Authenticated SSL LDAP connection, SSL cert C# with Example

does not match reverse DNS 
Set up some constants for the server and authentication information. Assuming LDAPv3, but it's easy enough to 
change that. 
// Authentication, and the name of the server. 
private const string LDAPUser = "cn=example:app:mygroup:accts,ou=Applications,dc=example,dc=com"; 
private readonly char[] password = { 'p', 'a', 's', 's', 'w', 'o', 'r', 'd' }; 
private const string TargetServer = "ldap.example.com"; 
// Specific to your company. Might start "cn=manager" instead of "ou=people", for example. 
private const string CompanyDN = "ou=people,dc=example,dc=com"; 
Actually create the connection with three parts: an LdapDirectoryIdentifier (the server), and NetworkCredentials. 
// Configure server and port. LDAP w/ SSL, aka LDAPS, uses port 636. 
// If you don't have SSL, don't give it the SSL port. 
LdapDirectoryIdentifier identifier = new LdapDirectoryIdentifier(TargetServer, 636); 
// Configure network credentials (userid and password) 
var secureString = new SecureString(); 
foreach (var character in password) 
secureString.AppendChar(character); 
NetworkCredential creds = new NetworkCredential(LDAPUser, secureString); 
// Actually create the connection 
LdapConnection connection = new LdapConnection(identifier, creds) 
{ 
AuthType = AuthType.Basic, 
SessionOptions = 
{ 
ProtocolVersion = 3, 
SecureSocketLayer = true 
} 
}; 
// Override SChannel reverse DNS lookup. 
// This gets us past the "The LDAP server is unavailable." exception 
// Could be 
// connection.SessionOptions.VerifyServerCertificate += { return true; }; 
// but some certificate validation is probably good. 
connection.SessionOptions.VerifyServerCertificate += 
(sender, certificate) => certificate.Subject.Contains(string.Format("CN={0},", TargetServer)); 
Use the LDAP server, e.g. search for someone by userid for all objectClass values. The objectClass is present to 
demonstrates a compound search: The ampersand is the boolean "and" operator for the two query clauses. 
SearchRequest searchRequest = new SearchRequest( 
CompanyDN, 
string.Format((&(objectClass=*)(uid={0})), uid), 
SearchScope.Subtree, 
 

null 
); 
// Look at your results 
foreach (SearchResultEntry entry in searchResponse.Entries) { 
// do something 
}