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quick optimization
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@Arvolear
Arvolear committed Oct 31, 2024
1 parent d68451b commit 8f99911
Showing 1 changed file with 62 additions and 171 deletions.
233 changes: 62 additions & 171 deletions contracts/certificate/signers/CECDSASHA2Signer.sol
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Original file line number Diff line number Diff line change
Expand Up @@ -94,30 +94,51 @@ contract CECDSASHA2Signer is ICertificateSigner, Initializable {
U384.moddiv(params.call, inputs.r, inputs.s, params.n)
);

uint256[3] memory P = _addAndReturnProjectivePoint(
(x1, y1, x2) = _addProj(
params.call,
params.p,
params.three,
params.a,
x1,
y1,
U384.init(1),
x2,
y2
y2,
U384.init(1)
);

if (U384.eqInteger(P[2], 0)) {
return U384.eq(U384.moddiv(params.call, x1, x2, params.p), inputs.r);
}
}

/**
* @dev Check if a point in affine coordinates is on the curve.
*/
function _isOnCurve(
uint256 call,
uint256 p,
uint256 a,
uint256 b,
uint256 x,
uint256 y
) internal view returns (bool) {
unchecked {
if (U384.eqInteger(x, 0) || U384.eq(x, p) || U384.eqInteger(y, 0) || U384.eq(y, p)) {
return false;
}

uint256 Px = U384.modinv(params.call, P[2], params.p);
Px = U384.modmul(
params.call,
P[0],
U384.modmul(params.call, Px, Px, params.p),
params.p
);
uint256 LHS = U384.modexp(call, y, 2, p);
uint256 RHS = U384.modexp(call, x, 3, p);

return U384.eq(U384.mod(params.call, Px, params.n), inputs.r);
if (!U384.eqInteger(a, 0)) {
RHS = U384.modadd(call, RHS, U384.modmul(call, x, a, p), p); // x^3 + a*x
}

if (!U384.eqInteger(b, 0)) {
RHS = U384.modadd(call, RHS, b, p); // x^3 + a*x + b
}

return U384.eq(LHS, RHS);
}
}

Expand All @@ -132,7 +153,7 @@ contract CECDSASHA2Signer is ICertificateSigner, Initializable {
) internal view returns (uint256 x1, uint256 y1) {
unchecked {
if (U384.eqInteger(scalar, 0)) {
return _zeroAffine();
return (U384.init(0), U384.init(0)); // zero affine coordinates
} else if (U384.eqInteger(scalar, 1)) {
return (x0, y0);
} else if (U384.eqInteger(scalar, 2)) {
Expand Down Expand Up @@ -193,7 +214,30 @@ contract CECDSASHA2Signer is ICertificateSigner, Initializable {
highBits_ >>= 1;
}

return _toAffinePoint(params.call, params.p, x1, y1, z1);
uint256 p_ = params.p;
uint256 call_ = params.call;

return (U384.moddiv(call_, x1, z1, p_), U384.moddiv(call_, y1, z1, p_));
}
}

/**
* @dev Double an elliptic curve point in affine coordinates.
*/
function _twice(
uint256 call,
uint256 p,
uint256 three,
uint256 a,
uint256 x0,
uint256 y0
) internal view returns (uint256, uint256) {
unchecked {
uint256 z0;

(x0, y0, z0) = _twiceProj(call, p, three, a, x0, y0, U384.init(1));

return (U384.moddiv(call, x0, z0, p), U384.moddiv(call, y0, z0, p));
}
}

Expand All @@ -211,8 +255,8 @@ contract CECDSASHA2Signer is ICertificateSigner, Initializable {
uint256 z0
) internal view returns (uint256 x1, uint256 y1, uint256 z1) {
unchecked {
if (_isZeroCurve(x0, y0)) {
return _zeroProj();
if (U384.eqInteger(x0, 0) && U384.eqInteger(y0, 0)) {
return (U384.init(0), U384.init(1), U384.init(0)); // zero proj
}

uint256 u = U384.modmul(call, y0, z0, p);
Expand Down Expand Up @@ -271,9 +315,9 @@ contract CECDSASHA2Signer is ICertificateSigner, Initializable {
uint256 z1
) internal view returns (uint256 x2, uint256 y2, uint256 z2) {
unchecked {
if (_isZeroCurve(x0, y0)) {
if (U384.eqInteger(x0, 0) && U384.eqInteger(y0, 0)) {
return (x1, y1, z1);
} else if (_isZeroCurve(x1, y1)) {
} else if (U384.eqInteger(x1, 0) && U384.eqInteger(y1, 0)) {
return (x0, y0, z0);
}

