How to export non-exportable private key from store

Question

I need to export private key from Windows store. What should I do if the key is marked as non-exportable? I know that it is possible, program jailbreak can export this key.

To export key I use Org.BouncyCastle.Security.DotNetUtilities.GetKeyPair() that exports key from (RSACryptoServiceProvider)cryptoProv.ExportParameters(true). Exported key I use in Org.BouncyCastle.Cms.CmsSignedDataGenerator for CMS signature.

I need solution for .Net, but any solution will be useful. Thank you.

Answer 1

You're right, no API at all that I'm aware to export PrivateKey marked as non-exportable. But if you patch (in memory) normal APIs, you can use the normal way to export :)

There is a new version of mimikatz that also support CNG Export (Windows Vista / 7 / 2008 ...)

1. download (and launch with administrative privileges) : http://blog.gentilkiwi.com/mimikatz (trunk version or last version)

Run it and enter the following commands in its prompt:

2. privilege::debug (unless you already have it or target only CryptoApi)
3. crypto::patchcng (nt 6) and/or crypto::patchcapi (nt 5 & 6)
4. crypto::exportCertificates and/or crypto::exportCertificates CERT_SYSTEM_STORE_LOCAL_MACHINE

The exported .pfx files are password protected with the password "mimikatz"