diff --git a/keystore2/src/crypto.hpp b/keystore2/src/crypto.hpp
new file mode 100644
index 0000000..9a9bb2e
--- /dev/null
+++ b/keystore2/src/crypto.hpp
@@ -0,0 +1,40 @@
+/*
+ * 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.
+ */
+
+#ifndef __CRYPTO_H__
+#define __CRYPTO_H__
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stddef.h>
+
+extern "C" {
+  bool AES_gcm_encrypt(const uint8_t* in, uint8_t* out, size_t len,
+                       const uint8_t* key, size_t key_size, const uint8_t* iv, uint8_t* tag);
+  bool AES_gcm_decrypt(const uint8_t* in, uint8_t* out, size_t len,
+                       const uint8_t* key, size_t key_size, const uint8_t* iv,
+                       const uint8_t* tag);
+
+  // Copied from system/security/keystore/keymaster_enforcement.h.
+  typedef uint64_t km_id_t;
+
+  bool CreateKeyId(const uint8_t* key_blob, size_t len, km_id_t* out_id);
+
+  void generateKeyFromPassword(uint8_t* key, size_t key_len, const char* pw,
+                               size_t pw_len, uint8_t* salt);
+}
+
+#endif  //  __CRYPTO_H__