X509Importer is a small library for importing DER-encoded public key files which follow the X.509 SubjectPublicKeyInfo format into .NET's Cryptography Next Generation library (or CNG for short). I originally wrote this library for my personal needs which is why it is by far not entirely standard compatible but at least I have been able to import both RSA and ECDSA keys I got from Java's PublicKey.getEncoded() method into .NET using it.
In order to use this library you will need to target .NET version 3.5 or higher.
Using this library is quite straightforward:
using BlackyPaw.Crypto;
// ...
// Import the DER file:
X509EncodedPublicKeyImporter importer = X509EncodedPublicKeyImporter.Import( <inputStreamHere> );
// for an RSA key:
CngKey rsaKey = ((RSAPublicKey) importer).ToCngKey();
// for an ECDH / ECDSA key:
CngKey ecdhKey = ((ECDSAPublicKey) importer).ToECDH();
CngKey ecdsaKey = ((ECDSAPublicKey) importer).ToECDSA();
// ...In case you don't know what algorithm the key you are importing is intended for, you can find out by using the Algorithm field of your importer object.
This library is licensed under the BSD-3-clause license found inside the LICENSE file in this source tree's root directory.
In case you don't want to compile the library yourself you may download the DLL-file found inside the Deploy sub-directory of this source tree.
If you would like to get in touch or if you have any question regarding this project, feel write to drop me a message at developers [at] blackypaw.com