NAME

Net::SSH::Perl::Cipher - Base cipher class, plus utility methods

SYNOPSIS

    use Net::SSH::Perl::Cipher;

    # Get list of supported cipher IDs.
    my $supported = Net::SSH::Perl::Cipher::supported();

    # Translate a cipher name into an ID.
    my $id = Net::SSH::Perl::Cipher::id($name);

    # Translate a cipher ID into a name.
    my $name = Net::SSH::Perl::Cipher::name($id);

DESCRIPTION

Net::SSH::Perl::Cipher provides a base class for each of the encryption cipher classes. In addition, it defines a set of utility methods that can be called either as functions or object methods.

UTILITY METHODS

supported( [ protocol => $protocol, ] [ $ciph_id [, $server_supports ] ])

Without arguments returns a reference to an array of ciphers supported by Net::SSH::Perl. These are ciphers that have working Net::SSH::Perl::Cipher:: implementations, essentially. Pass 'protocol => 2' to get a list of SSH2 ciphers.

With one argument $ciph_id, returns a true value if that cipher is supported by Net::SSH::Perl, and false otherwise.

With two arguments, $ciph_id and $server_supports, returns true if the cipher represented by $ciph_id is supported both by Net::SSH::Perl and by the sshd server. The list of ciphers supported by the server should be in $server_supports, a bit mask sent from the server during the session identification phase.

Can be called either as a non-exported function, i.e.

    my $i_support = Net::SSH::Perl::Cipher::supported();

or as an object method of a Net::SSH::Perl::Cipher object, or an object of a subclass:

    if ($ciph->supported($server_supports)) {
        print "Server supports cipher $ciph";
    }

id( [ $cipher_name ] )

Translates a cipher name into a cipher ID.

If given $cipher_name translates that name into the corresponding ID. If called as an object method, translates the object's cipher class name into the ID.

name( [ $cipher_id ] )

Translates a cipher ID into a cipher name.

If given $cipher_id translates that ID into the corresponding name. If called as an object method, returns the (stripped) object's cipher class name; for example, if the object were of type Net::SSH::Perl::Cipher::IDEA, name would return IDEA.

CIPHER USAGE

CIPHER DEVELOPMENT

Classes implementing an encryption cipher must implement the following three methods:

$class->new($key)
Given a key $key, should construct a new cipher object and bless it into $class, presumably.
$cipher->encrypt($text)
Given plain text $text, should encrypt the text and return the encrypted string.
$cipher->decrypt($text)
Given encrypted text $text, should decrypt the text and return the decrypted string.

AUTHOR & COPYRIGHTS

Please see the Net::SSH::Perl manpage for author, copyright, and license information.