diff options
Diffstat (limited to 'rand/rand_chacha/src')
-rw-r--r-- | rand/rand_chacha/src/chacha.rs | 567 | ||||
-rw-r--r-- | rand/rand_chacha/src/lib.rs | 11 |
2 files changed, 293 insertions, 285 deletions
diff --git a/rand/rand_chacha/src/chacha.rs b/rand/rand_chacha/src/chacha.rs index 86f191e..b1b89e0 100644 --- a/rand/rand_chacha/src/chacha.rs +++ b/rand/rand_chacha/src/chacha.rs @@ -1,5 +1,4 @@ // Copyright 2018 Developers of the Rand project. -// Copyright 2014 The Rust Project Developers. // // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or // https://www.apache.org/licenses/LICENSE-2.0> or the MIT license @@ -9,274 +8,251 @@ //! The ChaCha 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; // 8 words for the 256-bit key -const STATE_WORDS: usize = 16; - -/// A cryptographically secure random number generator that uses the ChaCha -/// algorithm. -/// -/// ChaCha is a stream cipher designed by Daniel J. Bernstein[^1], that we use -/// as an RNG. It is an improved variant of the Salsa20 cipher family, which was -/// selected as one of the "stream ciphers suitable for widespread adoption" by -/// eSTREAM[^2]. -/// -/// ChaCha uses add-rotate-xor (ARX) operations as its basis. These are safe -/// against timing attacks, although that is mostly a concern for ciphers and -/// not for RNGs. Also it is very suitable for SIMD implementation. -/// Here we do not provide a SIMD implementation yet, except for what is -/// provided by auto-vectorisation. -/// -/// With the ChaCha algorithm it is possible to choose the number of rounds the -/// core algorithm should run. The number of rounds is a tradeoff between -/// performance and security, where 8 rounds is the minimum potentially -/// secure configuration, and 20 rounds is widely used as a conservative choice. -/// We use 20 rounds in this implementation, but hope to allow type-level -/// configuration in the future. -/// -/// We use a 64-bit counter and 64-bit stream identifier as in Bernstein's -/// implementation[^1] except that we use a stream identifier in place of a -/// nonce. A 64-bit counter over 64-byte (16 word) blocks allows 1 ZiB of output -/// before cycling, and the stream identifier allows 2<sup>64</sup> unique -/// streams of output per seed. Both counter and stream are initialized to zero -/// but may be set via [`set_word_pos`] and [`set_stream`]. -/// -/// The word layout is: -/// -/// ```text -/// constant constant constant constant -/// seed seed seed seed -/// seed seed seed seed -/// counter counter stream_id stream_id -/// ``` -/// -/// This implementation uses an output buffer of sixteen `u32` words, and uses -/// [`BlockRng`] to implement the [`RngCore`] methods. -/// -/// [^1]: D. J. Bernstein, [*ChaCha, a variant of Salsa20*]( -/// https://cr.yp.to/chacha.html) -/// -/// [^2]: [eSTREAM: the ECRYPT Stream Cipher Project]( -/// http://www.ecrypt.eu.org/stream/) -/// -/// [`set_word_pos`]: #method.set_word_pos -/// [`set_stream`]: #method.set_stream -/// [`BlockRng`]: ../rand_core/block/struct.BlockRng.html -/// [`RngCore`]: ../rand_core/trait.RngCore.html -#[derive(Clone, Debug)] -pub struct ChaChaRng(BlockRng<ChaChaCore>); - -impl RngCore for ChaChaRng { - #[inline] - fn next_u32(&mut self) -> u32 { - self.0.next_u32() +#[cfg(feature = "std")] +use std as core; +#[cfg(not(feature = "std"))] +use core; + +use c2_chacha::guts::ChaCha; +use self::core::fmt; +use