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Crypt::OpenPGP::Cipher.3pm

NAME

Crypt::OpenPGP::Cipher - PGP symmetric cipher factory

SYNOPSIS

     use Crypt::OpenPGP::Cipher;
 
 

     my $cipher = Crypt::OpenPGP::Cipher->new($name);
 
 

     my $ct = $cipher->encrypt($plaintext);
     my $pt = $cipher->decrypt($ct);
 
 

DESCRIPTION

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

A Crypt::OpenPGP::Cipher object is a wrapper around a Crypt::OpenPGP::CFB object, which in turn wraps around the actual cipher implementation (eg. Crypt::Blowfish for a Blowfish cipher). This allows all ciphers to share a common interface and a simple instantiation method.

USAGE

Crypt::OpenPGP::Cipher->new($cipher)

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

Valid cipher names are: "IDEA", "DES3", "Blowfish", "Rijndael", "Rijndael192", "Rijndael256", "Twofish", and "CAST5".

Returns the new cipher 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 cipher name or ID.

$cipher->encrypt($plaintext)

Encrypts the plaintext $plaintext and returns the encrypted text (ie. ciphertext). The encryption is done in CFB mode using the underlying cipher implementation.

$cipher->decrypt($ciphertext)

Decrypts the ciphertext $ciphertext and returns the plaintext. The decryption is done in CFB mode using the underlying cipher implementation.

$cipher->alg

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

$cipher->alg_id

Returns the numeric ID of the cipher algorithm.

$cipher->blocksize

Returns the blocksize of the cipher algorithm (in bytes).

$cipher->keysize

Returns the keysize of the cipher algorithm (in bytes).

AUTHOR & COPYRIGHTS

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