Checks if the input byte array contains only safe values, the data does not need to be encoded for use with LDIF

   
 

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//
// Novell.Directory.Ldap.Utilclass.Base64.cs
//
// Author:
//   Sunil Kumar (Sunilk@novell.com)
//
// (C) 2003 Novell, Inc (http://www.novell.com)
//

using System;

namespace Novell.Directory.Ldap.Utilclass
{
  
  /// <summary> The Base64 utility class performs base64 encoding and decoding.
  /// 
  /// The Base64 Content-Transfer-Encoding is designed to represent
  /// arbitrary sequences of octets in a form that need not be humanly
  /// readable.  The encoding and decoding algorithms are simple, but the
  /// encoded data are consistently only about 33 percent larger than the
  /// unencoded data.  The base64 encoding algorithm is defined by
  /// RFC 2045.
  /// </summary>
  public class Base64
  {    
    /// <summary> Checks if the input byte array contains only safe values, that is,
    /// the data does not need to be encoded for use with LDIF.
    /// The rules for checking safety are based on the rules for LDIF
    /// (Ldap Data Interchange Format) per RFC 2849.  The data does
    /// not need to be encoded if all the following are true:
    /// 
    /// The data cannot start with the following byte values:
    /// <pre>
    /// 00 (NUL)
    /// 10 (LF)
    /// 13 (CR)
    /// 32 (SPACE)
    /// 58 (:)
    /// 60 (LESSTHAN)
    /// Any character with value greater than 127
    /// (Negative for a byte value)
    /// </pre>
    /// The data cannot contain any of the following byte values:
    /// <pre>
    /// 00 (NUL)
    /// 10 (LF)
    /// 13 (CR)
    /// Any character with value greater than 127
    /// (Negative for a byte value)
    /// </pre>
    /// The data cannot end with a space.
    /// 
    /// </summary>
    /// <param name="bytes">the bytes to be checked.
    /// 
    /// </param>
    /// <returns> true if encoding not required for LDIF
    /// </returns>
    [CLSCompliantAttribute(false)]
    public static bool isLDIFSafe(sbyte[] bytes)
    {
      int len = bytes.Length;
      if (len > 0)
      {
        int testChar = bytes[0];
        // unsafe if first character is a NON-SAFE-INIT-CHAR
        if ((testChar == 0x00) || (testChar == 0x0A) || (testChar == 0x0D) || (testChar == 0x20) || (testChar == 0x3A) || (testChar == 0x3C) || (testChar < 0))
        {
          // non ascii (>127 is negative)
          return false;
        }
        // unsafe if last character is a space
        if (bytes[len - 1] == &#039; &#039;)
        {
          return false;
        }
        // unsafe if contains any non safe character
        if (len > 1)
        {
          for (int i = 1; i < bytes.Length; i++)
          {
            testChar = bytes&#91;i&#93;;
            if ((testChar == 0x00) || (testChar == 0x0A) || (testChar == 0x0D) || (testChar < 0))
            {
              // non ascii (>127 is negative)
              return false;
            }
          }
        }
      }
      return true;
    }
    }
}