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author | Robin Krahl <me@robin-krahl.de> | 2018-12-11 23:50:45 +0100 |
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committer | Daniel Mueller <deso@posteo.net> | 2018-12-17 07:52:13 -0800 |
commit | 986ad2f782cf944990e4eda8bf88ea1821233302 (patch) | |
tree | 1717075a4eb11861c32e5c45d01e47360fb1264d /rand/src/prng/isaac.rs | |
parent | e97c287c01cf22a1b582a7da9b309b58f3935d0e (diff) | |
download | nitrocli-986ad2f782cf944990e4eda8bf88ea1821233302.tar.gz nitrocli-986ad2f782cf944990e4eda8bf88ea1821233302.tar.bz2 |
Add nitrokey as a dependency to nitrocli
The nitrokey crate provides a simple interface to the Nitrokey Storage
and the Nitrokey Pro based on the libnitrokey library developed by
Nitrokey UG. The low-level bindings to this library are available in
the nitrokey-sys crate.
This patch adds version v0.2.1 of the nitrokey crate as a dependency
for nitrocli. It includes the indirect dependencies nitrokey-sys
(version 3.4.1) and rand (version 0.4.3).
Import subrepo nitrokey/:nitrokey at 2eccc96ceec2282b868891befe9cda7f941fbe7b
Import subrepo nitrokey-sys/:nitrokey-sys at f1a11ebf72610fb9cf80ac7f9f147b4ba1a5336f
Import subrepo rand/:rand at d7d5da49daf7ceb3e5940072940d495cced3a1b3
Diffstat (limited to 'rand/src/prng/isaac.rs')
-rw-r--r-- | rand/src/prng/isaac.rs | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/rand/src/prng/isaac.rs b/rand/src/prng/isaac.rs new file mode 100644 index 0000000..cf5eb67 --- /dev/null +++ b/rand/src/prng/isaac.rs @@ -0,0 +1,328 @@ +// Copyright 2013 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// 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. + +//! The ISAAC random number generator. + +#![allow(non_camel_case_types)] + +use core::slice; +use core::iter::repeat; +use core::num::Wrapping as w; +use core::fmt; + +use {Rng, SeedableRng, Rand}; + +#[allow(bad_style)] +type w32 = w<u32>; + +const RAND_SIZE_LEN: usize = 8; +const RAND_SIZE: u32 = 1 << RAND_SIZE_LEN; +const RAND_SIZE_USIZE: usize = 1 << RAND_SIZE_LEN; + +/// A random number generator that uses the ISAAC algorithm[1]. +/// +/// The ISAAC algorithm is generally accepted as suitable for +/// cryptographic purposes, but this implementation has not be +/// verified as such. Prefer a generator like `OsRng` that defers to +/// the operating system for cases that need high security. +/// +/// [1]: Bob Jenkins, [*ISAAC: A fast cryptographic random number +/// generator*](http://www.burtleburtle.net/bob/rand/isaacafa.html) +#[derive(Copy)] +pub struct IsaacRng { + cnt: u32, + rsl: [w32; RAND_SIZE_USIZE], + mem: [w32; RAND_SIZE_USIZE], + a: w32, + b: w32, + c: w32, +} + +static EMPTY: IsaacRng = IsaacRng { + cnt: 0, + rsl: [w(0); RAND_SIZE_USIZE], + mem: [w(0); RAND_SIZE_USIZE], + a: w(0), b: w(0), c: w(0), +}; + +impl IsaacRng { + + /// Create an ISAAC random number generator using the default + /// fixed seed. + pub fn new_unseeded() -> IsaacRng { + let mut rng = EMPTY; + rng.init(false); + rng + } + + /// Initialises `self`. If `use_rsl` is true, then use the current value + /// of `rsl` as a seed, otherwise construct one algorithmically (not + /// randomly). + fn init(&mut self, use_rsl: bool) { + let mut a = w(0x9e3779b9); + let mut b = a; + let mut c = a; + let mut d = a; + let mut e = a; + let mut f = a; + let mut g = a; + let mut h = a; + + macro_rules! mix { + () => {{ + a=a^(b<<11); d=d+a; b=b+c; + b=b^(c>>2); e=e+b; c=c+d; + c=c^(d<<8); f=f+c; d=d+e; + d=d^(e>>16); g=g+d; e=e+f; + e=e^(f<<10); h=h+e; f=f+g; + f=f^(g>>4); a=a+f; g=g+h; + g=g^(h<<8); b=b+g; h=h+a; + h=h^(a>>9); c=c+h; a=a+b; + }} + } + + for _ in 0..4 { + mix!