Preserve interrupted state across waiting for future

A normal synchronous binder call would not be influenced by an
interrupted thread. With the move to asynchronous keystore IPC we wait
on a future which can throw an interrupted exception. The Java crypto
API does not expect the implementation to throw interrupted exceptions
though. So to preserve the expected behavior we wrap the Future.get()
calls in a loop that handles the interrupted exception and sets the
interrupted state after the get completed successfully.

Bug: 147398412
Bug: 155254932
Test: atest android.keystore.cts.CipherTest#testEncryptsAndDecryptsInterrupted
Change-Id: I066180e8028cc426fa1b3739fa007faa17c8c012
Merged-In: I066180e8028cc426fa1b3739fa007faa17c8c012

1 files changed, 43 insertions, 27 deletions

diff --git a/keystore/java/android/security/KeyStore.java b/keystore/java/android/security/KeyStore.java
index d35642e362b1..23283fa32b5e 100644
--- a/keystore/java/android/security/KeyStore.java
+++ b/keystore/java/android/security/KeyStore.java
@@ -485,14 +485,14 @@ public class KeyStore {
             mBinder.asBinder().linkToDeath(promise, 0);
             int errorCode = mBinder.addRngEntropy(promise, data, flags);
             if (errorCode == NO_ERROR) {
-                return promise.getFuture().get().getErrorCode() == NO_ERROR;
+                return interruptedPreservingGet(promise.getFuture()).getErrorCode() == NO_ERROR;
             } else {
                 return false;
             }
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return false;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "AddRngEntropy completed with exception", e);
             return false;
         } finally {
@@ -550,7 +550,7 @@ public class KeyStore {
 
     private int generateKeyInternal(String alias, KeymasterArguments args, byte[] entropy, int uid,
             int flags, KeyCharacteristics outCharacteristics)
-                    throws RemoteException, ExecutionException, InterruptedException {
+                    throws RemoteException, ExecutionException {
         KeyCharacteristicsPromise promise = new KeyCharacteristicsPromise();
         int error = NO_ERROR;
         KeyCharacteristicsCallbackResult result = null;
@@ -561,7 +561,7 @@ public class KeyStore {
                 Log.e(TAG, "generateKeyInternal failed on request " + error);
                 return error;
             }
-            result = promise.getFuture().get();
+            result = interruptedPreservingGet(promise.getFuture());
         } finally {
             mBinder.asBinder().unlinkToDeath(promise, 0);
         }
@@ -594,7 +594,7 @@ public class KeyStore {
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return SYSTEM_ERROR;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "generateKey completed with exception", e);
             return SYSTEM_ERROR;
         }
@@ -616,7 +616,7 @@ public class KeyStore {
             int error = mBinder.getKeyCharacteristics(promise, alias, clientId, appId, uid);
             if (error != NO_ERROR) return error;
 
-            KeyCharacteristicsCallbackResult result = promise.getFuture().get();
+            KeyCharacteristicsCallbackResult result = interruptedPreservingGet(promise.getFuture());
             error = result.getKeystoreResponse().getErrorCode();
             if (error != NO_ERROR) return error;
 
@@ -627,7 +627,7 @@ public class KeyStore {
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return SYSTEM_ERROR;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "GetKeyCharacteristics completed with exception", e);
             return SYSTEM_ERROR;
         } finally {
@@ -642,14 +642,14 @@ public class KeyStore {
 
     private int importKeyInternal(String alias, KeymasterArguments args, int format, byte[] keyData,
             int uid, int flags, KeyCharacteristics outCharacteristics)
-                    throws RemoteException, ExecutionException, InterruptedException {
+                    throws RemoteException, ExecutionException {
         KeyCharacteristicsPromise promise = new KeyCharacteristicsPromise();
         mBinder.asBinder().linkToDeath(promise, 0);
         try {
             int error = mBinder.importKey(promise, alias, args, format, keyData, uid, flags);
             if (error != NO_ERROR) return error;
 
-            KeyCharacteristicsCallbackResult result = promise.getFuture().get();
+            KeyCharacteristicsCallbackResult result = interruptedPreservingGet(promise.getFuture());
 
             error = result.getKeystoreResponse().getErrorCode();
             if (error != NO_ERROR) return error;
@@ -677,7 +677,7 @@ public class KeyStore {
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return SYSTEM_ERROR;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "ImportKey completed with exception", e);
             return SYSTEM_ERROR;
         }
@@ -749,7 +749,7 @@ public class KeyStore {
             String wrappingKeyAlias,
             byte[] maskingKey, KeymasterArguments args, long rootSid, long fingerprintSid,
             KeyCharacteristics outCharacteristics)
-                    throws RemoteException, ExecutionException, InterruptedException {
+                    throws RemoteException, ExecutionException {
         KeyCharacteristicsPromise promise = new KeyCharacteristicsPromise();
         mBinder.asBinder().linkToDeath(promise, 0);
         try {
@@ -757,7 +757,7 @@ public class KeyStore {
                     wrappingKeyAlias, maskingKey, args, rootSid, fingerprintSid);
             if (error != NO_ERROR) return error;
 
