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-

// 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 ChaCha random number generator.
-
-#[cfg(not(feature = "std"))] use core;
-#[cfg(feature = "std")] use std as core;
-
-use self::core::fmt;
-use crate::guts::ChaCha;
-use rand_core::block::{BlockRng, BlockRngCore};
-use rand_core::{CryptoRng, Error, RngCore, SeedableRng};
-
-#[cfg(feature = "serde1")] use serde::{Serialize, Deserialize, Serializer, Deserializer};
-
-// NB. this must remain consistent with some currently hard-coded numbers in this module
-const BUF_BLOCKS: u8 = 4;
-// number of 32-bit words per ChaCha block (fixed by algorithm definition)
-const BLOCK_WORDS: u8 = 16;
-
-#[repr(transparent)]
-pub struct Array64<T>([T; 64]);
-impl<T> Default for Array64<T>
-where T: Default
-{
-    #[rustfmt::skip]
-    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(),
-        ])
-    }
-}
-impl<T> AsRef<[T]> for Array64<T> {
-    fn as_ref(&self) -> &[T] {
-        &self.0
-    }
-}
-impl<T> AsMut<[T]> for Array64<T> {
-    fn as_mut(&mut self) -> &mut [T] {
-        &mut self.0
-    }
-}
-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
-    }
-}
-impl<T> fmt::Debug for Array64<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "Array64 {{}}")
-    }
-}
-
-macro_rules! chacha_impl {
-    ($ChaChaXCore:ident, $ChaChaXRng:ident, $rounds:expr, $doc:expr, $abst:ident) => {
-        #[doc=$doc]
-        #[derive(Clone, PartialEq, Eq)]
-        pub struct $ChaChaXCore {
-            state: ChaCha,
-        }
-
-        // 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 {{}}")
-            }
-        }
-
-        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();
-                }
-            }
-        }
-
-        impl SeedableRng for $ChaChaXCore {
-            type Seed = [u8; 32];
-            #[inline]
-            fn from_seed(seed: Self::Seed) -> Self {
-                $ChaChaXCore { state: ChaCha::new(&seed, &[0u8; 8]) }
-            }
-        }
-
-        impl CryptoRng for $ChaChaXCore {}
-
-        /// 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>,
-        }
-
-        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 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()
-            }
-            #[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)
-            }
-        }
-
-        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 buf_start_block = {
-                    let buf_end_block = self.rng.core.state.get_block_pos();
-                    u64::wrapping_sub(buf_end_block, BUF_BLOCKS.into())
-                };
-                let (buf_offset_blocks, block_offset_words) = {
-                    let buf_offset_words = self.rng.index() as u64;
-                    let blocks_part = buf_offset_words / u64::from(BLOCK_WORDS);
-                    let words_part = buf_offset_words % u64::from(BLOCK_WORDS);
-                    (blocks_part, words_part)
-                };
-                let pos_block = u64::wrapping_add(buf_start_block, buf_offset_blocks);
-                let pos_block_words = u128::from(pos_block) * u128::from(BLOCK_WORDS);
-                pos_block_words + u128::from(block_offset_words)
-            }
-
-            /// 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 / u128::from(BLOCK_WORDS)) as u64;
-                self.rng
-                    .core
-                    .state
-                    .set_block_pos(block);
-                self.rng.generate_and_set((word_offset % u128::from(BLOCK_WORDS)) as usize);
-            }
-
-            /// 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_nonce(stream);
-                if self.rng.index() != 64 {
-                    let wp = self.get_word_pos();
-                    self.set_word_pos(wp);
-                }
-            }
-
-            /// Get the stream number.
-            #[inline]
-            pub fn get_stream(&self) -> u64 {
-                self.rng
-                    .core
-                    .state
-                    .get_nonce()
-            }
-
-            /// Get the seed.
-            #[inline]
-            pub fn get_seed(&self) -> [u8; 32] {
-                self.rng
-                    .core
-                    .state
-                    .get_seed()
-            }
-        }
-
-        impl CryptoRng for $ChaChaXRng {}
-
-        impl From<$ChaChaXCore> for $ChaChaXRng {
-            fn from(core: $ChaChaXCore) -> Self {
-                $ChaChaXRng {
-                    rng: BlockRng::new(core),
-                }
-            }
-        }
-
-        impl PartialEq<$ChaChaXRng> for $ChaChaXRng {
-            fn eq(&self, rhs: &$ChaChaXRng) -> bool {
-                let a: $abst::$ChaChaXRng = self.into();
-                let b: $abst::$ChaChaXRng = rhs.into();
-                a == b
-            }
-        }
-        impl Eq for $ChaChaXRng {}
-
-        #[cfg(feature = "serde1")]
-        impl Serialize for $ChaChaXRng {
-            fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
-            where S: Serializer {
-                $abst::$ChaChaXRng::from(self).serialize(s)
-            }
-        }
-        #[cfg(feature = "serde1")]
-        impl<'de> Deserialize<'de> for $ChaChaXRng {
-            fn deserialize<D>(d: D) -> Result<Self, D::Error> where D: Deserializer<'de> {
-                $abst::$ChaChaXRng::deserialize(d).map(|x| Self::from(&x))
-            }
-        }
-
-        mod $abst {
-            #[cfg(feature = "serde1")] use serde::{Serialize, Deserialize};
-
-            // The abstract state of a ChaCha stream, independent of implementation choices. The
-            // comparison and serialization of this object is considered a semver-covered part of
-            // the API.
