Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
Crypt::OpenPGP::CipherUser(Contributed Perl DocumCrypt::OpenPGP::Ciphertext(3)

NAME
       Crypt::OpenPGP::Ciphertext - Encrypted data packet

SYNOPSIS
	   use Crypt::OpenPGP::Ciphertext;

	   my $key_data	= 'f' x	64;    ## Not a	very good key :)

	   my $ct = Crypt::OpenPGP::Ciphertext->new(
	       Data   => "foo bar baz",
	       SymKey => $key_data,
	   );
	   my $serialized = $ct->save;

	   my $buffer =	Crypt::OpenPGP::Buffer->new;
	   my $ct2 = Crypt::OpenPGP::Ciphertext->parse(	$buffer	);
	   my $data = $ct->decrypt( $key_data );

DESCRIPTION
       Crypt::OpenPGP::Ciphertext implements symmetrically encrypted data
       packets,	providing both encryption and decryption functionality.	Both
       standard	encrypted data packets and encrypted-MDC (modification
       detection code) packets are supported by	this class. In the first case,
       the encryption used in the packets is a variant on standard CFB mode,
       and is described	in the OpenPGP RFC, in section 12.8 (OpenPGP CFB
       mode).  In the second case (encrypted-MDC packets), the encryption is
       performed in standard CFB mode, without the special resync used in
       PGP's CFB.

USAGE
   Crypt::OpenPGP::Ciphertext->new( %arg )
       Creates a new symmetrically encrypted data packet object	and returns
       that object. If there are no arguments in %arg, the object is created
       with an empty data container; this is used, for example,	in parse
       (below),	to create an empty packet which	is then	filled from the	data
       in the buffer.

       If you wish to initialize a non-empty object, %arg can contain:

       o   Data

	   A block of octets that make up the plaintext	data to	be encrypted.

	   This	argument is required (for a non-empty object).

       o   SymKey

	   The symmetric cipher	key: a string of octets	that make up the key
	   data	of the symmetric cipher	key. This should be at least long
	   enough for the key length of	your chosen cipher (see	Cipher,
	   below), or, if you have not specified a cipher, at least 64 bytes
	   (to allow for long cipher key sizes).

	   This	argument is required (for a non-empty object).

       o   Cipher

	   The name (or	ID) of a supported PGP cipher. See
	   Crypt::OpenPGP::Cipher for a	list of	valid cipher names.

	   This	argument is optional; by default Crypt::OpenPGP::Cipher	will
	   use "DES3".

       o   MDC

	   When	set to a true value, encrypted texts will use encrypted	MDC
	   (modification detection code) packets instead of standard encrypted
	   data	packets. These are a newer form	of encrypted data packets that
	   are followed	by a "SHA-1" hash of the plaintext data. This prevents
	   attacks that	modify the encrypted text by using a message digest to
	   detect changes.

	   By default MDC is set to 0, and encrypted texts use standard
	   encrypted data packets. Set it to a true value to turn on MDC
	   packets.

   $ct->save
       Returns the block of ciphertext created in new (assuming	that you
       created a non-empty packet by specifying	some data; otherwise returns
       an empty	string).

   Crypt::OpenPGP::Ciphertext->parse($buffer)
       Given $buffer, a	Crypt::OpenPGP::Buffer object holding (or with offset
       pointing	to) a symmetrically encrypted data packet, returns a new
       Crypt::OpenPGP::Ciphertext object, initialized with the ciphertext in
       the buffer.

   $ct->decrypt($key, $alg)
       Decrypts	the ciphertext in the Crypt::OpenPGP::Ciphertext object	and
       returns the plaintext. $key is the encryption key, and $alg is the name
       (or ID) of the Crypt::OpenPGP::Cipher type used to encrypt the message.
       Obviously you can't just	guess at these parameters; this	method (along
       with parse, above) is best used along with the
       Crypt::OpenPGP::SessionKey object, which	holds an encrypted version of
       the key and cipher algorithm.

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

perl v5.24.1			  2017-07-02	 Crypt::OpenPGP::Ciphertext(3)

NAME | SYNOPSIS | DESCRIPTION | USAGE | AUTHOR & COPYRIGHTS

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=Crypt::OpenPGP::Ciphertext&sektion=3&manpath=FreeBSD+12.1-RELEASE+and+Ports>

home | help