| // Copyright 2018 Developers of the Rand project. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // https://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! The HC-128 random number generator. |
| |
| use core::fmt; |
| use rand_core::{CryptoRng, RngCore, SeedableRng, Error, le}; |
| use rand_core::block::{BlockRngCore, BlockRng}; |
| |
| const SEED_WORDS: usize = 8; // 128 bit key followed by 128 bit iv |
| |
| /// A cryptographically secure random number generator that uses the HC-128 |
| /// algorithm. |
| /// |
| /// HC-128 is a stream cipher designed by Hongjun Wu[^1], that we use as an |
| /// RNG. It is selected as one of the "stream ciphers suitable for widespread |
| /// adoption" by eSTREAM[^2]. |
| /// |
| /// HC-128 is an array based RNG. In this it is similar to RC-4 and ISAAC before |
| /// it, but those have never been proven cryptographically secure (or have even |
| /// been significantly compromised, as in the case of RC-4[^5]). |
| /// |
| /// Because HC-128 works with simple indexing into a large array and with a few |
| /// operations that parallelize well, it has very good performance. The size of |
| /// the array it needs, 4kb, can however be a disadvantage. |
| /// |
| /// This implementation is not based on the version of HC-128 submitted to the |
| /// eSTREAM contest, but on a later version by the author with a few small |
| /// improvements from December 15, 2009[^3]. |
| /// |
| /// HC-128 has no known weaknesses that are easier to exploit than doing a |
| /// brute-force search of 2<sup>128</sup>. A very comprehensive analysis of the |
| /// current state of known attacks / weaknesses of HC-128 is given in *Some |
| /// Results On Analysis And Implementation Of HC-128 Stream Cipher*[^4]. |
| /// |
| /// The average cycle length is expected to be |
| /// 2<sup>1024*32+10-1</sup> = 2<sup>32777</sup>. |
| /// We support seeding with a 256-bit array, which matches the 128-bit key |
| /// concatenated with a 128-bit IV from the stream cipher. |
| /// |
| /// This implementation uses an output buffer of sixteen `u32` words, and uses |
| /// [`BlockRng`] to implement the [`RngCore`] methods. |
| /// |
| /// ## References |
| /// [^1]: Hongjun Wu (2008). ["The Stream Cipher HC-128"]( |
| /// http://www.ecrypt.eu.org/stream/p3ciphers/hc/hc128_p3.pdf). |
| /// *The eSTREAM Finalists*, LNCS 4986, pp. 39–47, Springer-Verlag. |
| /// |
| /// [^2]: [eSTREAM: the ECRYPT Stream Cipher Project]( |
| /// http://www.ecrypt.eu.org/stream/) |
| /// |
| /// [^3]: Hongjun Wu, [Stream Ciphers HC-128 and HC-256]( |
| /// https://www.ntu.edu.sg/home/wuhj/research/hc/index.html) |
| /// |
| /// [^4]: Shashwat Raizada (January 2015),["Some Results On Analysis And |
| /// Implementation Of HC-128 Stream Cipher"]( |
| /// http://library.isical.ac.in:8080/jspui/bitstream/123456789/6636/1/TH431.pdf). |
| /// |
| /// [^5]: Internet Engineering Task Force (February 2015), |
| /// ["Prohibiting RC4 Cipher Suites"](https://tools.ietf.org/html/rfc7465). |
| #[derive(Clone, Debug)] |