-            KeyCharacteristicsCallbackResult result = promise.getFuture().get();
+            KeyCharacteristicsCallbackResult result = interruptedPreservingGet(promise.getFuture());
 
             error = result.getKeystoreResponse().getErrorCode();
             if (error != NO_ERROR) return error;
@@ -788,7 +788,7 @@ public class KeyStore {
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return SYSTEM_ERROR;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "ImportWrappedKey completed with exception", e);
             return SYSTEM_ERROR;
         }
@@ -820,14 +820,14 @@ public class KeyStore {
             appId = appId != null ? appId : new KeymasterBlob(new byte[0]);
             int error = mBinder.exportKey(promise, alias, format, clientId, appId, uid);
             if (error == NO_ERROR) {
-                return promise.getFuture().get();
+                return interruptedPreservingGet(promise.getFuture());
             } else {
                 return new ExportResult(error);
             }
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return null;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "ExportKey completed with exception", e);
             return null;
         } finally {
@@ -866,14 +866,14 @@ public class KeyStore {
             int errorCode =  mBinder.begin(promise, getToken(), alias, purpose, pruneable, args,
                                            entropy, uid);
             if (errorCode == NO_ERROR) {
-                return promise.getFuture().get();
+                return interruptedPreservingGet(promise.getFuture());
             } else {
                 return new OperationResult(errorCode);
             }
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return null;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "Begin completed with exception", e);
             return null;
         } finally {
@@ -896,14 +896,14 @@ public class KeyStore {
             input = input != null ? input : new byte[0];
             int errorCode =  mBinder.update(promise, token, arguments, input);
             if (errorCode == NO_ERROR) {
-                return promise.getFuture().get();
+                return interruptedPreservingGet(promise.getFuture());
             } else {
                 return new OperationResult(errorCode);
             }
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return null;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "Update completed with exception", e);
             return null;
         } finally {
@@ -932,14 +932,14 @@ public class KeyStore {
             signature = signature != null ? signature : new byte[0];
             int errorCode = mBinder.finish(promise, token, arguments, input, signature, entropy);
             if (errorCode == NO_ERROR) {
-                return promise.getFuture().get();
+                return interruptedPreservingGet(promise.getFuture());
             } else {
                 return new OperationResult(errorCode);
             }
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return null;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "Finish completed with exception", e);
             return null;
         } finally {
@@ -974,14 +974,14 @@ public class KeyStore {
             mBinder.asBinder().linkToDeath(promise, 0);
             int errorCode = mBinder.abort(promise, token);
             if (errorCode == NO_ERROR) {
-                return promise.getFuture().get().getErrorCode();
+                return interruptedPreservingGet(promise.getFuture()).getErrorCode();
             } else {
                 return errorCode;
             }
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return SYSTEM_ERROR;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "Abort completed with exception", e);
             return SYSTEM_ERROR;
         } finally {
@@ -1137,7 +1137,7 @@ public class KeyStore {
             }
             int error = mBinder.attestKey(promise, alias, params);
             if (error != NO_ERROR) return error;
-            KeyAttestationCallbackResult result = promise.getFuture().get();
+            KeyAttestationCallbackResult result = interruptedPreservingGet(promise.getFuture());
             error = result.getKeystoreResponse().getErrorCode();
             if (error == NO_ERROR) {
                 outChain.shallowCopyFrom(result.getCertificateChain());
@@ -1146,7 +1146,7 @@ public class KeyStore {
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return SYSTEM_ERROR;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "AttestKey completed with exception", e);
             return SYSTEM_ERROR;
         } finally {
@@ -1166,7 +1166,7 @@ public class KeyStore {
             }
             int error = mBinder.attestDeviceIds(promise, params);
             if (error != NO_ERROR) return error;
-            KeyAttestationCallbackResult result = promise.getFuture().get();
+            KeyAttestationCallbackResult result = interruptedPreservingGet(promise.getFuture());
             error = result.getKeystoreResponse().getErrorCode();
             if (error == NO_ERROR) {
                 outChain.shallowCopyFrom(result.getCertificateChain());
@@ -1175,7 +1175,7 @@ public class KeyStore {
         } catch (RemoteException e) {
             Log.w(TAG, "Cannot connect to keystore", e);
             return SYSTEM_ERROR;
-        } catch (ExecutionException | InterruptedException e) {
+        } catch (ExecutionException e) {
             Log.e(TAG, "AttestDevicdeIds completed with exception", e);
             return SYSTEM_ERROR;
         } finally {
@@ -1412,4 +1412,20 @@ public class KeyStore {
             int errorCode) {
         return getInvalidKeyException(keystoreKeyAlias, uid, getKeyStoreException(errorCode));
     }
+
+    private static <R> R interruptedPreservingGet(CompletableFuture<R> future)
+            throws ExecutionException {
+        boolean wasInterrupted = false;
+        while (true) {
+            try {
+                R result = future.get();
+                if (wasInterrupted) {
+                    Thread.currentThread().interrupt();
+                }
+                return result;
+            } catch (InterruptedException e) {
+                wasInterrupted = true;
+            }
+        }
+    }
 }