Initial commit!

src/unsigned/add.rs

@@ -0,0 +1,98 @@
+pub fn addition(dest: &mut [u64], src: &[u64])
+{
+    assert_eq!(dest.len(), src.len() + 1);
+    let mut carry: u128 = 0;
+
+    for i in 0..src.len() {
+        let x128 = dest[i] as u128;
+        let y128 = src[i] as u128;
+        let z128 = x128 + y128 + carry;
+
+        dest[i] = z128 as u64;
+        carry = z128 >> 64;
+    }
+    dest[src.len()] = carry as u64;
+}
+
+pub fn unsafe_addition(dest: &mut [u64], src: &[u64])
+{
+    assert_eq!(dest.len(), src.len());
+    let mut carry: u128 = 0;
+
+    for i in 0..src.len() {
+        let x128 = dest[i] as u128;
+        let y128 = src[i] as u128;
+        let z128 = x128 + y128 + carry;
+
+        dest[i] = z128 as u64;
+        carry = z128 >> 64;
+    }
+    assert_eq!(carry, 0, "Unsafe overflow in AddAssign");
+}
+
+macro_rules! addition_impls
+{
+    ($base: ident, $bigger: ident) => {
+        impl AddAssign<$base> for $base {
+            fn add_assign(&mut self, rhs: $base) {
+                unsafe_addition(&mut self.value, &rhs.value);
+            }
+        }
+
+        impl<'a> AddAssign<&'a $base> for $base {
+            fn add_assign(&mut self, rhs: &$base) {
+                unsafe_addition(&mut self.value, &rhs.value);
+            }
+        }
+
+        impl Add<$base> for $base {
+            type Output = $bigger;
+
+            fn add(self, rhs: $base) -> $bigger
+            {
+                let mut dest = $bigger::zero();
+                &dest.value[0..rhs.value.len()].copy_from_slice(&self.value);
+                addition(&mut dest.value, &rhs.value);
+                dest
+            }
+        }
+
+        impl<'a> Add<&'a $base> for $base {
+            type Output = $bigger;
+
+            fn add(self, rhs: &$base) -> $bigger
+            {
+                let mut dest = $bigger::zero();
+                &dest.value[0..rhs.value.len()].copy_from_slice(&self.value);
+                addition(&mut dest.value, &rhs.value);
+                dest
+            }
+        }
+
+        impl<'a> Add<$base> for &'a $base {
+            type Output = $bigger;
+
+            fn add(self, rhs: $base) -> $bigger
+            {
+                let mut dest = $bigger::zero();
+                &dest.value[0..rhs.value.len()].copy_from_slice(&self.value);
+                addition(&mut dest.value, &rhs.value);
+                dest
+            }
+        }
+
+        impl<'a,'b> Add<&'a $base> for &'b $base {
+            type Output = $bigger;
+
+            fn add(self, rhs: &$base) -> $bigger
+            {
+                let mut dest = $bigger::zero();
+                &dest.value[0..rhs.value.len()].copy_from_slice(&self.value);
+                addition(&mut dest.value, &rhs.value);
+                dest
+            }
+        }
+    }
+}
+
+//addition_impls!(U192,   U256);

src/unsigned/barrett.rs

@@ -0,0 +1,59 @@
+macro_rules! barrett_impl {
+    ($bar: ident, $name: ident, $name64: ident, $dbl: ident, $dbl64: ident) => {
+       pub struct $bar {
+           pub(crate) k:  usize,
+           pub(crate) m:  $name64,
+           pub(crate) mu: $name64
+       }
+
+       impl $bar {
+           pub fn new(m: $name) -> $bar {
+                // Step #1: Figure out k
+                let mut k = 0;
+                for i in 0..m.value.len() {
+                    if m.value[i] != 0 {
+                        k = i;
+                    }
+                }
+                k += 1;
+                // Step #2: Compute b
+                let mut b = $dbl64::zero();
+                b.value[2*k] = 1;
+                // Step #3: Divide b by m.
+                let bigm = $dbl64::from(&m);
+                let quot = b / &bigm;
+                let resm = $name64::from(&m);
+                let mu = $name64::from(&quot);
+                // Done!
+                $bar { k: k, m: resm, mu: mu }
+           }
+           
+           pub fn reduce(&self, x: &$dbl) -> $name {
+                let     m2: $dbl64  = $dbl64::from(&self.m);
+                // 1. q1←⌊x/bk−1⌋, q2←q1 · μ, q3←⌊q2/bk+1⌋.
+                let     q1: $name64 = $name64::from(x >> (self.k - 1));
+                let     q2: $dbl64  = $dbl64::from(q1 * &self.mu);
+                let     q3: $name64 = $name64::from(q2 >> (self.k + 1));
+                // 2. r1←x mod bk+1, r2←q3 · m mod bk+1, r←r1 − r2.
+                let mut r:  $dbl64  = $dbl64::from(x);
+                r.mask(self.k + 1);
+                let mut r2: $dbl64  = $dbl64::from(q3 * &self.m);
+                r2.mask(self.k + 1);
+                let went_negative = &r < &r2;
+                r -= &r2;
+                // 3. If r<0 then r←r+bk+1.
+                if went_negative {
+                    let mut bk1 = $dbl64::zero();
+                    bk1.value[self.k+1] = 1;
+                    r += &bk1;
+                }
+                // 4. While r≥m do: r←r−m.
+                while &r > &m2 {
+                    r -= &m2;
+                }
+                // Done!
+                $name::from(&r)
+           }
+       }
+    };
+}

