALSO 
+
+Crypt::RSA(3)
+
+=cut
+
+