On-device signing: Support keystore2 for keys.
Add code to support Keystore2. Keystore2 will offer a feature similar to
EARLY_BOOT_KEYS in Keymaster 4.1, but it will also be hardware-enforced
in older Keymaster versions. For now, have the code support both paths,
and stick with Keymaster 4.1 until Keystore2 is merged.
Bug: 165630556
Test: Local
Change-Id: If62837bf6fb1398bd30ce9422cbf3082a5cbf1e2
diff --git a/ondevice-signing/KeyConstants.h b/ondevice-signing/KeyConstants.h
new file mode 100644
index 0000000..9e1a513
--- /dev/null
+++ b/ondevice-signing/KeyConstants.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+static constexpr int kRsaKeySize = 2048;
+static constexpr int kRsaKeyExponent = 65537;