src/unsigned/base.rs

@@ -0,0 +1,83 @@
+pub trait CryptoNum {
+    fn zero() -> Self;
+    fn is_zero(&self) -> bool;
+    fn is_even(&self) -> bool;
+    fn is_odd(&self) -> bool;
+    fn mask(&mut self, len: usize);
+}
+
+macro_rules! generate_base
+{
+    ($name: ident, $size: expr) => {
+        #[derive(Clone)]
+        pub struct $name {
+            pub(crate) value: [u64; $size]
+        }
+
+        impl CryptoNum for $name {
+            fn zero() -> $name {
+                $name{ value: [0; $size] }
+            }
+
+            fn is_zero(&self) -> bool {
+                self.value.iter().all(|&x| x == 0)
+            }
+
+            fn is_even(&self) -> bool {
+                (self.value[0] & 0x1) == 0
+            }
+
+            fn is_odd(&self) -> bool {
+                (self.value[0] & 0x1) == 1
+            }
+
+            fn mask(&mut self, len: usize) {
+                let dellen = min(len, $size);
+                for i in dellen..$size {
+                    self.value[i] = 0;
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+macro_rules! generate_base_tests
+{
+    ($name: ident) => {
+        impl fmt::Debug for $name {
+            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                f.write_str(stringify!($name))?;
+                f.write_str("{")?;
+                f.debug_list().entries(self.value.iter()).finish()?;
+                f.write_str("}")
+            }
+        }
+
+        #[test]
+        #[allow(non_snake_case)]
+        fn $name() {
+            let fname = format!("testdata/base/{}.tests", stringify!($name));
+            run_test(fname.to_string(), 6, |case| {
+                let (neg0, xbytes) = case.get("x").unwrap();
+                let (neg1, mbytes) = case.get("m").unwrap();
+                let (neg2, zbytes) = case.get("z").unwrap();
+                let (neg3, ebytes) = case.get("e").unwrap();
+                let (neg4, obytes) = case.get("o").unwrap();
+                let (neg5, rbytes) = case.get("r").unwrap();
+                assert!(!neg0 && !neg1 && !neg2 && !neg3 && !neg4 && !neg5);
+                let mut x = $name::from_bytes(xbytes);
+                let m = $name::from_bytes(mbytes);
+                let z = 1 == zbytes[0];
+                let e = 1 == ebytes[0];
+                let o = 1 == obytes[0];
+                let r = $name::from_bytes(rbytes);
+                assert_eq!(x.is_zero(), z);
+                assert_eq!(x.is_even(), e);
+                assert_eq!(x.is_odd(),  o);
+                x.mask(usize::from(&m));
+                assert_eq!(x, r);
+            });
+        }
+    }
+}

