Novacoin/CKeyPair.cs

   1 \feffusing System;
   2 using System.Collections.Generic;
   3 using System.Linq;
   4 using System.Text;
   5 using System.Threading.Tasks;
   6
   7 using Org.BouncyCastle.Math;
   8 using Org.BouncyCastle.Math.EC;
   9
  10 using Org.BouncyCastle.Crypto;
  11 using Org.BouncyCastle.Crypto.Generators;
  12 using Org.BouncyCastle.Crypto.Parameters;
  13
  14 using Org.BouncyCastle.Asn1.X9;
  15 using Org.BouncyCastle.Security;
  16 using Org.BouncyCastle.Asn1.Sec;
  17
  18 namespace Novacoin
  19 {
  20     public class CKeyPair
  21     {
  22         private BigInteger D;
  23         private ECPoint Q;
  24
  25         private static X9ECParameters curve = SecNamedCurves.GetByName("secp256k1");
  26         private static ECDomainParameters domain = new ECDomainParameters(curve.Curve, curve.G, curve.N, curve.H, curve.GetSeed());
  27
  28         /// <summary>
  29         /// Initialize new CKeyPair instance with random secret.
  30         /// </summary>
  31         public CKeyPair()
  32         {
  33             ECKeyGenerationParameters genParams = new ECKeyGenerationParameters(domain, new SecureRandom());
  34
  35             ECKeyPairGenerator generator = new ECKeyPairGenerator("ECDSA");
  36             generator.Init(genParams);
  37             AsymmetricCipherKeyPair ecKeyPair = generator.GenerateKeyPair();
  38
  39             Q = ((ECPublicKeyParameters)ecKeyPair.Public).Q;
  40             D = ((ECPrivateKeyParameters)ecKeyPair.Private).D;
  41         }
  42
  43         /// <summary>
  44         /// Init key pair using secret sequence of bytes
  45         /// </summary>
  46         /// <param name="secretBytes">Byte sequence</param>
  47         public CKeyPair(IEnumerable<byte> secretBytes)
  48         {
  49             D = new BigInteger(secretBytes.ToArray());
  50             Q = curve.G.Multiply(D);
  51         }
  52
  53         /// <summary>
  54         /// Create signature for supplied data
  55         /// </summary>
  56         /// <param name="data">Data bytes sequence</param>
  57         /// <returns>Signature bytes sequence</returns>
  58         public IEnumerable<byte> Sign(IEnumerable<byte> data)
  59         {
  60             byte[] dataBytes = data.ToArray();
  61
  62             ISigner signer = SignerUtilities.GetSigner("SHA-256withECDSA");
  63             ECPrivateKeyParameters keyParameters = new ECPrivateKeyParameters(D, domain);
  64             signer.Init(true, keyParameters);
  65             signer.BlockUpdate(dataBytes, 0, dataBytes.Length);
  66
  67             return signer.GenerateSignature();
  68         }
  69
  70         public bool Verify(IEnumerable<byte> data, IEnumerable<byte> signature)
  71         {
  72             byte[] dataBytes = data.ToArray();
  73
  74             ISigner signer = SignerUtilities.GetSigner("SHA-256withECDSA");
  75             ECPublicKeyParameters keyParameters = new ECPublicKeyParameters(Q, domain);
  76             signer.Init(false, keyParameters);
  77             signer.BlockUpdate(dataBytes, 0, dataBytes.Length);
  78
  79             return signer.VerifySignature(signature.ToArray());
  80         }
  81
  82         /// <summary>
  83         /// Secret part of key pair
  84         /// </summary>
  85         public IEnumerable<byte> Secret
  86         {
  87             get { return D.ToByteArray(); }
  88         }
  89
  90         /// <summary>
  91         /// Public part of key pair
  92         /// </summary>
  93         public IEnumerable<byte> Public
  94         {
  95             get { return Q.GetEncoded(); }
  96         }
  97
  98         public override string ToString()
  99         {
 100             StringBuilder sb = new StringBuilder();
 101
 102             sb.AppendFormat("CKeyPair(Secret={0}, Public={1})", Interop.ToHex(Secret), Interop.ToHex(Public));
 103
 104             return sb.ToString();
 105         }
 106     }
 107 }