crypto/
hc128.rs

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
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.


use buffer::{BufferResult, RefReadBuffer, RefWriteBuffer};
use symmetriccipher::{Encryptor, Decryptor, SynchronousStreamCipher, SymmetricCipherError};
use cryptoutil::{read_u32_le, symm_enc_or_dec, write_u32_le};

use std::ptr;


#[derive(Copy)]
pub struct Hc128 {
    p: [u32; 512],
    q: [u32; 512],
    cnt: usize,
    output: [u8; 4],
    output_index: usize
}

impl Clone for Hc128 { fn clone(&self) -> Hc128 { *self } }

impl Hc128 {
    pub fn new(key: &[u8], nonce: &[u8]) -> Hc128 {
        assert!(key.len() == 16);
        assert!(nonce.len() == 16);
        let mut hc128 = Hc128 { p: [0; 512], q: [0; 512], cnt: 0, output: [0; 4], output_index: 0 };
        hc128.init(&key, &nonce);

        hc128
    }

    fn init(&mut self, key : &[u8], nonce : &[u8]) {
        self.cnt = 0;

        let mut w : [u32; 1280] = [0; 1280];

        for i in 0..16 {
            w[i >> 2] |= (key[i] as u32) << (8 * (i & 0x3));
        }
        unsafe {
            ptr::copy_nonoverlapping(w.as_ptr(), w.as_mut_ptr().offset(4), 4);
        }

        for i in 0..nonce.len() & 16 {
            w[(i >> 2) + 8] |= (nonce[i] as u32) << (8 * (i & 0x3));
        }
        unsafe {
            ptr::copy_nonoverlapping(w.as_ptr().offset(8), w.as_mut_ptr().offset(12), 4);
        }

        for i in 16..1280 {
            w[i] = f2(w[i - 2]).wrapping_add(w[i - 7]).wrapping_add(f1(w[i - 15])).wrapping_add(w[i - 16]).wrapping_add(i as u32);
        }

        // Copy contents of w into p and q
        unsafe {
            ptr::copy_nonoverlapping(w.as_ptr().offset(256), self.p.as_mut_ptr(),  512);
            ptr::copy_nonoverlapping(w.as_ptr().offset(768), self.q.as_mut_ptr(), 512);
        }

        for i in 0..512 {
            self.p[i] = self.step();
        }
        for i in 0..512 {
            self.q[i] = self.step();
        }

        self.cnt = 0;
    }

    fn step(&mut self) -> u32 {
        let j : usize = self.cnt & 0x1FF;

        // Precompute resources
        let dim_j3 : usize = (j.wrapping_sub(3)) & 0x1FF;
        let dim_j10 : usize = (j.wrapping_sub(10)) & 0x1FF;
        let dim_j511 : usize = (j.wrapping_sub(511)) & 0x1FF;
        let dim_j12 : usize = (j.wrapping_sub(12)) & 0x1FF;

        let ret : u32;

        if self.cnt < 512 {
            self.p[j] = self.p[j].wrapping_add(self.p[dim_j3].rotate_right(10) ^ self.p[dim_j511].rotate_right(23)).wrapping_add(self.p[dim_j10].rotate_right(8));
            ret = (self.q[(self.p[dim_j12] & 0xFF) as usize].wrapping_add(self.q[(((self.p[dim_j12] >> 16) & 0xFF) + 256) as usize])) ^ self.p[j];
        } else {
            self.q[j] = self.q[j].wrapping_add(self.q[dim_j3].rotate_left(10) ^ self.q[dim_j511].rotate_left(23)).wrapping_add(self.q[dim_j10].rotate_left(8));
            ret = (self.p[(self.q[dim_j12] & 0xFF) as usize].wrapping_add(self.p[(((self.q[dim_j12] >> 16) & 0xFF) + 256) as usize])) ^ self.q[j];
        }

