func NewECDSAPublicKey(creationTime time.Time, pub *ecdsa.PublicKey) *PublicKey {
pk := &PublicKey{
CreationTime: creationTime,
PubKeyAlgo: PubKeyAlgoECDSA,
PublicKey: pub,
ec: new(ecdsaKey),
}
switch pub.Curve {
case elliptic.P256():
pk.ec.oid = oidCurveP256
case elliptic.P384():
pk.ec.oid = oidCurveP384
case elliptic.P521():
pk.ec.oid = oidCurveP521
case brainpool.P256r1():
pk.ec.oid = oidCurveP256r1
case brainpool.P384r1():
pk.ec.oid = oidCurveP384r1
case brainpool.P512r1():
pk.ec.oid = oidCurveP512r1
}
pk.ec.p.bytes = elliptic.Marshal(pub.Curve, pub.X, pub.Y)
pk.ec.p.bitLength = uint16(8 * len(pk.ec.p.bytes))
pk.setFingerPrintAndKeyId()
return pk
}
func (f *ecdsaKey) newECDSA() (*ecdsa.PublicKey, error) {
var c elliptic.Curve
if bytes.Equal(f.oid, oidCurveP256) {
c = elliptic.P256()
} else if bytes.Equal(f.oid, oidCurveP384) {
c = elliptic.P384()
} else if bytes.Equal(f.oid, oidCurveP521) {
c = elliptic.P521()
} else if bytes.Equal(f.oid, oidCurveP256r1) {
c = brainpool.P256r1()
} else if bytes.Equal(f.oid, oidCurveP384r1) {
c = brainpool.P384r1()
} else if bytes.Equal(f.oid, oidCurveP512r1) {
c = brainpool.P512r1()
} else {
return nil, errors.UnsupportedError(fmt.Sprintf("unsupported oid: %x", f.oid))
}
x, y := elliptic.Unmarshal(c, f.p.bytes)
if x == nil {
return nil, errors.UnsupportedError("failed to parse EC point")
}
return &ecdsa.PublicKey{Curve: c, X: x, Y: y}, nil
}