-            #[derive(Debug, PartialEq, Eq)]
-            #[cfg_attr(
-                feature = "serde1",
-                derive(Serialize, Deserialize),
-            )]
-            pub(crate) struct $ChaChaXRng {
-                seed: [u8; 32],
-                stream: u64,
-                word_pos: u128,
-            }
-
-            impl From<&super::$ChaChaXRng> for $ChaChaXRng {
-                // Forget all information about the input except what is necessary to determine the
-                // outputs of any sequence of pub API calls.
-                fn from(r: &super::$ChaChaXRng) -> Self {
-                    Self {
-                        seed: r.get_seed(),
-                        stream: r.get_stream(),
-                        word_pos: r.get_word_pos(),
-                    }
-                }
-            }
-
-            impl From<&$ChaChaXRng> for super::$ChaChaXRng {
-                // Construct one of the possible concrete RNGs realizing an abstract state.
-                fn from(a: &$ChaChaXRng) -> Self {
-                    use rand_core::SeedableRng;
-                    let mut r = Self::from_seed(a.seed);
-                    r.set_stream(a.stream);
-                    r.set_word_pos(a.word_pos);
-                    r
-                }
-            }
-        }
-    }
-}
-
-chacha_impl!(ChaCha20Core, ChaCha20Rng, 10, "ChaCha with 20 rounds", abstract20);
-chacha_impl!(ChaCha12Core, ChaCha12Rng, 6, "ChaCha with 12 rounds", abstract12);
-chacha_impl!(ChaCha8Core, ChaCha8Rng, 4, "ChaCha with 8 rounds", abstract8);
-
-#[cfg(test)]
-mod test {
-    use rand_core::{RngCore, SeedableRng};
-
-    #[cfg(feature = "serde1")] use super::{ChaCha20Rng, ChaCha12Rng, ChaCha8Rng};
-
-    type ChaChaRng = super::ChaCha20Rng;
-
-    #[cfg(feature = "serde1")]
-    #[test]
-    fn test_chacha_serde_roundtrip() {
-        let seed = [
-            1, 0, 52, 0, 0, 0, 0, 0, 1, 0, 10, 0, 22, 32, 0, 0, 2, 0, 55, 49, 0, 11, 0, 0, 3, 0, 0, 0, 0,
-            0, 2, 92,
-        ];
-        let mut rng1 = ChaCha20Rng::from_seed(seed);
-        let mut rng2 = ChaCha12Rng::from_seed(seed);
-        let mut rng3 = ChaCha8Rng::from_seed(seed);
-
-        let encoded1 = serde_json::to_string(&rng1).unwrap();
-        let encoded2 = serde_json::to_string(&rng2).unwrap();
-        let encoded3 = serde_json::to_string(&rng3).unwrap();
-
-        let mut decoded1: ChaCha20Rng = serde_json::from_str(&encoded1).unwrap();
-        let mut decoded2: ChaCha12Rng = serde_json::from_str(&encoded2).unwrap();
-        let mut decoded3: ChaCha8Rng = serde_json::from_str(&encoded3).unwrap();
-
-        assert_eq!(rng1, decoded1);
-        assert_eq!(rng2, decoded2);
-        assert_eq!(rng3, decoded3);
-
-        assert_eq!(rng1.next_u32(), decoded1.next_u32());
-        assert_eq!(rng2.next_u32(), decoded2.next_u32());
-        assert_eq!(rng3.next_u32(), decoded3.next_u32());
-    }
-
-    // This test validates that:
-    // 1. a hard-coded serialization demonstrating the format at time of initial release can still
-    //    be deserialized to a ChaChaRng
-    // 2. re-serializing the resultant object produces exactly the original string
-    //
-    // Condition 2 is stronger than necessary: an equivalent serialization (e.g. with field order
-    // permuted, or whitespace differences) would also be admissible, but would fail this test.
-    // However testing for equivalence of serialized data is difficult, and there shouldn't be any
-    // reason we need to violate the stronger-than-needed condition, e.g. by changing the field
-    // definition order.
