dryoc 0.4.3

Don't Roll Your Own Crypto: pure-Rust, hard to misuse cryptography 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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320

use crate::constants::{
    CRYPTO_CORE_HCHACHA20_INPUTBYTES, CRYPTO_CORE_HCHACHA20_KEYBYTES,
    CRYPTO_CORE_HCHACHA20_OUTPUTBYTES, CRYPTO_CORE_HSALSA20_INPUTBYTES,
    CRYPTO_CORE_HSALSA20_KEYBYTES, CRYPTO_CORE_HSALSA20_OUTPUTBYTES, CRYPTO_SCALARMULT_BYTES,
    CRYPTO_SCALARMULT_SCALARBYTES,
};
use crate::scalarmult_curve25519::{
    crypto_scalarmult_curve25519, crypto_scalarmult_curve25519_base,
};
use crate::types::*;
use crate::utils::load_u32_le;

/// Stack-allocated HChaCha20 input.
pub type HChaCha20Input = [u8; CRYPTO_CORE_HCHACHA20_INPUTBYTES];
/// Stack-allocated HChaCha20 key.
pub type HChaCha20Key = [u8; CRYPTO_CORE_HCHACHA20_KEYBYTES];
/// Stack-allocated HChaCha20 output.
pub type HChaCha20Output = [u8; CRYPTO_CORE_HCHACHA20_OUTPUTBYTES];
/// Stack-allocated HSalsa20 input.
pub type HSalsa20Input = [u8; CRYPTO_CORE_HSALSA20_INPUTBYTES];
/// Stack-allocated HSalsa20 key.
pub type HSalsa20Key = [u8; CRYPTO_CORE_HSALSA20_KEYBYTES];
/// Stack-allocated HSalsa20 output.
pub type HSalsa20Output = [u8; CRYPTO_CORE_HSALSA20_OUTPUTBYTES];

/// Computes the public key for a previously generated secret key.
///
/// Compatible with libsodium's `crypto_scalarmult_base`.
pub fn crypto_scalarmult_base(
    q: &mut [u8; CRYPTO_SCALARMULT_BYTES],
    n: &[u8; CRYPTO_SCALARMULT_SCALARBYTES],
) {
    crypto_scalarmult_curve25519_base(q, n)
}

/// Computes a shared secret `q`, given `n`, our secret key, and `p`, their
/// public key, using a Diffie-Hellman key exchange.
///
/// Compatible with libsodium's `crypto_scalarmult`.
pub fn crypto_scalarmult(
    q: &mut [u8; CRYPTO_SCALARMULT_BYTES],
    n: &[u8; CRYPTO_SCALARMULT_SCALARBYTES],
    p: &[u8; CRYPTO_SCALARMULT_BYTES],
) {
    crypto_scalarmult_curve25519(q, n, p)
}

#[inline]
fn chacha20_round(x: &mut u32, y: &mut u32, z: &mut u32, rot: u32) {
    *x = x.wrapping_add(*y);
    *z = (*z ^ *x).rotate_left(rot);
}

#[inline]
fn chacha20_quarterround(a: &mut u32, b: &mut u32, c: &mut u32, d: &mut u32) {
    chacha20_round(a, b, d, 16);
    chacha20_round(c, d, b, 12);
    chacha20_round(a, b, d, 8);
    chacha20_round(c, d, b, 7);
}

/// Implements the HChaCha20 function.
///
/// Compatible with libsodium's `crypto_core_hchacha20`.
pub fn crypto_core_hchacha20(
    output: &mut HChaCha20Output,
    input: &HChaCha20Input,
    key: &HChaCha20Key,
    constants: Option<(u32, u32, u32, u32)>,
) {
    let input = input.as_array();
    let key = key.as_array();
    assert_eq!(input.len(), 16);
    assert_eq!(key.len(), 32);
    let (mut x0, mut x1, mut x2, mut x3) =
        constants.unwrap_or((0x61707865, 0x3320646e, 0x79622d32, 0x6b206574));
    let (
        mut x4,
        mut x5,
        mut x6,
        mut x7,
        mut x8,
        mut x9,
        mut x10,
        mut x11,
        mut x12,
        mut x13,
        mut x14,
        mut x15,
    ) = (
        load_u32_le(&key[0..4]),
        load_u32_le(&key[4..8]),
        load_u32_le(&key[8..12]),
        load_u32_le(&key[12..16]),
        load_u32_le(&key[16..20]),
        load_u32_le(&key[20..24]),
        load_u32_le(&key[24..28]),
        load_u32_le(&key[28..32]),
        load_u32_le(&input[0..4]),
        load_u32_le(&input[4..8]),
        load_u32_le(&input[8..12]),
        load_u32_le(&input[12..16]),
    );

