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

using System;

namespace Org.BouncyCastle.Asn1.X509{
  /**
   * <code>DisplayText</code> class, used in
   * <code>CertificatePolicies</code> X509 V3 extensions (in policy qualifiers).
   *
   * <p>It stores a string in a chosen encoding.
   * <pre>
   * DisplayText ::= CHOICE {
   *      ia5String        IA5String      (SIZE (1..200)),
   *      visibleString    VisibleString  (SIZE (1..200)),
   *      bmpString        BMPString      (SIZE (1..200)),
   *      utf8String       UTF8String     (SIZE (1..200)) }
   * </pre></p>
   * @see PolicyQualifierInfo
   * @see PolicyInformation
   */
  public class DisplayText
    : Asn1Encodable, IAsn1Choice
  {
    /**
     * Constant corresponding to ia5String encoding.
     *
     */
    public const int ContentTypeIA5String = 0;
    /**
     * Constant corresponding to bmpString encoding.
     *
     */
    public const int ContentTypeBmpString = 1;
    /**
     * Constant corresponding to utf8String encoding.
     *
     */
    public const int ContentTypeUtf8String = 2;
    /**
     * Constant corresponding to visibleString encoding.
     *
     */
    public const int ContentTypeVisibleString = 3;
    /**
     * Describe constant <code>DisplayTextMaximumSize</code> here.
     *
     */
    public const int DisplayTextMaximumSize = 200;

    internal readonly int contentType;
    internal readonly IAsn1String contents;

    /**
     * Creates a new <code>DisplayText</code> instance.
     *
     * @param type the desired encoding type for the text.
     * @param text the text to store. Strings longer than 200
     * characters are truncated.
     */
    public DisplayText(
      int    type,
      string  text)
    {
      if (text.Length > DisplayTextMaximumSize)
      {
        // RFC3280 limits these strings to 200 chars
        // truncate the string
        text = text.Substring(0, DisplayTextMaximumSize);
      }

      contentType = type;
      switch (type)
      {
        case ContentTypeIA5String:
          contents = (IAsn1String)new DerIA5String (text);
          break;
        case ContentTypeUtf8String:
          contents = (IAsn1String)new DerUtf8String(text);
          break;
        case ContentTypeVisibleString:
          contents = (IAsn1String)new DerVisibleString(text);
          break;
        case ContentTypeBmpString:
          contents = (IAsn1String)new DerBmpString(text);
          break;
        default:
          contents = (IAsn1String)new DerUtf8String(text);
          break;
      }
    }

//    /**
//     * return true if the passed in string can be represented without
//     * loss as a PrintableString, false otherwise.
//     */
//    private bool CanBePrintable(
//      string str)
//    {
//      for (int i = str.Length - 1; i >= 0; i--)
//      {
//        if (str[i] > 0x007f)
//        {
//          return false;
//        }
//      }
//
//      return true;
//    }

    /**
     * Creates a new <code>DisplayText</code> instance.
     *
     * @param text the text to encapsulate. Strings longer than 200
     * characters are truncated.
     */
    public DisplayText(
      string text)
    {
      // by default use UTF8String
      if (text.Length > DisplayTextMaximumSize)
      {
        text = text.Substring(0, DisplayTextMaximumSize);
      }

      contentType = ContentTypeUtf8String;
      contents = new DerUtf8String(text);
    }

    /**
     * Creates a new <code>DisplayText</code> instance.
     * <p>Useful when reading back a <code>DisplayText</code> class
     * from it's Asn1Encodable form.</p>
     *
     * @param contents an <code>Asn1Encodable</code> instance.
     */
    public DisplayText(
      IAsn1String contents)
    {
      this.contents = contents;
    }

    public static DisplayText GetInstance(
      object obj)
    {
      if (obj is IAsn1String)
      {
        return new DisplayText((IAsn1String) obj);
      }

      if (obj is DisplayText)
      {
        return (DisplayText) obj;
      }

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

    public override Asn1Object ToAsn1Object()
    {
      return (Asn1Object) contents;
    }

    /**
     * Returns the stored <code>string</code> object.
     *
     * @return the stored text as a <code>string</code>.
     */
    public string GetString()
    {
      return contents.GetString();
    }
  }
}