| pub struct Hc128Rng(BlockRng<Hc128Core>); |
| |
| impl RngCore for Hc128Rng { |
| #[inline] |
| fn next_u32(&mut self) -> u32 { |
| self.0.next_u32() |
| } |
| |
| #[inline] |
| fn next_u64(&mut self) -> u64 { |
| self.0.next_u64() |
| } |
| |
| #[inline] |
| fn fill_bytes(&mut self, dest: &mut [u8]) { |
| self.0.fill_bytes(dest) |
| } |
| |
| #[inline] |
| fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> { |
| self.0.try_fill_bytes(dest) |
| } |
| } |
| |
| impl SeedableRng for Hc128Rng { |
| type Seed = <Hc128Core as SeedableRng>::Seed; |
| |
| #[inline] |
| fn from_seed(seed: Self::Seed) -> Self { |
| Hc128Rng(BlockRng::<Hc128Core>::from_seed(seed)) |
| } |
| |
| #[inline] |
| fn from_rng<R: RngCore>(rng: R) -> Result<Self, Error> { |
| BlockRng::<Hc128Core>::from_rng(rng).map(Hc128Rng) |
| } |
| } |
| |
| impl CryptoRng for Hc128Rng {} |
| |
| /// The core of `Hc128Rng`, used with `BlockRng`. |
| #[derive(Clone)] |
| pub struct Hc128Core { |
| t: [u32; 1024], |
| counter1024: usize, |
| } |
| |
| // Custom Debug implementation that does not expose the internal state |
| impl fmt::Debug for Hc128Core { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| write!(f, "Hc128Core {{}}") |
| } |
| } |
| |
| impl BlockRngCore for Hc128Core { |
| type Item = u32; |
| type Results = [u32; 16]; |
| |
| fn generate(&mut self, results: &mut Self::Results) { |
| assert!(self.counter1024 % 16 == 0); |
| |
| let cc = self.counter1024 % 512; |
| let dd = (cc + 16) % 512; |
| let ee = cc.wrapping_sub(16) % 512; |
| |
| if self.counter1024 & 512 == 0 { |
| // P block |
| results[0] = self.step_p(cc+0, cc+1, ee+13, ee+6, ee+4); |
| results[1] = self.step_p(cc+1, cc+2, ee+14, ee+7, ee+5); |
| results[2] = self.step_p(cc+2, cc+3, ee+15, ee+8, ee+6); |
| results[3] = self.step_p(cc+3, cc+4, cc+0, ee+9, ee+7); |
| results[4] = self.step_p(cc+4, cc+5, cc+1, ee+10, ee+8); |
| results[5] = self.step_p(cc+5, cc+6, cc+2, ee+11, ee+9); |
| results[6] = self.step_p(cc+6, cc+7, cc+3, ee+12, ee+10); |
| results[7] = self.step_p(cc+7, cc+8, cc+4, ee+13, ee+11); |
| results[8] = self.step_p(cc+8, cc+9, cc+5, ee+14, ee+12); |
| results[9] = self.step_p(cc+9, cc+10, cc+6, ee+15, ee+13); |
| results[10] = self.step_p(cc+10, cc+11, cc+7, cc+0, ee+14); |
| results[11] = self.step_p(cc+11, cc+12, cc+8, cc+1, ee+15); |
| results[12] = self.step_p(cc+12, cc+13, cc+9, cc+2, cc+0); |
| results[13] = self.step_p(cc+13, cc+14, cc+10, cc+3, cc+1); |
| results[14] = self.step_p(cc+14, cc+15, cc+11, cc+4, cc+2); |
| results[15] = self.step_p(cc+15, dd+0, cc+12, cc+5, cc+3); |
| } else { |
| // Q block |
| results[0] = self.step_q(cc+0, cc+1, ee+13, ee+6, ee+4); |
| results[1] = self.step_q(cc+1, cc+2, ee+14, ee+7, ee+5); |
| results[2] = self.step_q(cc+2, cc+3, ee+15, ee+8, ee+6); |
| results[3] = self.step_q(cc+3, cc+4, cc+0, ee+9, ee+7); |
| results[4] = self.step_q(cc+4, cc+5, cc+1, ee+10, ee+8); |
| results[5] = self.step_q(cc+5, cc+6, cc+2, ee+11, ee+9); |
| results[6] = self.step_q(cc+6, cc+7, cc+3, ee+12, ee+10); |