    for _ in 0..10 {
        chacha20_quarterround(&mut x0, &mut x4, &mut x8, &mut x12);
        chacha20_quarterround(&mut x1, &mut x5, &mut x9, &mut x13);
        chacha20_quarterround(&mut x2, &mut x6, &mut x10, &mut x14);
        chacha20_quarterround(&mut x3, &mut x7, &mut x11, &mut x15);
        chacha20_quarterround(&mut x0, &mut x5, &mut x10, &mut x15);
        chacha20_quarterround(&mut x1, &mut x6, &mut x11, &mut x12);
        chacha20_quarterround(&mut x2, &mut x7, &mut x8, &mut x13);
        chacha20_quarterround(&mut x3, &mut x4, &mut x9, &mut x14);
    }

    output[0..4].copy_from_slice(&x0.to_le_bytes());
    output[4..8].copy_from_slice(&x1.to_le_bytes());
    output[8..12].copy_from_slice(&x2.to_le_bytes());
    output[12..16].copy_from_slice(&x3.to_le_bytes());
    output[16..20].copy_from_slice(&x12.to_le_bytes());
    output[20..24].copy_from_slice(&x13.to_le_bytes());
    output[24..28].copy_from_slice(&x14.to_le_bytes());
    output[28..32].copy_from_slice(&x15.to_le_bytes());
}

#[inline]
fn salsa20_rotl32(x: u32, y: u32, rot: u32) -> u32 {
    x.wrapping_add(y).rotate_left(rot)
}

/// Implements the HSalsa20 function.
///
/// Compatible with libsodium's `crypto_core_hsalsa20`.
pub fn crypto_core_hsalsa20(
    output: &mut HSalsa20Output,
    input: &HSalsa20Input,
    key: &HSalsa20Key,
    constants: Option<(u32, u32, u32, u32)>,
) {
    let (mut x0, mut x5, mut x10, mut x15) =
        constants.unwrap_or((0x61707865, 0x3320646e, 0x79622d32, 0x6b206574));
    let (
        mut x1,
        mut x2,
        mut x3,
        mut x4,
        mut x11,
        mut x12,
        mut x13,
        mut x14,
        mut x6,
        mut x7,
        mut x8,
        mut x9,
    ) = (
        load_u32_le(&key[0..4]),
        load_u32_le(&key[4..8]),
        load_u32_le(&key[8..12]),
        load_u32_le(&key[12..16]),
        load_u32_le(&key[16..20]),
        load_u32_le(&key[20..24]),
        load_u32_le(&key[24..28]),
        load_u32_le(&key[28..32]),
        load_u32_le(&input[0..4]),
        load_u32_le(&input[4..8]),
        load_u32_le(&input[8..12]),
        load_u32_le(&input[12..16]),
    );

    for _ in (0..20).step_by(2) {
        x4 ^= salsa20_rotl32(x0, x12, 7);
        x8 ^= salsa20_rotl32(x4, x0, 9);
        x12 ^= salsa20_rotl32(x8, x4, 13);
        x0 ^= salsa20_rotl32(x12, x8, 18);
        x9 ^= salsa20_rotl32(x5, x1, 7);
        x13 ^= salsa20_rotl32(x9, x5, 9);
        x1 ^= salsa20_rotl32(x13, x9, 13);
        x5 ^= salsa20_rotl32(x1, x13, 18);
        x14 ^= salsa20_rotl32(x10, x6, 7);
        x2 ^= salsa20_rotl32(x14, x10, 9);
        x6 ^= salsa20_rotl32(x2, x14, 13);
        x10 ^= salsa20_rotl32(x6, x2, 18);
        x3 ^= salsa20_rotl32(x15, x11, 7);
        x7 ^= salsa20_rotl32(x3, x15, 9);
        x11 ^= salsa20_rotl32(x7, x3, 13);
        x15 ^= salsa20_rotl32(x11, x7, 18);
        x1 ^= salsa20_rotl32(x0, x3, 7);
        x2 ^= salsa20_rotl32(x1, x0, 9);
        x3 ^= salsa20_rotl32(x2, x1, 13);
        x0 ^= salsa20_rotl32(x3, x2, 18);
        x6 ^= salsa20_rotl32(x5, x4, 7);
        x7 ^= salsa20_rotl32(x6, x5, 9);
        x4 ^= salsa20_rotl32(x7, x6, 13);
        x5 ^= salsa20_rotl32(x4, x7, 18);
        x11 ^= salsa20_rotl32(x10, x9, 7);
        x8 ^= salsa20_rotl32(x11, x10, 9);
        x9 ^= salsa20_rotl32(x8, x11, 13);
        x10 ^= salsa20_rotl32(x9, x8, 18);
        x12 ^= salsa20_rotl32(x15, x14, 7);
        x13 ^= salsa20_rotl32(x12, x15, 9);
        x14 ^= salsa20_rotl32(x13, x12, 13);
        x15 ^= salsa20_rotl32(x14, x13, 18);
    }