src/unsigned/cmp.rs

@@ -0,0 +1,42 @@
+use std::cmp::*;
+
+pub fn compare(a: &[u64], b: &[u64]) -> Ordering {
+    assert_eq!(a.len(), b.len(), "Incompatible numbers in comparison");
+
+    let mut i = (a.len() - 1) as isize;
+
+    while i >= 0 {
+        let iu = i as usize;
+        match a[iu].cmp(&b[iu]) {
+            Ordering::Greater => return Ordering::Greater,
+            Ordering::Less    => return Ordering::Less,
+            Ordering::Equal   => i -= 1
+        }
+    }
+
+    Ordering::Equal
+}
+
+macro_rules! cmp_impls {
+    ($name: ident) => {
+        impl PartialEq for $name {
+            fn eq(&self, rhs: &$name) -> bool {
+                compare(&self.value, &rhs.value) == Ordering::Equal
+            }
+        }
+
+        impl Eq for $name {}
+
+        impl PartialOrd for $name {
+            fn partial_cmp(&self, rhs: &$name) -> Option<Ordering> {
+                Some(compare(&self.value, &rhs.value))
+            }
+        }
+
+        impl Ord for $name {
+            fn cmp(&self, rhs: &$name) -> Ordering {
+                compare(&self.value, &rhs.value)
+            }
+        }
+    }
+}

src/unsigned/codec.rs

@@ -0,0 +1,70 @@
+pub trait Decoder {
+    fn from_bytes(x: &[u8]) -> Self;
+}
+
+pub trait Encoder {
+    fn to_bytes(&self) -> Vec<u8>;
+}
+
+pub(crate) fn raw_decoder(input: &[u8], output: &mut [u64])
+{
+    let mut item = 0;
+    let mut shift = 0;
+    let mut idx = 0;
+
+    for v in input.iter().rev() {
+        item |= (*v as u64) << shift;
+        shift += 8;
+        if shift == 64 {
+            shift = 0;
+            output[idx] = item;
+            idx += 1;
+            item = 0;
+        }
+    }
+    if item != 0 {
+        output[idx] = item;
+    }
+}
+
+macro_rules! generate_decoder {
+    ($name: ident) => {
+        impl Decoder for $name {
+            fn from_bytes(x: &[u8]) -> $name {
+                let mut res = $name::zero();
+                raw_decoder(x, &mut res.value);
+                res
+            }
+        }
+    }
+}
+
+macro_rules! generate_encoder {
+    ($name: ident) => {
+        impl Encoder for $name {
+            fn to_bytes(&self) -> Vec<u8> {
+                let mut res = Vec::with_capacity(self.value.len() * 8);
+                for v in self.value.iter().rev() {
+                    let val = *v;
+                    res.push( (val >> 56) as u8);
+                    res.push( (val >> 48) as u8);
+                    res.push( (val >> 40) as u8);
+                    res.push( (val >> 32) as u8);
+                    res.push( (val >> 24) as u8);
+                    res.push( (val >> 16) as u8);
+                    res.push( (val >>  8) as u8);
+                    res.push( (val >>  0) as u8);
+                }
+                res
+            }
+        }
+    }
+}
+
+macro_rules! generate_codec
+{
+    ($name: ident) => {
+        generate_decoder!($name);
+        generate_encoder!($name);
+    }
+}

src/unsigned/conversion.rs

@@ -0,0 +1,83 @@
+macro_rules! generate_base_conversions
+{
+    ($name: ident) => {
+        generate_base_type_convert!($name, u8);
+        generate_base_type_convert!($name, u16);
+        generate_base_type_convert!($name, u32);
+        generate_base_type_convert!($name, u64);
+        generate_base_type_convert!($name, usize);
+
+        impl From<u128> for $name {
+            fn from(x: u128) -> $name {
+                let mut res = $name::zero();
+                res.value[0] = x as u64;
+                res.value[1] = (x >> 64) as u64;
+                res
+            }
+        }
+    };
+    () => {};
+}
+
+macro_rules! conversion_impls
+{
+    ($name: ident, $other: ident) => {
+        impl<'a> From<&'a $other> for $name {
+            fn from(x: &$other) -> $name {
+                let mut res = $name::zero();
+                let     len = res.value.len();
+                assert!(x.value.len() > res.value.len());
+                res.value.copy_from_slice(&x.value[0..len]);
+                res
+            }
+        }
+
+        impl<'a> From<&'a $name> for $other {
+            fn from(x: &$name) -> $other {
+                let mut res = $other::zero();
+                let     len = x.value.len();
+
+                assert!(x.value.len() < res.value.len());
+                res.value[0..len].copy_from_slice(&x.value);
+                res
+            }
+        }
+
+        impl From<$other> for $name {
+            fn from(x: $other) -> $name {
+                $name::from(&x)
+            }
+        }
+
+        impl From<$name> for $other {
+            fn from(x: $name) -> $other {
+                $other::from(&x)
+            }
+        }
+    };
+}
+
+macro_rules! generate_base_type_convert
+{
+    ($name: ident, $base: ident) => {
+        impl From<$base> for $name {
+            fn from(x: $base) -> $name {
+                let mut res = $name::zero();
+                res.value[0] = x as u64;
+                res
+            }
+        }
+
+        impl From<$name> for $base {
+            fn from(x: $name) -> $base {
+                x.value[0] as $base
+            }
+        }
+
+        impl<'a> From<&'a $name> for $base {
+            fn from(x: &$name) -> $base {
+                x.value[0] as $base
+            }
+        }
+    }
+}

