Error creating a user with more than 20 chars in sAMAccountName using .NET

Question

I'm trying to programatically create a new Active Directory user setting the sAMAccountName attribute with a value larger than 20 chars.

When I call the DirectoryEntry.CommitChanges(), I get the error:

00000523: SysErr: DSID-031A0FB6, problem 22 (Invalid argument), data 0

If I try to create a new user setting the sAMAccountName smaller than 20 chars everything work.

Before someone says the the limit of the sAMAccountName is 20 chars, I want to point out that if I try to create the same user having the sAMAccountName more than 20 chars using the Windows tool "Active Directory Users and Computers" everything works. I can see the new entry in AD using the LDP tool and the entry has the sAMAccountName with more than 20 chars.

Why can't I create the user programatically using .NET?

Below is the code I'm using:

Using objDirEnt As DirectoryEntry = New DirectoryEntry("LDAP://my.domain.com/cn=Users,dc=my,dc=domain,dc=com", "username", "Password", AuthenticationTypes.Secure Or AuthenticationTypes.Sealing)
    Using usuario As DirectoryEntry = objDirEnt.Children.Add("CN=aaaaaa bbbbbbbbbb ccccccccc (aaaaaa.bbbbbb.ccccccccc)", "user")
        usuario.Properties("sAMAccountName").Value = "aaaaaa.bbbbbb.ccccccccc"
        usuario.Properties("userAccountControl").Value = AdsUserFlags.PasswordNotRequired
        usuario.Properties("name").Value = "aaaaaa bbbbbbbbbb ccccccccc"
        usuario.Properties("givenName").Value = "aaaaaa"
        usuario.Properties("sn").Value = "bbbbbbbbbb ccccccccc"
        usuario.CommitChanges()
    End Using
End Using

Answer 1

the default restriction for this field is less than 20 chars according to this article: http://msdn.microsoft.com/en-us/library/ms679635.aspx i've not tried to create a user with a 20chars sAMAccountName but maybe its possible with the Novell LDAP Library. I had to use it because we needed to support other LDAP services too. http://www.novell.com/coolsolutions/feature/11204.html

I also found these posts: https://serverfault.com/questions/344815/how-to-add-a-user-in-active-directory-with-name-longer-than-20-characters