NAME

SYNOPSIS

    use Crypt::RIPEMD160;
    
    $context = Crypt::RIPEMD160->new;
    $context->reset();
    
    $context->add(LIST);
    $context->addfile(HANDLE);
    
    $digest = $context->digest();
    $string = $context->hexdigest();

    $digest = Crypt::RIPEMD160->hash(SCALAR);
    $string = Crypt::RIPEMD160->hexhash(SCALAR);

DESCRIPTION

The module is based on the implementation from Antoon Bosselaers from Katholieke Universiteit Leuven.

A new RIPEMD160 context object is created with the new operation. Multiple simultaneous digest contexts can be maintained, if desired. The context is updated with the add operation which adds the strings contained in the LIST parameter. Note, however, that "add('foo', 'bar')", "add('foo')" followed by "add('bar')" and "add('foobar')" should all give the same result.

The final message digest value is returned by the digest operation as a 20-byte binary string. This operation delivers the result of add operations since the last new or reset operation. Note that the digest operation is effectively a destructive, read-once operation. Once it has been performed, the context must be reset before being used to calculate another digest value.

Several convenience functions are also provided. The addfile operation takes an open file-handle and reads it until end-of file in 8192 byte blocks adding the contents to the context. The file-handle can either be specified by name or passed as a type-glob reference, as shown in the examples below. The hexdigest operation calls digest and returns the result as a printable string of hexdecimal digits. This is exactly the same operation as performed by the unpack operation in the examples below.

The hash operation can act as either a static member function (ie you invoke it on the RIPEMD160 class as in the synopsis above) or as a normal virtual function. In both cases it performs the complete RIPEMD160 cycle (reset, add, digest) on the supplied scalar value. This is convenient for handling small quantities of data. When invoked on the class a temporary context is created. When invoked through an already created context object, this context is used. The latter form is slightly more efficient. The hexhash operation is analogous to hexdigest.

EXAMPLES

    use Crypt::RIPEMD160;
    
    $ripemd160 = Crypt::RIPEMD160->new;
    $ripemd160->add('foo', 'bar');
    $ripemd160->add('baz');
    $digest = $ripemd160->digest();
    
    print("Digest is " . unpack("H*", $digest) . "\n");

The above example would print out the message

    Digest is f137cb536c05ec2bc97e73327937b6e81d3a4cc9

provided that the implementation is working correctly.

Remembering the Perl motto ("There's more than one way to do it"), the following should all give the same result:

    use Crypt::RIPEMD160;
    $ripemd160 = Crypt::RIPEMD160->new;

    die "Can't open /etc/passwd ($!)\n" unless open(P, "/etc/passwd");

    seek(P, 0, 0);
    $ripemd160->reset;
    $ripemd160->addfile(P);
    $d = $ripemd160->hexdigest;
    print "addfile (handle name) = $d\n";

    seek(P, 0, 0);
    $ripemd160->reset;
    $ripemd160->addfile(\*P);
    $d = $ripemd160->hexdigest;
    print "addfile (type-glob reference) = $d\n";

    seek(P, 0, 0);
    $ripemd160->reset;
    while (<P>)
    {
        $ripemd160->add($_);
    }
    $d = $ripemd160->hexdigest;
    print "Line at a time = $d\n";

    seek(P, 0, 0);
    $ripemd160->reset;
    $ripemd160->add(<P>);
    $d = $ripemd160->hexdigest;
    print "All lines at once = $d\n";

    seek(P, 0, 0);
    $ripemd160->reset;
    while (read(P, $data, (rand % 128) + 1))
    {
        $ripemd160->add($data);
    }
    $d = $ripemd160->hexdigest;
    print "Random chunks = $d\n";

    seek(P, 0, 0);
    $ripemd160->reset;
    undef $/;
    $data = <P>;
    $d = $ripemd160->hexhash($data);
    print "Single string = $d\n";

    close(P);

NOTE

The basic C code implementing the algorithm is covered by the following copyright:

RIPEMD-160 test suite results (ASCII):

This copyright does not prohibit distribution of any version of Perl containing this extension under the terms of the GNU or Artistic licences.

AUTHOR

SEE ALSO