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

6       Crypt::AuthEnc::EAX - Authenticated encryption in EAX mode
7

SYNOPSIS

9        ### OO interface
10        use Crypt::AuthEnc::EAX;
11
12        # encrypt and authenticate
13        my $ae = Crypt::AuthEnc::EAX->new("AES", $key, $iv);
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        $tag = $ae->encrypt_done();
20
21        # decrypt and verify
22        my $ae = Crypt::AuthEnc::EAX->new("AES", $key, $iv);
23        $ae->adata_add('additional_authenticated_data1');
24        $ae->adata_add('additional_authenticated_data2');
25        $pt = $ae->decrypt_add('ciphertext1');
26        $pt = $ae->decrypt_add('ciphertext2');
27        $pt = $ae->decrypt_add('ciphertext3');
28        $tag = $ae->decrypt_done();
29        die "decrypt failed" unless $tag eq $expected_tag;
30
31        #or
32        my $result = $ae->decrypt_done($expected_tag) die "decrypt failed";
33
34        ### functional interface
35        use Crypt::AuthEnc::EAX qw(eax_encrypt_authenticate eax_decrypt_verify);
36
37        my ($ciphertext, $tag) = eax_encrypt_authenticate('AES', $key, $iv, $adata, $plaintext);
38        my $plaintext = eax_decrypt_verify('AES', $key, $iv, $adata, $ciphertext, $tag);
39

DESCRIPTION

41       EAX is a mode that requires a cipher, CTR and OMAC support and provides
42       encryption and authentication.  It is initialized with a random IV that
43       can be shared publicly, additional authenticated data which can be
44       fixed and public, and a random secret symmetric key.
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EXPORT

47       Nothing is exported by default.
48
49       You can export selected functions:
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51         use Crypt::AuthEnc::EAX qw(eax_encrypt_authenticate eax_decrypt_verify);
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FUNCTIONS

54   eax_encrypt_authenticate
55        my ($ciphertext, $tag) = eax_encrypt_authenticate($cipher, $key, $iv, $adata, $plaintext);
56
57        # $cipher .. 'AES' or name of any other cipher with 16-byte block len
58        # $key ..... AES key of proper length (128/192/256bits)
59        # $iv ...... unique initialization vector (no need to keep it secret)
60        # $adata ... additional authenticated data
61
62   eax_decrypt_verify
63         my $plaintext = eax_decrypt_verify($cipher, $key, $iv, $adata, $ciphertext, $tag);
64
65         # on error returns undef
66

METHODS

68   new
69        my $ae = Crypt::AuthEnc::EAX->new($cipher, $key, $iv);
70        #or
71        my $ae = Crypt::AuthEnc::EAX->new($cipher, $key, $iv, $adata);
72
73        # $cipher .. 'AES' or name of any other cipher with 16-byte block len
74        # $key ..... AES key of proper length (128/192/256bits)
75        # $iv ...... unique initialization vector (no need to keep it secret)
76        # $adata ... additional authenticated data (optional)
77
78   adata_add
79        $ae->adata_add($adata);                          #can be called multiple times
80
81   encrypt_add
82        $ciphertext = $ae->encrypt_add($data);         #can be called multiple times
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   decrypt_done
91        my $result = $ae->decrypt_done($tag);  # returns 1 (success) or 0 (failure)
92        #or
93        my $tag = $ae->decrypt_done;           # returns $tag value
94
95   clone
96        my $ae_new = $ae->clone;
97

SEE ALSO

99       •   CryptX, Crypt::AuthEnc::CCM, Crypt::AuthEnc::GCM,
100           Crypt::AuthEnc::OCB
101
102       •   <https://en.wikipedia.org/wiki/EAX_mode>
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106perl v5.34.0                      2021-07-22            Crypt::AuthEnc::EAX(3)