| results[7] = self.step_q(cc+7, cc+8, cc+4, ee+13, ee+11); |
| results[8] = self.step_q(cc+8, cc+9, cc+5, ee+14, ee+12); |
| results[9] = self.step_q(cc+9, cc+10, cc+6, ee+15, ee+13); |
| results[10] = self.step_q(cc+10, cc+11, cc+7, cc+0, ee+14); |
| results[11] = self.step_q(cc+11, cc+12, cc+8, cc+1, ee+15); |
| results[12] = self.step_q(cc+12, cc+13, cc+9, cc+2, cc+0); |
| results[13] = self.step_q(cc+13, cc+14, cc+10, cc+3, cc+1); |
| results[14] = self.step_q(cc+14, cc+15, cc+11, cc+4, cc+2); |
| results[15] = self.step_q(cc+15, dd+0, cc+12, cc+5, cc+3); |
| } |
| self.counter1024 = self.counter1024.wrapping_add(16); |
| } |
| } |
| |
| impl Hc128Core { |
| // One step of HC-128, update P and generate 32 bits keystream |
| #[inline(always)] |
| fn step_p(&mut self, i: usize, i511: usize, i3: usize, i10: usize, i12: usize) |
| -> u32 |
| { |
| let (p, q) = self.t.split_at_mut(512); |
| // FIXME: it would be great if we the bounds checks here could be |
| // optimized out, and we would not need unsafe. |
| // This improves performance by about 7%. |
| unsafe { |
| let temp0 = p.get_unchecked(i511).rotate_right(23); |
| let temp1 = p.get_unchecked(i3).rotate_right(10); |
| let temp2 = p.get_unchecked(i10).rotate_right(8); |
| *p.get_unchecked_mut(i) = p.get_unchecked(i) |
| .wrapping_add(temp2) |
| .wrapping_add(temp0 ^ temp1); |
| let temp3 = { |
| // The h1 function in HC-128 |
| let a = *p.get_unchecked(i12) as u8; |
| let c = (p.get_unchecked(i12) >> 16) as u8; |
| q[a as usize].wrapping_add(q[256 + c as usize]) |
| }; |
| temp3 ^ p.get_unchecked(i) |
| } |
| } |
| |
| // One step of HC-128, update Q and generate 32 bits keystream |
| // Similar to `step_p`, but `p` and `q` are swapped, and the rotates are to |
| // the left instead of to the right. |
| #[inline(always)] |
| fn step_q(&mut self, i: usize, i511: usize, i3: usize, i10: usize, i12: usize) |
| -> u32 |
| { |
| let (p, q) = self.t.split_at_mut(512); |
| unsafe { |
| let temp0 = q.get_unchecked(i511).rotate_left(23); |
| let temp1 = q.get_unchecked(i3).rotate_left(10); |
| let temp2 = q.get_unchecked(i10).rotate_left(8); |
| *q.get_unchecked_mut(i) = q.get_unchecked(i) |
| .wrapping_add(temp2) |
| .wrapping_add(temp0 ^ temp1); |
| let temp3 = { |
| // The h2 function in HC-128 |
| let a = *q.get_unchecked(i12) as u8; |
| let c = (q.get_unchecked(i12) >> 16) as u8; |
| p[a as usize].wrapping_add(p[256 + c as usize]) |
| }; |
| temp3 ^ q.get_unchecked(i) |
| } |
| } |
| |
| fn sixteen_steps(&mut self) { |
| assert!(self.counter1024 % 16 == 0); |
| |
| let cc = self.counter1024 % 512; |
| let dd = (cc + 16) % 512; |
| let ee = cc.wrapping_sub(16) % 512; |
| |
| if self.counter1024 < 512 { |
| // P block |
| self.t[cc+0] = self.step_p(cc+0, cc+1, ee+13, ee+6, ee+4); |
| self.t[cc+1] = self.step_p(cc+1, cc+2, ee+14, ee+7, ee+5); |
| self.t[cc+2] = self.step_p(cc+2, cc+3, ee+15, ee+8, ee+6); |
| self.t[cc+3] = self.step_p(cc+3, cc+4, cc+0, ee+9, ee+7); |
| self.t[cc+4] = self.step_p(cc+4, cc+5, cc+1, ee+10, ee+8); |
