Files
simple_crypto/src/ecdsa/point.rs
2019-04-17 21:20:52 -05:00

329 lines
12 KiB
Rust

use cryptonum::signed::*;
use cryptonum::unsigned::*;
use ecdsa::curve::*;
pub trait ECCPoint : Sized {
type Curve: EllipticCurve;
type Scale;
fn default() -> Self;
fn negate(&self) -> Self;
fn double(&self) -> Self;
fn add(&self, other: &Self) -> Self;
fn scale(&self, amt: &Self::Scale) -> Self;
fn double_scalar_mult(x1: &Self::Scale, p1: &Self, x2: &Self::Scale, p2: &Self) -> Self
{
// FIXME: Replace this with something not stupid.
let big1 = p1.scale(x1);
let big2 = p2.scale(x2);
big1.add(&big2)
}
}
#[derive(Debug,PartialEq)]
pub struct Point<T: EllipticCurve>
{
pub x: T::Signed,
pub y: T::Signed
}
macro_rules! point_impl
{
($curve: ident, $base: ident,
$s2: ident, $u2: ident,
$s2p1: ident, $u2p1: ident) =>
{
impl Clone for Point<$curve> {
fn clone(&self) -> Point<$curve> {
Point {
x: self.x.clone(),
y: self.y.clone()
}
}
}
impl ECCPoint for Point<$curve> {
type Curve = $curve;
type Scale = $base;
fn default() -> Point<$curve>
{
Point {
x: $curve::Gx(),
y: $curve::Gy()
}
}
fn negate(&self) -> Point<$curve>
{
let mut newy = $base::new(false, $curve::p());
newy -= &self.y;
Point{ x: self.x.clone(), y: newy }
}
fn double(&self) -> Point<$curve>
{
let up = $curve::p();
let bigp = $s2::new(false, $u2::from(&up));
// lambda = (3 * xp ^ 2 + a) / 2 yp
let xsquared = self.x.square();
let mut lambda_top = &xsquared * 3u64;
lambda_top += $s2p1::new(false, $u2p1::from($curve::a()));
let mut lambda_bot = $s2p1::from(&self.y);
lambda_bot <<= 1;
let lambda = $base::from(lambda_top.moddiv(&lambda_bot, &$s2p1::from(&bigp)));
// xr = lambda^2 - 2 xp
let mut xr = lambda.square();
let mut xr_right = $s2::from(&self.x);
xr_right <<= 1;
xr -= xr_right;
xr %= &bigp;
let x = $base::from(xr);
// yr = lambda (xp - xr) - yp
let xdiff = $base::from(&self.x - &x);
let mut yr = &lambda * &xdiff;
yr -= $s2::from(&self.y);
let y = $base::from(&yr % &bigp);
//
Point{ x, y }
}
fn add(&self, other: &Point<$curve>) -> Point<$curve>
{
let mut xdiff = self.x.clone(); xdiff -= &other.x;
let mut ydiff = self.y.clone(); ydiff -= &other.y;
let signedp = $base::new(false, $curve::p());
let s = ydiff.moddiv(&xdiff, &signedp);
let mut xr = &s * &s;
xr -= $s2::from(&self.x);
xr -= $s2::from(&other.x);
let bigsignedp = $s2::from(&signedp);
xr %= &bigsignedp;
let mut yr = $s2::from(&self.x);
yr -= &xr;
yr *= $s2::from(&s);
yr -= $s2::from(&self.y);
yr %= &bigsignedp;
Point{ x: $base::from(xr), y: $base::from(yr) }
}
fn scale(&self, d: &$base) -> Point<$curve>
{
assert!(!d.is_zero());
#[allow(non_snake_case)]
let mut Q: Point<$curve> = self.clone();
let mut bit = ($base::bit_length() - 1) as isize;
// Skip down until we hit a set bit
while !d.testbit(bit as usize) {
bit -= 1;
}
// drop one
bit -= 1;
// do the double and add algorithm
while bit >= 0 {
Q = Q.double();
let test = d.testbit(bit as usize);
if test {
Q = Q.add(&self);
}
bit -= 1;
}
if d.is_negative() {
Q.negate()
} else {
Q
}
}
}
}
}
point_impl!(P192, I192, I384, U384, I448, U448);
point_impl!(P224, I256, I512, U512, I576, U576);
