X509SignatureUtil.cs :  » PDF » iTextSharp » Org » BouncyCastle » X509 » C# / CSharp Open Source

using System;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.CryptoPro;
using Org.BouncyCastle.Asn1.Nist;
using Org.BouncyCastle.Asn1.Oiw;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.TeleTrust;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Asn1.X9;
using Org.BouncyCastle.Crypto;

namespace Org.BouncyCastle.X509{
  internal class X509SignatureUtilities
  {
    private static readonly Asn1Null derNull = DerNull.Instance;

    internal static void SetSignatureParameters(
      ISigner      signature,
      Asn1Encodable  parameters)
    {
      if (parameters != null && !derNull.Equals(parameters))
      {
        // TODO Put back in
//        AlgorithmParameters sigParams = AlgorithmParameters.GetInstance(signature.getAlgorithm());
//
//        try
//        {
//          sigParams.Init(parameters.ToAsn1Object().GetDerEncoded());
//        }
//        catch (IOException e)
//        {
//          throw new SignatureException("IOException decoding parameters: " + e.Message);
//        }
//
//        if (signature.getAlgorithm().EndsWith("MGF1"))
//        {
//          try
//          {
//            signature.setParameter(sigParams.getParameterSpec(PSSParameterSpec.class));
//          }
//          catch (GeneralSecurityException e)
//          {
//            throw new SignatureException("Exception extracting parameters: " + e.Message);
//          }
//        }
      }
    }

    internal static string GetSignatureName(
      AlgorithmIdentifier sigAlgId)
    {
      Asn1Encodable parameters = sigAlgId.Parameters;

      if (parameters != null && !derNull.Equals(parameters))
      {
        if (sigAlgId.ObjectID.Equals(PkcsObjectIdentifiers.IdRsassaPss))
        {
          RsassaPssParameters rsaParams = RsassaPssParameters.GetInstance(parameters);

          return GetDigestAlgName(rsaParams.HashAlgorithm.ObjectID) + "withRSAandMGF1";
        }
        if (sigAlgId.ObjectID.Equals(X9ObjectIdentifiers.ECDsaWithSha2))
        {
          Asn1Sequence ecDsaParams = Asn1Sequence.GetInstance(parameters);

          return GetDigestAlgName((DerObjectIdentifier)ecDsaParams[0]) + "withECDSA";
        }
      }

      return sigAlgId.ObjectID.Id;
    }

    /**
     * Return the digest algorithm using one of the standard JCA string
     * representations rather than the algorithm identifier (if possible).
     */
    private static string GetDigestAlgName(
      DerObjectIdentifier digestAlgOID)
    {
      if (PkcsObjectIdentifiers.MD5.Equals(digestAlgOID))
      {
        return "MD5";
      }
      else if (OiwObjectIdentifiers.IdSha1.Equals(digestAlgOID))
      {
        return "SHA1";
      }
      else if (NistObjectIdentifiers.IdSha224.Equals(digestAlgOID))
      {
        return "SHA224";
      }
      else if (NistObjectIdentifiers.IdSha256.Equals(digestAlgOID))
      {
        return "SHA256";
      }
      else if (NistObjectIdentifiers.IdSha384.Equals(digestAlgOID))
      {
        return "SHA384";
      }
      else if (NistObjectIdentifiers.IdSha512.Equals(digestAlgOID))
      {
        return "SHA512";
      }
      else if (TeleTrusTObjectIdentifiers.RipeMD128.Equals(digestAlgOID))
      {
        return "RIPEMD128";
      }
      else if (TeleTrusTObjectIdentifiers.RipeMD160.Equals(digestAlgOID))
      {
        return "RIPEMD160";
      }
      else if (TeleTrusTObjectIdentifiers.RipeMD256.Equals(digestAlgOID))
      {
        return "RIPEMD256";
      }
      else if (CryptoProObjectIdentifiers.GostR3411.Equals(digestAlgOID))
      {
        return "GOST3411";
      }
      else
      {
        return digestAlgOID.Id;
      }
    }
  }
}