I am looking for a method to generate a onetime password for provisioning purposes in ASP.NET-MVC. I came across the Membership.GeneratePassword which is in the System.Web.Security namespace. Is this a secure way to generate a one time use password?
Yup, it's fine. Underneath the covers it users the RNGCryptoServiceProvider to generate the password data, which is .NET's wrapper around the CryptoAPI's CSPRNG to generate the data for the password. It's good enough for strongly random key material, so its certainly also good enough for a one-time use password as well.