src/unsigned/div.rs

@@ -0,0 +1,222 @@
+pub trait DivMod
+ where Self: Sized
+{
+    fn divmod(&self, rhs: &Self) -> (Self, Self);
+}
+
+pub fn get_number_size(v: &[u64]) -> Option<usize>
+{
+    for (idx, val) in v.iter().enumerate().rev() {
+        if *val != 0 {
+            return Some(idx);
+        }
+    }
+    None
+}
+
+macro_rules! safesubidx
+{
+    ($array: expr, $index: expr, $amt: expr) => ({
+        let idx = $index;
+        let amt = $amt;
+
+        if idx < amt {
+            0
+        } else {
+            $array[idx-amt]
+        }
+    })
+}
+
+macro_rules! div_impls
+{
+    ($name: ident, $dbl: ident) => {
+        impl DivMod for $name {
+            fn divmod(&self, rhs: &$name) -> ($name, $name) {
+                // if the divisor is larger, then the answer is pretty simple
+                if rhs > self {
+                    return ($name::zero(), self.clone());
+                }
+                // compute the basic number sizes
+                let mut n = match get_number_size(&self.value) {
+                                None    => 0,
+                                Some(v) => v
+                            };
+                let t = match get_number_size(&rhs.value) {
+                            None    => panic!("Division by zero!"),
+                            Some(v) => v
+                        };
+                assert!(t <= n);
+                // now generate mutable versions we can mess with
+                let mut x = $dbl::from(self);
+                let mut y = $dbl::from(rhs);
+                // If we want this to perform reasonable, it's useful if the
+                // value of y[t] is shifted so that the high bit is set.
+                let lambda_shift = y.value[t].leading_zeros() as usize;
+                if lambda_shift != 0 {
+                    let dupx = x.value.clone();
+                    let dupy = y.value.clone();
+
+                    shiftl(&mut x.value, &dupx, lambda_shift);
+                    shiftl(&mut y.value, &dupy, lambda_shift);
+                    n = get_number_size(&x.value).unwrap();
+                }
+                // now go!
+                // 1. For j from 0 to (n-t) do: q[j] = 0;
+                //      [NB: I take some liberties with this concept]
+                let mut q = $dbl::zero();
+                // 2. While (x >= y * b^(n-t)) do the following:
+                let mut ybnt = $dbl::zero();
+                for i in 0..self.value.len() {
+                    ybnt.value[(n-t)+i] = y.value[i];
+                    if (n-t)+i >= ybnt.value.len() {
+                        break;
+                    }
+                }
+                while x > ybnt {
+                    q.value[n - t] += 1;
+                    x -= &ybnt;
+                }
+                // 3. For i from n down to t+1 do the following:
+                let mut i = n;
+                while i >= (t + 1) {
+                    // 3.1. If x[i] = y[t]
+                    if x.value[i] == y.value[t] {
+                        // ... then set q[i-t-1] = b - 1
+                        q.value[i-t-1] = 0xFFFFFFFFFFFFFFFF;
+                    } else {
+                        // ... otherwise set q[i-t-1] =
+                        //        floor((x[i] * b + x[i-1]) / y[t])
+                        let xib         = (x.value[i] as u128) << 64;
+                        let xi1         = safesubidx!(x.value,i,1) as u128;
+                        let yt          = y.value[t] as u128;
+                        let qit1        = (xib + xi1) / yt;
+                        q.value[i-t-1] = qit1 as u64;
+                    }
+                    // 3.2. While q[i-t-1] * (y[t]*b + y[t-1]) >
+                    //                  (x[i] * b^2 + x[i-1] * b + x[i-2])
+                    loop {
+                        // three is very close to 2.
+                        let     qit1    = U192::from(safesubidx!(q.value,i-t,1));
+                        let mut ybits   = U192::zero();
+                        ybits.value[0]  = safesubidx!(y.value, t, 1);
