Using LDAP in a web service

[Chris Kormann]

I am attempting to use LDAP to retrieve a list of users from within a web
service. When the FindAll() method is invoked, I receive the following
exception: "The specified domain either does not exist or could not be
contacted."

The code that does not work from within the web service works fine from
within a Windows forms application, so my first guess is that the issue is
security related.

Any ideas on how to use LDAP from within a web service?

Thanks for your help.

Chris

Here is the relevant code from the web service:

DirectorySearcher ds = new DirectorySearcher();
ds.SearchRoot = new DirectoryEntry(""); // start searching from local domain
ds.Filter = String.Format("(&(objectCategory=user)(name={0}))" ,
txtUserName.Text);
ds.PropertyNamesOnly = true;
ds.PropertiesToLoad.Add("name");
ds.PropertiesToLoad.Add("SAMAccountName");
ds.SearchScope = SearchScope.Subtree;
ds.CacheResults = false;
ds.ReferralChasing = ReferralChasingOption.None;
ds.Sort = new SortOption("name", SortDirection.Ascending);

// start searching
SearchResultCollection src = ds.FindAll();

[Marc Scheuner]

>I am attempting to use LDAP to retrieve a list of users from within a web

service. When the FindAll() method is invoked, I receive the following
exception: "The specified domain either does not exist or could not be
contacted."

This either means your LDAP path is invalid (but since you didn't
specify any, that's not likely :-), or then you have an issue with
permissions (most likely). Most likely, the user context the web
service runs under is not privileged to reach into your corporate AD.

I would assume that if used from a web service, you'll need to provide
explicit credentials to use in your LDAP query. You can do this by
instantiating the DirectoryEntry for the root of your search
separately:

DirectorySearcher ds = new DirectorySearcher();

DirectoryEntry deRoot = new
DirectoryEntry("LDAP://yourserver01.yourdomain.com/ou=SomeOU,dc=yourdomain,dc=com",
"your user name", "your user password", AuthenticationTypes.Secure);

ds.SearchRoot = deRoot;
and so forth....

Provided that user you specify is privileged enough to query the AD,
you should be able to run this code and get data back.

Marc

[Chris Kormann]

Thanks Marc, I think that did it.

Chris

"Marc Scheuner" wrote:

I am attempting to use LDAP to retrieve a list of users from within a web
service. When the FindAll() method is invoked, I receive the following
exception: "The specified domain either does not exist or could not be
contacted."

This either means your LDAP path is invalid (but since you didn't
specify any, that's not likely :-), or then you have an issue with
permissions (most likely). Most likely, the user context the web
service runs under is not privileged to reach into your corporate AD.

I would assume that if used from a web service, you'll need to provide
explicit credentials to use in your LDAP query. You can do this by
instantiating the DirectoryEntry for the root of your search
separately:

DirectorySearcher ds = new DirectorySearcher();

DirectoryEntry deRoot = new
DirectoryEntry("LDAP://yourserver01.yourdomain.com/ou=SomeOU,dc=yourdomain,dc=com",
"your user name", "your user password", AuthenticationTypes.Secure);

ds.SearchRoot = deRoot;
and so forth....

Provided that user you specify is privileged enough to query the AD,
you should be able to run this code and get data back.

Marc