cerc-io/plugeth
18
0
Fork 1
Code Issues 4 Pull Requests Packages Projects Releases Wiki Activity

crypto/secp256k1: add checking z sign in affineFromJacobian (#18419)

Browse Source 
The z == 0 check is hit whenever we Add two points with the same x1/x2
coordinate. crypto/elliptic uses the same check in their affineFromJacobian
function. This change does not affect block processing or tx signature verification
in any way, because it does not use the Add or Double methods.
This commit is contained in:
Abd ar-Rahman Hamidi 2020-11-17 15:47:17 +05:00 committed by GitHub
parent 844485ec6a
commit db87223269
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
crypto/secp256k1/curve.go
View File

@ -116,6 +116,10 @@ func (BitCurve *BitCurve) IsOnCurve(x, y *big.Int) bool {
// affineFromJacobian reverses the Jacobian transform. See the comment at the
// top of the file.
func (BitCurve *BitCurve) affineFromJacobian(x, y, z *big.Int) (xOut, yOut *big.Int) {
if z.Sign() == 0 {
return new(big.Int), new(big.Int)
}
zinv := new(big.Int).ModInverse(z, BitCurve.P)
zinvsq := new(big.Int).Mul(zinv, zinv)