Novacoin/CKey.cs

   1 \feffusing System.Collections.Generic;
   2 using System.Linq;
   3
   4 using Org.BouncyCastle.Crypto;
   5 using Org.BouncyCastle.Crypto.Parameters;
   6
   7 using Org.BouncyCastle.Asn1.X9;
   8 using Org.BouncyCastle.Security;
   9 using Org.BouncyCastle.Asn1.Sec;
  10
  11 using Org.BouncyCastle.Math.EC;
  12
  13
  14 namespace Novacoin
  15 {
  16     /// <summary>
  17     /// Basic pubkey functionality
  18     /// </summary>
  19     public abstract class CKey
  20     {
  21         // These fields are inherited by CPubKey and CKeyPair
  22         protected ECPublicKeyParameters _Public;
  23
  24         protected static X9ECParameters curve = SecNamedCurves.GetByName("secp256k1");
  25         protected static ECDomainParameters domain = new ECDomainParameters(curve.Curve, curve.G, curve.N, curve.H, curve.GetSeed());
  26
  27         /// <summary>
  28         /// Regenerate public key parameters (ECPoint compression)
  29         /// </summary>
  30         /// <param name="pubKeyParams">Non-compressed key parameters</param>
  31         /// <returns>Parameters for compressed key</returns>
  32         protected ECPublicKeyParameters Compress(ECPublicKeyParameters pubKeyParams)
  33         {
  34             if (pubKeyParams.Q.IsCompressed)
  35             {
  36                 // Already compressed
  37                 return pubKeyParams;
  38             }
  39
  40             ECPoint q = new FpPoint(curve.Curve, pubKeyParams.Q.X, pubKeyParams.Q.Y, true);
  41
  42             return new ECPublicKeyParameters(q, domain);
  43         }
  44
  45         /// <summary>
  46         /// Regenerate public key parameters (ECPoint decompression)
  47         /// </summary>
  48         /// <param name="pubKeyParams">Compressed key parameters</param>
  49         /// <returns>Parameters for non-compressed key</returns>
  50         protected ECPublicKeyParameters Decompress(ECPublicKeyParameters pubKeyParams)
  51         {
  52             if (!pubKeyParams.Q.IsCompressed)
  53             {
  54                 // Isn't compressed
  55                 return pubKeyParams;
  56             }
  57
  58             ECPoint q = new FpPoint(curve.Curve, pubKeyParams.Q.X, pubKeyParams.Q.Y, false);
  59
  60             return new ECPublicKeyParameters(q, domain);
  61         }
  62
  63         /// <summary>
  64         /// Does the signature matches our public key?
  65         /// </summary>
  66         /// <param name="data">Data bytes</param>
  67         /// <param name="signature">Signature bytes</param>
  68         /// <returns>Checking result</returns>
  69         public bool VerifySignature(IEnumerable<byte> data, IEnumerable<byte> signature)
  70         {
  71             byte[] dataBytes = data.ToArray();
  72
  73             ISigner signer = SignerUtilities.GetSigner("SHA-256withECDSA");
  74             signer.Init(false, _Public);
  75             signer.BlockUpdate(dataBytes, 0, dataBytes.Length);
  76
  77             return signer.VerifySignature(signature.ToArray());
  78         }
  79
  80         /// <summary>
  81         /// Calculate Hash160 and create new CKeyID instance.
  82         /// </summary>
  83         /// <returns>New key ID</returns>
  84         public CKeyID GetKeyID()
  85         {
  86             return new CKeyID(Hash160.Compute160(Public));
  87         }
  88
  89         /// <summary>
  90         /// Public part of key pair
  91         /// </summary>
  92         public IEnumerable<byte> Public
  93         {
  94             get { return _Public.Q.GetEncoded(); }
  95         }
  96     }
  97 }