From f95265d6aecfd1a74f567273d786da0735c6065e Mon Sep 17 00:00:00 2001 From: debris Date: Thu, 26 Nov 2015 13:42:42 +0100 Subject: [PATCH] uint256 --- src/lib.rs | 1 + src/uint.rs | 593 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 594 insertions(+) create mode 100644 src/uint.rs diff --git a/src/lib.rs b/src/lib.rs index 8a65c9873..ab8cac701 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -2,6 +2,7 @@ extern crate rustc_serialize; pub mod error; pub mod hash; +pub mod uint; pub mod bytes; pub mod rlp; diff --git a/src/uint.rs b/src/uint.rs new file mode 100644 index 000000000..149ff5efb --- /dev/null +++ b/src/uint.rs @@ -0,0 +1,593 @@ +// taken from Rust Bitcoin Library (https://github.com/apoelstra/rust-bitcoin) +// original author: Andrew Poelstra + +// Rust Bitcoin Library +// Written in 2014 by +// Andrew Poelstra +// +// To the extent possible under law, the author(s) have dedicated all +// copyright and related and neighboring rights to this software to +// the public domain worldwide. This software is distributed without +// any warranty. +// +// You should have received a copy of the CC0 Public Domain Dedication +// along with this software. +// If not, see . +// + +//! Big unsigned integer types +///! +///! Implementation of a various large-but-fixed sized unsigned integer types. +///! The functions here are designed to be fast. +///! + +use std::fmt; +use std::cmp::{Ord, PartialOrd, Ordering}; +use std::ops::*; +use std::str::FromStr; +use rustc_serialize::hex::{FromHex, FromHexError}; + +macro_rules! impl_map_from { + ($thing:ident, $from:ty, $to:ty) => { + impl From<$from> for $thing { + fn from(value: $from) -> $thing { + From::from(value as $to) + } + } + } +} + +macro_rules! impl_array_newtype { + ($thing:ident, $ty:ty, $len:expr) => { + impl $thing { + #[inline] + /// Converts the object to a raw pointer + pub fn as_ptr(&self) -> *const $ty { + let &$thing(ref dat) = self; + dat.as_ptr() + } + + #[inline] + /// Converts the object to a mutable raw pointer + pub fn as_mut_ptr(&mut self) -> *mut $ty { + let &mut $thing(ref mut dat) = self; + dat.as_mut_ptr() + } + + #[inline] + /// Returns the length of the object as an array + pub fn len(&self) -> usize { $len } + + #[inline] + /// Returns whether the object, as an array, is empty. Always false. + pub fn is_empty(&self) -> bool { false } + } + + impl<'a> From<&'a [$ty]> for $thing { + fn from(data: &'a [$ty]) -> $thing { + assert_eq!(data.len(), $len); + unsafe { + use std::intrinsics::copy_nonoverlapping; + use std::mem; + let mut ret: $thing = mem::uninitialized(); + copy_nonoverlapping(data.as_ptr(), + ret.as_mut_ptr(), + mem::size_of::<$thing>()); + ret + } + } + } + + impl Index for $thing { + type Output = $ty; + + #[inline] + fn index(&self, index: usize) -> &$ty { + let &$thing(ref dat) = self; + &dat[index] + } + } + + impl_index_newtype!