Is there a .NET class that can parse CN= strings out of LDAP?

Question

I\'ve got a string that I\'m fetching from LDAP for Active Directory group membership and I need to parse it to check if the user is a member of the AD group. Is there a cl

Answer 1

To parse the DistinquishedName you have to pay attention to the escape characters. Here's a method that will parse the string correctly and return a list of key value pairs.

    public static List> ParseDistinguishedName(string input)
    {
        int i = 0;
        int a = 0;
        int v = 0;
        var attribute = new char[50];
        var value = new char[200];
        var inAttribute = true;
        string attributeString, valueString;
        var names = new List>();

        while (i < input.Length)
        {
            char ch = input[i++];
            switch(ch)
            {
                case '\\':
                    value[v++] = ch;
                    value[v++] = input[i++];
                    break;
                case '=':
                    inAttribute = false;
                    break;
                case ',':
                    inAttribute = true;
                    attributeString = new string(attribute).Substring(0, a);
                    valueString = new string(value).Substring(0, v);
                    names.Add(new KeyValuePair(attributeString, valueString));
                    a = v = 0;
                    break;
                default:
                    if (inAttribute)
                    {
                        attribute[a++] = ch;
                    }
                    else
                    {
                        value[v++] = ch;
                    }
                    break;
            }
        }

        attributeString = new string(attribute).Substring(0, a);
        valueString = new string(value).Substring(0, v);
        names.Add(new KeyValuePair(attributeString, valueString));
        return names;
    }

    static void Main(string[] args)
    {
        const string TestString = "CN=BY2STRAKRJOB2,OU=MSNStorage,OU=RESOURCE,OU=PRODUCTION,DC=phx,DC=gbl,STREET=street address,L=locality Name,C=Country Name,UID=user id,STUFF=\\,\\.\\+\"<>;\\=\\0A";

        var names = ParseDistinguishedName(TestString);
        foreach (var pair in names)
        {
            Console.WriteLine("{0} = {1}", pair.Key, pair.Value);
        }
    }