hardware keyguard HAL
simple API for signing/verifying passwords
with a hardware-backed keyguard
Change-Id: Ib2e25c7419e113494c2b0a4579ce8264a2335e07
diff --git a/include/hardware/keyguard.h b/include/hardware/keyguard.h
new file mode 100644
index 0000000..2d65d4b
--- /dev/null
+++ b/include/hardware/keyguard.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2015 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 ANDROID_HARDWARE_KEYGUARD_H
+#define ANDROID_HARDWARE_KEYGUARD_H
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <hardware/hardware.h>
+
+__BEGIN_DECLS
+
+#define KEYGUARD_HARDWARE_MODULE_ID "keyguard"
+
+#define KEYGUARD_MODULE_API_VERSION_0_1 HARDWARE_MODULE_API_VERSION(0, 1)
+
+#define HARDWARE_KEYGUARD "keyguard"
+
+struct keyguard_module {
+ /**
+ * Comon methods of the keyguard module. This *must* be the first member of
+ * keyguard_module as users of this structure will cast a hw_module_t to
+ * a keyguard_module pointer in the appropriate context.
+ */
+ hw_module_t common;
+};
+
+struct keyguard_device {
+ /**
+ * Common methods of the keyguard device. As above, this must be the first
+ * member of keymaster_device.
+ */
+ hw_device_t common;
+
+ /**
+ * Enrolls password_payload, which should be derived from a user selected pin or password,
+ * with the authentication factor private key used only for enrolling authentication
+ * factor data.
+ *
+ * Returns: 0 on success or an error code less than 0 on error.
+ * On error, enrolled_password_handle will not be allocated.
+ */
+ int (*enroll)(const struct keyguard_device *dev, const uint8_t *password_payload,
+ const uint8_t password_payload_length, uint8_t **enrolled_password_handle,
+ uint8_t *enrolled_password_handle_length);
+
+ /**
+ * Verifies provided_password matches enrolled_password_handle.
+ *
+ * Implementations of this module may retain the result of this call
+ * to attest to the recency of authentication.
+ *
+ * On success, writes the address of a verification token to verification_token,
+ * usable to attest password verification to other trusted services. Clients
+ * may pass NULL for this value.
+ *
+ * Returns: 0 on success or an error code less than 0 on error
+ * On error, verification token will not be allocated
+ */
+ int (*verify)(const struct keyguard_device *dev, const uint8_t *enrolled_password_handle,
+ const uint8_t enrolled_password_handle_length, const uint8_t *provided_password,
+ const uint8_t provided_password_length, uint8_t **verification_token);
+
+};
+typedef struct keyguard_device keyguard_device_t;
+
+static inline int keyguard_open(const struct hw_module_t *module,
+ keyguard_device_t **device) {
+ return module->methods->open(module, HARDWARE_KEYGUARD,
+ (struct hw_device_t **) device);
+}
+
+static inline int keyguard_close(keyguard_device_t *device) {
+ return device->common.close(&device->common);
+}
+
+__END_DECLS
+
+#endif // ANDROID_HARDWARE_KEYGUARD_H