(); + } + + if use_rsl { + macro_rules! memloop { + ($arr:expr) => {{ + for i in (0..RAND_SIZE_USIZE/8).map(|i| i * 8) { + a=a+$arr[i ]; b=b+$arr[i+1]; + c=c+$arr[i+2]; d=d+$arr[i+3]; + e=e+$arr[i+4]; f=f+$arr[i+5]; + g=g+$arr[i+6]; h=h+$arr[i+7]; + mix!(); + self.mem[i ]=a; self.mem[i+1]=b; + self.mem[i+2]=c; self.mem[i+3]=d; + self.mem[i+4]=e; self.mem[i+5]=f; + self.mem[i+6]=g; self.mem[i+7]=h; + } + }} + } + + memloop!(self.rsl); + memloop!(self.mem); + } else { + for i in (0..RAND_SIZE_USIZE/8).map(|i| i * 8) { + mix!(); + self.mem[i ]=a; self.mem[i+1]=b; + self.mem[i+2]=c; self.mem[i+3]=d; + self.mem[i+4]=e; self.mem[i+5]=f; + self.mem[i+6]=g; self.mem[i+7]=h; + } + } + + self.isaac(); + } + + /// Refills the output buffer (`self.rsl`) + #[inline] + fn isaac(&mut self) { + self.c = self.c + w(1); + // abbreviations + let mut a = self.a; + let mut b = self.b + self.c; + + const MIDPOINT: usize = RAND_SIZE_USIZE / 2; + + macro_rules! ind { + ($x:expr) => ( self.mem[($x >> 2usize).0 as usize & (RAND_SIZE_USIZE - 1)] ) + } + + let r = [(0, MIDPOINT), (MIDPOINT, 0)]; + for &(mr_offset, m2_offset) in r.iter() { + + macro_rules! rngstepp { + ($j:expr, $shift:expr) => {{ + let base = $j; + let mix = a << $shift; + + let x = self.mem[base + mr_offset]; + a = (a ^ mix) + self.mem[base + m2_offset]; + let y = ind!(x) + a + b; + self.mem[base + mr_offset] = y; + + b = ind!(y >> RAND_SIZE_LEN) + x; + self.rsl[base + mr_offset] = b; + }} + } + + macro_rules! rngstepn { + ($j:expr, $shift:expr) => {{ + let base = $j; + let mix = a >> $shift; + + let x = self.mem[base + mr_offset]; + a = (a ^ mix) + self.mem[base + m2_offset]; + let y = ind!(x) + a + b; + self.mem[base + mr_offset] = y; + + b = ind!(y >> RAND_SIZE_LEN) + x; + self.rsl[base + mr_offset] = b; + }} + } + + for i in (0..MIDPOINT/4).map(|i| i * 4) { + rngstepp!(i + 0, 13); + rngstepn!(i + 1, 6); + rngstepp!(i + 2, 2); + rngstepn!(i + 3, 16); + } + } + + self.a = a; + self.b = b; + self.cnt = RAND_SIZE; + } +} + +// Cannot be derived because [u32; 256] does not implement Clone +impl Clone for IsaacRng { + fn clone(&self) -> IsaacRng { + *self + } +} + +impl Rng for IsaacRng { + #[inline] + fn next_u32(&mut self) -> u32 { + if self.cnt == 0 { + // make some more numbers + self.isaac(); + } + self.cnt -= 1; + + // self.cnt is at most RAND_SIZE, but that is before the + // subtraction above. We want to index without bounds + // checking, but this could lead to incorrect code if someone + // misrefactors, so we check, sometimes. + // + // (Changes here should be reflected in Isaac64Rng.next_u64.) + debug_assert!