The distinguished name contains invalid syntax error - openldap

Question

I'm trying using LDAP to authenticate user, but I have a problem with LDAP.
This is my code:
string hostOrDomainName = "MrHand-PC";
string targetOu = "cn=Huy Pham,ou=people,dc=example,dc=com";
// create a search filter to find all objects
string ldapSearchFilter = "uid=pdhuy";
// establish a connection to the directory
LdapConnection connection = new LdapConnection(hostOrDomainName);
Console.WriteLine("\r\nPerforming a simple search ...");
SearchRequest searchRequest = new SearchRequest(targetOu, ldapSearchFilter,
System.DirectoryServices.Protocols.SearchScope.OneLevel, null);
// cast the returned directory response as a SearchResponse object
SearchResponse searchResponse =
(SearchResponse)connection.SendRequest(searchRequest);
The last line throws an exception: The distinguished name contains invalid syntax.
Can anyone help my solve this problem?

Answer 1

To authenticate against LDAP, you can try the following (domain, username and password are arguments):
bool IsAuthenticated = false;
string domainAndUsername = domain + #"\" + username;
string dirContext = GetAuthenticatingDirectory(domain);
using (DirectoryEntry entry = new DirectoryEntry("LDAP://" + dirContext, domainAndUsername, password))
{
try
{
Object obj = entry.NativeObject;
DirectorySearcher search = new DirectorySearcher(entry);
search.Filter = "(SAMAccountName=" + username + ")";
search.PropertiesToLoad.Add("cn");
SearchResult result = search.FindOne();
if (result != null)
{
IsAuthenticated = true;
}
}
catch (Exception e)
{
//handle appropriately according to your requirements
}
}
return IsAuthenticated;
where GetAuthenticatingDirectory() is defined as
private string GetAuthenticatingDirectory(string domain)
{
string authenticatingDirectory = string.Empty;
string dotComDomain = domain + #".com";
// Connect to RootDSE
using (DirectoryEntry RootDSE = new DirectoryEntry("LDAP://rootDSE"))
{
// Retrieve the Configuration Naming Context from RootDSE
string configNC = RootDSE.Properties["configurationNamingContext"].Value.ToString();
// Connect to the Configuration Naming Context
using (DirectoryEntry configSearchRoot = new DirectoryEntry("LDAP://" + configNC))
{
// Search for all partitions where the NetBIOSName is set.
using (DirectorySearcher configSearch = new DirectorySearcher(configSearchRoot))
{
configSearch.Filter = ("(NETBIOSName=*)");
// Configure search to return dnsroot and ncname attributes
configSearch.PropertiesToLoad.Add("dnsroot");
configSearch.PropertiesToLoad.Add("ncname");
using (SearchResultCollection forestPartitionList = configSearch.FindAll())
{
// Loop through each returned domain in the result collection
foreach (SearchResult domainPartition in forestPartitionList)
{
// domainName like "domain.com". ncName like "DC=domain,DC=com"
string domainName = domainPartition.Properties["dnsroot"][0].ToString();
string ncName = domainPartition.Properties["ncname"][0].ToString();
if (dotComDomain.Equals(domainName, StringComparison.OrdinalIgnoreCase))
{
authenticatingDirectory = ncName;
break;
}
}
}
}
}
}
return authenticatingDirectory;
}