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Crypt::AuthEnc::OCB(3)User Contributed Perl DocumentatioCrypt::AuthEnc::OCB(3)

NAME
       Crypt::AuthEnc::OCB - Authenticated encryption in OCBv3 mode

SYNOPSIS
	### OO interface
	use Crypt::AuthEnc::OCB;

	# encrypt and authenticate
	my $ae = Crypt::AuthEnc::OCB->new("AES", $key, $nonce);
	$ae->aad_add('additional_authenticated_data1');
	$ae->aad_add('additional_authenticated_data2');
	$ct = $ae->encrypt_add('data1');
	$ct = $ae->encrypt_add('data2');
	$ct = $ae->encrypt_add('data3');
	$ct = $ae->encrypt_last('rest of data');
	($ct,$tag) = $ae->encrypt_done();

	# decrypt and verify
	my $ae = Crypt::AuthEnc::OCB->new("AES", $key, $nonce);
	$ae->aad_add('additional_authenticated_data1');
	$ae->aad_add('additional_authenticated_data2');
	$pt = $ae->decrypt_add('ciphertext1');
	$pt = $ae->decrypt_add('ciphertext2');
	$pt = $ae->decrypt_add('ciphertext3');
	$pt = $ae->decrypt_last('rest of data');
	($pt,$tag) = $ae->decrypt_done();

	### functional interface
	use Crypt::AuthEnc::OCB	qw(ocb_encrypt_authenticate ocb_decrypt_verify);

	my ($ciphertext, $tag) = ocb_encrypt_authenticate('AES', $key, $nonce, $adata, $plaintext);
	my $plaintext =	ocb_decrypt_verify('AES', $key,	$nonce,	$adata,	$ciphertext, $tag);

DESCRIPTION
       This module implements OCB version 3 according
       http://datatracker.ietf.org/doc/draft-irtf-cfrg-ocb/

EXPORT
       Nothing is exported by default.

       You can export selected functions:

	 use Crypt::AuthEnc::OCB qw(ocb_encrypt_authenticate ocb_decrypt_verify);

FUNCTIONS
   ocb_encrypt_authenticate
	my ($ciphertext, $tag) = ocb_encrypt_authenticate($cipher, $key, $nonce, $adata, $plaintext);

	# $cipher .. 'AES' or name of any other	cipher with 16-byte block len
	# $key ..... AES key of	proper length (128/192/256bits)
	# $nonce ... unique nonce/salt (no need	to keep	it secret)
	# $adata ... additional	authenticated data

   ocb_decrypt_verify
	 my $plaintext = ocb_decrypt_verify($cipher, $key, $nonce, $adata, $ciphertext,	$tag);

	 # on error returns undef

METHODS
   new
	my $ae = Crypt::AuthEnc::OCB->new($cipher, $key, $nonce);

	# $cipher .. 'AES' or name of any other	cipher with 16-byte block len
	# $key ..... AES key of	proper length (128/192/256bits)
	# $nonce ... unique nonce/salt (no need	to keep	it secret)

   aad_add
	$ae->aad_add($adata);			       #can be called multiple times

   encrypt_add
	$ciphertext = $ae->encrypt_add($data);	       #can be called multiple times

	#BEWARE: size of $data has to be multiple of blocklen (16 for AES)

   encrypt_last
	$ciphertext = $ae->encrypt_last($data);

   encrypt_done
	$tag = $ae->encrypt_done();

   decrypt_add
	$plaintext = $ae->decrypt_add($ciphertext);    #can be called multiple times

	#BEWARE: size of $ciphertext has to be multiple	of blocklen (16	for AES)

   encrypt_last
	$plaintext = $ae->decrypt_last($data);

   decrypt_done
	my $result = $ae->decrypt_done($tag);  # returns 1 (success) or	0 (failure)
	#or
	my $tag	= $ae->decrypt_done;	       # returns $tag value

   clone
	my $ae_new = $ae->clone;

SEE ALSO
       o   CryptX, Crypt::AuthEnc::CCM,	Crypt::AuthEnc::GCM,
	   Crypt::AuthEnc::EAX

       o   <https://en.wikipedia.org/wiki/OCB_mode>

perl v5.24.1			  2017-05-30		Crypt::AuthEnc::OCB(3)

NAME | SYNOPSIS | DESCRIPTION | EXPORT | FUNCTIONS | METHODS | SEE ALSO

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