        self.cnt = (self.cnt + 1) & 0x3FF;
        ret
    }

    fn next(&mut self) -> u8 {
        if self.output_index == 0 {
            let step = self.step();
            write_u32_le(&mut self.output, step);
        }
        let ret = self.output[self.output_index];
        self.output_index = (self.output_index + 1) & 0x3;

        ret
    }
}

fn f1(x: u32) -> u32 {
    let ret : u32 = x.rotate_right(7) ^ x.rotate_right(18) ^ (x >> 3);
    ret
}

fn f2(x: u32) -> u32 {
    let ret : u32 = x.rotate_right(17) ^ x.rotate_right(19) ^ (x >> 10);
    ret
}

impl SynchronousStreamCipher for Hc128 {
    fn process(&mut self, input: &[u8], output: &mut [u8]) {
        assert!(input.len() == output.len());

        if input.len() <= 4 {
            // Process data bytewise
            for (inb, outb) in input.iter().zip(output.iter_mut()) {
                *outb = *inb ^ self.next();
            }
        } else {
            let mut data_index = 0;
            let data_index_end = data_index + input.len();

            /*  Process any unused keystream (self.buffer)
             *  remaining from previous operations */
            while self.output_index > 0 && data_index < data_index_end {
                output[data_index] = input[data_index] ^ self.next();
                data_index += 1;
            }

            /*  Process input data blockwise until depleted,
             *  or remaining length less than block size
             *  (size of the keystream buffer, self.buffer : 4 bytes) */
            while data_index + 4 <= data_index_end {
                let data_index_inc = data_index + 4;

                // Read input as le-u32
                let input_u32 = read_u32_le(&input[data_index..data_index_inc]);
                // XOR with keystream u32
                let xored = input_u32 ^ self.step();
                // Write output as le-u32
                write_u32_le(&mut output[data_index..data_index_inc], xored);

                data_index = data_index_inc;
            }

            /*  Process remaining data, if any
             *  (e.g. input length not divisible by 4) */
            while data_index < data_index_end {
                output[data_index] = input[data_index] ^ self.next();
                data_index += 1;
            }
        }
    }
}

impl Encryptor for Hc128 {
    fn encrypt(&mut self, input: &mut RefReadBuffer, output: &mut RefWriteBuffer, _: bool)
            -> Result<BufferResult, SymmetricCipherError> {
        symm_enc_or_dec(self, input, output)
    }
}

impl Decryptor for Hc128 {
    fn decrypt(&mut self, input: &mut RefReadBuffer, output: &mut RefWriteBuffer, _: bool)
            -> Result<BufferResult, SymmetricCipherError> {
        symm_enc_or_dec(self, input, output)
    }
}


#[cfg(test)]
mod test {
    use hc128::Hc128;
    use symmetriccipher::SynchronousStreamCipher;
    use serialize::hex::{FromHex};

    // Vectors from http://www.ecrypt.eu.org/stream/svn/viewcvs.cgi/ecrypt/trunk/submissions/hc-256/hc-128/verified.test-vectors?rev=210&view=markup

    #[test]
    fn test_hc128_ecrypt_set_2_vector_0() {
        let key = "00000000000000000000000000000000".from_hex().unwrap();
        let nonce = "00000000000000000000000000000000".from_hex().unwrap();

        let input = [0u8; 64];
        let expected_output_hex = "82001573A003FD3B7FD72FFB0EAF63AAC62F12DEB629DCA72785A66268EC758B1EDB36900560898178E0AD009ABF1F491330DC1C246E3D6CB264F6900271D59C";
        let expected_output = expected_output_hex.from_hex().unwrap();

        let mut output = [0u8; 64];

        let mut hc128 = Hc128::new(key.as_ref(), nonce.as_ref());
        hc128.process(&input, &mut output);
        let result: &[u8] = output.as_ref();
        let expected: &[u8] = expected_output.as_ref();
        assert!(result == expected);    }