(self.cnt < RAND_SIZE); + + // (the % is cheaply telling the optimiser that we're always + // in bounds, without unsafe. NB. this is a power of two, so + // it optimises to a bitwise mask). + self.rsl[(self.cnt % RAND_SIZE) as usize].0 + } +} + +impl<'a> SeedableRng<&'a [u32]> for IsaacRng { + fn reseed(&mut self, seed: &'a [u32]) { + // make the seed into [seed[0], seed[1], ..., seed[seed.len() + // - 1], 0, 0, ...], to fill rng.rsl. + let seed_iter = seed.iter().map(|&x| x).chain(repeat(0u32)); + + for (rsl_elem, seed_elem) in self.rsl.iter_mut().zip(seed_iter) { + *rsl_elem = w(seed_elem); + } + self.cnt = 0; + self.a = w(0); + self.b = w(0); + self.c = w(0); + + self.init(true); + } + + /// Create an ISAAC random number generator with a seed. This can + /// be any length, although the maximum number of elements used is + /// 256 and any more will be silently ignored. A generator + /// constructed with a given seed will generate the same sequence + /// of values as all other generators constructed with that seed. + fn from_seed(seed: &'a [u32]) -> IsaacRng { + let mut rng = EMPTY; + rng.reseed(seed); + rng + } +} + +impl Rand for IsaacRng { + fn rand<R: Rng>(other: &mut R) -> IsaacRng { + let mut ret = EMPTY; + unsafe { + let ptr = ret.rsl.as_mut_ptr() as *mut u8; + + let slice = slice::from_raw_parts_mut(ptr, RAND_SIZE_USIZE * 4); + other.fill_bytes(slice); + } + ret.cnt = 0; + ret.a = w(0); + ret.b = w(0); + ret.c = w(0); + + ret.init(true); + return ret; + } +} + +impl fmt::Debug for IsaacRng { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!(f, "IsaacRng {{}}") + } +} + +#[cfg(test)] +mod test { + use {Rng, SeedableRng}; + use super::IsaacRng; + + #[test] + fn test_rng_32_rand_seeded() { + let s = ::test::rng().gen_iter::<u32>().take(256).collect::<Vec<u32>>(); + let mut ra: IsaacRng = SeedableRng::from_seed(&s[..]); + let mut rb: IsaacRng = SeedableRng::from_seed(&s[..]); + assert!(::test::iter_eq(ra.gen_ascii_chars().take(100), + rb.gen_ascii_chars().take(100))); + } + + #[test] + fn test_rng_32_seeded() { + let seed: &[_] = &[1, 23, 456, 7890, 12345]; + let mut ra: IsaacRng = SeedableRng::from_seed(seed); + let mut rb: IsaacRng = SeedableRng::from_seed(seed); + assert!(::test::iter_eq(ra.gen_ascii_chars().take(100), + rb.gen_ascii_chars().take(100))); + } + + #[test] + fn test_rng_32_reseed() { + let s = ::test::rng().gen_iter::<u32>().take(256).collect::<Vec<u32>>(); + let mut r: IsaacRng = SeedableRng::from_seed(&s[..]); + let string1: String = r.gen_ascii_chars().take(100).collect(); + + r.reseed(&s[..]); + + let string2: String = r.gen_ascii_chars().take(100).collect(); + assert_eq!(string1, string2); + } + + #[test] + fn test_rng_32_true_values() { + let seed: &[_] = &[1, 23, 456, 7890, 12345]; + let mut ra: IsaacRng = SeedableRng::from_seed(seed); + // Regression test that isaac is actually using the above vector + let v = (0..10).map(|_| ra.next_u32()).collect::<Vec<_>>(); + assert_eq!(v, + vec!(2558573138, 873787463, 263499565, 2103644246, 3595684709, + 4203127393, 264982119, 2765226902, 2737944514, 3900253796)); + + let seed: &[_] = &[12345, 67890, 54321, 9876]; + let mut rb: IsaacRng = SeedableRng::from_seed(seed); + // skip forward to the 10000th number + for _ in 0..10000 { rb.next_u32(); } + + let v = (0..10).map(|_| rb.next_u32()).collect::<Vec<_>>(); + assert_eq!(v, + vec!(3676831399, 3183332890, 2834741178, 3854698763, 2717568474, + 1576568959, 3507990155, 179069555, 141456972, 2478885421)); + } +} |