X509ExtensionBase.cs :  » PDF » iTextSharp » Org » BouncyCastle » X509 » C# / CSharp Open Source

using System;

using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Utilities.Collections;

namespace Org.BouncyCastle.X509{
  public abstract class X509ExtensionBase
    : IX509Extension
  {
    protected abstract X509Extensions GetX509Extensions();

    protected virtual ISet GetExtensionOids(
      bool critical)
    {
      X509Extensions extensions = GetX509Extensions();
      if (extensions != null)
      {
        HashSet set = new HashSet();
        foreach (DerObjectIdentifier oid in extensions.ExtensionOids)
        {
          X509Extension ext = extensions.GetExtension(oid);
          if (ext.IsCritical == critical)
          {
            set.Add(oid.Id);
          }
        }

        return set;
      }

      return null;
    }

    /// <summary>
    /// Get non critical extensions.
    /// </summary>
    /// <returns>A set of non critical extension oids.</returns>
    public virtual ISet GetNonCriticalExtensionOids()
    {
      return GetExtensionOids(false);
    }

    /// <summary>
    /// Get any critical extensions.
    /// </summary>
    /// <returns>A sorted list of critical entension.</returns>
    public virtual ISet GetCriticalExtensionOids()
    {
      return GetExtensionOids(true);
    }

    /// <summary>
    /// Get the value of a given extension.
    /// </summary>
    /// <param name="oid">The object ID of the extension. </param>
    /// <returns>An Asn1OctetString object if that extension is found or null if not.</returns>
    [Obsolete("Use version taking a DerObjectIdentifier instead")]
    public Asn1OctetString GetExtensionValue(
      string oid)
    {
      return GetExtensionValue(new DerObjectIdentifier(oid));
    }

    public virtual Asn1OctetString GetExtensionValue(
      DerObjectIdentifier oid)
    {
      X509Extensions exts = GetX509Extensions();
      if (exts != null)
      {
        X509Extension ext = exts.GetExtension(oid);
        if (ext != null)
        {
          return ext.Value;
        }
      }

      return null;
    }
  }
}