NAME

Crypt::KeyWrap - AES key wrap / unwrap functions

SYNOPSIS

   # wrapping
   use Crypt::KeyWrap qw(aes_key_wrap);
   my $kek     = pack("H*", "5840df6e29b02af1ab493b705bf16ea1ae8338f4dcc176a8"); # shared secret, keep private
   my $pt_data = pack("H*", "c37b7e6492584340bed12207808941155068f738");
   my $ct_data = aes_key_wrap($kek, $pt_data);

   # unwrapping
   use Crypt::KeyWrap qw(aes_key_unwrap);
   my $kek     = pack("H*", "5840df6e29b02af1ab493b705bf16ea1ae8338f4dcc176a8"); # shared secret, keep private
   my $ct_data = pack("H*", "138bdeaa9b8fa7fc61f97742e72248ee5ae6ae5360d1ae6a5f54f373fa543b6a");
   my $pt_data = aes_key_unwrap($kek, $pt_data);

DESCRIPTION

Implements key wrapping algorithms defined in https://tools.ietf.org/html/rfc7518

Currently supported:

 A128KW
 A192KW
 A256KW
 A128GCMKW
 A192GCMKW
 A256GCMKW

Not supported yet:

 ECDH-ES
 ECDH-ES+A128KW
 ECDH-ES+A192KW
 ECDH-ES+A256KW
 PBES2-HS256+A128KW
 PBES2-HS384+A192KW
 PBES2-HS512+A256KW
 RSA-OAEP
 RSA-OAEP-256
 RSA1_5

FUNCTIONS

aes_key_wrap

AES key wrap algorithm as defined in https://tools.ietf.org/html/rfc7518#section-4.4 (implements algorithms A128KW, A192KW, A256KW).

Implementation follows https://tools.ietf.org/html/rfc5649 and https://tools.ietf.org/html/rfc3394.

The implementation is also compatible with http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38F.pdf (it supports AES based KW, KWP + TDEA/DES_EDE based TKW).

AES Key Wrap algorithm.

   $ct_data = aes_key_wrap($kek, $pt_data);
   # or
   $ct_data = aes_key_wrap($kek, $pt_data, $cipher, $padding, $inverse);

   # params:
   #  $kek     .. key encryption key (16bytes for AES128, 24 for AES192, 32 for AES256)
   #  $pt_data .. plaintext data
   # optional params:
   #  $cipher  .. 'AES' (default) or 'DES_EDE'
   #  $padding .. 1 (default) or 0 handle $pt_data padding (relevant for AES only)
   #  $inverse .. 0 (default) or 1 use cipher in inverse mode as defined by SP.800-38F

Values $ct_data, $pt_data and $kek are binary octets. If you disable padding you have to make sure that $pt_data length is multiply of 8 (for AES) or multiply of 4 (for DES_EDE);

aes_key_unwrap

AES key unwrap algorithm as defined in https://tools.ietf.org/html/rfc7518#section-4.4 (implements algorithms A128KW, A192KW, A256KW).

AES Key Unwrap algorithm.

   $pt_data = aes_key_unwrap($kek, $ct_data);
   # or
   $pt_data = aes_key_unwrap($kek, $ct_data, $cipher, $padding, $inverse);

   # params:
   #  $kek     .. key encryption key (16bytes for AES128, 24 for AES192, 32 for AES256)
   #  $ct_data .. ciphertext data
   # optional params:
   #  $cipher  .. 'AES' (default) or 'DES_EDE'
   #  $padding .. 1 (default) or 0 - use $pt_data padding (relevant for AES only)
   #  $inverse .. 0 (default) or 1 - use cipher in inverse mode as defined by SP.800-38F

Values $ct_data, $pt_data and $kek are binary octets.

gcm_key_wrap

AES GCM key wrap algorithm as defined in https://tools.ietf.org/html/rfc7518#section-4.7 (implements algorithms A128GCMKW, A192GCMKW, A256GCMKW).

   ($ct_data, $tag, $iv) = gcm_key_wrap($kek, $pt_data);
   #or
   ($ct_data, $tag, $iv) = gcm_key_wrap($kek, $pt_data, $aad);
   #or
   ($ct_data, $tag, $iv) = gcm_key_wrap($kek, $pt_data, $aad, $cipher, $iv);

   # params:
   #  $kek     .. key encryption key (16bytes for AES128, 24 for AES192, 32 for AES256)
   #  $pt_data .. plaintext data
   # optional params:
   #  $aad     .. additional authenticated data, DEFAULT is '' (empty string)
   #  $cipher  .. cipher to be used by GCM, DEFAULT is 'AES'
   #  $iv      .. initialization vector (if not defined a random IV is generated)

Values $ct_data, $pt_data, $aad, $iv, $tag and $kek are binary octets.

gcm_key_unwrap

AES GCM key unwrap algorithm as defined in https://tools.ietf.org/html/rfc7518#section-4.7 (implements algorithms A128GCMKW, A192GCMKW, A256GCMKW).

   $pt_data = gcm_key_unwrap($kek, $ct_data, $tag, $iv);
   # or
   $pt_data = gcm_key_unwrap($kek, $ct_data, $tag, $iv, $aad);
   # or
   $pt_data = gcm_key_unwrap($kek, $ct_data, $tag, $iv, $aad, $cipher);

   # params:
   #  $kek     .. key encryption key (16bytes for AES128, 24 for AES192, 32 for AES256)
   #  $ct_data .. ciphertext data
   #  $tag     .. GCM's tag
   #  $iv      .. initialization vector
   # optional params:
   #  $aad     .. additional authenticated data, DEFAULT is '' (empty string)
   #  $cipher  .. cipher to be used by GCM, DEFAULT is 'AES'