Pkcs12Utilities.cs :  » PDF » iTextSharp » Org » BouncyCastle » Pkcs » C# / CSharp Open Source

using System;
using System.IO;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.X509;

namespace Org.BouncyCastle.Pkcs{
  /**
   * Utility class for reencoding PKCS#12 files to definite length.
   */
  public class Pkcs12Utilities
  {
    /**
     * Just re-encode the outer layer of the PKCS#12 file to definite length encoding.
     *
     * @param berPKCS12File - original PKCS#12 file
     * @return a byte array representing the DER encoding of the PFX structure
     * @throws IOException
     */
    public static byte[] ConvertToDefiniteLength(
      byte[] berPkcs12File)
    {
      Pfx pfx = new Pfx(Asn1Sequence.GetInstance(Asn1Object.FromByteArray(berPkcs12File)));

      return pfx.GetEncoded(Asn1Encodable.Der);
    }

    /**
    * Re-encode the PKCS#12 structure to definite length encoding at the inner layer
    * as well, recomputing the MAC accordingly.
    *
    * @param berPKCS12File - original PKCS12 file.
    * @param provider - provider to use for MAC calculation.
    * @return a byte array representing the DER encoding of the PFX structure.
    * @throws IOException on parsing, encoding errors.
    */
    public static byte[] ConvertToDefiniteLength(
      byte[]  berPkcs12File,
      char[]  passwd)
    {
      Pfx pfx = new Pfx(Asn1Sequence.GetInstance(Asn1Object.FromByteArray(berPkcs12File)));

      ContentInfo info = pfx.AuthSafe;

      Asn1OctetString content = Asn1OctetString.GetInstance(info.Content);
      Asn1Object obj = Asn1Object.FromByteArray(content.GetOctets());

      info = new ContentInfo(info.ContentType, new DerOctetString(obj.GetEncoded(Asn1Encodable.Der)));

      MacData mData = pfx.MacData;

      try
      {
        int itCount = mData.IterationCount.IntValue;
        byte[] data = Asn1OctetString.GetInstance(info.Content).GetOctets();
        byte[] res = Pkcs12Store.CalculatePbeMac(
          mData.Mac.AlgorithmID.ObjectID, mData.GetSalt(), itCount, passwd, false, data);

        AlgorithmIdentifier algId = new AlgorithmIdentifier(
          mData.Mac.AlgorithmID.ObjectID, DerNull.Instance);
        DigestInfo dInfo = new DigestInfo(algId, res);

        mData = new MacData(dInfo, mData.GetSalt(), itCount);
      }
      catch (Exception e)
      {
        throw new IOException("error constructing MAC: " + e.ToString());
      }

      pfx = new Pfx(info, mData);

      return pfx.GetEncoded(Asn1Encodable.Der);
    }
  }
}