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

using System;
using System.Text;

namespace Org.BouncyCastle.Asn1{
    /**
     * Der NumericString object - this is an ascii string of characters {0,1,2,3,4,5,6,7,8,9, }.
     */
    public class DerNumericString
        : DerStringBase
    {
        private readonly string str;

        /**
         * return a Numeric string from the passed in object
         *
         * @exception ArgumentException if the object cannot be converted.
         */
        public static DerNumericString GetInstance(
            object obj)
        {
            if (obj == null || obj is DerNumericString)
            {
                return (DerNumericString)obj;
            }

            if (obj is Asn1OctetString)
            {
                return new DerNumericString(((Asn1OctetString)obj).GetOctets());
            }

            if (obj is Asn1TaggedObject)
            {
                return GetInstance(((Asn1TaggedObject)obj).GetObject());
            }

            throw new ArgumentException("illegal object in GetInstance: " + obj.GetType().Name);
        }

        /**
         * return an Numeric string from a tagged object.
         *
         * @param obj the tagged object holding the object we want
         * @param explicitly true if the object is meant to be explicitly
         *              tagged false otherwise.
         * @exception ArgumentException if the tagged object cannot
         *               be converted.
         */
        public static DerNumericString GetInstance(
            Asn1TaggedObject  obj,
            bool        explicitly)
        {
            return GetInstance(obj.GetObject());
        }

    /**
     * basic constructor - with bytes.
     */
    public DerNumericString(
      byte[] str)
      : this(Encoding.ASCII.GetString(str, 0, str.Length), false)
    {
    }

    /**
     * basic constructor -  without validation..
     */
    public DerNumericString(
      string str)
      : this(str, false)
    {
    }

    /**
    * Constructor with optional validation.
    *
    * @param string the base string to wrap.
    * @param validate whether or not to check the string.
    * @throws ArgumentException if validate is true and the string
    * contains characters that should not be in a NumericString.
    */
    public DerNumericString(
      string  str,
      bool  validate)
    {
      if (str == null)
        throw new ArgumentNullException("str");
      if (validate && !IsNumericString(str))
        throw new ArgumentException("string contains illegal characters", "str");

      this.str = str;
    }

    public override string GetString()
        {
            return str;
        }

    public byte[] GetOctets()
        {
      return Encoding.ASCII.GetBytes(str);
        }

    internal override void Encode(
            DerOutputStream derOut)
        {
            derOut.WriteEncoded(Asn1Tags.NumericString, GetOctets());
        }

    protected override bool Asn1Equals(
      Asn1Object asn1Object)
    {
      DerNumericString other = asn1Object as DerNumericString;

      if (other == null)
        return false;

      return this.str.Equals(other.str);
        }

    /**
     * Return true if the string can be represented as a NumericString ('0'..'9', ' ')
     *
     * @param str string to validate.
     * @return true if numeric, fale otherwise.
     */
    public static bool IsNumericString(
      string str)
    {
      foreach (char ch in str)
      {
        if (ch > 0x007f || (ch != ' ' && !char.IsDigit(ch)))
          return false;
      }

      return true;
    }
  }
}