Crypt::AuthEnc::EAX − Authenticated encryption in EAX mode
### OO interface
use Crypt::AuthEnc::EAX;
# encrypt and authenticate
my $ae = Crypt::AuthEnc::EAX−>new("AES",
$key, $iv);
$ae−>adata_add('additional_authenticated_data1');
$ae−>adata_add('additional_authenticated_data2');
my $ct = $ae−>encrypt_add('data1');
$ct .= $ae−>encrypt_add('data2');
$ct .= $ae−>encrypt_add('data3');
my $tag = $ae−>encrypt_done();
# decrypt and verify
my $ae = Crypt::AuthEnc::EAX−>new("AES",
$key, $iv);
$ae−>adata_add('additional_authenticated_data1');
$ae−>adata_add('additional_authenticated_data2');
my $pt = $ae−>decrypt_add('ciphertext1');
$pt .= $ae−>decrypt_add('ciphertext2');
$pt .= $ae−>decrypt_add('ciphertext3');
my $tag = $ae−>decrypt_done();
die "decrypt failed" unless $tag eq $expected_tag;
#or
my $result = $ae−>decrypt_done($expected_tag); # 0
or 1
### functional interface
use Crypt::AuthEnc::EAX qw(eax_encrypt_authenticate
eax_decrypt_verify);
my ($ciphertext, $tag) = eax_encrypt_authenticate('AES',
$key, $iv, $adata, $plaintext);
my $plaintext = eax_decrypt_verify('AES', $key, $iv, $adata,
$ciphertext, $tag);
EAX is a mode that requires a cipher, CTR and OMAC support and provides encryption and authentication. It is initialized with a random IV that can be shared publicly, additional authenticated data which can be fixed and public, and a random secret symmetric key.
Nothing is exported by default.
You can export selected functions:
use Crypt::AuthEnc::EAX qw(eax_encrypt_authenticate eax_decrypt_verify);
my ($ciphertext,
$tag) = eax_encrypt_authenticate($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 ...... unique initialization vector (no need to keep
it secret)
# $adata ... additional authenticated data
my $plaintext =
eax_decrypt_verify($cipher, $key, $iv, $adata, $ciphertext,
$tag);
# on error returns undef
my $ae =
Crypt::AuthEnc::EAX−>new($cipher, $key, $iv);
#or
my $ae = Crypt::AuthEnc::EAX−>new($cipher, $key,
$iv, $adata);
# $cipher .. 'AES' or name of any other cipher with
16−byte block len
# $key ..... AES key of proper length (128/192/256bits)
# $iv ...... unique initialization vector (no need to keep
it secret)
# $adata ... additional authenticated data (optional)
$ae−>adata_add($adata); # can be called multiple times
$ciphertext = $ae−>encrypt_add($data); # can be called multiple times
$tag = $ae−>encrypt_done(); # returns $tag value
$plaintext = $ae−>decrypt_add($ciphertext); # can be called multiple times
my $tag =
$ae−>decrypt_done; # returns $tag value
#or
my $result = $ae−>decrypt_done($tag); # returns 1
(success) or 0 (failure)
my $ae_new = $ae−>clone;
• |
CryptX, Crypt::AuthEnc::CCM, Crypt::AuthEnc::GCM, Crypt::AuthEnc::OCB | ||
• |
<https://en.wikipedia.org/wiki/EAX_mode> |