($thing, $ty); + + impl PartialEq for $thing { + #[inline] + fn eq(&self, other: &$thing) -> bool { + &self[..] == &other[..] + } + } + + impl Eq for $thing {} + + impl Clone for $thing { + #[inline] + fn clone(&self) -> $thing { + $thing::from(&self[..]) + } + } + + impl Copy for $thing {} + } +} + +macro_rules! impl_index_newtype { + ($thing:ident, $ty:ty) => { + impl Index> for $thing { + type Output = [$ty]; + + #[inline] + fn index(&self, index: Range) -> &[$ty] { + &self.0[index] + } + } + + impl Index> for $thing { + type Output = [$ty]; + + #[inline] + fn index(&self, index: RangeTo) -> &[$ty] { + &self.0[index] + } + } + + impl Index> for $thing { + type Output = [$ty]; + + #[inline] + fn index(&self, index: RangeFrom) -> &[$ty] { + &self.0[index] + } + } + + impl Index for $thing { + type Output = [$ty]; + + #[inline] + fn index(&self, _: RangeFull) -> &[$ty] { + &self.0[..] + } + } + } +} + +macro_rules! construct_uint { + ($name:ident, $n_words:expr) => ( + /// Little-endian large integer type + pub struct $name(pub [u64; $n_words]); + impl_array_newtype!($name, u64, $n_words); + + impl $name { + /// Conversion to u32 + #[inline] + fn low_u32(&self) -> u32 { + let &$name(ref arr) = self; + arr[0] as u32 + } + + /// Return the least number of bits needed to represent the number + #[inline] + pub fn bits(&self) -> usize { + let &$name(ref arr) = self; + for i in 1..$n_words { + if arr[$n_words - i] > 0 { return (0x40 * ($n_words - i + 1)) - arr[$n_words - i].leading_zeros() as usize; } + } + 0x40 - arr[0].leading_zeros() as usize + } + + #[inline] + pub fn bit(&self, index: usize) -> bool { + let &$name(ref arr) = self; + arr[index / 64] & (1 << (index % 64)) != 0 + } + + /// Multiplication by u32 + fn mul_u32(self, other: u32) -> $name { + let $name(ref arr) = self; + let mut carry = [0u64; $n_words]; + let mut ret = [0u64; $n_words]; + for i in 0..$n_words { + let upper = other as u64 * (arr[i] >> 32); + let lower = other as u64 * (arr[i] & 0xFFFFFFFF); + if i < 3 { + carry[i + 1] += upper >> 32; + } + ret[i] = lower + (upper << 32); + } + $name(ret) + $name(carry) + } + } + + impl From for $name { + fn from(value: u64) -> $name { + let mut ret = [0; $n_words]; + ret[0] = value; + $name(ret) + } + } + + impl_map_from!($name, u8, u64); + impl_map_from!($name, u16, u64); + impl_map_from!($name, u32, u64); + + impl<'a> From<&'a [u8]> for $name { + fn from(bytes: &[u8]) -> $name { + assert!($n_words * 8 >= bytes.len()); + + let mut ret = [0; $n_words]; + for i in 0..bytes.len() { + let rev = bytes.len() - 1 - i; + let pos = rev / 8; + ret[pos] += (bytes[i] as u64) << (rev % 8) * 8; + } + $name(ret) + } + } + + impl FromStr for $name { + type Err = FromHexError; + + fn from_str(value: &str) -> Result<$name, Self::Err> { + println!("{}", value); + let bytes: &[u8] = &try!(value.from_hex()); + Ok(From::from(bytes)) + } + } + + impl Add<$name> for $name { + type Output = $name; + + fn add(self, other: $name) -> $name { + let $name(ref me) = self; + let $name(ref you) = other; + let mut ret = [0u64; $n_words]; + let mut carry = [0u64; $n_words]; + let mut b_carry = false; + for i in 0..