2 * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * This class contains an EC private key, consisting of two elements:
31 * -- an elliptic curve
32 * -- the private integer (X)
34 * The private integer is always handled as an integer modulo the
35 * curve subbroup order. Its binary representation is unsigned big-endian
36 * with exactly the same length as the subgroup order.
39 public class ECPrivateKey : IPrivateKey {
41 public ECCurve Curve {
53 public int KeySizeBits {
55 return BigInt.BitLength(curve.SubgroupOrder);
59 public string AlgorithmName {
65 IPublicKey IPrivateKey.PublicKey {
67 return this.PublicKey;
71 public ECPublicKey PublicKey {
74 MutableECPoint G = curve.MakeGenerator();
76 dpk = new ECPublicKey(curve, G.Encode(false));
87 * Create a new instance with the provided elements. The
88 * constructor verifies that the provided private integer
89 * is non-zero and is less than the subgroup order.
91 public ECPrivateKey(ECCurve curve, byte[] X)
94 ModInt ms = new ModInt(curve.SubgroupOrder);
95 uint good = ms.Decode(X);
98 throw new CryptoException("Invalid private key");
105 * CheckValid() runs the validity tests on the curve.
107 public void CheckValid()