No runtime exceptions during normal use of AndroidKeyStore crypto.

This changes the implementation of AndroidKeyStore-backed Cipher and
Mac to avoid throwing runtime exceptions during normal use. Runtime
exceptions will now be thrown only due to truly exceptional and
unrecoverable errors (e.g., keystore unreachable, or crypto primitive
not initialized).

This also changes the implementation of Cipher to cache any errors
encountered in Cipher.update until Cipher.doFinal which then throws
them as checked exceptions.

Bug: 20525947
Change-Id: I3c4ad57fe70abfbb817a79402f722a0208660727

1 files changed, 16 insertions, 8 deletions

diff --git a/keystore/java/android/security/KeyStoreHmacSpi.java b/keystore/java/android/security/KeyStoreHmacSpi.java
index f8b6fef..175369c 100644
--- a/keystore/java/android/security/KeyStoreHmacSpi.java
+++ b/keystore/java/android/security/KeyStoreHmacSpi.java
@@ -147,7 +147,7 @@ public abstract class KeyStoreHmacSpi extends MacSpi implements KeyStoreCryptoOp
         resetWhilePreservingInitState();
     }
 
-    private void ensureKeystoreOperationInitialized() {
+    private void ensureKeystoreOperationInitialized() throws InvalidKeyException {
         if (mChunkedStreamer != null) {
             return;
         }
@@ -169,10 +169,10 @@ public abstract class KeyStoreHmacSpi extends MacSpi implements KeyStoreCryptoOp
         if (opResult == null) {
             throw new KeyStoreConnectException();
         } else if (opResult.resultCode != KeyStore.NO_ERROR) {
-            throw KeyStore.getCryptoOperationException(opResult.resultCode);
+            throw KeyStore.getInvalidKeyException(opResult.resultCode);
         }
         if (opResult.token == null) {
-            throw new CryptoOperationException("Keystore returned null operation token");
+            throw new IllegalStateException("Keystore returned null operation token");
         }
         mOperationToken = opResult.token;
         mOperationHandle = opResult.operationHandle;
@@ -188,28 +188,36 @@ public abstract class KeyStoreHmacSpi extends MacSpi implements KeyStoreCryptoOp
 
     @Override
     protected void engineUpdate(byte[] input, int offset, int len) {
-        ensureKeystoreOperationInitialized();
+        try {
+            ensureKeystoreOperationInitialized();
+        } catch (InvalidKeyException e) {
+            throw new IllegalStateException("Failed to reinitialize MAC", e);
+        }
 
         byte[] output;
         try {
             output = mChunkedStreamer.update(input, offset, len);
         } catch (KeyStoreException e) {
-            throw KeyStore.getCryptoOperationException(e);
+            throw new IllegalStateException("Keystore operation failed", e);
         }
         if ((output != null) && (output.length != 0)) {
-            throw new CryptoOperationException("Update operation unexpectedly produced output");
+            throw new IllegalStateException("Update operation unexpectedly produced output");
         }
     }
 
     @Override
     protected byte[] engineDoFinal() {
-        ensureKeystoreOperationInitialized();
+        try {
+            ensureKeystoreOperationInitialized();
+        } catch (InvalidKeyException e) {
+            throw new IllegalStateException("Failed to reinitialize MAC", e);
+        }
 
         byte[] result;
         try {
             result = mChunkedStreamer.doFinal(null, 0, 0);
         } catch (KeyStoreException e) {
-            throw KeyStore.getCryptoOperationException(e);
+            throw new IllegalStateException("Keystore operation failed", e);
         }
 
         resetWhilePreservingInitState();