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authorLibravatar dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>2023-04-10 12:35:05 +0200
committerLibravatar GitHub <noreply@github.com>2023-04-10 12:35:05 +0200
commit1d8f9c6b1626d05856ac5aa99a216cee5c0d3e6a (patch)
tree482bb23426953fd1282f62f6595a9f73a49b0b3f /vendor/golang.org/x/crypto/curve25519/curve25519_compat.go
parent[chore]: Bump github.com/spf13/cobra from 1.6.1 to 1.7.0 (#1686) (diff)
downloadgotosocial-1d8f9c6b1626d05856ac5aa99a216cee5c0d3e6a.tar.xz
[chore]: Bump golang.org/x/crypto from 0.7.0 to 0.8.0 (#1685)
Bumps [golang.org/x/crypto](https://github.com/golang/crypto) from 0.7.0 to 0.8.0. - [Release notes](https://github.com/golang/crypto/releases) - [Commits](https://github.com/golang/crypto/compare/v0.7.0...v0.8.0) --- updated-dependencies: - dependency-name: golang.org/x/crypto dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Diffstat (limited to 'vendor/golang.org/x/crypto/curve25519/curve25519_compat.go')
-rw-r--r--vendor/golang.org/x/crypto/curve25519/curve25519_compat.go105
1 files changed, 105 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/curve25519/curve25519_compat.go b/vendor/golang.org/x/crypto/curve25519/curve25519_compat.go
new file mode 100644
index 000000000..ba647e8d7
--- /dev/null
+++ b/vendor/golang.org/x/crypto/curve25519/curve25519_compat.go
@@ -0,0 +1,105 @@
+// Copyright 2019 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 !go1.20
+
+package curve25519
+
+import (
+ "crypto/subtle"
+ "errors"
+ "strconv"
+
+ "golang.org/x/crypto/curve25519/internal/field"
+)
+
+func scalarMult(dst, scalar, point *[32]byte) {
+ var e [32]byte
+
+ copy(e[:], scalar[:])
+ e[0] &= 248
+ e[31] &= 127
+ e[31] |= 64
+
+ var x1, x2, z2, x3, z3, tmp0, tmp1 field.Element
+ x1.SetBytes(point[:])
+ x2.One()
+ x3.Set(&x1)
+ z3.One()
+
+ swap := 0
+ for pos := 254; pos >= 0; pos-- {
+ b := e[pos/8] >> uint(pos&7)
+ b &= 1
+ swap ^= int(b)
+ x2.Swap(&x3, swap)
+ z2.Swap(&z3, swap)
+ swap = int(b)
+
+ tmp0.Subtract(&x3, &z3)
+ tmp1.Subtract(&x2, &z2)
+ x2.Add(&x2, &z2)
+ z2.Add(&x3, &z3)
+ z3.Multiply(&tmp0, &x2)
+ z2.Multiply(&z2, &tmp1)
+ tmp0.Square(&tmp1)
+ tmp1.Square(&x2)
+ x3.Add(&z3, &z2)
+ z2.Subtract(&z3, &z2)
+ x2.Multiply(&tmp1, &tmp0)
+ tmp1.Subtract(&tmp1, &tmp0)
+ z2.Square(&z2)
+
+ z3.Mult32(&tmp1, 121666)
+ x3.Square(&x3)
+ tmp0.Add(&tmp0, &z3)
+ z3.Multiply(&x1, &z2)
+ z2.Multiply(&tmp1, &tmp0)
+ }
+
+ x2.Swap(&x3, swap)
+ z2.Swap(&z3, swap)
+
+ z2.Invert(&z2)
+ x2.Multiply(&x2, &z2)
+ copy(dst[:], x2.Bytes())
+}
+
+func scalarBaseMult(dst, scalar *[32]byte) {
+ checkBasepoint()
+ scalarMult(dst, scalar, &basePoint)
+}
+
+func x25519(dst *[32]byte, scalar, point []byte) ([]byte, error) {
+ var in [32]byte
+ if l := len(scalar); l != 32 {
+ return nil, errors.New("bad scalar length: " + strconv.Itoa(l) + ", expected 32")
+ }
+ if l := len(point); l != 32 {
+ return nil, errors.New("bad point length: " + strconv.Itoa(l) + ", expected 32")
+ }
+ copy(in[:], scalar)
+ if &point[0] == &Basepoint[0] {
+ scalarBaseMult(dst, &in)
+ } else {
+ var base, zero [32]byte
+ copy(base[:], point)
+ scalarMult(dst, &in, &base)
+ if subtle.ConstantTimeCompare(dst[:], zero[:]) == 1 {
+ return nil, errors.New("bad input point: low order point")
+ }
+ }
+ return dst[:], nil
+}
+
+func checkBasepoint() {
+ if subtle.ConstantTimeCompare(Basepoint, []byte{
+ 0x09, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ }) != 1 {
+ panic("curve25519: global Basepoint value was modified")
+ }
+}