| self.t[cc+5] = self.step_p(cc+5, cc+6, cc+2, ee+11, ee+9); |
| self.t[cc+6] = self.step_p(cc+6, cc+7, cc+3, ee+12, ee+10); |
| self.t[cc+7] = self.step_p(cc+7, cc+8, cc+4, ee+13, ee+11); |
| self.t[cc+8] = self.step_p(cc+8, cc+9, cc+5, ee+14, ee+12); |
| self.t[cc+9] = self.step_p(cc+9, cc+10, cc+6, ee+15, ee+13); |
| self.t[cc+10] = self.step_p(cc+10, cc+11, cc+7, cc+0, ee+14); |
| self.t[cc+11] = self.step_p(cc+11, cc+12, cc+8, cc+1, ee+15); |
| self.t[cc+12] = self.step_p(cc+12, cc+13, cc+9, cc+2, cc+0); |
| self.t[cc+13] = self.step_p(cc+13, cc+14, cc+10, cc+3, cc+1); |
| self.t[cc+14] = self.step_p(cc+14, cc+15, cc+11, cc+4, cc+2); |
| self.t[cc+15] = self.step_p(cc+15, dd+0, cc+12, cc+5, cc+3); |
| } else { |
| // Q block |
| self.t[cc+512+0] = self.step_q(cc+0, cc+1, ee+13, ee+6, ee+4); |
| self.t[cc+512+1] = self.step_q(cc+1, cc+2, ee+14, ee+7, ee+5); |
| self.t[cc+512+2] = self.step_q(cc+2, cc+3, ee+15, ee+8, ee+6); |
| self.t[cc+512+3] = self.step_q(cc+3, cc+4, cc+0, ee+9, ee+7); |
| self.t[cc+512+4] = self.step_q(cc+4, cc+5, cc+1, ee+10, ee+8); |
| self.t[cc+512+5] = self.step_q(cc+5, cc+6, cc+2, ee+11, ee+9); |
| self.t[cc+512+6] = self.step_q(cc+6, cc+7, cc+3, ee+12, ee+10); |
| self.t[cc+512+7] = self.step_q(cc+7, cc+8, cc+4, ee+13, ee+11); |
| self.t[cc+512+8] = self.step_q(cc+8, cc+9, cc+5, ee+14, ee+12); |
| self.t[cc+512+9] = self.step_q(cc+9, cc+10, cc+6, ee+15, ee+13); |
| self.t[cc+512+10] = self.step_q(cc+10, cc+11, cc+7, cc+0, ee+14); |
| self.t[cc+512+11] = self.step_q(cc+11, cc+12, cc+8, cc+1, ee+15); |
| self.t[cc+512+12] = self.step_q(cc+12, cc+13, cc+9, cc+2, cc+0); |
| self.t[cc+512+13] = self.step_q(cc+13, cc+14, cc+10, cc+3, cc+1); |
| self.t[cc+512+14] = self.step_q(cc+14, cc+15, cc+11, cc+4, cc+2); |
| self.t[cc+512+15] = self.step_q(cc+15, dd+0, cc+12, cc+5, cc+3); |
| } |
| self.counter1024 += 16; |
| } |
| |
| // Initialize an HC-128 random number generator. The seed has to be |
| // 256 bits in length (`[u32; 8]`), matching the 128 bit `key` followed by |
| // 128 bit `iv` when HC-128 where to be used as a stream cipher. |
| #[inline(always)] // single use: SeedableRng::from_seed |
| fn init(seed: [u32; SEED_WORDS]) -> Self { |
| #[inline] |
| fn f1(x: u32) -> u32 { |
| x.rotate_right(7) ^ x.rotate_right(18) ^ (x >> 3) |
| } |
| |
| #[inline] |
| fn f2(x: u32) -> u32 { |
| x.rotate_right(17) ^ x.rotate_right(19) ^ (x >> 10) |
| } |
| |
| let mut t = [0u32; 1024]; |
| |
| // Expand the key and iv into P and Q |
| let (key, iv) = seed.split_at(4); |
| t[..4].copy_from_slice(key); |
| t[4..8].copy_from_slice(key); |
| t[8..12].copy_from_slice(iv); |
| t[12..16].copy_from_slice(iv); |
| |
| // Generate the 256 intermediate values W[16] ... W[256+16-1], and |
| // copy the last 16 generated values to the start op P. |
| for i in 16..256+16 { |
| t[i] = f2(t[i-2]).wrapping_add(t[i-7]).wrapping_add(f1(t[i-15])) |
| .wrapping_add(t[i-16]).wrapping_add(i as u32); |
| } |
| { |
| let (p1, p2) = t.split_at_mut(256); |
| p1[0..16].copy_from_slice(&p2[0..16]); |
| } |
