platform_hardware_libhardware/include/hardware/keyguard.h
Andres Morales 3b48ae5a64 hardware keyguard HAL
simple API for signing/verifying passwords
with a hardware-backed keyguard

Change-Id: Ib2e25c7419e113494c2b0a4579ce8264a2335e07
2015-01-30 12:18:10 -08:00

92 lines
3.2 KiB
C

/*
* 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