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CryptX-0.085
River stage three • 72 direct dependents • 283 total dependents
/ Crypt::AuthEnc::OCB

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