PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(PGPUtil.getDecoderStream(keyringInput));
PGPObjectFactory factory = new PGPObjectFactory(PGPUtil.getDecoderStream(encryptedInput));
PGPEncryptedDataList enc;
Object o = factory.nextObject();
if (o == null) {
throw new PGPException("Provided input is not encrypted.");
}
if (o instanceof PGPEncryptedDataList) {
enc = (PGPEncryptedDataList) o;
} else {
enc = (PGPEncryptedDataList) factory.nextObject();
}
encryptedInput.reset(); // nextObject() method reads from the InputStream, so rewind it!
Iterator<?> encryptedDataObjects = enc.getEncryptedDataObjects();
PGPPrivateKey privateKey = null;
PGPPublicKeyEncryptedData encryptedData = null;
while (privateKey == null && encryptedDataObjects.hasNext()) {
encryptedData = (PGPPublicKeyEncryptedData) encryptedDataObjects.next();
PGPSecretKey pgpSecKey = pgpSec.getSecretKey(encryptedData.getKeyID());
if (pgpSecKey != null) {
if (passphrase == null && passphraseAccessor != null) {
// get passphrase from accessor
@SuppressWarnings("unchecked")
Iterator<String> userIDs = pgpSecKey.getUserIDs();
while (passphrase == null && userIDs.hasNext()) {
passphrase = passphraseAccessor.getPassphrase(userIDs.next());
}
}
privateKey = pgpSecKey.extractPrivateKey(new JcePBESecretKeyDecryptorBuilder().setProvider(provider).build(
passphrase.toCharArray()));
}
}
if (privateKey == null && pgpSec.size() > 0 && encryptedData != null) {
throw new PGPException("Provided input is encrypted with unknown pair of keys.");
}
return privateKey;
}