nettle 7.0.2

Rust bindings for the Nettle cryptographic library
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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156

use nettle_sys::{
    aes192_ctx, nettle_aes192_decrypt, nettle_aes192_encrypt,
    nettle_aes192_invert_key, nettle_aes192_set_decrypt_key,
    nettle_aes192_set_encrypt_key,
};
use std::cmp::min;
use std::mem::zeroed;
use std::os::raw::c_void;

use crate::cipher::RawCipherFunctionPointer;
use crate::{cipher::Cipher, Error, Result};

/// 192 bit variant of the Advanced Encryption Standard (AES, formerly RIJNDAEL) defined in FIPS 197.
pub struct Aes192 {
    context: aes192_ctx,
}

impl Aes192 {
    /// Creates a new `Aes192` instance for decryption that uses the same key as `encrypt`. The
    /// `encrypt` instance must be configured for encryption. This is faster than calling
    /// `with_decrypt_key`.
    pub fn with_inverted_key(encrypt: &Self) -> Self {
        let mut ctx = unsafe { zeroed() };
        unsafe {
            nettle_aes192_invert_key(
                &mut ctx as *mut _,
                &encrypt.context as *const _,
            );
        }

        Aes192 { context: ctx }
    }
}

impl Cipher for Aes192 {
    const BLOCK_SIZE: usize = ::nettle_sys::AES_BLOCK_SIZE as usize;
    const KEY_SIZE: usize = ::nettle_sys::AES192_KEY_SIZE as usize;

    fn with_encrypt_key(key: &[u8]) -> Result<Aes192> {
        if key.len() != Aes192::KEY_SIZE {
            return Err(Error::InvalidArgument { argument_name: "key" });
        }

        let mut ctx = unsafe { zeroed() };
        unsafe {
            nettle_aes192_set_encrypt_key(&mut ctx as *mut _, key.as_ptr());
        }

        Ok(Aes192 { context: ctx })
    }

    fn with_decrypt_key(key: &[u8]) -> Result<Aes192> {
        if key.len() != Aes192::KEY_SIZE {
            return Err(Error::InvalidArgument { argument_name: "key" });
        }

        let mut ctx = unsafe { zeroed() };
        unsafe {
            nettle_aes192_set_decrypt_key(&mut ctx as *mut _, key.as_ptr());
        }

        Ok(Aes192 { context: ctx })
    }

    fn encrypt(&mut self, dst: &mut [u8], src: &[u8]) {
        unsafe {
            nettle_aes192_encrypt(
                &mut self.context as *mut _,
                min(src.len(), dst.len()),
                dst.as_mut_ptr(),
                src.as_ptr(),
            )
        };
    }

    fn decrypt(&mut self, dst: &mut [u8], src: &[u8]) {
        unsafe {
            nettle_aes192_decrypt(
                &mut self.context as *mut _,
                min(src.len(), dst.len()),
                dst.as_mut_ptr(),
                src.as_ptr(),
            )
        };
    }

    fn context(&mut self) -> *mut c_void {
        ((&mut self.context) as *mut aes192_ctx) as *mut c_void
    }

    fn raw_encrypt_function() -> RawCipherFunctionPointer {
        RawCipherFunctionPointer::new(nettle_aes192_encrypt)
    }

    fn raw_decrypt_function() -> RawCipherFunctionPointer {
        RawCipherFunctionPointer::new(nettle_aes192_decrypt)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn set_key() {
        let key = &(b"\x01\x02\x03\x04\x05\x06\x07\x08\x09\x10\x11\x12\x13\x14\x15\x16\x09\x10\x11\x12\x13\x14\x15\x16"[..]);
        let _ = Aes192::with_encrypt_key(key).unwrap();
        let _ = Aes192::with_decrypt_key(key).unwrap();
    }

    #[test]
    fn round_trip() {
        let key = vec![
            0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10, 0x11,
            0x12, 0x13, 0x14, 0x15, 0x16, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14,
            0x15, 0x16,
        ];
        let input = vec![
            0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10, 0x11,
            0x12, 0x13, 0x14, 0x15, 0x16,
        ];
        let mut cipher = vec![0; 16];
        let mut output = vec![0; 16];

        let mut enc = Aes192::with_encrypt_key(&key).unwrap();
        let mut dec = Aes192::with_decrypt_key(&key).unwrap();

        enc.encrypt(&mut cipher, &input);
        dec.decrypt(&mut output, &cipher);

        assert_eq!(output, input);
    }

    #[test]
    fn round_trip_invert() {
        let key = vec![
            0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10, 0x11,
            0x12, 0x13, 0x14, 0x15, 0x16, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14,
            0x15, 0x16,
        ];
        let input = vec![
            0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10, 0x11,
            0x12, 0x13, 0x14, 0x15, 0x16,
        ];
        let mut cipher = vec![0; 16];
        let mut output = vec![0; 16];

        let mut enc = Aes192::with_encrypt_key(&key).unwrap();
        let mut dec = Aes192::with_inverted_key(&enc);

        enc.encrypt(&mut cipher, &input);
        dec.decrypt(&mut output, &cipher);

        assert_eq!(output, input);
    }
}