Expand All @@ -286,7 +330,7 @@ contract CECDSASHA2Signer is ICertificateSigner, Initializable {
if (U384.eq(x2, y2)) {
return _twiceProj(call, p, three, a, x0, y0, z0);
} else {
return _zeroProj();
return (U384.init(0), U384.init(1), U384.init(0)); // zero proj
}
}

Expand Down Expand Up @@ -341,157 +385,4 @@ contract CECDSASHA2Signer is ICertificateSigner, Initializable {
U384.modmulAssignTo(call, z2, u3, v, p);
}
}

/**
* @dev Add two elliptic curve points in affine coordinates.
*/
function _add(
uint256 call,
uint256 p,
uint256 three,
uint256 a,
uint256 x0,
uint256 y0,
uint256 x1,
uint256 y1
) internal view returns (uint256, uint256) {
unchecked {
uint256 z0;

(x0, y0, z0) = _addProj(call, p, three, a, x0, y0, U384.init(1), x1, y1, U384.init(1));

return _toAffinePoint(call, p, x0, y0, z0);
}
}

/**
* @dev Double an elliptic curve point in affine coordinates.
*/
function _twice(
uint256 call,
uint256 p,
uint256 three,
uint256 a,
uint256 x0,
uint256 y0
) internal view returns (uint256, uint256) {
unchecked {
uint256 z0;

(x0, y0, z0) = _twiceProj(call, p, three, a, x0, y0, U384.init(1));

return _toAffinePoint(call, p, x0, y0, z0);
}
}

/**
* @dev Add two points in affine coordinates and return projective point.
*/
function _addAndReturnProjectivePoint(
uint256 call,
uint256 p,
uint256 three,
uint256 a,
uint256 x1,
uint256 y1,
uint256 x2,
uint256 y2
) internal view returns (uint256[3] memory P) {
unchecked {
uint256 x;
uint256 y;

(x, y) = _add(call, p, three, a, x1, y1, x2, y2);
return _toProjectivePoint(call, p, x, y);
}
}

/**
* @dev Transform from projective to affine coordinates.
*/
function _toAffinePoint(
uint256 call,
uint256 p,
uint256 x0,
uint256 y0,
uint256 z0
) internal view returns (uint256 x1, uint256 y1) {
unchecked {
return (U384.moddiv(call, x0, z0, p), U384.moddiv(call, y0, z0, p));
}
}

/**
* @dev Check if a point in affine coordinates is on the curve.
*/
function _isOnCurve(
uint256 call,
uint256 p,
uint256 a,
uint256 b,
uint256 x,
uint256 y
) internal view returns (bool) {
unchecked {
if (U384.eqInteger(x, 0) || U384.eq(x, p) || U384.eqInteger(y, 0) || U384.eq(y, p)) {
return false;
}

uint256 LHS = U384.modexp(call, y, 2, p);
uint256 RHS = U384.modexp(call, x, 3, p);

if (!U384.eqInteger(a, 0)) {
RHS = U384.modadd(call, RHS, U384.modmul(call, x, a, p), p); // x^3 + a*x
}

if (!U384.eqInteger(b, 0)) {
RHS = U384.modadd(call, RHS, b, p); // x^3 + a*x + b
}

return U384.eq(LHS, RHS);
}
}

/**
* @dev Transform affine coordinates into projective coordinates.
*/
function _toProjectivePoint(
uint256 call,
uint256 p,
uint256 x0,
uint256 y0
) internal view returns (uint256[3] memory P) {
unchecked {
P[2] = U384.init(1);
P[0] = U384.modmul(call, x0, P[2], p);
P[1] = U384.modmul(call, y0, P[2], p);
}
}

/**
* @dev Return the zero curve in projective coordinates.
*/
function _zeroProj() internal pure returns (uint256 x, uint256 y, uint256 z) {
unchecked {
return (U384.init(0), U384.init(1), U384.init(0));
}
}

/**
* @dev Return the zero curve in affine coordinates.
*/
function _zeroAffine() internal pure returns (uint256 x, uint256 y) {
unchecked {
return (U384.init(0), U384.init(0));
}
}

/**
* @dev Check if the curve is the zero curve.
*/
function _isZeroCurve(uint256 x0, uint256 y0) internal pure returns (bool isZero) {
unchecked {
return U384.eqInteger(x0, 0) && U384.eqInteger(y0, 0);
}
}
}

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