$n_words { + ret[i] = me[i].wrapping_add(you[i]); + if i < $n_words - 1 && ret[i] < me[i] { + carry[i + 1] = 1; + b_carry = true; + } + } + if b_carry { $name(ret) + $name(carry) } else { $name(ret) } + } + } + + impl Sub<$name> for $name { + type Output = $name; + + #[inline] + fn sub(self, other: $name) -> $name { + self + !other + From::from(1u64) + } + } + + impl Mul<$name> for $name { + type Output = $name; + + fn mul(self, other: $name) -> $name { + let mut me = self; + // TODO: be more efficient about this + for i in 0..(2 * $n_words) { + me = (me + me.mul_u32((other >> (32 * i)).low_u32())) << (32 * i); + } + me + } + } + + impl Div<$name> for $name { + type Output = $name; + + fn div(self, other: $name) -> $name { + let mut sub_copy = self; + let mut shift_copy = other; + let mut ret = [0u64; $n_words]; + + let my_bits = self.bits(); + let your_bits = other.bits(); + + // Check for division by 0 + assert!(your_bits != 0); + + // Early return in case we are dividing by a larger number than us + if my_bits < your_bits { + return $name(ret); + } + + // Bitwise long division + let mut shift = my_bits - your_bits; + shift_copy = shift_copy << shift; + loop { + if sub_copy >= shift_copy { + ret[shift / 64] |= 1 << (shift % 64); + sub_copy = sub_copy - shift_copy; + } + shift_copy = shift_copy >> 1; + if shift == 0 { break; } + shift -= 1; + } + + $name(ret) + } + } + + impl BitAnd<$name> for $name { + type Output = $name; + + #[inline] + fn bitand(self, other: $name) -> $name { + let $name(ref arr1) = self; + let $name(ref arr2) = other; + let mut ret = [0u64; $n_words]; + for i in 0..$n_words { + ret[i] = arr1[i] & arr2[i]; + } + $name(ret) + } + } + + impl BitXor<$name> for $name { + type Output = $name; + + #[inline] + fn bitxor(self, other: $name) -> $name { + let $name(ref arr1) = self; + let $name(ref arr2) = other; + let mut ret = [0u64; $n_words]; + for i in 0..$n_words { + ret[i] = arr1[i] ^ arr2[i]; + } + $name(ret) + } + } + + impl BitOr<$name> for $name { + type Output = $name; + + #[inline] + fn bitor(self, other: $name) -> $name { + let $name(ref arr1) = self; + let $name(ref arr2) = other; + let mut ret = [0u64; $n_words]; + for i in 0..$n_words { + ret[i] = arr1[i] | arr2[i]; + } + $name(ret) + } + } + + impl Not for $name { + type Output = $name; + + #[inline] + fn not(self) -> $name { + let $name(ref arr) = self; + let mut ret = [0u64; $n_words]; + for i in 0..$n_words { + ret[i] = !arr[i]; + } + $name(ret) + } + } + + impl Shl for $name { + type Output = $name; + + fn shl(self, shift: usize) -> $name { + let $name(ref original) = self; + let mut ret = [0u64; $n_words]; + let word_shift = shift / 64; + let bit_shift = shift % 64; + for i in 0..$n_words { + // Shift + if bit_shift < 64 && i + word_shift < $n_words { + ret[i + word_shift] += original[i] << bit_shift; + } + // Carry + if bit_shift > 0 && i + word_shift + 1 < $n_words { + ret[i + word_shift + 1] += original[i] >> (64 - bit_shift); + } + } + $name(ret) + } + } + + impl Shr for $name { + type Output = $name; + + fn shr(self, shift: usize) -> $name { + let $name(ref original) = self; + let mut ret = [0u64; $n_words]; + let word_shift = shift / 64; + let bit_shift = shift % 64; + for i in word_shift..