Crypt::OpenPGP::MDC - MDC (modification detection code) packet
use Crypt::OpenPGP::MDC;
my $mdc = Crypt::OpenPGP::MDC->new( Data => 'foobar' );
my $digest = $mdc->digest;
my $serialized = $mdc->save;
Crypt::OpenPGP::MDC is a PGP MDC (modification detection code) packet.
Such a packet is used alongside Encrypted-MDC data packets so that
modifications to the ciphertext can be detected. The MDC packet contains a
"SHA-1" digest of the plaintext for
comparison with the decrypted plaintext.
You generally will never need to construct a
Crypt::OpenPGP::MDC packet yourself; usage is by the
Crypt::OpenPGP::Ciphertext object.
Creates a new MDC packet object and returns that object. If you do not supply
any data $data, the object is created empty; 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, supply new
with the Data parameter along with a value
$data. $data should contain the
plaintext prefix (length = cipher blocksize + 2), the actual plaintext, and
two octets corresponding to the hex digits 0xd3 and
0x14.
Returns the text of the MDC packet; this is the digest of the data passed to
new (above) as $data, for example.
Given $buffer, a Crypt::OpenPGP::Buffer object
holding (or with offset pointing to) an MDC packet, returns a new
<Crypt::OpenPGP::MDC> object, initialized with the MDC data in the
buffer.
Returns the MDC digest data (eg. the string passed as $data
to new, above).
Please see the Crypt::OpenPGP manpage for author, copyright, and license
information.