NotationData.cs :  » PDF » iTextSharp » Org » BouncyCastle » Bcpg » Sig » C# / CSharp Open Source

using System;
using System.IO;
using System.Text;

namespace Org.BouncyCastle.Bcpg.Sig{
  /**
  * Class provided a NotationData object according to
  * RFC2440, Chapter 5.2.3.15. Notation Data
  */
  public class NotationData
    : SignatureSubpacket
  {
    public const int HeaderFlagLength = 4;
    public const int HeaderNameLength = 2;
    public const int HeaderValueLength = 2;

    public NotationData(
      bool  critical,
      byte[]  data)
      : base(SignatureSubpacketTag.NotationData, critical, data)
    {
    }

    public NotationData(
      bool  critical,
      bool  humanReadable,
      string  notationName,
      string  notationValue)
      : base(SignatureSubpacketTag.NotationData, critical,
        createData(humanReadable, notationName, notationValue))
    {
    }

    private static byte[] createData(
      bool  humanReadable,
      string  notationName,
      string  notationValue)
    {
      MemoryStream os = new MemoryStream();

      // (4 octets of flags, 2 octets of name length (M),
      // 2 octets of value length (N),
      // M octets of name data,
      // N octets of value data)

      // flags
      os.WriteByte(humanReadable ? (byte)0x80 : (byte)0x00);
      os.WriteByte(0x0);
      os.WriteByte(0x0);
      os.WriteByte(0x0);

      byte[] nameData, valueData = null;
      int nameLength, valueLength;

      nameData = Encoding.UTF8.GetBytes(notationName);
      nameLength = System.Math.Min(nameData.Length, 0xFF);

      valueData = Encoding.UTF8.GetBytes(notationValue);
      valueLength = System.Math.Min(valueData.Length, 0xFF);

      // name length
      os.WriteByte((byte)(nameLength >> 8));
      os.WriteByte((byte)(nameLength >> 0));

      // value length
      os.WriteByte((byte)(valueLength >> 8));
      os.WriteByte((byte)(valueLength >> 0));

      // name
      os.Write(nameData, 0, nameLength);

      // value
      os.Write(valueData, 0, valueLength);

      return os.ToArray();
    }

    public bool IsHumanReadable
    {
      get { return data[0] == (byte)0x80; }
    }

    public string GetNotationName()
    {
      int nameLength = ((data[HeaderFlagLength] << 8) + (data[HeaderFlagLength + 1] << 0));
      int namePos = HeaderFlagLength + HeaderNameLength + HeaderValueLength;

      return Encoding.UTF8.GetString(data, namePos, nameLength);
    }

    public string GetNotationValue()
    {
      int nameLength = ((data[HeaderFlagLength] << 8) + (data[HeaderFlagLength + 1] << 0));
      int valueLength = ((data[HeaderFlagLength + HeaderNameLength] << 8) + (data[HeaderFlagLength + HeaderNameLength + 1] << 0));
      int valuePos = HeaderFlagLength + HeaderNameLength + HeaderValueLength + nameLength;

      return Encoding.UTF8.GetString(data, valuePos, valueLength);
    }

    public byte[] GetNotationValueBytes()
    {
      int nameLength = ((data[HeaderFlagLength] << 8) + (data[HeaderFlagLength + 1] << 0));
      int valueLength = ((data[HeaderFlagLength + HeaderNameLength] << 8) + (data[HeaderFlagLength + HeaderNameLength + 1] << 0));
      int valuePos = HeaderFlagLength + HeaderNameLength + HeaderValueLength + nameLength;

      byte[] bytes = new byte[valueLength];
      Array.Copy(data, valuePos, bytes, 0, valueLength);
      return bytes;
    }
  }
}