1Crypt::Mode::CFB(3) User Contributed Perl Documentation Crypt::Mode::CFB(3)
2
3
4
6 Crypt::Mode::CFB - Block cipher mode CFB [Cipher feedback]
7
9 use Crypt::Mode::CFB;
10 my $m = Crypt::Mode::CFB->new('AES');
11
12 #(en|de)crypt at once
13 my $ciphertext = $m->encrypt($plaintext, $key, $iv);
14 my $plaintext = $m->decrypt($ciphertext, $key, $iv);
15
16 #encrypt more chunks
17 $m->start_encrypt($key, $iv);
18 my $ciphertext = $m->add('some data');
19 $ciphertext .= $m->add('more data');
20
21 #decrypt more chunks
22 $m->start_decrypt($key, $iv);
23 my $plaintext = $m->add($some_ciphertext);
24 $plaintext .= $m->add($more_ciphertext);
25
27 This module implements CFB cipher mode. NOTE: it works only with
28 ciphers from CryptX (Crypt::Cipher::NNNN).
29
31 new
32 my $m = Crypt::Mode::CFB->new($name);
33 #or
34 my $m = Crypt::Mode::CFB->new($name, $cipher_rounds);
35
36 # $name ............ one of 'AES', 'Anubis', 'Blowfish', 'CAST5', 'Camellia', 'DES', 'DES_EDE',
37 # 'KASUMI', 'Khazad', 'MULTI2', 'Noekeon', 'RC2', 'RC5', 'RC6',
38 # 'SAFERP', 'SAFER_K128', 'SAFER_K64', 'SAFER_SK128', 'SAFER_SK64',
39 # 'SEED', 'Skipjack', 'Twofish', 'XTEA', 'IDEA', 'Serpent'
40 # simply any <NAME> for which there exists Crypt::Cipher::<NAME>
41 # $cipher_rounds ... optional num of rounds for given cipher
42
43 encrypt
44 my $ciphertext = $m->encrypt($plaintext, $key, $iv);
45
46 decrypt
47 my $plaintext = $m->decrypt($ciphertext, $key, $iv);
48
49 start_encrypt
50 $m->start_encrypt($key, $iv);
51
52 start_decrypt
53 $m->start_decrypt($key, $iv);
54
55 add
56 # in encrypt mode
57 my $plaintext = $m->add($ciphertext);
58
59 # in decrypt mode
60 my $ciphertext = $m->add($plaintext);
61
63 • CryptX, Crypt::Cipher
64
65 • Crypt::Cipher::AES, Crypt::Cipher::Blowfish, ...
66
67 • <https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Cipher_feedback_.28CFB.29>
68
69
70
71perl v5.36.0 2022-07-22 Crypt::Mode::CFB(3)