Crypt::AuthEnc::GCM − Authenticated encryption in GCM mode
### OO interface
use Crypt::AuthEnc::GCM;
# encrypt and authenticate
my $ae = Crypt::AuthEnc::GCM−>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::GCM−>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::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, $tag);
Galois/Counter Mode (GCM) − provides encryption and authentication.
Nothing is exported by default.
You can export selected functions:
use Crypt::AuthEnc::GCM qw(gcm_encrypt_authenticate gcm_decrypt_verify);
my ($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
my $plaintext =
gcm_decrypt_verify($cipher, $key, $iv, $adata, $ciphertext,
$tag);
# on error returns undef
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)
Set initialization vector (IV).
$ae−>iv_add($iv_data); #can be called multiple times
Add additional authenticated data. Can be called after all "iv_add" calls but before the first "encrypt_add" or "decrypt_add".
$ae−>adata_add($aad_data); # 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)
$ae−>reset;
my $ae_new = $ae−>clone;
• |
CryptX, Crypt::AuthEnc::CCM, Crypt::AuthEnc::EAX, Crypt::AuthEnc::OCB | ||
• |
<https://en.wikipedia.org/wiki/Galois/Counter_Mode> |