From 109be507377fe7f6e8819ac94041d3fdcdf6fd2f Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 15:18:25 +0200 Subject: Adding upstream version 1.19.8. Signed-off-by: Daniel Baumann --- src/crypto/elliptic/nistec_p256.go | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 src/crypto/elliptic/nistec_p256.go (limited to 'src/crypto/elliptic/nistec_p256.go') diff --git a/src/crypto/elliptic/nistec_p256.go b/src/crypto/elliptic/nistec_p256.go new file mode 100644 index 0000000..304f8f2 --- /dev/null +++ b/src/crypto/elliptic/nistec_p256.go @@ -0,0 +1,29 @@ +// Copyright 2022 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build amd64 || arm64 + +package elliptic + +import ( + "crypto/internal/nistec" + "math/big" +) + +func (c p256Curve) Inverse(k *big.Int) *big.Int { + if k.Sign() < 0 { + // This should never happen. + k = new(big.Int).Neg(k) + } + if k.Cmp(c.params.N) >= 0 { + // This should never happen. + k = new(big.Int).Mod(k, c.params.N) + } + scalar := k.FillBytes(make([]byte, 32)) + inverse, err := nistec.P256OrdInverse(scalar) + if err != nil { + panic("crypto/elliptic: nistec rejected normalized scalar") + } + return new(big.Int).SetBytes(inverse) +} -- cgit v1.2.3