Crypt::AuthEnc::GCMSIV(3) User Contributed Perl Documentation
NAME
Crypt::AuthEnc::GCMSIV - Authenticated encryption in AES-GCM-SIV mode
(RFC 8452)
SYNOPSIS
use Crypt::AuthEnc::GCMSIV qw( gcm_siv_encrypt_authenticate gcm_siv_decrypt_verify );
my $ciphertext = gcm_siv_encrypt_authenticate('AES', $key, $nonce, $adata, $plaintext);
my $plaintext = gcm_siv_decrypt_verify('AES', $key, $nonce, $adata, $ciphertext); # undef on failure
DESCRIPTION
Since: CryptX-0.090
AES-GCM-SIV is a nonce-misuse-resistant authenticated encryption scheme
defined in RFC 8452 <https://www.rfc-editor.org/rfc/rfc8452>. Reusing a
nonce with the same key no longer reveals the plaintext or the
authentication key; it only reveals whether the same (plaintext, AAD)
pair was encrypted twice.
The output of "gcm_siv_encrypt_authenticate" is the ciphertext with a
16-byte authentication tag appended (total output length is
"length($plaintext) + 16").
GCM-SIV is defined only for 128-bit block ciphers (i.e. AES); the nonce
must be exactly 12 bytes long and the key must be 16 or 32 bytes
(AES-128 / AES-256).
EXPORT
Nothing is exported by default.
You can export selected functions:
use Crypt::AuthEnc::GCMSIV qw( gcm_siv_encrypt_authenticate gcm_siv_decrypt_verify );
FUNCTIONS
gcm_siv_encrypt_authenticate
my $ciphertext = gcm_siv_encrypt_authenticate($cipher, $key, $nonce, $adata, $plaintext);
# $cipher ... [string] cipher name (must be 'AES')
# $key ... [binary string] 16- or 32-byte key
# $nonce ... [binary string] 12-byte nonce
# $adata ... [binary string | undef] optional associated data
# $plaintext ... [binary string] plaintext to encrypt
Returns a string of "length($plaintext) + 16" bytes: ciphertext
followed by the 16-byte authentication tag.
The required string/buffer arguments must be plain scalars; $adata may
be "undef" to indicate no associated data. String-overloaded objects
are accepted.
gcm_siv_decrypt_verify
my $plaintext = gcm_siv_decrypt_verify($cipher, $key, $nonce, $adata, $ciphertext);
# $cipher ... [string] cipher name (must be 'AES')
# $key ... [binary string] 16- or 32-byte key
# $nonce ... [binary string] 12-byte nonce
# $adata ... [binary string | undef] optional associated data (must match the value used during encryption)
# $ciphertext ... [binary string] ciphertext with 16-byte tag appended
Returns the plaintext on success, or "undef" if authentication fails.
Malformed input shorter than 16 bytes croaks because it cannot contain
the required appended tag.
SEE ALSO
o CryptX(3), Crypt::AuthEnc::GCM(3), Crypt::AuthEnc::SIV(3)
o RFC 8452 <https://www.rfc-editor.org/rfc/rfc8452>
perl v5.34.3 2026-06-18 Crypt::AuthEnc::GCMSIV(3)
cryptx 0.90.0 - Generated Sun Jun 21 15:56:32 CDT 2026