X509AttrCertParser.cs :  » PDF » iTextSharp » Org » BouncyCastle » X509 » C# / CSharp Open Source

using System;
using System.Collections;
using System.IO;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Security.Certificates;
using Org.BouncyCastle.Utilities.IO;

namespace Org.BouncyCastle.X509{
  public class X509AttrCertParser
  {
    private static readonly PemParser PemAttrCertParser = new PemParser("ATTRIBUTE CERTIFICATE");

    private Asn1Set  sData;
    private int    sDataObjectCount;
    private Stream  currentStream;

    private IX509AttributeCertificate ReadDerCertificate(
      Asn1InputStream dIn)
    {
      Asn1Sequence seq = (Asn1Sequence)dIn.ReadObject();

      if (seq.Count > 1 && seq[0] is DerObjectIdentifier)
      {
        if (seq[0].Equals(PkcsObjectIdentifiers.SignedData))
        {
          sData = SignedData.GetInstance(
            Asn1Sequence.GetInstance((Asn1TaggedObject) seq[1], true)).Certificates;

          return GetCertificate();
        }
      }

//      return new X509V2AttributeCertificate(seq.getEncoded());
      return new X509V2AttributeCertificate(AttributeCertificate.GetInstance(seq));
    }

    private IX509AttributeCertificate GetCertificate()
    {
      if (sData != null)
      {
        while (sDataObjectCount < sData.Count)
        {
          object obj = sData[sDataObjectCount++];

          if (obj is Asn1TaggedObject && ((Asn1TaggedObject)obj).TagNo == 2)
          {
            //return new X509V2AttributeCertificate(
            //  Asn1Sequence.GetInstance((Asn1TaggedObject)obj, false).GetEncoded());
            return new X509V2AttributeCertificate(
              AttributeCertificate.GetInstance(
                Asn1Sequence.GetInstance((Asn1TaggedObject)obj, false)));
          }
        }
      }

      return null;
    }

    private IX509AttributeCertificate ReadPemCertificate(
      Stream inStream)
    {
      Asn1Sequence seq = PemAttrCertParser.ReadPemObject(inStream);

      return seq == null
        ?  null
        //:  new X509V2AttributeCertificate(seq.getEncoded());
        :  new X509V2AttributeCertificate(AttributeCertificate.GetInstance(seq));
    }

    /// <summary>
    /// Create loading data from byte array.
    /// </summary>
    /// <param name="input"></param>
    public IX509AttributeCertificate ReadAttrCert(
      byte[] input)
    {
      return ReadAttrCert(new MemoryStream(input, false));
    }

    /// <summary>
    /// Create loading data from byte array.
    /// </summary>
    /// <param name="input"></param>
    public ICollection ReadAttrCerts(
      byte[] input)
    {
      return ReadAttrCerts(new MemoryStream(input, false));
    }

    /**
     * Generates a certificate object and initializes it with the data
     * read from the input stream inStream.
     */
    public IX509AttributeCertificate ReadAttrCert(
      Stream inStream)
    {
      if (inStream == null)
        throw new ArgumentNullException("inStream");
      if (!inStream.CanRead)
        throw new ArgumentException("inStream must be read-able", "inStream");

      if (currentStream == null)
      {
        currentStream = inStream;
        sData = null;
        sDataObjectCount = 0;
      }
      else if (currentStream != inStream) // reset if input stream has changed
      {
        currentStream = inStream;
        sData = null;
        sDataObjectCount = 0;
      }

      try
      {
        if (sData != null)
        {
          if (sDataObjectCount != sData.Count)
          {
            return GetCertificate();
          }

          sData = null;
          sDataObjectCount = 0;
          return null;
        }

        PushbackStream pis = new PushbackStream(inStream);
        int tag = pis.ReadByte();

        if (tag < 0)
          return null;

        pis.Unread(tag);

        if (tag != 0x30)  // assume ascii PEM encoded.
        {
          return ReadPemCertificate(pis);
        }

        return ReadDerCertificate(new Asn1InputStream(pis));
      }
      catch (Exception e)
      {
        throw new CertificateException(e.ToString());
      }
    }

    /**
     * Returns a (possibly empty) collection view of the certificates
     * read from the given input stream inStream.
     */
    public ICollection ReadAttrCerts(
      Stream inStream)
    {
      IX509AttributeCertificate attrCert;
      IList attrCerts = new ArrayList();

      while ((attrCert = ReadAttrCert(inStream)) != null)
      {
        attrCerts.Add(attrCert);
      }

      return attrCerts;
    }
  }
}