1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef TRUSTY_GATEKEEPER_H
18 #define TRUSTY_GATEKEEPER_H
19 
20 #include <hardware/gatekeeper.h>
21 #include <gatekeeper/gatekeeper_messages.h>
22 
23 #include "gatekeeper_ipc.h"
24 
25 namespace gatekeeper {
26 
27 class TrustyGateKeeperDevice {
28     public:
29 
30     explicit TrustyGateKeeperDevice(const hw_module_t* module);
31     ~TrustyGateKeeperDevice();
32 
33     hw_device_t* hw_device();
34 
35     /**
36      * Enrolls password_payload, which should be derived from a user selected pin or password,
37      * with the authentication factor private key used only for enrolling authentication
38      * factor data.
39      *
40      * Returns: 0 on success or an error code less than 0 on error.
41      * On error, enrolled_password will not be allocated.
42      */
43     int Enroll(uint32_t uid, const uint8_t *current_password_handle,
44             uint32_t current_password_handle_length, const uint8_t *current_password,
45             uint32_t current_password_length, const uint8_t *desired_password,
46             uint32_t desired_password_length, uint8_t **enrolled_password_handle,
47             uint32_t *enrolled_password_handle_length);
48 
49     /**
50      * Verifies provided_password matches expected_password after enrolling
51      * with the authentication factor private key.
52      *
53      * Implementations of this module may retain the result of this call
54      * to attest to the recency of authentication.
55      *
56      * On success, writes the address of a verification token to verification_token,
57      *
58      * Returns: 0 on success or an error code less than 0 on error
59      * On error, verification token will not be allocated
60      */
61     int Verify(uint32_t uid, uint64_t challenge, const uint8_t *enrolled_password_handle,
62             uint32_t enrolled_password_handle_length, const uint8_t *provided_password,
63             uint32_t provided_password_length, uint8_t **auth_token, uint32_t *auth_token_length,
64             bool *request_reenroll);
65 
66     private:
67 
68     gatekeeper_error_t Send(uint32_t command, const GateKeeperMessage& request,
69                            GateKeeperMessage* response);
70 
Send(const EnrollRequest & request,EnrollResponse * response)71     gatekeeper_error_t Send(const EnrollRequest& request, EnrollResponse *response) {
72         return Send(GK_ENROLL, request, response);
73     }
74 
Send(const VerifyRequest & request,VerifyResponse * response)75     gatekeeper_error_t Send(const VerifyRequest& request, VerifyResponse *response) {
76         return Send(GK_VERIFY, request, response);
77     }
78 
79     // Static methods interfacing the HAL API with the TrustyGateKeeper device
80 
81     /**
82      * Enrolls desired_password, which should be derived from a user selected pin or password,
83      * with the authentication factor private key used only for enrolling authentication
84      * factor data.
85      *
86      * If there was already a password enrolled, it should be provided in
87      * current_password_handle, along with the current password in current_password
88      * that should validate against current_password_handle.
89      *
90      * Returns: 0 on success or an error code less than 0 on error.
91      * On error, enrolled_password_handle will not be allocated.
92      */
93     static int enroll(const struct gatekeeper_device *dev, uint32_t uid,
94             const uint8_t *current_password_handle, uint32_t current_password_handle_length,
95             const uint8_t *current_password, uint32_t current_password_length,
96             const uint8_t *desired_password, uint32_t desired_password_length,
97             uint8_t **enrolled_password_handle, uint32_t *enrolled_password_handle_length);
98 
99     /**
100      * Verifies provided_password matches enrolled_password_handle.
101      *
102      * Implementations of this module may retain the result of this call
103      * to attest to the recency of authentication.
104      *
105      * On success, writes the address of a verification token to auth_token,
106      * usable to attest password verification to other trusted services. Clients
107      * may pass NULL for this value.
108      *
109      * Returns: 0 on success or an error code less than 0 on error
110      * On error, verification token will not be allocated
111      */
112     static int verify(const struct gatekeeper_device *dev, uint32_t uid, uint64_t challenge,
113             const uint8_t *enrolled_password_handle, uint32_t enrolled_password_handle_length,
114             const uint8_t *provided_password, uint32_t provided_password_length,
115             uint8_t **auth_token, uint32_t *auth_token_length, bool *request_reenroll);
116 
117     static int close_device(hw_device_t* dev);
118 
119     gatekeeper_device device_;
120     int error_;
121 
122 };
123 }
124 
125 #endif
126 
127