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Diffstat (limited to 'src/crypto/elliptic/p224.go')
-rw-r--r-- | src/crypto/elliptic/p224.go | 139 |
1 files changed, 0 insertions, 139 deletions
diff --git a/src/crypto/elliptic/p224.go b/src/crypto/elliptic/p224.go deleted file mode 100644 index 8a431c4769..0000000000 --- a/src/crypto/elliptic/p224.go +++ /dev/null @@ -1,139 +0,0 @@ -// Copyright 2013 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. - -package elliptic - -import ( - "crypto/elliptic/internal/nistec" - "crypto/rand" - "math/big" -) - -// p224Curve is a Curve implementation based on nistec.P224Point. -// -// It's a wrapper that exposes the big.Int-based Curve interface and encodes the -// legacy idiosyncrasies it requires, such as invalid and infinity point -// handling. -// -// To interact with the nistec package, points are encoded into and decoded from -// properly formatted byte slices. All big.Int use is limited to this package. -// Encoding and decoding is 1/1000th of the runtime of a scalar multiplication, -// so the overhead is acceptable. -type p224Curve struct { - params *CurveParams -} - -var p224 p224Curve -var _ Curve = p224 - -func initP224() { - p224.params = &CurveParams{ - Name: "P-224", - BitSize: 224, - // FIPS 186-4, section D.1.2.2 - P: bigFromDecimal("26959946667150639794667015087019630673557916260026308143510066298881"), - N: bigFromDecimal("26959946667150639794667015087019625940457807714424391721682722368061"), - B: bigFromHex("b4050a850c04b3abf54132565044b0b7d7bfd8ba270b39432355ffb4"), - Gx: bigFromHex("b70e0cbd6bb4bf7f321390b94a03c1d356c21122343280d6115c1d21"), - Gy: bigFromHex("bd376388b5f723fb4c22dfe6cd4375a05a07476444d5819985007e34"), - } -} - -func (curve p224Curve) Params() *CurveParams { - return curve.params -} - -func (curve p224Curve) IsOnCurve(x, y *big.Int) bool { - // IsOnCurve is documented to reject (0, 0), the conventional point at - // infinity, which however is accepted by p224PointFromAffine. - if x.Sign() == 0 && y.Sign() == 0 { - return false - } - _, ok := p224PointFromAffine(x, y) - return ok -} - -func p224PointFromAffine(x, y *big.Int) (p *nistec.P224Point, ok bool) { - // (0, 0) is by convention the point at infinity, which can't be represented - // in affine coordinates. Marshal incorrectly encodes it as an uncompressed - // point, which SetBytes would correctly reject. See Issue 37294. - if x.Sign() == 0 && y.Sign() == 0 { - return nistec.NewP224Point(), true - } - if x.Sign() < 0 || y.Sign() < 0 { - return nil, false - } - if x.BitLen() > 224 || y.BitLen() > 224 { - return nil, false - } - p, err := nistec.NewP224Point().SetBytes(Marshal(P224(), x, y)) - if err != nil { - return nil, false - } - return p, true -} - -func p224PointToAffine(p *nistec.P224Point) (x, y *big.Int) { - out := p.Bytes() - if len(out) == 1 && out[0] == 0 { - // This is the correct encoding of the point at infinity, which - // Unmarshal does not support. See Issue 37294. - return new(big.Int), new(big.Int) - } - x, y = Unmarshal(P224(), out) - if x == nil { - panic("crypto/elliptic: internal error: Unmarshal rejected a valid point encoding") - } - return x, y -} - -// p224RandomPoint returns a random point on the curve. It's used when Add, -// Double, or ScalarMult are fed a point not on the curve, which is undefined -// behavior. Originally, we used to do the math on it anyway (which allows -// invalid curve attacks) and relied on the caller and Unmarshal to avoid this -// happening in the first place. Now, we just can't construct a nistec.P224Point -// for an invalid pair of coordinates, because that API is safer. If we panic, -// we risk introducing a DoS. If we return nil, we risk a panic. If we return -// the input, ecdsa.Verify might fail open. The safest course seems to be to -// return a valid, random point, which hopefully won't help the attacker. -func p224RandomPoint() (x, y *big.Int) { - _, x, y, err := GenerateKey(P224(), rand.Reader) - if err != nil { - panic("crypto/elliptic: failed to generate random point") - } - return x, y -} - -func (p224Curve) Add(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) { - p1, ok := p224PointFromAffine(x1, y1) - if !ok { - return p224RandomPoint() - } - p2, ok := p224PointFromAffine(x2, y2) - if !ok { - return p224RandomPoint() - } - return p224PointToAffine(p1.Add(p1, p2)) -} - -func (p224Curve) Double(x1, y1 *big.Int) (*big.Int, *big.Int) { - p, ok := p224PointFromAffine(x1, y1) - if !ok { - return p224RandomPoint() - } - return p224PointToAffine(p.Double(p)) -} - -func (p224Curve) ScalarMult(Bx, By *big.Int, scalar []byte) (*big.Int, *big.Int) { - p, ok := p224PointFromAffine(Bx, By) - if !ok { - return p224RandomPoint() - } - return p224PointToAffine(p.ScalarMult(p, scalar)) -} - -func (p224Curve) ScalarBaseMult(scalar []byte) (*big.Int, *big.Int) { - p := nistec.NewP224Generator() - return p224PointToAffine(p.ScalarMult(p, scalar)) -} |