rand_core::block::{BlockRng, BlockRngCore}; +use rand_core::{CryptoRng, Error, RngCore, SeedableRng}; + +const STREAM_PARAM_NONCE: u32 = 1; +const STREAM_PARAM_BLOCK: u32 = 0; + +pub struct Array64<T>([T; 64]); +impl<T> Default for Array64<T> where T: Default { + fn default() -> Self { + Self([T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), + T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), + T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), + T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), + T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), + T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), + T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), + T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default(), T::default()]) } - - #[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) +} +impl<T> AsRef<[T]> for Array64<T> { + fn as_ref(&self) -> &[T] { + &self.0 } - - #[inline] - fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error> { - self.0.try_fill_bytes(dest) +} +impl<T> AsMut<[T]> for Array64<T> { + fn as_mut(&mut self) -> &mut [T] { + &mut self.0 } } - -impl SeedableRng for ChaChaRng { - type Seed = <ChaChaCore as SeedableRng>::Seed; - - fn from_seed(seed: Self::Seed) -> Self { - ChaChaRng(BlockRng::<ChaChaCore>::from_seed(seed)) +impl<T> Clone for Array64<T> where T: Copy + Default { + fn clone(&self) -> Self { + let mut new = Self::default(); + new.0.copy_from_slice(&self.0); + new } - - fn from_rng<R: RngCore>(rng: R) -> Result<Self, Error> { - BlockRng::<ChaChaCore>::from_rng(rng).map(ChaChaRng) +} +impl<T> fmt::Debug for Array64<T> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!(f, "Array64 {{}}") } } -impl CryptoRng for ChaChaRng {} - -impl ChaChaRng { - /// Get the offset from the start of the stream, in 32-bit words. - /// - /// Since the generated blocks are 16 words (2<sup>4</sup>) long and the - /// counter is 64-bits, the offset is a 68-bit number. Sub-word offsets are - /// not supported, hence the result can simply be multiplied by 4 to get a - /// byte-offset. - /// - /// Note: this function is currently only available with Rust 1.26 or later. - #[cfg(all(rustc_1_26, not(target_os = "emscripten")))] - pub fn get_word_pos(&self) -> u128 { - let mut c = (self.0.core.state[13] as u64) << 32 - | (self.0.core.state[12] as u64); - let mut index = self.0.index(); - // c is the end of the last block generated, unless index is at end - if index >= STATE_WORDS { - index = 0; - } else { - c = c.wrapping_sub(1); +macro_rules! chacha_impl { + ($ChaChaXCore:ident, $ChaChaXRng:ident, $rounds:expr, $doc:expr) => { + #[doc=$doc] + #[derive(Clone)] + pub struct $ChaChaXCore { + state: ChaCha, } - ((c as u128) << 4) | (index as u128) - } - /// Set the offset from the start of the stream, in 32-bit words. - /// - /// As with `get_word_pos`, we use a 68-bit number. Since the generator - /// simply cycles at the end of its period (1 ZiB), we ignore the upper - /// 60 bits. - /// - /// Note: this function is currently only available with Rust 1.26 or later. - #[cfg(all(rustc_1_26, not(target_os = "emscripten")))] - pub fn set_word_pos(&mut self, word_offset: u128) { - let index = (word_offset as usize) & 0xF; - let counter = (word_offset >> 4) as u64; - self.0.core.state[12] = counter as u32; - self.0.core.state[13] = (counter >> 32) as u32; - if index != 0 { - self.0.generate_and_set(index); // also increments counter - } else { - self.0.reset(); + // Custom Debug implementation that does not expose the internal state + impl fmt::Debug for $ChaChaXCore { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!