NAME

Crypt::OpenPGP::Digest - PGP message digest factory

SYNOPSIS

    use Crypt::OpenPGP::Digest;

    my $alg = 'SHA1';
    my $dgst = Crypt::OpenPGP::Digest->new( $alg );
    my $data = 'foo bar';
    my $hashed_data = $dgst->hash($data);

DESCRIPTION

Crypt::OpenPGP::Digest is a factory class for PGP message digest objects. All digest objects are subclasses of this class and share a common interface; when creating a new digest object, the object is blessed into the subclass to take on algorithm-specific functionality.

A Crypt::OpenPGP::Digest object wraps around a function reference providing the actual digest implementation (eg. Digest::MD::md5 for an MD5 digest). This allows all digest objects to share a common interface and a simple instantiation method.

USAGE

Crypt::OpenPGP::Digest->new($digest)

Creates a new message digest object of type $digest; $digest can be either the name of a digest algorithm (in Crypt::OpenPGP parlance) or the numeric ID of the algorithm (as defined in the OpenPGP RFC). Using an algorithm name is recommended, for the simple reason that it is easier to understand quickly (not everyone knows the algorithm IDs).

Valid digest names are: MD5, SHA1, and RIPEMD160.

Returns the new digest object on success. On failure returns undef; the caller should check for failure and call the class method errstr if a failure occurs. A typical reason this might happen is an unsupported digest name or ID.

$dgst->hash($data)

Creates a message digest hash of the data $data, a string of octets, and returns the digest.

$dgst->alg

Returns the name of the digest algorithm (as listed above in new).

$dgst->alg_id

Returns the numeric ID of the digest algorithm.

AUTHOR & COPYRIGHTS

Please see the Crypt::OpenPGP manpage for author, copyright, and license information.