How to generate OpenPGP KeyPair without passphrase using BouncyCastle?

I'm working on a project which needs to generate GPG-Keys for public-key encryption. My language of choice for it is Scala and the library for the cryptographic stuff is BouncyCastle

Key generation works fine, but I can't find a way to generate keys without a passphrase. Every class and every way to gen开发者_运维百科erate keys in BounceyCastle needs a passphrase.

Using an empty passphrase results in gpg still asking me for it when decrypting/signing something, passing null throws an exception on key generation.

Here's the code I'm using (imports stripped):

object KeyGenerator {
  Security.addProvider(new BouncyCastleProvider())

  val kpg = KeyPairGenerator.getInstance("RSA", "BC")
  kpg.initialize(2048)

  def generateKeyPair(userID: String, 
                      expiration: Option[Date]): PGPSecretKeyRing = {


    val now = new Date

    val keyPair = kpg.generateKeyPair();
    val secretKey = new PGPKeyPair(RSA_GENERAL,     
                                   keyPair,   
                                   now)

    val keyPair2 = kpg.generateKeyPair();
    val secretKey2 = new PGPKeyPair(RSA_GENERAL,     
                                    keyPair2,     
                                    now)

    val subpacketGen = new PGPSignatureSubpacketGenerator
    subpacketGen.setKeyFlags(true, KeyFlags.CERTIFY_OTHER | KeyFlags.SIGN_DATA
                             | KeyFlags.ENCRYPT_COMMS | KeyFlags.ENCRYPT_STORAGE)


    val keyRingGen = new PGPKeyRingGenerator(PGPSignature.POSITIVE_CERTIFICATION, 
                                             secretKey,  
                                             userID,
                                             RSA_GENERAL,
                                             "".toCharArray,
                                             true,   
                                             subpacketGen.generate,
                                             null, 
                                             new SecureRandom(), 
                                             "BC");   
    keyRingGen.addSubKey(secretKey2)
    keyRingGen.generateSecretKeyRing
  }
}

You could try using SymmetricKeyAlgorithmTags.NULL (i.e. don't encrypt) for the encAlgorithm parameter to PGPKeyRingGenerator constructor. It may be that the API still requires a placeholder 'passPhrase' but I believe it will be ignored in this case.

@peter-dettman is still relevant. You can use PGPSignatureSubpacketGenerator's setPreferredSymmetricAlgorithms(true, new Int[]{SymmetricKeyAlgorithmTags.NULL}) and pass in "".toCharArray() in JcePBESecretKeyEncryptorBuilder.build as passphrase to remove the need to use passphrase in gpg.