-    #[cfg(feature = "serde1")]
-    #[test]
-    fn test_chacha_serde_format_stability() {
-        let j = r#"{"seed":[4,8,15,16,23,42,4,8,15,16,23,42,4,8,15,16,23,42,4,8,15,16,23,42,4,8,15,16,23,42,4,8],"stream":27182818284,"word_pos":314159265359}"#;
-        let r: ChaChaRng = serde_json::from_str(&j).unwrap();
-        let j1 = serde_json::to_string(&r).unwrap();
-        assert_eq!(j, j1);
-    }
-
-    #[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 mut rng1 = ChaChaRng::from_seed(seed);
-        assert_eq!(rng1.next_u32(), 137206642);
-
-        let mut rng2 = ChaChaRng::from_rng(rng1).unwrap();
-        assert_eq!(rng2.next_u32(), 1325750369);
-    }
-
-    #[test]
-    fn test_chacha_true_values_a() {
-        // Test vectors 1 and 2 from
-        // https://tools.ietf.org/html/draft-nir-cfrg-chacha20-poly1305-04
-        let seed = [0u8; 32];
-        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,
-        ];
-        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,
-        ];
-        assert_eq!(results, expected);
-    }
-
-    #[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 mut rng = ChaChaRng::from_seed(seed);
-
-        // Skip block 0
-        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,
-        ];
-        assert_eq!(results, expected);
-    }
-
-    #[test]
-    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 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();
-        }
-        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();
-        }
-        assert_eq!(results, expected);
-        assert_eq!(rng2.get_word_pos(), expected_end);
-
-        // Test skipping behaviour with other types
-        let mut buf = [0u8; 32];
-        rng2.fill_bytes(&mut buf[..]);
-        assert_eq!(rng2.get_word_pos(), expected_end + 8);
-        rng2.fill_bytes(&mut buf[0..25]);
-        assert_eq!(rng2.get_word_pos(), expected_end + 15);
-        rng2.next_u64();
-        assert_eq!(rng2.get_word_pos(), expected_end + 17);
-        rng2.next_u32();
-        rng2.next_u64();
-        assert_eq!(rng2.get_word_pos(), expected_end + 20);
-        rng2.fill_bytes(&mut buf[0..1]);
-        assert_eq!(rng2.get_word_pos(), expected_end + 21);
-    }
-
-    #[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 mut rng = ChaChaRng::from_seed(seed);
-
-        // Store the 17*i-th 32-bit word,
-        // i.e., the i-th word of the i-th 16-word block
-        let mut results = [0u32; 16];
-        for i in results.iter_mut() {
-            *i = rng.next_u32();
-            for _ in 0..16 {
-                rng.next_u32();
-            }
-        }
-        let expected = [
-            0xf225c81a, 0x6ab1be57, 0x04d42951, 0x70858036, 0x49884684, 0x64efec72, 0x4be2d186,
-            0x3615b384, 0x11cfa18e, 0xd3c50049, 0x75c775f6, 0x434c6530, 0x2c5bad8f, 0x898881dc,
-            0x5f1c86d9, 0xc1f8e7f4,
-        ];
-        assert_eq!(results, expected);
-    }
-
-    #[test]
-    fn test_chacha_true_bytes() {
-        let seed = [0u8; 32];
-        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,
-        ];
-        assert_eq!(results, expected);
-    }
-
-    #[test]
-    fn test_chacha_nonce() {
-        // Test vector 5 from
-        // https://tools.ietf.org/html/draft-nir-cfrg-chacha20-poly1305-04
-        // Although we do not support setting a nonce, we try it here anyway so
-        // we can use this test vector.
-        let seed = [0u8; 32];
-        let mut rng = ChaChaRng::from_seed(seed);
-        // 96-bit nonce in LE order is: 0,0,0,0, 0,0,0,0, 0,0,0,2
-        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,
-        ];
-        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 mut rng = ChaChaRng::from_seed(seed);
-        let mut clone = rng.clone();
-        for _ in 0..16 {
-            assert_eq!(rng.next_u64(), clone.next_u64());
-        }
-
-        rng.set_stream(51);
-        for _ in 0..7 {
-            assert!(rng.next_u32() != clone.next_u32());
-        }
-        clone.set_stream(51); // switch part way through block
-        for _ in 7..16 {
-            assert_eq!(rng.next_u32(), clone.next_u32());
-        }
-    }
-
-    #[test]
-    fn test_chacha_word_pos_wrap_exact() {
-        use super::{BUF_BLOCKS, BLOCK_WORDS};
-        let mut rng = ChaChaRng::from_seed(Default::default());
-        // refilling the buffer in set_word_pos will wrap the block counter to 0
-        let last_block = (1 << 68) - u128::from(BUF_BLOCKS * BLOCK_WORDS);
-        rng.set_word_pos(last_block);
-        assert_eq!(rng.get_word_pos(), last_block);
-    }
-
-    #[test]
-    fn test_chacha_word_pos_wrap_excess() {
-        use super::BLOCK_WORDS;
-        let mut rng = ChaChaRng::from_seed(Default::default());
-        // refilling the buffer in set_word_pos will wrap the block counter past 0
-        let last_block = (1 << 68) - u128::from(BLOCK_WORDS);
-        rng.set_word_pos(last_block);
-        assert_eq!(rng.get_word_pos(), last_block);
-    }
-
-    #[test]
-    fn test_chacha_word_pos_zero() {
-        let mut rng = ChaChaRng::from_seed(Default::default());
-        assert_eq!(rng.get_word_pos(), 0);
-        rng.set_word_pos(0);
-        assert_eq!(rng.get_word_pos(), 0);
-    }
-}
-

-