| |
| // Generate both the P and Q tables |
| for i in 16..1024 { |
| t[i] = f2(t[i-2]).wrapping_add(t[i-7]).wrapping_add(f1(t[i-15])) |
| .wrapping_add(t[i-16]).wrapping_add(256 + i as u32); |
| } |
| |
| let mut core = Self { t, counter1024: 0 }; |
| |
| // run the cipher 1024 steps |
| for _ in 0..64 { core.sixteen_steps() }; |
| core.counter1024 = 0; |
| core |
| } |
| } |
| |
| impl SeedableRng for Hc128Core { |
| type Seed = [u8; SEED_WORDS*4]; |
| |
| /// Create an HC-128 random number generator with a seed. The seed has to be |
| /// 256 bits in length, matching the 128 bit `key` followed by 128 bit `iv` |
| /// when HC-128 where to be used as a stream cipher. |
| fn from_seed(seed: Self::Seed) -> Self { |
| let mut seed_u32 = [0u32; SEED_WORDS]; |
| le::read_u32_into(&seed, &mut seed_u32); |
| Self::init(seed_u32) |
| } |
| } |
| |
| impl CryptoRng for Hc128Core {} |
| |
| #[cfg(test)] |
| mod test { |
| use ::rand_core::{RngCore, SeedableRng}; |
| use super::Hc128Rng; |
| |
| #[test] |
| // Test vector 1 from the paper "The Stream Cipher HC-128" |
| fn test_hc128_true_values_a() { |
| let seed = [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, // key |
| 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0]; // iv |
| let mut rng = Hc128Rng::from_seed(seed); |
| |
| let mut results = [0u32; 16]; |
| for i in results.iter_mut() { *i = rng.next_u32(); } |
| let expected = [0x73150082, 0x3bfd03a0, 0xfb2fd77f, 0xaa63af0e, |
| 0xde122fc6, 0xa7dc29b6, 0x62a68527, 0x8b75ec68, |
| 0x9036db1e, 0x81896005, 0x00ade078, 0x491fbf9a, |
| 0x1cdc3013, 0x6c3d6e24, 0x90f664b2, 0x9cd57102]; |
| assert_eq!(results, expected); |
| } |
| |
| #[test] |
| // Test vector 2 from the paper "The Stream Cipher HC-128" |
| fn test_hc128_true_values_b() { |
| let seed = [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, // key |
| 1,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0]; // iv |
| let mut rng = Hc128Rng::from_seed(seed); |
| |
| let mut results = [0u32; 16]; |
| for i in results.iter_mut() { *i = rng.next_u32(); } |
| let expected = [0xc01893d5, 0xb7dbe958, 0x8f65ec98, 0x64176604, |
| 0x36fc6724, 0xc82c6eec, 0x1b1c38a7, 0xc9b42a95, |
| 0x323ef123, 0x0a6a908b, 0xce757b68, 0x9f14f7bb, |
| 0xe4cde011, 0xaeb5173f, 0x89608c94, 0xb5cf46ca]; |
| assert_eq!(results, expected); |
| } |
| |
| #[test] |
| // Test vector 3 from the paper "The Stream Cipher HC-128" |
| fn test_hc128_true_values_c() { |
| let seed = [0x55,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, // key |
| 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0]; // iv |
| let mut rng = Hc128Rng::from_seed(seed); |
| |
| let mut results = [0u32; 16]; |
| for i in results.iter_mut() { *i = rng.next_u32(); } |
| let expected = [0x518251a4, 0x04b4930a, 0xb02af931, 0x0639f032, |
| 0xbcb4a47a, 0x5722480b, 0x2bf99f72, 0xcdc0e566, |
| 0x310f0c56, 0xd3cc83e8, 0x663db8ef, 0x62dfe07f, |
| 0x593e1790, 0xc5ceaa9c, 0xab03806f, 0xc9a6e5a0]; |
| assert_eq!(results, expected); |
| } |
| |
| #[test] |
| fn test_hc128_true_values_u64() { |
