java - RSA - bouncycastle PEMReader returning PEMKeyPair instead of AsymmetricCipherKeyPair for reading private key -

i have function reads openssl formatted private key:

static asymmetrickeyparameter readprivatekey(string privatekeyfilename) {     asymmetriccipherkeypair keypair;      using (var reader = file.opentext(privatekeyfilename))         keypair = (asymmetriccipherkeypair)new pemreader(reader).readobject();      return keypair.private; } 

and returns asymmetrickeyparameter used decrypt encrypted text.

below decrypt code:

public static byte[] decrypt3(byte[] data, string pemfilename) {     string result = "";     try {         asymmetrickeyparameter key = readprivatekey(pemfilename);          rsaengine e = new rsaengine();          e.init(false, key);         //byte[] cipheredbytes = getbytes(encryptedmsg);          //debug.log (encryptedmsg);          byte[] cipheredbytes = e.processblock(data, 0, data.length);         //result = encoding.utf8.getstring(cipheredbytes);         //return result;         return cipheredbytes;      } catch (exception e) {         debug.log ("exception in decrypt3: " + e.message);         return getbytes(e.message);     } } 

these work in c# using bouncy castle library , correct decrypted text. however, when added java, pemparser.readobject() returns object of type pemkeypair instead of asymmetriccipherkeypair , java throws exception trying cast it. checked in c# , returning asymmetriccipherkeypair.

i don't know why java behaves differently hope here can how cast object or read privatekey file , decrypt successfully. used same public , privatekey files in both c# , java code don't think error them.

here reference java version of how i'm reading privatekey:

public static string readprivatekey3(string pemfilename) throws filenotfoundexception, ioexception {     asymmetriccipherkeypair keyparam = null;     asymmetrickeyparameter keypair = null;     pemkeypair kp = null;     //privatekeyinfo pi = null;      try {         //var filestream = system.io.file.opentext(pemfilename);         string absolutepath = "";         absolutepath = encryption.class.getprotectiondomain().getcodesource().getlocation().getpath();         absolutepath = absolutepath.substring(0, (absolutepath.lastindexof("/")+1));         string filepath = "";         filepath = absolutepath + pemfilename;          file f = new file(filepath);         //return filepath;          filereader filereader  = new filereader(f);         pemparser r = new pemparser(filereader);          keyparam = (asymmetriccipherkeypair) r.readobject();          return keyparam.tostring();      }     catch (exception e) {         return "hello: " + e.getmessage() + e.getlocalizedmessage() + e.tostring();         //return e.tostring();         //return pi;     } } 

the java code has been updated new api, yet ported across c#. try equivalent (but deprecated) java pemreader class. return jce keypair though (part of reason change because original version worked jce types, not bc lightweight classes).

if using pemparser, , pemkeypair, can use org.bouncycastle.openssl.jcajce.jcapemkeyconverter.getkeypair jce keypair it. ideally there bcpemkeyconverter, doesn't appear have been written yet. in case, should easy make asymmetriccipherkeypair:

pemkeypair kp = ...; asymmetrickeyparameter privkey = privatekeyfactory.createkey(kp.getprivatekeyinfo()); asymmetrickeyparameter pubkey = publickeyfactory.createkey(kp.getpublickeyinfo()); new asymmetriccipherkeypair(pubkey, privkey); 

those factory classes in org.bouncycastle.crypto.util package.