Crypt::AuthEnc::OCB(3) | User Contributed Perl Documentation | Crypt::AuthEnc::OCB(3) |
NAME
Crypt::AuthEnc::OCB - Authenticated encryption in OCBv3 mode
SYNOPSIS
### OO interface use Crypt::AuthEnc::OCB; # encrypt and authenticate my $ae = Crypt::AuthEnc::OCB->new("AES", $key, $nonce, $tag_len); $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'); $ct .= $ae->encrypt_last('rest of data'); my $tag = $ae->encrypt_done(); # decrypt and verify my $ae = Crypt::AuthEnc::OCB->new("AES", $key, $nonce, $tag_len); $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'); $pt .= $ae->decrypt_last('rest of data'); 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::OCB qw(ocb_encrypt_authenticate ocb_decrypt_verify); my ($ciphertext, $tag) = ocb_encrypt_authenticate('AES', $key, $nonce, $adata, $tag_len, $plaintext); my $plaintext = ocb_decrypt_verify('AES', $key, $nonce, $adata, $ciphertext, $tag);
DESCRIPTION
This module implements OCB v3 according to https://tools.ietf.org/html/rfc7253
EXPORT
Nothing is exported by default.
You can export selected functions:
use Crypt::AuthEnc::OCB qw(ocb_encrypt_authenticate ocb_decrypt_verify);
FUNCTIONS
ocb_encrypt_authenticate
my ($ciphertext, $tag) = ocb_encrypt_authenticate($cipher, $key, $nonce, $adata, $tag_len, $plaintext); # $cipher .. 'AES' or name of any other cipher with 16-byte block len # $key ..... AES key of proper length (128/192/256bits) # $nonce ... unique nonce/salt (no need to keep it secret) # $adata ... additional authenticated data # $tag_len . required length of output tag
ocb_decrypt_verify
my $plaintext = ocb_decrypt_verify($cipher, $key, $nonce, $adata, $ciphertext, $tag); # on error returns undef
METHODS
new
my $ae = Crypt::AuthEnc::OCB->new($cipher, $key, $nonce, $tag_len); # $cipher .. 'AES' or name of any other cipher with 16-byte block len # $key ..... AES key of proper length (128/192/256bits) # $nonce ... unique nonce/salt (no need to keep it secret) # $tag_len . required length of output tag
adata_add
$ae->adata_add($adata); #can be called multiple times
encrypt_add
$ciphertext = $ae->encrypt_add($data); # can be called multiple times #BEWARE: size of $data has to be multiple of blocklen (16 for AES)
encrypt_last
$ciphertext = $ae->encrypt_last($data);
encrypt_done
$tag = $ae->encrypt_done(); # returns $tag value
decrypt_add
$plaintext = $ae->decrypt_add($ciphertext); # can be called multiple times #BEWARE: size of $ciphertext has to be multiple of blocklen (16 for AES)
decrypt_last
$plaintext = $ae->decrypt_last($data);
decrypt_done
my $tag = $ae->decrypt_done; # returns $tag value #or my $result = $ae->decrypt_done($tag); # returns 1 (success) or 0 (failure)
clone
my $ae_new = $ae->clone;
SEE ALSO
- CryptX, Crypt::AuthEnc::CCM, Crypt::AuthEnc::GCM, Crypt::AuthEnc::EAX
- https://en.wikipedia.org/wiki/OCB_mode
- https://tools.ietf.org/html/rfc7253
2024-10-20 | perl v5.40.0 |