point_impl!(P256, I256, I512, U512, I576, U576);
point_impl!(P384, I384, I768, U768, I832, U832);
point_impl!(P521, I576, I1152, U1152, I1216, U1216);
#[cfg(test)]
macro_rules! negate_test_body
{
($curve: ident, $lcurve: ident, $stype: ident, $utype: ident) => {
let fname = build_test_path("ecc/negate",stringify!($curve));
run_test(fname.to_string(), 4, |case| {
let (negx, xbytes) = case.get("x").unwrap();
let (negy, ybytes) = case.get("y").unwrap();
let (nega, abytes) = case.get("a").unwrap();
let (negb, bbytes) = case.get("b").unwrap();
let x = $stype::new(*negx, $utype::from_bytes(xbytes));
let y = $stype::new(*negy, $utype::from_bytes(ybytes));
let a = $stype::new(*nega, $utype::from_bytes(abytes));
let b = $stype::new(*negb, $utype::from_bytes(bbytes));
let point = Point::<$curve>{ x, y };
let dbl = point.negate();
assert_eq!(a, dbl.x, "x equivalence");
assert_eq!(b, dbl.y, "y equivalence");
});
}
}
#[cfg(test)]
macro_rules! double_test_body
{
($curve: ident, $lcurve: ident, $stype: ident, $utype: ident) => {
let fname = build_test_path("ecc/double",stringify!($curve));
run_test(fname.to_string(), 4, |case| {
let (negx, xbytes) = case.get("x").unwrap();
let (negy, ybytes) = case.get("y").unwrap();
let (nega, abytes) = case.get("a").unwrap();
let (negb, bbytes) = case.get("b").unwrap();
let x = $stype::new(*negx, $utype::from_bytes(xbytes));
let y = $stype::new(*negy, $utype::from_bytes(ybytes));
let a = $stype::new(*nega, $utype::from_bytes(abytes));
let b = $stype::new(*negb, $utype::from_bytes(bbytes));
let point = Point::<$curve>{ x, y };
let dbl = point.double();
assert_eq!(a, dbl.x, "x equivalence");
assert_eq!(b, dbl.y, "y equivalence");
});
}
}
#[cfg(test)]
macro_rules! add_test_body
{
($curve: ident, $lcurve: ident, $stype: ident, $utype: ident) => {
let fname = build_test_path("ecc/add",stringify!($curve));
run_test(fname.to_string(), 6, move |case| {
let (negx, xbytes) = case.get("x").unwrap();
let (negy, ybytes) = case.get("y").unwrap();
let (negu, ubytes) = case.get("u").unwrap();
let (negv, vbytes) = case.get("v").unwrap();
let (nega, abytes) = case.get("a").unwrap();
let (negb, bbytes) = case.get("b").unwrap();
let x = $stype::new(*negx, $utype::from_bytes(xbytes));
let y = $stype::new(*negy, $utype::from_bytes(ybytes));
let u = $stype::new(*negu, $utype::from_bytes(ubytes));
let v = $stype::new(*negv, $utype::from_bytes(vbytes));
let a = $stype::new(*nega, $utype::from_bytes(abytes));
let b = $stype::new(*negb, $utype::from_bytes(bbytes));
let point1 = Point::<$curve>{ x: x, y: y };
let point2 = Point::<$curve>{ x: u, y: v };
let res = point1.add(&point2);
assert_eq!(a, res.x, "x equivalence");
assert_eq!(b, res.y, "y equivalence");
});
}
}
#[cfg(test)]
macro_rules! scale_test_body
{
($curve: ident, $lcurve: ident, $stype: ident, $utype: ident) => {
let fname = build_test_path("ecc/scale",stringify!($curve));
run_test(fname.to_string(), 5, |case| {
let (negx, xbytes) = case.get("x").unwrap();
let (negy, ybytes) = case.get("y").unwrap();
let (negk, kbytes) = case.get("k").unwrap();
let (nega, abytes) = case.get("a").unwrap();
