literate-crypto 0.0.3

Literate Cryptography by 12hbender
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90

use {
    crate::{BlockCipher, BlockDecrypt, BlockEncrypt, Cbc, CipherDecrypt, CipherEncrypt, Padding},
    std::convert::Infallible,
};

#[test]
fn cbc() {
    let iv = [1, 2];
    let cip = Cbc::new(TestCipher, NoPadding, iv);
    let data = [1, 2, 3, 4, 5, 6].to_vec();
    let key = [7, 8];

    let ciphertext = cip.encrypt(data.clone(), key).unwrap();
    #[allow(clippy::identity_op)]
    let expected = [
        1 ^ 1 ^ 7,
        2 ^ 2 ^ 8,
        1 ^ 1 ^ 7 ^ 3 ^ 7,
        2 ^ 2 ^ 8 ^ 4 ^ 8,
        1 ^ 1 ^ 7 ^ 3 ^ 7 ^ 5 ^ 7,
        2 ^ 2 ^ 8 ^ 4 ^ 8 ^ 6 ^ 8,
    ];
    assert_eq!(
        ciphertext, expected,
        "invalid cbc encryption\nexpected: {expected:?}\nciphertext: {ciphertext:?}"
    );

    let plaintext = cip.decrypt(ciphertext, key).unwrap();
    assert_eq!(
        plaintext, data,
        "invalid cbc decryption\nexpected: {data:?}\nplaintext: {plaintext:?}"
    );
}

/// Test block cipher which XORs the data with the key.
struct TestCipher;

impl BlockEncrypt for TestCipher {
    type EncryptionBlock = [u8; 2];
    type EncryptionKey = [u8; 2];

    fn encrypt(
        &self,
        data: Self::EncryptionBlock,
        key: Self::EncryptionKey,
    ) -> Self::EncryptionBlock {
        [data[0] ^ key[0], data[1] ^ key[1]]
    }
}

impl BlockDecrypt for TestCipher {
    type DecryptionBlock = [u8; 2];
    type DecryptionKey = [u8; 2];

    fn decrypt(
        &self,
        data: Self::DecryptionBlock,
        key: Self::DecryptionKey,
    ) -> Self::DecryptionBlock {
        [data[0] ^ key[0], data[1] ^ key[1]]
    }
}

impl BlockCipher for TestCipher {
    type Block = [u8; 2];
    type Key = [u8; 2];
}

/// Test padding which does nothing.
struct NoPadding;

impl Padding for NoPadding {
    type Err = Infallible;

    fn pad(&self, data: Vec<u8>, n: usize) -> Vec<u8> {
        if data.len() % n != 0 {
            panic!("invalid test setup: data length not a multiple of block size");
        }

        data
    }

    fn unpad(&self, data: Vec<u8>, n: usize) -> Result<Vec<u8>, Self::Err> {
        if data.len() % n != 0 {
            panic!("invalid test setup: data length not a multiple of block size");
        }

        Ok(data)
    }
}