    output[0..4].copy_from_slice(&x0.to_le_bytes());
    output[4..8].copy_from_slice(&x5.to_le_bytes());
    output[8..12].copy_from_slice(&x10.to_le_bytes());
    output[12..16].copy_from_slice(&x15.to_le_bytes());
    output[16..20].copy_from_slice(&x6.to_le_bytes());
    output[20..24].copy_from_slice(&x7.to_le_bytes());
    output[24..28].copy_from_slice(&x8.to_le_bytes());
    output[28..32].copy_from_slice(&x9.to_le_bytes());
}

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

    #[test]
    fn test_crypto_scalarmult_base() {
        use base64::encode;
        for _ in 0..20 {
            use sodiumoxide::crypto::scalarmult::curve25519::{scalarmult_base, Scalar};

            let (pk, sk) = crypto_box_keypair();

            let mut public_key = [0u8; CRYPTO_SCALARMULT_BYTES];
            crypto_scalarmult_base(&mut public_key, &sk);

            assert_eq!(&pk, &public_key);

            let ge = scalarmult_base(&Scalar::from_slice(&sk).unwrap());

            assert_eq!(encode(ge.as_ref()), encode(public_key));
        }
    }

    #[test]
    fn test_crypto_scalarmult() {
        use base64::encode;
        for _ in 0..20 {
            use sodiumoxide::crypto::scalarmult::curve25519::{scalarmult, GroupElement, Scalar};

            let (_our_pk, our_sk) = crypto_box_keypair();
            let (their_pk, _their_sk) = crypto_box_keypair();

            let mut shared_secret = [0u8; CRYPTO_SCALARMULT_BYTES];
            crypto_scalarmult(&mut shared_secret, &our_sk, &their_pk);

            let ge = scalarmult(
                &Scalar::from_slice(&our_sk).unwrap(),
                &GroupElement::from_slice(&their_pk).unwrap(),
            )
            .expect("scalarmult failed");

            assert_eq!(encode(ge.as_ref()), encode(shared_secret));
        }
    }

    #[test]
    fn test_crypto_core_hchacha20() {
        use base64::encode;
        use libsodium_sys::crypto_core_hchacha20 as so_crypto_core_hchacha20;

        use crate::rng::copy_randombytes;

        for _ in 0..10 {
            let mut key = [0u8; 32];
            let mut data = [0u8; 16];
            copy_randombytes(&mut key);
            copy_randombytes(&mut data);

            let mut out = [0u8; CRYPTO_CORE_HCHACHA20_OUTPUTBYTES];
            crypto_core_hchacha20(&mut out, &data, &key, None);

            let mut so_out = [0u8; 32];
            unsafe {
                let ret = so_crypto_core_hchacha20(
                    so_out.as_mut_ptr(),
                    data.as_ptr(),
                    key.as_ptr(),
                    std::ptr::null(),
                );
                assert_eq!(ret, 0);
            }
            assert_eq!(encode(&out), encode(&so_out));
        }
    }

    #[test]
    fn test_crypto_core_hsalsa20() {
        use base64::encode;
        use libsodium_sys::crypto_core_hsalsa20 as so_crypto_core_hsalsa20;

        use crate::rng::copy_randombytes;

        for _ in 0..10 {
            let mut key = [0u8; CRYPTO_CORE_HSALSA20_KEYBYTES];
            let mut data = [0u8; CRYPTO_CORE_HSALSA20_INPUTBYTES];
            copy_randombytes(&mut key);
            copy_randombytes(&mut data);

            let mut out = [0u8; CRYPTO_CORE_HSALSA20_OUTPUTBYTES];
            crypto_core_hsalsa20(&mut out, &data, &key, None);

            let mut so_out = [0u8; 32];
            unsafe {
                let ret = so_crypto_core_hsalsa20(
                    so_out.as_mut_ptr(),
                    data.as_ptr(),
                    key.as_ptr(),
                    std::ptr::null(),
                );
                assert_eq!(ret, 0);
            }
            assert_eq!(encode(&out), encode(&so_out));
        }
    }
}