nettle 7.5.0

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
157

use nettle_sys::{
    camellia256_ctx, nettle_camellia256_crypt, nettle_camellia256_invert_key,
    nettle_camellia256_set_decrypt_key, nettle_camellia256_set_encrypt_key,
};
use std::cmp::min;
use std::mem::MaybeUninit;
use std::os::raw::c_void;

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

/// 256 bit variant of the Camellia block cipher developed by Mitsubishi & NTT, defined in RFC 3713.
pub struct Camellia256 {
    context: Box<camellia256_ctx>,
}

impl_zeroing_drop_for!(Camellia256);

impl Camellia256 {
    /// Creates a new `Camellia256` 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 context = unsafe {
            let mut ctx = Box::new(MaybeUninit::uninit());
            nettle_camellia256_invert_key(ctx.as_mut_ptr(),
                                     encrypt.context.as_ref() as *const _);
            ctx.assume_init()
        };

        Camellia256 { context }
    }

    /// Encrypt/decrypt data from `src` to `dst`.
    pub fn crypt(&mut self, dst: &mut [u8], src: &[u8]) {
        unsafe {
            nettle_camellia256_crypt(
                self.context.as_mut() as *mut _,
                min(src.len(), dst.len()),
                dst.as_mut_ptr(),
                src.as_ptr(),
            )
        };
    }
}

impl Cipher for Camellia256 {
    const BLOCK_SIZE: usize = ::nettle_sys::CAMELLIA_BLOCK_SIZE as usize;
    const KEY_SIZE: usize = ::nettle_sys::CAMELLIA256_KEY_SIZE as usize;

    fn with_encrypt_key(key: &[u8]) -> Result<Camellia256> {
        if key.len() != Camellia256::KEY_SIZE {
            return Err(Error::InvalidArgument { argument_name: "key" });
        }

        let context = unsafe {
            let mut ctx = Box::new(MaybeUninit::uninit());
            nettle_camellia256_set_encrypt_key(ctx.as_mut_ptr(), key.as_ptr());
            ctx.assume_init()
        };

        Ok(Camellia256 { context })
    }

    fn with_decrypt_key(key: &[u8]) -> Result<Camellia256> {
        if key.len() != Camellia256::KEY_SIZE {
            return Err(Error::InvalidArgument { argument_name: "key" });
        }

        let context = unsafe {
            let mut ctx = Box::new(MaybeUninit::uninit());
            nettle_camellia256_set_decrypt_key(ctx.as_mut_ptr(), key.as_ptr());
            ctx.assume_init()
        };

        Ok(Camellia256 { context })
    }

    fn encrypt(&mut self, dst: &mut [u8], src: &[u8]) {
        self.crypt(dst, src)
    }

    fn decrypt(&mut self, dst: &mut [u8], src: &[u8]) {
        self.crypt(dst, src)
    }

    fn context(&mut self) -> *mut c_void {
        (self.context.as_mut() as *mut camellia256_ctx) as *mut c_void
    }

    fn raw_encrypt_function() -> RawCipherFunctionPointer {
        RawCipherFunctionPointer::new(nettle_camellia256_crypt)
    }

    fn raw_decrypt_function() -> RawCipherFunctionPointer {
        RawCipherFunctionPointer::new(nettle_camellia256_crypt)
    }
}

#[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\x09\x10\x11\x12\x13\x14\x15\x16"[..]);
        let _ = Camellia256::with_encrypt_key(key).unwrap();
        let _ = Camellia256::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, 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 = Camellia256::with_encrypt_key(&key).unwrap();
        let mut dec = Camellia256::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, 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 = Camellia256::with_encrypt_key(&key).unwrap();
        let mut dec = Camellia256::with_inverted_key(&enc);

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

        assert_eq!(output, input);
    }
}