I have private key stored in file in PKCS8 DER format and protected by password. What is the easiest way to read it?
Here is the code I use to load unencrypted one:
InputStream in = new FileInputStream(privateKeyFilename);
byte[] privateKeydata = new byte[in.available()];
in.read(privateKeydata);
in.close();
KeyFactory privateKeyFactory = KeyFactory.getInstance("RSA");
PKCS8EncodedKeySpec encodedKeySpec = new PKCS8EncodedKeySpec(privateKeydata);
PrivateKey privateKey = privateKeyFactory.generatePrivate(encodedKeySpec);
It works fine for unencrypted keys with the same specification. By the way, I am using BouncyCastle.
I can view this private key using following openssl command
openssl pkcs8 -in ./privatekey.key -inform DER -passin pass:thisismypass
Please, Help!!!
I,ve posted some solutions in my own answer to this topic. But I keep question unanswered in case anybody can help with making it work without extra library, just BouncyCastle.
I found the solution! Maybe its not so elegant, but... Here I will post two solutions:
First:
I found a kind of solution here, but it throws exception. Solution:
import java.io.*;
import java.security.*;
import java.security.interfaces.RSAPrivateCrtKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.*;
import javax.crypto.*;
import javax.crypto.spec.*;
/*
* This class demonstrates how to import an encrypted RSA private key as
* generated by openssl. The input file is presumed to be in DER
* format.
*/
public class ImportEncryptedPrivateKey
{
public static byte[] readPK8FromFile(String fileName) throws IOException
{
File f = new File(fileName);
DataInputStream dis = new DataInputStream(new FileInputStream(f));
byte[] theData = new byte[(int) f.length()];
dis.readFully(theData);
return theData;
}
public static void main(String[] args) throws IOException,
NoSuchAlgorithmException, NoSuchPaddingException,
InvalidKeySpecException, InvalidKeyException,
InvalidAlgorithmParameterException
{
byte[] encryptedPKInfo = readPK8FromFile("rsapriv.pk8");
EncryptedPrivateKeyInfo ePKInfo = new EncryptedPrivateKeyInfo(
encryptedPKInfo);
char[] password = { 'p', 'a', 's', 's', 'w', 'o', 'r', 'd' };
Cipher cipher = Cipher.getInstance(ePKInfo.getAlgName());
PBEKeySpec pbeKeySpec = new PBEKeySpec(password);
// Now create the Key from the PBEKeySpec
SecretKeyFactory skFac = SecretKeyFactory.getInstance(ePKInfo
.getAlgName());
Key pbeKey = skFac.generateSecret(pbeKeySpec);
// Extract the iteration count and the salt
AlgorithmParameters algParams = ePKInfo.getAlgParameters();
cipher.init(Cipher.DECRYPT_MODE, pbeKey, algParams);
// Decrypt the encryped private key into a PKCS8EncodedKeySpec
KeySpec pkcs8KeySpec = ePKInfo.getKeySpec(cipher);
// Now retrieve the RSA Public and private keys by using an
// RSA keyfactory.
KeyFactory rsaKeyFac = KeyFactory.getInstance("RSA");
// First get the private key
RSAPrivateCrtKey rsaPriv = (RSAPrivateCrtKey) rsaKeyFac.generatePrivate(pkcs8KeySpec);
// Now derive the RSA public key from the private key
RSAPublicKeySpec rsaPubKeySpec = new RSAPublicKeySpec(rsaPriv.getModulus(), rsaPriv.getPublicExponent());
RSAPublicKey rsaPubKey = (RSAPublicKey) rsaKeyFac.generatePublic(rsaPubKeySpec);
}
}
And my exception:
Exception in thread "main" java.security.NoSuchAlgorithmException: No such algorithm: 1.2.840.113549.1.5.13
Second:
And following this http://juliusdavies.ca/commons-ssl/pkcs8.html you can read about the second, working solution