+                        ybits.value[1]  = y.value[t];
+                        let       qiybs = &qit1 * &ybits;
+                        let mut   xbits = U384::zero();
+                        xbits.value[0]  = safesubidx!(x.value,i,2);
+                        xbits.value[1]  = safesubidx!(x.value,i,1);
+                        xbits.value[2]  = x.value[i];
+
+                        if !(&qiybs > &xbits) {
+                            break;
+                        }
+
+                        // ... do q[i-t-1] = q[i-t-1] - 1
+                        q.value[i-t-1] -= 1;
+                    }
+                    // 3.3. x = x - q[i-t-1] * y * b^(i-t-1)
+                    // 3.4. If x < 0
+                    //      then set x = x + y * b^(i-t-1) and
+                    //               q[i-t-1] = q[i-t-1] - 1
+                    let mut qbit1 = $name::zero();
+                    qbit1.value[i-t-1] = q.value[i-t-1];
+                    let smallery = $name::from(&y);
+                    let mut subpart = &smallery * &qbit1;
+                    if subpart > x {
+                        let mut addback = $dbl::zero();
+                        for (idx, val) in y.value.iter().enumerate() {
+                            let dest = idx + (i - t - 1);
+                            if dest < addback.value.len() {
+                                addback.value[dest] = *val;
+                            }
+                        }
+                        q.value[i-t-1] -= 1;
+                        subpart -= &addback;
+                    }
+                    assert!(subpart <= x);
+                    x -= &subpart;
+                    i -= 1;
+                }
+                // 4. r = x ... sort of. Remember, we potentially did a bit of shifting
+                // around at the very beginning, which we now need to account for. On the
+                // bright side, we only need to account for this in the remainder.
+                let mut r = $name::from(&x);
+                let dupr = r.value.clone();
+                shiftr(&mut r.value, &dupr, lambda_shift);
+                // 5. Return (q,r)
+                let resq = $name::from(&q);
+                (resq, r)
+            }
+        }
+        impl Div for $name {
+            type Output = $name;
+
+            fn div(self, rhs: $name) -> $name {
+                let (res, _) = self.divmod(&rhs);
+                res
+            }
+        }
+
+        impl<'a> Div<&'a $name> for $name {
+            type Output = $name;
+
+            fn div(self, rhs: &$name) -> $name {
+                let (res, _) = self.divmod(rhs);
+                res
+            }
+        }
+
+        impl<'a> Div<$name> for &'a $name {
+            type Output = $name;
+
+            fn div(self, rhs: $name) -> $name {
+                let (res, _) = self.divmod(&rhs);
+                res
+            }
+        }
+        impl<'a,'b> Div<&'a $name> for &'b $name {
+            type Output = $name;
+
+            fn div(self, rhs: &$name) -> $name {
+                let (res, _) = self.divmod(rhs);
+                res
+            }
+        }
+
+        impl Rem for $name {
+            type Output = $name;
+
+            fn rem(self, rhs: $name) -> $name {
+                let (_, res) = self.divmod(&rhs);
+                res
+            }
+        }
+
+        impl<'a> Rem<&'a $name> for $name {
+            type Output = $name;
+
+            fn rem(self, rhs: &$name) -> $name {
+                let (_, res) = self.divmod(&rhs);
+                res
+            }
+        }
+
+        impl<'a> Rem<$name> for &'a $name {
+            type Output = $name;
+
+            fn rem(self, rhs: $name) -> $name {
+                let (_, res) = self.divmod(&rhs);
+                res
+            }
+        }
+
+        impl<'a,'b> Rem<&'a $name> for &'b $name {
+            type Output = $name;
+
+            fn rem(self, rhs: &$name) -> $name {
+                let (_, res) = self.divmod(&rhs);
+                res
+            }
+        }
+    }
+}