(f, "ChaChaXCore {{}}") + } } - } - /// Set the stream number. - /// - /// This is initialized to zero; 2<sup>64</sup> unique streams of output - /// are available per seed/key. - /// - /// Note that in order to reproduce ChaCha output with a specific 64-bit - /// nonce, one can convert that nonce to a `u64` in little-endian fashion - /// and pass to this function. In theory a 96-bit nonce can be used by - /// passing the last 64-bits to this function and using the first 32-bits as - /// the most significant half of the 64-bit counter (which may be set - /// indirectly via `set_word_pos`), but this is not directly supported. - pub fn set_stream(&mut self, stream: u64) { - let index = self.0.index(); - self.0.core.state[14] = stream as u32; - self.0.core.state[15] = (stream >> 32) as u32; - if index < STATE_WORDS { - // we need to regenerate a partial result buffer - { - // reverse of counter adjustment in generate() - if self.0.core.state[12] == 0 { - self.0.core.state[13] = self.0.core.state[13].wrapping_sub(1); + impl BlockRngCore for $ChaChaXCore { + type Item = u32; + type Results = Array64<u32>; + #[inline] + fn generate(&mut self, r: &mut Self::Results) { + // Fill slice of words by writing to equivalent slice of bytes, then fixing endianness. + self.state.refill4($rounds, unsafe { + &mut *(&mut *r as *mut Array64<u32> as *mut [u8; 256]) + }); + for x in r.as_mut() { + *x = x.to_le(); } - self.0.core.state[12] = self.0.core.state[12].wrapping_sub(1); } - self.0.generate_and_set(index); } - } -} -/// The core of `ChaChaRng`, used with `BlockRng`. -#[derive(Clone)] -pub struct ChaChaCore { - state: [u32; STATE_WORDS], -} - -// Custom Debug implementation that does not expose the internal state -impl fmt::Debug for ChaChaCore { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - write!(f, "ChaChaCore {{}}") - } -} + impl SeedableRng for $ChaChaXCore { + type Seed = [u8; 32]; + #[inline] + fn from_seed(seed: Self::Seed) -> Self { + $ChaChaXCore { state: ChaCha::new(&seed, &[0u8; 8]) } + } + } -macro_rules! quarter_round{ - ($a: expr, $b: expr, $c: expr, $d: expr) => {{ - $a = $a.wrapping_add($b); $d ^= $a; $d = $d.rotate_left(16); - $c = $c.wrapping_add($d); $b ^= $c; $b = $b.rotate_left(12); - $a = $a.wrapping_add($b); $d ^= $a; $d = $d.rotate_left( 8); - $c = $c.wrapping_add($d); $b ^= $c; $b = $b.rotate_left( 7); - }} -} + /// A cryptographically secure random number generator that uses the ChaCha algorithm. + /// + /// ChaCha is a stream cipher designed by Daniel J. Bernstein[^1], that we use as an RNG. It is + /// an improved variant of the Salsa20 cipher family, which was selected as one of the "stream + /// ciphers suitable for widespread adoption" by eSTREAM[^2]. + /// + /// ChaCha uses add-rotate-xor (ARX) operations as its basis. These are safe against timing + /// attacks, although that is mostly a concern for ciphers and not for RNGs. We provide a SIMD + /// implementation to support high throughput on a variety of common hardware platforms. + /// + /// With the ChaCha algorithm it is possible to choose the number of rounds the core algorithm + /// should run. The number of rounds is a tradeoff between performance and security, where 8 + /// rounds is the minimum