NAME
Crypt::AuthEnc::EAX - Authenticated encryption in EAX mode
SYNOPSIS
### example 1
use Crypt::AuthEnc::EAX;
# encrypt + authenticate
my $ae = Crypt::AuthEnc::EAX->new("AES", $key, $nonce);
$ae->header_add('headerdata part1');
$ae->header_add('headerdata part2');
$ct = $ae->encrypt_add('data1');
$ct = $ae->encrypt_add('data2');
$ct = $ae->encrypt_add('data3');
$tag = $ae->encrypt_done();
# decrypt + verify
my $ae = Crypt::AuthEnc::EAX->new("AES", $key, $nonce);
$ae->header_add('headerdata part1');
$ae->header_add('headerdata part2');
$pt = $ae->decrypt_add('ciphertext1');
$pt = $ae->decrypt_add('ciphertext2');
$pt = $ae->decrypt_add('ciphertext3');
my $result = $ae->decrypt_done($tag);
#or
my $tag_dec = $ae->decrypt_done;
die "TAG mismatch" unless $tag eq $tag_dec;
### example 2
use Crypt::AuthEnc::EAX qw(eax_encrypt_authenticate eax_decrypt_verify);
my ($ciphertext, $tag) = eax_encrypt_authenticate('AES', $key, $nonce, $header, $plaintext);
my $plaintext = eax_decrypt_verify('AES', $key, $nonce, $header, $ciphertext, $tag);DESCRIPTION
EAX is a mode that requires a cipher, CTR and OMAC support and provides encryption and authentication. It is initialized with a random nonce that can be shared publicly, a header which can be fixed and public, and a random secret symmetric key.
EXPORT
Nothing is exported by default.
You can export selected functions:
use Crypt::AuthEnc::EAX qw(eax_encrypt_authenticate eax_decrypt_verify);FUNCTIONS
eax_encrypt_authenticate
my ($ciphertext, $tag) = eax_encrypt_authenticate($cipher, $key, $nonce, $header, $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)
# $header .. meta-data you want to send with the message but not have encryptedeax_decrypt_verify
my $plaintext = eax_decrypt_verify($cipher, $key, $nonce, $header, $ciphertext, $tag);
# on error returns undefMETHODS
new
my $ae = Crypt::AuthEnc::EAX->new($cipher, $key, $nonce);
#or
my $ae = Crypt::AuthEnc::EAX->new($cipher, $key, $nonce, $header);
# $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)
# $header .. meta-data you want to send with the message but not have encryptedheader_add
$ae->header_add($header_data); #can be called multiple timesencrypt_add
$ciphertext = $ae->encrypt_add($data); #can be called multiple timesencrypt_done
$tag = $ae->encrypt_done();decrypt_add
$plaintext = $ae->decrypt_add($ciphertext); #can be called multiple timesdecrypt_done
my $result = $ae->decrypt_done($tag); # returns 1 (success) or 0 (failure)
#or
my $tag = $ae->decrypt_done; # returns $tag valueclone
my $ae_new = $ae->clone;