    #[test]
    fn test_hc128_ecrypt_set_6_vector_1() {
        let key = "0558ABFE51A4F74A9DF04396E93C8FE2".from_hex().unwrap();
        let nonce = "167DE44BB21980E74EB51C83EA51B81F".from_hex().unwrap();

        let input = [0u8; 64];
        let expected_output_hex = "4F864BF3C96D0363B1903F0739189138F6ED2BC0AF583FEEA0CEA66BA7E06E63FB28BF8B3CA0031D24ABB511C57DD17BFC2861C32400072CB680DF2E58A5CECC";
        let expected_output = expected_output_hex.from_hex().unwrap();

        let mut output = [0u8; 64];

        let mut hc128 = Hc128::new(key.as_ref(), nonce.as_ref());
        hc128.process(&input, &mut output);
        let result: &[u8] = output.as_ref();
        let expected: &[u8] = expected_output.as_ref();
        assert!(result == expected);
    }

    #[test]
    fn test_hc128_ecrypt_set_6_vector_2() {
        let key = "0A5DB00356A9FC4FA2F5489BEE4194E7".from_hex().unwrap();
        let nonce = "1F86ED54BB2289F057BE258CF35AC128".from_hex().unwrap();

        let input = [0u8; 64];
        let expected_output_hex = "82168AB0023B79AAF1E6B4D823855E14A7084378036A951B1CFEF35173875ED86CB66AB8410491A08582BE40080C3102193BA567F9E95D096C3CC60927DD7901";
        let expected_output = expected_output_hex.from_hex().unwrap();

        let mut output = [0u8; 64];

        let mut hc128 = Hc128::new(key.as_ref(), nonce.as_ref());
        hc128.process(&input, &mut output);
        let result: &[u8] = output.as_ref();
        let expected: &[u8] = expected_output.as_ref();
        assert!(result == expected);
    }

    #[test]
    fn test_hc128_ecrypt_set_6_vector_3() {
        let key = "0F62B5085BAE0154A7FA4DA0F34699EC".from_hex().unwrap();
        let nonce = "288FF65DC42B92F960C72E95FC63CA31".from_hex().unwrap();

        let input = [0u8; 64];
        let expected_output_hex = "1CD8AEDDFE52E217E835D0B7E84E2922D04B1ADBCA53C4522B1AA604C42856A90AF83E2614BCE65C0AECABDD8975B55700D6A26D52FFF0888DA38F1DE20B77B7";
        let expected_output = expected_output_hex.from_hex().unwrap();

        let mut output = [0u8; 64];

        let mut hc128 = Hc128::new(&key, &nonce);
        hc128.process(&input, &mut output);
        assert!(&output[..] == &expected_output[..]);
    }
}

#[cfg(all(test, feature = "with-bench"))]
mod bench {
    use test::Bencher;
    use symmetriccipher::SynchronousStreamCipher;
    use hc128::Hc128;

    #[bench]
    pub fn hc128_10(bh: & mut Bencher) {
        let mut hc128 = Hc128::new(&[0; 16], &[0; 16]);
        let input = [1u8; 10];
        let mut output = [0u8; 10];
        bh.iter( || {
            hc128.process(&input, &mut output);
        });
        bh.bytes = input.len() as u64;
    }

    #[bench]
    pub fn hc128_1k(bh: & mut Bencher) {
        let mut hc128 = Hc128::new(&[0; 16], &[0; 16]);
        let input = [1u8; 1024];
        let mut output = [0u8; 1024];
        bh.iter( || {
            hc128.process(&input, &mut output);
        });
        bh.bytes = input.len() as u64;
    }

    #[bench]
    pub fn hc128_64k(bh: & mut Bencher) {
        let mut hc128 = Hc128::new(&[0; 16], &[0; 16]);
        let input = [1u8; 65536];
        let mut output = [0u8; 65536];
        bh.iter( || {
            hc128.process(&input, &mut output);
        });
        bh.bytes = input.len() as u64;
    }
}