$n_words { + // Shift + ret[i - word_shift] += original[i] >> bit_shift; + // Carry + if bit_shift > 0 && i < $n_words - 1 { + ret[i - word_shift] += original[i + 1] << (64 - bit_shift); + } + } + $name(ret) + } + } + + impl Ord for $name { + fn cmp(&self, other: &$name) -> Ordering { + let &$name(ref me) = self; + let &$name(ref you) = other; + for i in 0..$n_words { + if me[$n_words - 1 - i] < you[$n_words - 1 - i] { return Ordering::Less; } + if me[$n_words - 1 - i] > you[$n_words - 1 - i] { return Ordering::Greater; } + } + Ordering::Equal + } + } + + impl PartialOrd for $name { + fn partial_cmp(&self, other: &$name) -> Option { + Some(self.cmp(other)) + } + } + + impl fmt::Debug for $name { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + let &$name(ref data) = self; + try!(write!(f, "0x")); + for ch in data.iter().rev() { + try!(write!(f, "{:02x}", ch)); + } + Ok(()) + } + } + ); +} + +construct_uint!(U256, 4); +construct_uint!(U128, 2); + +impl From for U256 { + fn from(value: U128) -> U256 { + let U128(ref arr) = value; + let mut ret = [0; 4]; + ret[0] = arr[0]; + ret[1] = arr[1]; + U256(ret) + } +} + +#[cfg(test)] +mod tests { + use uint::U256; + use std::str::FromStr; + + #[test] + pub fn uint256_from() { + let e = U256([10, 0, 0, 0]); + + // test unsigned initialization + let ua = U256::from(10u8); + let ub = U256::from(10u16); + let uc = U256::from(10u32); + let ud = U256::from(10u64); + assert_eq!(e, ua); + assert_eq!(e, ub); + assert_eq!(e, uc); + assert_eq!(e, ud); + + // test initialization from bytes + let va = U256::from(&[10u8][..]); + assert_eq!(e, va); + + // more tests for initialization from bytes + assert_eq!(U256([0x1010, 0, 0, 0]), U256::from(&[0x10u8, 0x10][..])); + assert_eq!(U256([0x12f0, 0, 0, 0]), U256::from(&[0x12u8, 0xf0][..])); + assert_eq!(U256([0x12f0, 0, 0, 0]), U256::from(&[0, 0x12u8, 0xf0][..])); + assert_eq!(U256([0x12f0, 0 , 0, 0]), U256::from(&[0, 0, 0, 0, 0, 0, 0, 0x12u8, 0xf0][..])); + assert_eq!(U256([0x12f0, 1 , 0, 0]), U256::from(&[1, 0, 0, 0, 0, 0, 0, 0x12u8, 0xf0][..])); + assert_eq!(U256([0x12f0, 1 , 0x0910203040506077, 0x8090a0b0c0d0e0f0]), U256::from(&[ + 0x80, 0x90, 0xa0, 0xb0, 0xc0, 0xd0, 0xe0, 0xf0, + 0x09, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x77, + 0, 0, 0, 0, 0, 0, 0, 1, + 0, 0, 0, 0, 0, 0, 0x12u8, 0xf0][..])); + assert_eq!(U256([0x00192437100019fa, 0x243710, 0, 0]), U256::from(&[ + 0x24u8, 0x37, 0x10, + 0, 0x19, 0x24, 0x37, 0x10, 0, 0x19, 0xfa][..])); + + // test initializtion from string + let sa = U256::from_str("0a").unwrap(); + assert_eq!(e, sa); + assert_eq!(U256([0x1010, 0, 0, 0]), U256::from_str("1010").unwrap()); + assert_eq!(U256([0x12f0, 0, 0, 0]), U256::from_str("12f0").unwrap()); + assert_eq!(U256([0x12f0, 0, 0, 0]), U256::from_str("12f0").unwrap()); + assert_eq!(U256([0x12f0, 0 , 0, 0]), U256::from_str("0000000012f0").unwrap()); + assert_eq!(U256([0x12f0, 1 , 0, 0]), U256::from_str("0100000000000012f0").unwrap()); + assert_eq!