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, 5 insertions, 5 deletions

diff --git a/vespaclient-java/src/main/java/com/yahoo/vespa/security/tool/crypto/CipherUtils.java b/vespaclient-java/src/main/java/com/yahoo/vespa/security/tool/crypto/CipherUtils.java
index 051189c20b6..87d3cb4d9f0 100644
--- a/vespaclient-java/src/main/java/com/yahoo/vespa/security/tool/crypto/CipherUtils.java
+++ b/vespaclient-java/src/main/java/com/yahoo/vespa/security/tool/crypto/CipherUtils.java
@@ -1,8 +1,8 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.security.tool.crypto;
 
-import javax.crypto.Cipher;
-import javax.crypto.CipherOutputStream;
+import com.yahoo.security.AeadCipher;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -19,11 +19,11 @@ public class CipherUtils {
      *
      * @param input source stream to read from
      * @param output destination stream to write to
-     * @param cipher a Cipher in either ENCRYPT or DECRYPT mode
+     * @param cipher an {@link AeadCipher} created with for either encryption or decryption
      * @throws IOException if any file operation fails
      */
-    public static void streamEncipher(InputStream input, OutputStream output, Cipher cipher) throws IOException {
-        try (var cipherStream = new CipherOutputStream(output, cipher)) {
+    public static void streamEncipher(InputStream input, OutputStream output, AeadCipher cipher) throws IOException {
+        try (var cipherStream = cipher.wrapOutputStream(output)) {
             input.transferTo(cipherStream);
             cipherStream.flush();
         }