potentially secure configuration, and 20 rounds is widely used as a + /// conservative choice. + /// + /// We use a 64-bit counter and 64-bit stream identifier as in Bernstein's implementation[^1] + /// except that we use a stream identifier in place of a nonce. A 64-bit counter over 64-byte + /// (16 word) blocks allows 1 ZiB of output before cycling, and the stream identifier allows + /// 2<sup>64</sup> unique streams of output per seed. Both counter and stream are initialized + /// to zero but may be set via the `set_word_pos` and `set_stream` methods. + /// + /// The word layout is: + /// + /// ```text + /// constant constant constant constant + /// seed seed seed seed + /// seed seed seed seed + /// counter counter stream_id stream_id + /// ``` + /// + /// This implementation uses an output buffer of sixteen `u32` words, and uses + /// [`BlockRng`] to implement the [`RngCore`] methods. + /// + /// [^1]: D. J. Bernstein, [*ChaCha, a variant of Salsa20*]( + /// https://cr.yp.to/chacha.html) + /// + /// [^2]: [eSTREAM: the ECRYPT Stream Cipher Project]( + /// http://www.ecrypt.eu.org/stream/) + #[derive(Clone, Debug)] + pub struct $ChaChaXRng { + rng: BlockRng<$ChaChaXCore>, + } -macro_rules! double_round{ - ($x: expr) => {{ - // Column round - quarter_round!($x[ 0], $x[ 4], $x[ 8], $x[12]); - quarter_round!($x[ 1], $x[ 5], $x[ 9], $x[13]); - quarter_round!($x[ 2], $x[ 6], $x[10], $x[14]); - quarter_round!($x[ 3], $x[ 7], $x[11], $x[15]); - // Diagonal round - quarter_round!($x[ 0], $x[ 5], $x[10], $x[15]); - quarter_round!($x[ 1], $x[ 6], $x[11], $x[12]); - quarter_round!($x[ 2], $x[ 7], $x[ 8], $x[13]); - quarter_round!($x[ 3], $x[ 4], $x[ 9], $x[14]); - }} -} + impl SeedableRng for $ChaChaXRng { + type Seed = [u8; 32]; + #[inline] + fn from_seed(seed: Self::Seed) -> Self { + let core = $ChaChaXCore::from_seed(seed); + Self { + rng: BlockRng::new(core), + } + } + } -impl BlockRngCore for ChaChaCore { - type Item = u32; - type Results = [u32; STATE_WORDS]; - - fn generate(&mut self, results: &mut Self::Results) { - // For some reason extracting this part into a separate function - // improves performance by 50%. - fn core(results: &mut [u32; STATE_WORDS], - state: &[u32; STATE_WORDS]) - { - let mut tmp = *state; - let rounds = 20; - for _ in 0..rounds / 2 { - double_round!(tmp); + impl RngCore for $ChaChaXRng { + #[inline] + fn next_u32(&mut self) -> u32 { + self.rng.next_u32() + } + #[inline] + fn next_u64(&mut self) -> u64 { + self.rng.next_u64() } - for i in 0..STATE_WORDS { - results[i] = tmp[i].wrapping_add(state[i]); + #[inline] + fn fill_bytes(&mut self, bytes: &mut [u8]) { + self.rng.fill_bytes(bytes) + } + #[inline] + fn try_fill_bytes(&mut self, bytes: &mut [u8]) -> Result<(), Error> { + self.rng.try_fill_bytes(bytes) } } - core(results, &self.state); + impl $ChaChaXRng { + // The buffer is a 4-block window, i.e. it is always at a block-aligned position in the + // stream but if the stream has been seeked it may not be self-aligned. + + /// Get the offset from the start of the stream, in 32-bit words. + /// + /// Since the generated blocks are 16 words (2<sup>4</sup>) long and the + /// counter is 64-bits, the offset is a 68-bit number. Sub-word offsets are + /// not supported, hence the result can simply be multiplied by 4 to get a + /// byte-offset. + #[inline] + pub fn get_word_pos(&self) -> u128 { + let mut block = u128::from(self.rng.core.state.get_stream_param(STREAM_PARAM_BLOCK)); + // counter is incremented *after* filling buffer + block -= 4; + (block << 4) + self.rng.index() as u128 + } - // update 64-bit counter - self.state[12] = self.state[12].wrapping_add(1); - if self.state[12] != 0 { return; }; - self.state[13] = self.state[13].wrapping_add(1); - } -} + /// Set the offset from the start of the stream, in 32-bit words. + /// + /// As with `get_word_pos`, we use a 68-bit number. Since the generator + /// simply cycles at the end of its period (1 ZiB), we ignore the upper + /// 60 bits. + #[inline] + pub fn set_word_pos(&mut self, word_offset: u128) { + let block = (word_offset >> 4) as u64; + self.rng + .core + .state + .set_stream_param(STREAM_PARAM_BLOCK, block); + self.rng.generate_and_set((word_offset & 15) as usize); + } -impl SeedableRng for ChaChaCore { - type Seed = [u8; SEED_WORDS*4]; - - fn from_seed(seed: Self::Seed) -> Self { - let mut seed_le = [0u32; SEED_WORDS]; - le::read_u32_into(&seed, &mut seed_le); - Self { - state: [0x61707865, 0x3320646E, 0x79622D32, 0x6B206574, // constants - seed_le[0], seed_le[1], seed_le[2], seed_le[3], // seed - seed_le[4], seed_le[5], seed_le[6], seed_le[7], // seed - 0, 0, 0, 0], // counter - } - } -} + /// Set the stream number. + /// + /// This is initialized to zero; 2<sup>64</sup> unique streams of output + /// are available per seed/key. + /// + /// Note that in order to reproduce ChaCha output with a specific 64-bit + /// nonce, one can convert that nonce to a `u64` in little-endian fashion + /// and pass to this function. In theory a 96-bit nonce can be used by + /// passing the last 64-bits to this function and using the first 32-bits as + /// the most significant half of the 64-bit counter (which may be set + /// indirectly via `set_word_pos`), but this is not directly supported. + #[inline] + pub fn set_stream(&mut self, stream: u64) { + self.rng + .core + .state + .set_stream_param(STREAM_PARAM_NONCE, stream); + if self.rng.index() != 64 { + let wp = self.get_word_pos(); + self.set_word_pos(wp); + } + } + } -impl CryptoRng for ChaChaCore {} + impl CryptoRng for $ChaChaXRng {} -impl From<ChaChaCore> for ChaChaRng { - fn from(core: ChaChaCore) -> Self { - ChaChaRng(BlockRng::new(core)) + impl From<$ChaChaXCore> for $ChaChaXRng { + fn from(core: $ChaChaXCore) -> Self { + $ChaChaXRng { + rng: BlockRng::new(core), + } + } + } } } +chacha_impl!(ChaCha20Core, ChaCha20Rng, 10, "ChaCha with 20 rounds"); +chacha_impl!(ChaCha12Core, ChaCha12Rng, 6, "ChaCha with 12 rounds"); +chacha_impl!(ChaCha8Core, ChaCha8Rng, 4, "ChaCha with 8 rounds"); + #[cfg(test)] mod test { - use ::rand_core::{RngCore, SeedableRng}; - use super::ChaChaRng; + use rand_core::{RngCore, SeedableRng}; + + type ChaChaRng = super::ChaCha20Rng; #[test] fn test_chacha_construction() { - let seed = [0,0,0,0,0,0,0,0, - 1,0,0,0,0,0,0,0, - 2,0,0,0,0,0,0,0, - 3,0,0,0,0,0,0,0]; + let seed = [ + 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, + 0, 0, 0, + ]; let mut rng1 = ChaChaRng::from_seed(seed); assert_eq!(rng1.next_u32(), 137206642); @@ -292,18 +268,24 @@ mod test { let mut rng = ChaChaRng::from_seed(seed); let mut results = [0u32; 16]; - for i in results.iter_mut() { *i = rng.next_u32(); } - let expected = [0xade0b876, 0x903df1a0, 0xe56a5d40, 0x28bd8653, - 0xb819d2bd, 0x1aed8da0, 0xccef36a8, 0xc70d778b, - 0x7c5941da, 0x8d485751, 0x3fe02477, 0x374ad8b8, - 0xf4b8436a, 0x1ca11815, 0x69b687c3, 0x8665eeb2]; + for i in results.iter_mut() { + *i = rng.next_u32(); + } + let expected = [ + 0xade0b876, 0x903df1a0, 0xe56a5d40, 0x28bd8653, 0xb819d2bd, 0x1aed8da0, 0xccef36a8, + 0xc70d778b, 0x7c5941da, 0x8d485751, 0x3fe02477, 0x374ad8b8, 0xf4b8436a, 0x1ca11815, + 0x69b687c3, 0x8665eeb2, + ]; assert_eq!