src/unsigned/mod.rs

@@ -0,0 +1,63 @@
+#[macro_use]
+mod add;
+#[macro_use]
+mod barrett;
+#[macro_use]
+mod base;
+#[macro_use]
+mod cmp;
+#[macro_use]
+mod codec;
+#[macro_use]
+mod conversion;
+#[macro_use]
+mod div;
+#[macro_use]
+mod mul;
+#[macro_use]
+mod shifts;
+#[macro_use]
+mod sub;
+
+use self::add::{addition,unsafe_addition};
+use self::base::CryptoNum;
+use self::cmp::compare;
+use self::div::{DivMod,get_number_size};
+use self::codec::{Encoder,Decoder,raw_decoder};
+use self::mul::multiply;
+use self::shifts::{shiftl,shiftr};
+use self::sub::subtract;
+use std::cmp::{Ordering,min};
+use std::ops::{Add,AddAssign};
+use std::ops::{Div,Mul,Rem};
+use std::ops::{Shl,ShlAssign,Shr,ShrAssign};
+use std::ops::{Sub,SubAssign};
+
+#[cfg(test)]
+use std::fmt;
+
+macro_rules! generate_number
+{
+    ($name: ident, $size: expr) => {
+        generate_base!($name, $size);
+        generate_base_conversions!($name);
+        generate_codec!($name);
+
+        cmp_impls!($name);
+
+        subtraction_impls!($name, $size);
+        shift_impls!($name, $size);
+    };
+    ($name: ident, $size: expr, $plus1: ident, $times2: ident) => {
+        generate_number!($name, $size);
+        addition_impls!($name, $plus1);
+        multiply_impls!($name, $times2);
+        div_impls!($name, $times2);
+    };
+    ($name: ident, $size: expr, $plus1: ident, $times2: ident, $big: ident, $bar: ident) => {
+        generate_number!($name, $size, $plus1, $times2);
+        barrett_impl!($bar, $name, $plus1, $times2, $big);
+    }
+}
+
+include!("invoc.rs");

src/unsigned/mul.rs

@@ -0,0 +1,65 @@
+pub fn multiply(dest: &mut [u64], left: &[u64], right: &[u64])
+{
+    let len = right.len();
+
+    assert_eq!(left.len(), len,   "Uneven argument lengths in multiply");
+    assert_eq!(dest.len(), len*2, "Bad destination size in multiply");
+
+    for i in 0..len {
+        let mut carry = 0;
+
+        for j in 0..len {
+            let old = dest[i+j] as u128;
+            let l128 = left[j] as u128;
+            let r128 = right[i] as u128;
+            let uv = old + (l128 * r128) + carry;
+            dest[i+j] = uv as u64;
+            carry = uv >> 64;
+        }
+        dest[i+len] = carry as u64;
+    }
+}
+
+macro_rules! multiply_impls {
+    ($name: ident, $dbl: ident) => {
+        impl Mul<$name> for $name {
+            type Output = $dbl;
+
+            fn mul(self, rhs: $name) -> $dbl {
+                let mut res = $dbl::zero();
+                multiply(&mut res.value, &self.value, &rhs.value);
+                res
+            }
+        }
+
+        impl<'a> Mul<$name> for &'a $name {
+            type Output = $dbl;
+
+            fn mul(self, rhs: $name) -> $dbl {
+                let mut res = $dbl::zero();
+                multiply(&mut res.value, &self.value, &rhs.value);
+                res
+            }
+        }
+
+        impl<'a> Mul<&'a $name> for $name {
+            type Output = $dbl;
+
+            fn mul(self, rhs: &$name) -> $dbl {
+                let mut res = $dbl::zero();
+                multiply(&mut res.value, &self.value, &rhs.value);
+                res
+            }
+        }
+
+        impl<'a,'b> Mul<&'a $name> for &'b $name {
+            type Output = $dbl;
+
+            fn mul(self, rhs: &$name) -> $dbl {
+                let mut res = $dbl::zero();
+                multiply(&mut res.value, &self.value, &rhs.value);
+                res
+            }
+        }
+    };
+}

