NAME¶

Crypt::AuthEnc::SIV - Authenticated encryption in SIV mode

SYNOPSIS¶

  use Crypt::AuthEnc::SIV qw( siv_encrypt_authenticate siv_decrypt_verify );
  my $ciphertext = siv_encrypt_authenticate('AES', $key, $plaintext);
  my $ciphertext = siv_encrypt_authenticate('AES', $key, $plaintext, $adata);
  my $ciphertext = siv_encrypt_authenticate('AES', $key, $plaintext, [$ad1, $ad2, ...]);
  my $plaintext = siv_decrypt_verify('AES', $key, $ciphertext);
  my $plaintext = siv_decrypt_verify('AES', $key, $ciphertext, $adata);
  my $plaintext = siv_decrypt_verify('AES', $key, $ciphertext, [$ad1, $ad2, ...]); # undef on failure

DESCRIPTION¶

Since: CryptX-0.089

SIV (Synthetic IV) is a deterministic authenticated encryption scheme defined in RFC 5297 <https://www.rfc-editor.org/rfc/rfc5297>. Unlike nonce-based modes, SIV derives the authentication tag (the IV) synthetically from the key, associated data, and plaintext, making it nonce-misuse resistant.

The output of "siv_encrypt_authenticate" is the 16-byte SIV tag prepended to the ciphertext (total output length is "length($plaintext) + 16").

BEWARE: SIV requires a key that is twice the length of the underlying cipher key (e.g. 256 bits for AES-128-SIV, 512 bits for AES-256-SIV).

If you pass associated data as an arrayref, at most 126 components are accepted.

EXPORT¶

Nothing is exported by default.

You can export selected functions:

  use Crypt::AuthEnc::SIV qw( siv_encrypt_authenticate siv_decrypt_verify );

FUNCTIONS¶

  my $ciphertext = siv_encrypt_authenticate($cipher, $key, $plaintext);
  #or
  my $ciphertext = siv_encrypt_authenticate($cipher, $key, $plaintext, $adata);
  #or
  my $ciphertext = siv_encrypt_authenticate($cipher, $key, $plaintext, [$ad1, $ad2, ...]);
  # $cipher    ... [string] cipher name (e.g. 'AES')
  # $key       ... [binary string] key (must be double the cipher's standard key length)
  # $plaintext ... [binary string] plaintext to encrypt
  # $adata     ... [binary string | arrayref] optional associated data: a scalar string or an arrayref of up to 126 string/buffer scalars

  my $plaintext = siv_decrypt_verify($cipher, $key, $ciphertext);
  #or
  my $plaintext = siv_decrypt_verify($cipher, $key, $ciphertext, $adata);
  #or
  my $plaintext = siv_decrypt_verify($cipher, $key, $ciphertext, [$ad1, $ad2, ...]);
  # $cipher     ... [string] cipher name (e.g. 'AES')
  # $key        ... [binary string] key (must be double the cipher's standard key length)
  # $ciphertext ... [binary string] ciphertext with 16-byte SIV tag prepended
  # $adata      ... [binary string | arrayref] optional associated data: a scalar string or an arrayref of up to 126 string/buffer scalars

SEE ALSO¶

• CryptX, Crypt::AuthEnc::EAX, Crypt::AuthEnc::GCM
• RFC 5297 <https://www.rfc-editor.org/rfc/rfc5297>