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

NAME
       Crypt::AuthEnc::GCM - Authenticated encryption in GCM mode

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

	# encrypt and authenticate
	my $ae = Crypt::AuthEnc::GCM->new("AES", $key, $iv);
	$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');
	$tag = $ae->encrypt_done();

	# decrypt and verify
	my $ae = Crypt::AuthEnc::GCM->new("AES", $key, $iv);
	$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');
	$tag = $ae->decrypt_done();
	die "decrypt failed" unless $tag eq $expected_tag;

	#or
	my $result = $ae->decrypt_done($expected_tag) die "decrypt failed";

	### functional interface
	use Crypt::AuthEnc::GCM	qw(gcm_encrypt_authenticate gcm_decrypt_verify);

	my ($ciphertext, $tag) = gcm_encrypt_authenticate('AES', $key, $iv, $adata, $plaintext);
	my $plaintext =	gcm_decrypt_verify('AES', $key,	$iv, $adata, $ciphertext, $tag);

DESCRIPTION
       Galois/Counter Mode (GCM) - provides encryption and authentication.

EXPORT
       Nothing is exported by default.

       You can export selected functions:

	 use Crypt::AuthEnc::GCM qw(gcm_encrypt_authenticate gcm_decrypt_verify);

FUNCTIONS
   gcm_encrypt_authenticate
	my ($ciphertext, $tag) = gcm_encrypt_authenticate($cipher, $key, $iv, $adata, $plaintext);

	# $cipher .. 'AES' or name of any other	cipher with 16-byte block len
	# $key ..... AES key of	proper length (128/192/256bits)
	# $iv ...... initialization vector
	# $adata ... additional	authenticated data

   gcm_decrypt_verify
	my $plaintext =	gcm_decrypt_verify($cipher, $key, $iv, $adata, $ciphertext, $tag);

	# on error returns undef

METHODS
   new
	my $ae = Crypt::AuthEnc::GCM->new($cipher, $key);
	#or
	my $ae = Crypt::AuthEnc::GCM->new($cipher, $key, $iv);

	# $cipher .. 'AES' or name of any other	cipher
	# $key ..... encryption	key of proper length
	# $iv ...... initialization vector (optional, you can set it later via iv_add method)

   iv_add
	$ae->iv_add($iv_data);		       #can be called multiple times

   aad_add
       Can be called after all "iv_add"	calls but before the first
       "encrypt_add" or	"decrypt_add";

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

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

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

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

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

   reset
	$ae->reset;

   clone
	my $ae_new = $ae->clone;

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

       o   <https://en.wikipedia.org/wiki/Galois/Counter_Mode>

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

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

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