(results, expected); - for i in results.iter_mut() { *i = rng.next_u32(); } - let expected = [0xbee7079f, 0x7a385155, 0x7c97ba98, 0x0d082d73, - 0xa0290fcb, 0x6965e348, 0x3e53c612, 0xed7aee32, - 0x7621b729, 0x434ee69c, 0xb03371d5, 0xd539d874, - 0x281fed31, 0x45fb0a51, 0x1f0ae1ac, 0x6f4d794b]; + for i in results.iter_mut() { + *i = rng.next_u32(); + } + let expected = [ + 0xbee7079f, 0x7a385155, 0x7c97ba98, 0x0d082d73, 0xa0290fcb, 0x6965e348, 0x3e53c612, + 0xed7aee32, 0x7621b729, 0x434ee69c, 0xb03371d5, 0xd539d874, 0x281fed31, 0x45fb0a51, + 0x1f0ae1ac, 0x6f4d794b, + ]; assert_eq!(results, expected); } @@ -311,51 +293,62 @@ mod test { fn test_chacha_true_values_b() { // Test vector 3 from // https://tools.ietf.org/html/draft-nir-cfrg-chacha20-poly1305-04 - let seed = [0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 1]; + let seed = [ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 1, + ]; let mut rng = ChaChaRng::from_seed(seed); // Skip block 0 - for _ in 0..16 { rng.next_u32(); } + for _ in 0..16 { + rng.next_u32(); + } let mut results = [0u32; 16]; - for i in results.iter_mut() { *i = rng.next_u32(); } - let expected = [0x2452eb3a, 0x9249f8ec, 0x8d829d9b, 0xddd4ceb1, - 0xe8252083, 0x60818b01, 0xf38422b8, 0x5aaa49c9, - 0xbb00ca8e, 0xda3ba7b4, 0xc4b592d1, 0xfdf2732f, - 0x4436274e, 0x2561b3c8, 0xebdd4aa6, 0xa0136c00]; + for i in results.iter_mut() { + *i = rng.next_u32(); + } + let expected = [ + 0x2452eb3a, 0x9249f8ec, 0x8d829d9b, 0xddd4ceb1, 0xe8252083, 0x60818b01, 0xf38422b8, + 0x5aaa49c9, 0xbb00ca8e, 0xda3ba7b4, 0xc4b592d1, 0xfdf2732f, 0x4436274e, 0x2561b3c8, + 0xebdd4aa6, 0xa0136c00, + ]; assert_eq!(results, expected); } #[test] - #[cfg(all(rustc_1_26, not(target_os = "emscripten")))] fn test_chacha_true_values_c() { // Test vector 4 from // https://tools.ietf.org/html/draft-nir-cfrg-chacha20-poly1305-04 - let seed = [0, 0xff, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0]; - let expected = [0xfb4dd572, 0x4bc42ef1, 0xdf922636, 0x327f1394, - 0xa78dea8f, 0x5e269039, 0xa1bebbc1, 0xcaf09aae, - 0xa25ab213, 0x48a6b46c, 0x1b9d9bcb, 0x092c5be6, - 0x546ca624, 0x1bec45d5, 0x87f47473, 0x96f0992e]; + let seed = [ + 0, 0xff, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, + ]; + let expected = [ + 0xfb4dd572, 0x4bc42ef1, 0xdf922636, 0x327f1394, 0xa78dea8f, 0x5e269039, 0xa1bebbc1, + 0xcaf09aae, 0xa25ab213, 0x48a6b46c, 0x1b9d9bcb, 0x092c5be6, 0x546ca624, 0x1bec45d5, + 0x87f47473, 0x96f0992e, + ]; let expected_end = 3 * 16; let mut results = [0u32; 16]; // Test block 2 by skipping block 0 and 1 let mut rng1 = ChaChaRng::from_seed(seed); - for _ in 0..32 { rng1.next_u32(); } - for i in results.iter_mut() { *i = rng1.next_u32(); } + for _ in 0..32 { + rng1.next_u32(); + } + for i in results.iter_mut() { + *i = rng1.next_u32(); + } assert_eq!(results, expected); assert_eq!(rng1.get_word_pos(), expected_end); // Test block 2 by using `set_word_pos` let mut rng2 = ChaChaRng::from_seed(seed); rng2.set_word_pos(2 * 16); - for i in results.iter_mut() { *i = rng2.next_u32(); } + for i in results.iter_mut() { + *i = rng2.next_u32(); + } assert_eq!(results, expected); assert_eq!