src/unsigned/shifts.rs

@@ -0,0 +1,92 @@
+pub(crate) fn shiftl(res: &mut [u64], copy: &[u64], amt: usize) {
+    let digits = amt / 64;
+    let bits   = amt % 64;
+
+    let mut carry = 0;
+    let     shift = 64 - bits;
+
+    for i in 0..res.len() {
+        let base = if i >= digits { copy[i-digits] } else { 0 };
+        let new_carry = if shift == 64 { 0 } else { base >> shift };
+        res[i] = (base << bits) | carry;
+        carry = new_carry;
+    }
+}
+
+pub(crate) fn shiftr(res: &mut [u64], copy: &[u64], amt: usize) {
+    let digits = amt / 64;
+    let bits   = amt % 64;
+
+    let mut carry = 0;
+    let mask = !(0xFFFFFFFFFFFFFFFF << bits);
+    let shift = (64 - bits) as u32;
+
+    for (idx, val) in res.iter_mut().enumerate().rev() {
+        let target = idx + digits;
+        let base = if target >= copy.len() { 0 } else { copy[target] };
+        let (new_carry, _) = (base & mask).overflowing_shl(shift);
+        *val = (base >> bits) | carry;
+        carry = new_carry;
+    }
+}
+
+macro_rules! shift_impls
+{
+    ($name: ident, $size: expr) => {
+        impl ShlAssign<usize> for $name {
+            fn shl_assign(&mut self, amt: usize) {
+                let copy = self.value.clone();
+                shiftl(&mut self.value, &copy, amt);
+            }
+        }
+
+        impl Shl<usize> for $name {
+            type Output = $name;
+
+            fn shl(mut self, amt: usize) -> $name {
+                let copy = self.value.clone();
+                shiftl(&mut self.value, &copy, amt);
+                self
+            }
+        }
+
+        impl<'a> Shl<usize> for &'a $name {
+            type Output = $name;
+
+            fn shl(self, amt: usize) -> $name {
+                let mut res = $name{ value: self.value.clone() };
+                shiftl(&mut res.value, &self.value, amt);
+                res
+            }
+        }
+
+        impl ShrAssign<usize> for $name {
+            fn shr_assign(&mut self, amt: usize) {
+                let copy = self.value.clone();
+                shiftr(&mut self.value, &copy, amt);
+            }
+        }
+
+        impl Shr<usize> for $name {
+            type Output = $name;
+
+            fn shr(mut self, amt: usize) -> $name {
+                let copy = self.value.clone();
+                shiftr(&mut self.value, &copy, amt);
+                self
+            }
+        }
+
+        impl<'a> Shr<usize> for &'a $name {
+            type Output = $name;
+
+            fn shr(self, amt: usize) -> $name {
+                let mut res = $name{ value: self.value.clone() };
+                shiftr(&mut res.value, &self.value, amt);
+                res
+            }
+        }
+    }
+}
+
+//shift_impls!(U192,   3);

src/unsigned/sub.rs

@@ -0,0 +1,76 @@
+use unsigned::add::unsafe_addition;
+
+pub fn subtract(res: &mut [u64], spare: &mut [u64], other: &[u64])
+{
+    for i in 0..res.len() {
+        res[i] = !res[i];
+    }
+    spare[0] = 1;
+    unsafe_addition(res, &spare);
+    unsafe_addition(res, &other);
+}
+
+macro_rules! subtraction_impls
+{
+    ($name: ident, $size: expr) => {
+        impl SubAssign for $name {
+            fn sub_assign(&mut self, rhs: $name) {
+                let mut temp = [0; $size];
+                subtract(&mut self.value, &mut temp, &rhs.value);
+            }
+        }
+
+        impl<'a> SubAssign<&'a $name> for $name {
+            fn sub_assign(&mut self, rhs: &$name) {
+                let mut temp = [0; $size];
+                subtract(&mut self.value, &mut temp, &rhs.value);
+            }
+        }
+
+        impl Sub for $name {
+            type Output = $name;
+
+            fn sub(self, rhs: $name) -> $name {
+                let mut res  = $name::zero();
+                let mut temp = [0; $size];
+                subtract(&mut res.value, &mut temp, &rhs.value);
+                res
+            }
+        }
+
+        impl<'a> Sub<$name> for &'a $name {
+            type Output = $name;
+
+            fn sub(self, rhs: $name) -> $name {
+                let mut res  = $name::zero();
+                let mut temp = [0; $size];
+                subtract(&mut res.value, &mut temp, &rhs.value);
+                res
+            }
+        }
+
+        impl<'a> Sub<&'a $name> for $name {
+            type Output = $name;
+
+            fn sub(self, rhs: &$name) -> $name {
+                let mut res  = $name::zero();
+                let mut temp = [0; $size];
+                subtract(&mut res.value, &mut temp, &rhs.value);
+                res
+            }
+        }
+
+        impl<'a,'b> Sub<&'a $name> for &'b $name {
+            type Output = $name;
+
+            fn sub(self, rhs: &$name) -> $name {
+                let mut res  = $name::zero();
+                let mut temp = [0; $size];
+                subtract(&mut res.value, &mut temp, &rhs.value);
+                res
+            }
+        }
+    }
+}
+
+//subtraction_impls!(U192,   3);