C# Crypto API examples

Question

Hello, I'm looking for examples + information on how to extract certificate information from the windows certificate store and perform operations like verifying signatures using the retrieved certificates. The API documentation for C# in this regard is quite poor, with many of the entries in msdn marked with "This language is not supported, or no code example is available.", I'm sorry I can't be more specific, I haven't done any programming using cryptographic api's. The particular certificate will be provided via a USB token. Any help or pointers would be much appreciated, thanks.

Answer 1

Regarding the certificate store, you will want to look at the class called X509Store. It will return instances of X509Certificate2 that you can work with. You can also get instances of X509Certificate2 from a file (the constructor that takes a string). If you have access to the certificates' private key, you can use it to decrypt data by casting it to a DSACryptoServiceProvider.