(rng2.get_word_pos(), expected_end); @@ -376,7 +369,10 @@ mod test { #[test] fn test_chacha_multiple_blocks() { - let seed = [0,0,0,0, 1,0,0,0, 2,0,0,0, 3,0,0,0, 4,0,0,0, 5,0,0,0, 6,0,0,0, 7,0,0,0]; + let seed = [ + 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 6, 0, 0, 0, 7, + 0, 0, 0, + ]; let mut rng = ChaChaRng::from_seed(seed); // Store the 17*i-th 32-bit word, @@ -388,10 +384,11 @@ mod test { rng.next_u32(); } } - let expected = [0xf225c81a, 0x6ab1be57, 0x04d42951, 0x70858036, - 0x49884684, 0x64efec72, 0x4be2d186, 0x3615b384, - 0x11cfa18e, 0xd3c50049, 0x75c775f6, 0x434c6530, - 0x2c5bad8f, 0x898881dc, 0x5f1c86d9, 0xc1f8e7f4]; + let expected = [ + 0xf225c81a, 0x6ab1be57, 0x04d42951, 0x70858036, 0x49884684, 0x64efec72, 0x4be2d186, + 0x3615b384, 0x11cfa18e, 0xd3c50049, 0x75c775f6, 0x434c6530, 0x2c5bad8f, 0x898881dc, + 0x5f1c86d9, 0xc1f8e7f4, + ]; assert_eq!(results, expected); } @@ -401,10 +398,10 @@ mod test { let mut rng = ChaChaRng::from_seed(seed); let mut results = [0u8; 32]; rng.fill_bytes(&mut results); - let expected = [118, 184, 224, 173, 160, 241, 61, 144, - 64, 93, 106, 229, 83, 134, 189, 40, - 189, 210, 25, 184, 160, 141, 237, 26, - 168, 54, 239, 204, 139, 119, 13, 199]; + let expected = [ + 118, 184, 224, 173, 160, 241, 61, 144, 64, 93, 106, 229, 83, 134, 189, 40, 189, 210, + 25, 184, 160, 141, 237, 26, 168, 54, 239, 204, 139, 119, 13, 199, + ]; assert_eq!(results, expected); } @@ -420,17 +417,23 @@ mod test { rng.set_stream(2u64 << (24 + 32)); let mut results = [0u32; 16]; - for i in results.iter_mut() { *i = rng.next_u32(); } - let expected = [0x374dc6c2, 0x3736d58c, 0xb904e24a, 0xcd3f93ef, - 0x88228b1a, 0x96a4dfb3, 0x5b76ab72, 0xc727ee54, - 0x0e0e978a, 0xf3145c95, 0x1b748ea8, 0xf786c297, - 0x99c28f5f, 0x628314e8, 0x398a19fa, 0x6ded1b53]; + for i in results.iter_mut() { + *i = rng.next_u32(); + } + let expected = [ + 0x374dc6c2, 0x3736d58c, 0xb904e24a, 0xcd3f93ef, 0x88228b1a, 0x96a4dfb3, 0x5b76ab72, + 0xc727ee54, 0x0e0e978a, 0xf3145c95, 0x1b748ea8, 0xf786c297, 0x99c28f5f, 0x628314e8, + 0x398a19fa, 0x6ded1b53, + ]; assert_eq!(results, expected); } #[test] fn test_chacha_clone_streams() { - let seed = [0,0,0,0, 1,0,0,0, 2,0,0,0, 3,0,0,0, 4,0,0,0, 5,0,0,0, 6,0,0,0, 7,0,0,0]; + let seed = [ + 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0, 5, 0, 0, 0, 6, 0, 0, 0, 7, + 0, 0, 0, + ]; let mut rng = ChaChaRng::from_seed(seed); let mut clone = rng.clone(); for _ in 0..16 { @@ -441,7 +444,7 @@ mod test { for _ in 0..7 { assert!(rng.next_u32() != clone.next_u32()); } - clone.set_stream(51); // switch part way through block + clone.set_stream(51); // switch part way through block for _ in 7..16 { assert_eq!(rng.next_u32(), clone.next_u32()); } diff --git a/rand/rand_chacha/src/lib.rs b/rand/rand_chacha/src/lib.rs index 74ad466..e374bdd 100644 --- a/rand/rand_chacha/src/lib.rs +++ b/rand/rand_chacha/src/lib.rs @@ -16,10 +16,15 @@ #![deny(missing_debug_implementations)] #![doc(test(attr(allow(unused_variables), deny(warnings))))] -#![no_std] +#![cfg_attr(not(feature = "std"), no_std)] -pub extern crate rand_core; +pub use rand_core; mod chacha; -pub use chacha::{ChaChaRng, ChaChaCore}; +pub use crate::chacha::{ChaCha12Core, ChaCha12Rng, ChaCha20Core, ChaCha20Rng, ChaCha8Core, ChaCha8Rng}; + +/// ChaCha with 20 rounds +pub type ChaChaRng = ChaCha20Rng; +/// ChaCha with 20 rounds, low-level interface +pub type ChaChaCore = ChaCha20Core; |