'Cannot find the requested object' exception while creating X509Certificate2 from string

Question

I am trying to create X509Certificate2 from string. Let me show an example:

string keyBase64String = Convert.ToBase64String(file.PKCS7);
var cer         


        

Answer 1

The constructor of of X509Certificate2 expects to get a the certificate file name, but you are giving it a key (X509Certificate2 Constructor (String))

I assume that keyBase64String is the certificate key, and that the certificate is installed on the machine that executes the code. Try this:

var store = new X509Store(StoreName.My, StoreLocation.LocalMachine);
store.Open(OpenFlags.ReadOnly);
var certCollection = store.Certificates.Find(X509FindType.FindByThumbprint, keyBase64String , false);
//var certCollection = store.Certificates.Find(X509FindType.FindByKeyUsage, keyBase64String , false);
//var certCollection = store.Certificates.Find(X509FindType.FindBySubjectKeyIdentifier, keyBase64String , false);
var cert = certCollection[0];

You can also try FindByKeyUsage, FindBySubjectKeyIdentifier, or other types of X509FindType Enumeration