| let seed = [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, // key |
| 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0]; // iv |
| let mut rng = Hc128Rng::from_seed(seed); |
| |
| let mut results = [0u64; 8]; |
| for i in results.iter_mut() { *i = rng.next_u64(); } |
| let expected = [0x3bfd03a073150082, 0xaa63af0efb2fd77f, |
| 0xa7dc29b6de122fc6, 0x8b75ec6862a68527, |
| 0x818960059036db1e, 0x491fbf9a00ade078, |
| 0x6c3d6e241cdc3013, 0x9cd5710290f664b2]; |
| assert_eq!(results, expected); |
| |
| // The RNG operates in a P block of 512 results and next a Q block. |
| // After skipping 2*800 u32 results we end up somewhere in the Q block |
| // of the second round |
| for _ in 0..800 { rng.next_u64(); } |
| |
| for i in results.iter_mut() { *i = rng.next_u64(); } |
| let expected = [0xd8c4d6ca84d0fc10, 0xf16a5d91dc66e8e7, |
| 0xd800de5bc37a8653, 0x7bae1f88c0dfbb4c, |
| 0x3bfe1f374e6d4d14, 0x424b55676be3fa06, |
| 0xe3a1e8758cbff579, 0x417f7198c5652bcd]; |
| assert_eq!(results, expected); |
| } |
| |
| #[test] |
| fn test_hc128_true_values_bytes() { |
| let seed = [0x55,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, // key |
| 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0]; // iv |
| let mut rng = Hc128Rng::from_seed(seed); |
| let expected = [0x31, 0xf9, 0x2a, 0xb0, 0x32, 0xf0, 0x39, 0x06, |
| 0x7a, 0xa4, 0xb4, 0xbc, 0x0b, 0x48, 0x22, 0x57, |
| 0x72, 0x9f, 0xf9, 0x2b, 0x66, 0xe5, 0xc0, 0xcd, |
| 0x56, 0x0c, 0x0f, 0x31, 0xe8, 0x83, 0xcc, 0xd3, |
| 0xef, 0xb8, 0x3d, 0x66, 0x7f, 0xe0, 0xdf, 0x62, |
| 0x90, 0x17, 0x3e, 0x59, 0x9c, 0xaa, 0xce, 0xc5, |
| 0x6f, 0x80, 0x03, 0xab, 0xa0, 0xe5, 0xa6, 0xc9, |
| 0x60, 0x95, 0x84, 0x7a, 0xa5, 0x68, 0x5a, 0x84, |
| 0xea, 0xd5, 0xf3, 0xea, 0x73, 0xa9, 0xad, 0x01, |
| 0x79, 0x7d, 0xbe, 0x9f, 0xea, 0xe3, 0xf9, 0x74, |
| 0x0e, 0xda, 0x2f, 0xa0, 0xe4, 0x7b, 0x4b, 0x1b, |
| 0xdd, 0x17, 0x69, 0x4a, 0xfe, 0x9f, 0x56, 0x95, |
| 0xad, 0x83, 0x6b, 0x9d, 0x60, 0xa1, 0x99, 0x96, |
| 0x90, 0x00, 0x66, 0x7f, 0xfa, 0x7e, 0x65, 0xe9, |
| 0xac, 0x8b, 0x92, 0x34, 0x77, 0xb4, 0x23, 0xd0, |
| 0xb9, 0xab, 0xb1, 0x47, 0x7d, 0x4a, 0x13, 0x0a]; |
| |
| // Pick a somewhat large buffer so we can test filling with the |
| // remainder from `state.results`, directly filling the buffer, and |
| // filling the remainder of the buffer. |
| let mut buffer = [0u8; 16*4*2]; |
| // Consume a value so that we have a remainder. |
| assert!(rng.next_u64() == 0x04b4930a518251a4); |
| rng.fill_bytes(&mut buffer); |
| |
| // [u8; 128] doesn't implement PartialEq |
| assert_eq!(buffer.len(), expected.len()); |
| for (b, e) in buffer.iter().zip(expected.iter()) { |
| assert_eq!(b, e); |
| } |
| } |
| |
| #[test] |
| fn test_hc128_clone() { |
| let seed = [0x55,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0, // key |
| 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0]; // iv |
| let mut rng1 = Hc128Rng::from_seed(seed); |
| let mut rng2 = rng1.clone(); |
| for _ in 0..16 { |
| assert_eq!(rng1.next_u32(), rng2.next_u32()); |
| } |
| } |
| } |
