AuthorityKeyIdentifier.cs :  » PDF » iTextSharp » Org » BouncyCastle » Asn1 » X509 » C# / CSharp Open Source

using System;
using System.Collections;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Digests;
using Org.BouncyCastle.Math;

namespace Org.BouncyCastle.Asn1.X509{
    /**
     * The AuthorityKeyIdentifier object.
     * <pre>
     * id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::=  { id-ce 35 }
     *
     *   AuthorityKeyIdentifier ::= Sequence {
     *      keyIdentifier             [0] IMPLICIT KeyIdentifier           OPTIONAL,
     *      authorityCertIssuer       [1] IMPLICIT GeneralNames            OPTIONAL,
     *      authorityCertSerialNumber [2] IMPLICIT CertificateSerialNumber OPTIONAL  }
     *
     *   KeyIdentifier ::= OCTET STRING
     * </pre>
     *
     */
    public class AuthorityKeyIdentifier
        : Asn1Encodable
    {
        internal readonly Asn1OctetString  keyidentifier;
        internal readonly GeneralNames    certissuer;
        internal readonly DerInteger    certserno;

    public static AuthorityKeyIdentifier GetInstance(
            Asn1TaggedObject  obj,
            bool        explicitly)
        {
            return GetInstance(Asn1Sequence.GetInstance(obj, explicitly));
        }

    public static AuthorityKeyIdentifier GetInstance(
            object obj)
        {
            if (obj is AuthorityKeyIdentifier)
            {
                return (AuthorityKeyIdentifier) obj;
            }

      if (obj is Asn1Sequence)
            {
                return new AuthorityKeyIdentifier((Asn1Sequence) obj);
            }

          if (obj is X509Extension)
      {
        return GetInstance(X509Extension.ConvertValueToObject((X509Extension) obj));
      }

      throw new ArgumentException("unknown object in factory: " + obj.GetType().Name, "obj");
    }

    protected internal AuthorityKeyIdentifier(
            Asn1Sequence seq)
        {
      foreach (Asn1TaggedObject o in seq)
      {
        switch (o.TagNo)
                {
          case 0:
            this.keyidentifier = Asn1OctetString.GetInstance(o, false);
            break;
          case 1:
            this.certissuer = GeneralNames.GetInstance(o, false);
            break;
          case 2:
            this.certserno = DerInteger.GetInstance(o, false);
            break;
          default:
            throw new ArgumentException("illegal tag");
                }
            }
        }

    /**
         *
         * Calulates the keyidentifier using a SHA1 hash over the BIT STRING
         * from SubjectPublicKeyInfo as defined in RFC2459.
         *
         * Example of making a AuthorityKeyIdentifier:
         * <pre>
       *   SubjectPublicKeyInfo apki = new SubjectPublicKeyInfo((ASN1Sequence)new ASN1InputStream(
     *       publicKey.getEncoded()).readObject());
         *   AuthorityKeyIdentifier aki = new AuthorityKeyIdentifier(apki);
         * </pre>
         *
         **/
        public AuthorityKeyIdentifier(
            SubjectPublicKeyInfo spki)
        {
            IDigest digest = new Sha1Digest();
            byte[] resBuf = new byte[digest.GetDigestSize()];

      byte[] bytes = spki.PublicKeyData.GetBytes();
            digest.BlockUpdate(bytes, 0, bytes.Length);
            digest.DoFinal(resBuf, 0);
            this.keyidentifier = new DerOctetString(resBuf);
        }

        /**
         * create an AuthorityKeyIdentifier with the GeneralNames tag and
         * the serial number provided as well.
         */
        public AuthorityKeyIdentifier(
            SubjectPublicKeyInfo  spki,
            GeneralNames      name,
            BigInteger        serialNumber)
        {
            IDigest digest = new Sha1Digest();
            byte[] resBuf = new byte[digest.GetDigestSize()];

      byte[] bytes = spki.PublicKeyData.GetBytes();
            digest.BlockUpdate(bytes, 0, bytes.Length);
            digest.DoFinal(resBuf, 0);

      this.keyidentifier = new DerOctetString(resBuf);
            this.certissuer = name;
            this.certserno = new DerInteger(serialNumber);
        }

    /**
     * create an AuthorityKeyIdentifier with the GeneralNames tag and
     * the serial number provided.
     */
    public AuthorityKeyIdentifier(
      GeneralNames  name,
      BigInteger    serialNumber)
    {
      this.keyidentifier = null;
      this.certissuer = GeneralNames.GetInstance(name.ToAsn1Object());
      this.certserno = new DerInteger(serialNumber);
    }

    /**
     * create an AuthorityKeyIdentifier with a precomputed key identifier
     */
    public AuthorityKeyIdentifier(
      byte[] keyIdentifier)
    {
      this.keyidentifier = new DerOctetString(keyIdentifier);
      this.certissuer = null;
      this.certserno = null;
    }

    /**
     * create an AuthorityKeyIdentifier with a precomupted key identifier
     * and the GeneralNames tag and the serial number provided as well.
     */
    public AuthorityKeyIdentifier(
      byte[]      keyIdentifier,
      GeneralNames  name,
      BigInteger    serialNumber)
    {
      this.keyidentifier = new DerOctetString(keyIdentifier);
      this.certissuer = GeneralNames.GetInstance(name.ToAsn1Object());
      this.certserno = new DerInteger(serialNumber);
    }

    public byte[] GetKeyIdentifier()
        {
      return keyidentifier == null ? null : keyidentifier.GetOctets();
        }

    public GeneralNames AuthorityCertIssuer
    {
      get { return certissuer; }
    }

    public BigInteger AuthorityCertSerialNumber
        {
            get { return certserno == null ? null : certserno.Value; }
        }

    /**
         * Produce an object suitable for an Asn1OutputStream.
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector();

      if (keyidentifier != null)
            {
                v.Add(new DerTaggedObject(false, 0, keyidentifier));
            }

      if (certissuer != null)
            {
                v.Add(new DerTaggedObject(false, 1, certissuer));
            }

      if (certserno != null)
            {
                v.Add(new DerTaggedObject(false, 2, certserno));
            }

      return new DerSequence(v);
        }

    public override string ToString()
        {
            return ("AuthorityKeyIdentifier: KeyID(" + this.keyidentifier.GetOctets() + ")");
        }
    }
}