Extract Common Name from Distinguished Name

Question

Is there a call in .NET that parses the CN from a rfc-2253 encoded distinguished name? I know there are some third-party libraries that do this, but I would prefer to use native .NET libraries if possible.

Examples of a string encoded DN

CN=L. Eagle,O=Sue\, Grabbit and Runn,C=GB

CN=Jeff Smith,OU=Sales,DC=Fabrikam,DC=COM

Answer 1

If you are working with an X509Certificate2, there is a native method that you can use to extract the Simple Name. The Simple Name is equivalent to the Common Name RDN within the Subject field of the main certificate:

x5092Cert.GetNameInfo(X509NameType.SimpleName, false);

Alternatively, X509NameType.DnsName can be used to retrieve the Subject Alternative Name, if present; otherwise, it will default to the Common Name:

x5092Cert.GetNameInfo(X509NameType.DnsName, false);