Reading a GPG keyring using BouncyCastle OpenPGP

Question

Has anyone successfully used the BouncyCastle OpenPGP library to read a public keyring?
Here's my attempt:
    File publicKeyFile = new File(System.getProperty("user.home"), ".gnupg/pubring.gpg");
    Security.addProvider(new BouncyCastleProvider());
    FileInputStream in = new FileInputStream(publicKeyFile);
    PGPObjectFactory objectFactory = new PGPObjectFactory(in);
    while (true)
        Object object = objectFactory.nextObject();
        if (object instanceof PGPPublicKeyRing)
            PGPPublicKeyRing keyRing = (PGPPublicKeyRing) object;
    in.close();But I get an error:
java.io.IOException: unknown object in stream 12
     at org.bouncycastle.openpgp.PGPObjectFactory.nextObject(PGPObjectFactory.java:109)
     at net.xaoza.pgpvis.Test.main(Test.java:36)
What am I doing wrong? I've stared at this for ages, and can't yet see anything out of place.

Answer 1

There are a bunch of examples in the BC source code (looking at the tests) and this question has also been asked on the mailing lists at BC, so if you search the archives, you should see some quite comprehensive responses.
Cheers,
-- jon