Use BouncyCastle AES GCM cipher and I/O streams instead of JCA

This resolves two issues:
 * `javax.crypto.OutputCipherStream` swallows MAC tag mismatch exceptions
   when the stream is closed, which means that corruptions (intentional
   or not) are not caught. This is documented behavior, but still very
   surprising and a rather questionable default. BC's interchangeable
   `CipherOutputStream` throws as expected. To avoid regressions, add an
   explicit test that both ciphertext and MAC tag corruptions are propagated.
 * The default-provided `AES/GCM/NoPadding` `Cipher` instance will not emit
   decrypted plaintext per `update()` chunk, but buffer everything until
   `doFinal()` is invoked when the stream is closed. This means that decrypting
   very large ciphertexts can blow up memory usage since internal output
   buffers are reallocated and increased per iteration...! Instead use an
   explicit BC `GCMBlockCipher` which has the expected behavior (and actually
   lets cipher streams, well, _stream_). Add an `AeadCipher` abstraction to
   avoid leaking BC APIs outside the security module.

1 files changed, 1 insertions, 3 deletions

diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/coredump/CoredumpHandler.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/coredump/CoredumpHandler.java
index f4cd35bc5bd..4a8353d92ec 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/coredump/CoredumpHandler.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/maintenance/coredump/CoredumpHandler.java
@@ -29,7 +29,6 @@ import com.yahoo.vespa.hosted.node.admin.task.util.file.MakeDirectory;
 import com.yahoo.vespa.hosted.node.admin.task.util.file.UnixPath;
 import com.yahoo.vespa.hosted.node.admin.task.util.fs.ContainerPath;
 
-import javax.crypto.CipherOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.UncheckedIOException;
@@ -49,7 +48,6 @@ import java.util.function.Supplier;
 import java.util.logging.Logger;
 import java.util.regex.Pattern;
 import java.util.stream.IntStream;
-import java.util.stream.Stream;
 
 import static com.yahoo.vespa.hosted.node.admin.task.util.file.FileFinder.nameEndsWith;
 import static com.yahoo.vespa.hosted.node.admin.task.util.file.FileFinder.nameMatches;
@@ -275,7 +273,7 @@ public class CoredumpHandler {
 
     static OutputStream maybeWrapWithEncryption(OutputStream wrappedStream, Optional<SecretSharedKey> sharedCoreKey) {
         return sharedCoreKey
-                .map(key -> (OutputStream)new CipherOutputStream(wrappedStream, SharedKeyGenerator.makeAesGcmEncryptionCipher(key)))
+                .map(key -> SharedKeyGenerator.makeAesGcmEncryptionCipher(key).wrapOutputStream(wrappedStream))
                 .orElse(wrappedStream);
     }