let (negb, bbytes) = case.get("b").unwrap();
let x = $stype::new(*negx, $utype::from_bytes(xbytes));
let y = $stype::new(*negy, $utype::from_bytes(ybytes));
let k = $stype::new(*negk, $utype::from_bytes(kbytes));
let a = $stype::new(*nega, $utype::from_bytes(abytes));
let b = $stype::new(*negb, $utype::from_bytes(bbytes));
let point = Point::<$curve>{ x: x, y: y };
let res = point.scale(&k);
assert_eq!(a, res.x, "x equivalence");
assert_eq!(b, res.y, "y equivalence");
});
}
}
#[cfg(test)]
macro_rules! add_scale2_test_body
{
($curve: ident, $lcurve: ident, $stype: ident, $utype: ident) => {
let fname = build_test_path("ecc/add_scale2",stringify!($curve));
run_test(fname.to_string(), 8, |case| {
let (negx, xbytes) = case.get("x").unwrap();
let (negy, ybytes) = case.get("y").unwrap();
let (negp, pbytes) = case.get("p").unwrap();
let (negq, qbytes) = case.get("q").unwrap();
let (negn, nbytes) = case.get("n").unwrap();
let (negm, mbytes) = case.get("m").unwrap();
let (negr, rbytes) = case.get("r").unwrap();
let (negs, sbytes) = case.get("s").unwrap();
let x = $stype::new(*negx, $utype::from_bytes(xbytes));
let y = $stype::new(*negy, $utype::from_bytes(ybytes));
let p = $stype::new(*negp, $utype::from_bytes(pbytes));
let q = $stype::new(*negq, $utype::from_bytes(qbytes));
let n = $stype::new(*negn, $utype::from_bytes(nbytes));
let m = $stype::new(*negm, $utype::from_bytes(mbytes));
let r = $stype::new(*negr, $utype::from_bytes(rbytes));
let s = $stype::new(*negs, $utype::from_bytes(sbytes));
let p1 = Point::<$curve>{ x: x, y: y };
let p2 = Point::<$curve>{ x: p, y: q };
let res = Point::<$curve>::double_scalar_mult(&n, &p1, &m, &p2);
assert_eq!(r, res.x, "x equivalence");
assert_eq!(s, res.y, "y equivalence");
});
}
}
macro_rules! point_tests
{
($curve: ident, $lcurve: ident, $stype: ident, $utype: ident) => {
#[cfg(test)]
mod $lcurve {
use super::*;
use testing::*;
#[test]
fn negate() { negate_test_body!($curve, $lcurve, $stype, $utype); }
#[test]
fn double() { double_test_body!($curve, $lcurve, $stype, $utype); }
#[test]
fn add() { add_test_body!($curve, $lcurve, $stype, $utype); }
#[test]
fn scale() { scale_test_body!($curve, $lcurve, $stype, $utype); }
#[ignore]
#[test]
fn add_scale2() { add_scale2_test_body!($curve, $lcurve, $stype, $utype); }
}
};
(ignore_expensive $curve: ident, $lcurve: ident, $stype: ident, $utype: ident) => {
#[cfg(test)]
mod $lcurve {
use super::*;
use testing::*;
#[test]
fn negate() { negate_test_body!($curve, $lcurve, $stype, $utype); }
#[test]
fn double() { double_test_body!($curve, $lcurve, $stype, $utype); }
#[test]
fn add() { add_test_body!($curve, $lcurve, $stype, $utype); }
#[ignore]
#[test]
fn scale() { scale_test_body!($curve, $lcurve, $stype, $utype); }
#[ignore]
#[test]
fn add_scale2() { add_scale2_test_body!($curve, $lcurve, $stype, $utype); }
}
}
}
point_tests!(P192, p192, I192, U192);
point_tests!(ignore_expensive P224, p224, I256, U256);
point_tests!(ignore_expensive P256, p256, I256, U256);
point_tests!(ignore_expensive P384, p384, I384, U384);
point_tests!(ignore_expensive P521, p521, I576, U576);