Crypt::AuthEnc::OCB(3pm)

1Crypt::AuthEnc::OCB(3)User Contributed Perl DocumentationCrypt::AuthEnc::OCB(3)
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NAME

6       Crypt::AuthEnc::OCB - Authenticated encryption in OCBv3 mode
7

SYNOPSIS

9        ### OO interface
10        use Crypt::AuthEnc::OCB;
11
12        # encrypt and authenticate
13        my $ae = Crypt::AuthEnc::OCB->new("AES", $key, $nonce, $tag_len);
14        $ae->adata_add('additional_authenticated_data1');
15        $ae->adata_add('additional_authenticated_data2');
16        $ct = $ae->encrypt_add('data1');
17        $ct = $ae->encrypt_add('data2');
18        $ct = $ae->encrypt_add('data3');
19        $ct = $ae->encrypt_last('rest of data');
20        ($ct,$tag) = $ae->encrypt_done();
21
22        # decrypt and verify
23        my $ae = Crypt::AuthEnc::OCB->new("AES", $key, $nonce, $tag_len);
24        $ae->adata_add('additional_authenticated_data1');
25        $ae->adata_add('additional_authenticated_data2');
26        $pt = $ae->decrypt_add('ciphertext1');
27        $pt = $ae->decrypt_add('ciphertext2');
28        $pt = $ae->decrypt_add('ciphertext3');
29        $pt = $ae->decrypt_last('rest of data');
30        ($pt,$tag) = $ae->decrypt_done();
31
32        ### functional interface
33        use Crypt::AuthEnc::OCB qw(ocb_encrypt_authenticate ocb_decrypt_verify);
34
35        my ($ciphertext, $tag) = ocb_encrypt_authenticate('AES', $key, $nonce, $adata, $tag_len, $plaintext);
36        my $plaintext = ocb_decrypt_verify('AES', $key, $nonce, $adata, $ciphertext, $tag);
37

DESCRIPTION

39       This module implements OCB v3 according to
40       <https://tools.ietf.org/html/rfc7253>
41

EXPORT

43       Nothing is exported by default.
44
45       You can export selected functions:
46
47         use Crypt::AuthEnc::OCB qw(ocb_encrypt_authenticate ocb_decrypt_verify);
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FUNCTIONS

50   ocb_encrypt_authenticate
51        my ($ciphertext, $tag) = ocb_encrypt_authenticate($cipher, $key, $nonce, $adata, $tag_len, $plaintext);
52
53        # $cipher .. 'AES' or name of any other cipher with 16-byte block len
54        # $key ..... AES key of proper length (128/192/256bits)
55        # $nonce ... unique nonce/salt (no need to keep it secret)
56        # $adata ... additional authenticated data
57        # $tag_len . required length of output tag
58
59   ocb_decrypt_verify
60         my $plaintext = ocb_decrypt_verify($cipher, $key, $nonce, $adata, $ciphertext, $tag);
61
62         # on error returns undef
63

METHODS

65   new
66        my $ae = Crypt::AuthEnc::OCB->new($cipher, $key, $nonce, $tag_len);
67
68        # $cipher .. 'AES' or name of any other cipher with 16-byte block len
69        # $key ..... AES key of proper length (128/192/256bits)
70        # $nonce ... unique nonce/salt (no need to keep it secret)
71        # $tag_len . required length of output tag
72
73   adata_add
74        $ae->adata_add($adata);                        #can be called multiple times
75
76   encrypt_add
77        $ciphertext = $ae->encrypt_add($data);         #can be called multiple times
78
79        #BEWARE: size of $data has to be multiple of blocklen (16 for AES)
80
81   encrypt_last
82        $ciphertext = $ae->encrypt_last($data);
83
84   encrypt_done
85        $tag = $ae->encrypt_done();
86
87   decrypt_add
88        $plaintext = $ae->decrypt_add($ciphertext);    #can be called multiple times
89
90        #BEWARE: size of $ciphertext has to be multiple of blocklen (16 for AES)
91
92   encrypt_last
93        $plaintext = $ae->decrypt_last($data);
94
95   decrypt_done
96        my $result = $ae->decrypt_done($tag);  # returns 1 (success) or 0 (failure)
97        #or
98        my $tag = $ae->decrypt_done;           # returns $tag value
99
100   clone
101        my $ae_new = $ae->clone;
102

NAME

SYNOPSIS

DESCRIPTION

EXPORT

FUNCTIONS

METHODS

SEE ALSO