(U256([0x12f0, 1 , 0x0910203040506077, 0x8090a0b0c0d0e0f0]), U256::from_str("8090a0b0c0d0e0f00910203040506077000000000000000100000000000012f0").unwrap()); + } + + #[test] + pub fn uint256_bits_test() { + assert_eq!(U256::from(255u64).bits(), 8); + assert_eq!(U256::from(256u64).bits(), 9); + assert_eq!(U256::from(300u64).bits(), 9); + assert_eq!(U256::from(60000u64).bits(), 16); + assert_eq!(U256::from(70000u64).bits(), 17); + + //// Try to read the following lines out loud quickly + let mut shl = U256::from(70000u64); + shl = shl << 100; + assert_eq!(shl.bits(), 117); + shl = shl << 100; + assert_eq!(shl.bits(), 217); + shl = shl << 100; + assert_eq!(shl.bits(), 0); + + //// Bit set check + assert!(!U256::from(10u8).bit(0)); + assert!(U256::from(10u8).bit(1)); + assert!(!U256::from(10u8).bit(2)); + assert!(U256::from(10u8).bit(3)); + assert!(!U256::from(10u8).bit(4)); + } + + #[test] + pub fn uint256_comp_test() { + let small = U256([10u64, 0, 0, 0]); + let big = U256([0x8C8C3EE70C644118u64, 0x0209E7378231E632, 0, 0]); + let bigger = U256([0x9C8C3EE70C644118u64, 0x0209E7378231E632, 0, 0]); + let biggest = U256([0x5C8C3EE70C644118u64, 0x0209E7378231E632, 0, 1]); + + assert!(small < big); + assert!(big < bigger); + assert!(bigger < biggest); + assert!(bigger <= biggest); + assert!(biggest <= biggest); + assert!(bigger >= big); + assert!(bigger >= small); + assert!(small <= small); + } + + #[test] + pub fn uint256_arithmetic_test() { + let init = U256::from(0xDEADBEEFDEADBEEFu64); + let copy = init; + + let add = init + copy; + assert_eq!(add, U256([0xBD5B7DDFBD5B7DDEu64, 1, 0, 0])); + // Bitshifts + let shl = add << 88; + assert_eq!(shl, U256([0u64, 0xDFBD5B7DDE000000, 0x1BD5B7D, 0])); + let shr = shl >> 40; + assert_eq!(shr, U256([0x7DDE000000000000u64, 0x0001BD5B7DDFBD5B, 0, 0])); + // Increment + let incr = shr + U256::from(1u64); + assert_eq!(incr, U256([0x7DDE000000000001u64, 0x0001BD5B7DDFBD5B, 0, 0])); + // Subtraction + let sub = incr - init; + assert_eq!(sub, U256([0x9F30411021524112u64, 0x0001BD5B7DDFBD5A, 0, 0])); + // Multiplication + let mult = sub.mul_u32(300); + assert_eq!(mult, U256([0x8C8C3EE70C644118u64, 0x0209E7378231E632, 0, 0])); + // Division + assert_eq!(U256::from(105u8) / U256::from(5u8), U256::from(21u8)); + let div = mult / U256::from(300u16); + assert_eq!(div, U256([0x9F30411021524112u64, 0x0001BD5B7DDFBD5A, 0, 0])); + //// TODO: bit inversion + } + + #[test] + pub fn uint256_extreme_bitshift_test() { + //// Shifting a u64 by 64 bits gives an undefined value, so make sure that + //// we're doing the Right Thing here + let init = U256::from(0xDEADBEEFDEADBEEFu64); + + assert_eq!(init << 64, U256([0, 0xDEADBEEFDEADBEEF, 0, 0])); + let add = (init << 64) + init; + assert_eq!(add, U256([0xDEADBEEFDEADBEEF, 0xDEADBEEFDEADBEEF, 0, 0])); + assert_eq!(add >> 0, U256([0xDEADBEEFDEADBEEF, 0xDEADBEEFDEADBEEF, 0, 0])); + assert_eq!(add << 0, U256([0xDEADBEEFDEADBEEF, 0xDEADBEEFDEADBEEF, 0, 0])); + assert_eq!(add >> 64, U256([0xDEADBEEFDEADBEEF, 0, 0, 0])); + assert_eq!(add << 64, U256([0, 0xDEADBEEFDEADBEEF, 0xDEADBEEFDEADBEEF, 0])); + } +} +