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 ANDROID_INCLUDE_HARDWARE_FINGERPRINT_H
18 #define ANDROID_INCLUDE_HARDWARE_FINGERPRINT_H
19 
20 #include <hardware/hw_auth_token.h>
21 
22 #define FINGERPRINT_MODULE_API_VERSION_1_0 HARDWARE_MODULE_API_VERSION(1, 0)
23 #define FINGERPRINT_MODULE_API_VERSION_2_0 HARDWARE_MODULE_API_VERSION(2, 0)
24 #define FINGERPRINT_MODULE_API_VERSION_2_1 HARDWARE_MODULE_API_VERSION(2, 1)
25 #define FINGERPRINT_HARDWARE_MODULE_ID "fingerprint"
26 
27 typedef enum fingerprint_msg_type {
28     FINGERPRINT_ERROR = -1,
29     FINGERPRINT_ACQUIRED = 1,
30     FINGERPRINT_TEMPLATE_ENROLLING = 3,
31     FINGERPRINT_TEMPLATE_REMOVED = 4,
32     FINGERPRINT_AUTHENTICATED = 5,
33     FINGERPRINT_TEMPLATE_ENUMERATING = 6,
34 } fingerprint_msg_type_t;
35 
36 /*
37  * Fingerprint errors are meant to tell the framework to terminate the current operation and ask
38  * for the user to correct the situation. These will almost always result in messaging and user
39  * interaction to correct the problem.
40  *
41  * For example, FINGERPRINT_ERROR_CANCELED should follow any acquisition message that results in
42  * a situation where the current operation can't continue without user interaction. For example,
43  * if the sensor is dirty during enrollment and no further enrollment progress can be made,
44  * send FINGERPRINT_ACQUIRED_IMAGER_DIRTY followed by FINGERPRINT_ERROR_CANCELED.
45  */
46 typedef enum fingerprint_error {
47     FINGERPRINT_ERROR_HW_UNAVAILABLE = 1, /* The hardware has an error that can't be resolved. */
48     FINGERPRINT_ERROR_UNABLE_TO_PROCESS = 2, /* Bad data; operation can't continue */
49     FINGERPRINT_ERROR_TIMEOUT = 3, /* The operation has timed out waiting for user input. */
50     FINGERPRINT_ERROR_NO_SPACE = 4, /* No space available to store a template */
51     FINGERPRINT_ERROR_CANCELED = 5, /* The current operation can't proceed. See above. */
52     FINGERPRINT_ERROR_UNABLE_TO_REMOVE = 6, /* fingerprint with given id can't be removed */
53     FINGERPRINT_ERROR_VENDOR_BASE = 1000 /* vendor-specific error messages start here */
54 } fingerprint_error_t;
55 
56 /*
57  * Fingerprint acquisition info is meant as feedback for the current operation.  Anything but
58  * FINGERPRINT_ACQUIRED_GOOD will be shown to the user as feedback on how to take action on the
59  * current operation. For example, FINGERPRINT_ACQUIRED_IMAGER_DIRTY can be used to tell the user
60  * to clean the sensor.  If this will cause the current operation to fail, an additional
61  * FINGERPRINT_ERROR_CANCELED can be sent to stop the operation in progress (e.g. enrollment).
62  * In general, these messages will result in a "Try again" message.
63  */
64 typedef enum fingerprint_acquired_info {
65     FINGERPRINT_ACQUIRED_GOOD = 0,
66     FINGERPRINT_ACQUIRED_PARTIAL = 1, /* sensor needs more data, i.e. longer swipe. */
67     FINGERPRINT_ACQUIRED_INSUFFICIENT = 2, /* image doesn't contain enough detail for recognition*/
68     FINGERPRINT_ACQUIRED_IMAGER_DIRTY = 3, /* sensor needs to be cleaned */
69     FINGERPRINT_ACQUIRED_TOO_SLOW = 4, /* mostly swipe-type sensors; not enough data collected */
70     FINGERPRINT_ACQUIRED_TOO_FAST = 5, /* for swipe and area sensors; tell user to slow down*/
71     FINGERPRINT_ACQUIRED_VENDOR_BASE = 1000 /* vendor-specific acquisition messages start here */
72 } fingerprint_acquired_info_t;
73 
74 typedef struct fingerprint_finger_id {
75     uint32_t gid;
76     uint32_t fid;
77 } fingerprint_finger_id_t;
78 
79 typedef struct fingerprint_enroll {
80     fingerprint_finger_id_t finger;
81     /* samples_remaining goes from N (no data collected, but N scans needed)
82      * to 0 (no more data is needed to build a template). */
83     uint32_t samples_remaining;
84     uint64_t msg; /* Vendor specific message. Used for user guidance */
85 } fingerprint_enroll_t;
86 
87 typedef struct fingerprint_enumerated {
88     fingerprint_finger_id_t finger;
89     uint32_t remaining_templates;
90 } fingerprint_enumerated_t;
91 
92 typedef struct fingerprint_removed {
93     fingerprint_finger_id_t finger;
94 } fingerprint_removed_t;
95 
96 typedef struct fingerprint_acquired {
97     fingerprint_acquired_info_t acquired_info; /* information about the image */
98 } fingerprint_acquired_t;
99 
100 typedef struct fingerprint_authenticated {
101     fingerprint_finger_id_t finger;
102     hw_auth_token_t hat;
103 } fingerprint_authenticated_t;
104 
105 typedef struct fingerprint_msg {
106     fingerprint_msg_type_t type;
107     union {
108         fingerprint_error_t error;
109         fingerprint_enroll_t enroll;
110         fingerprint_enumerated_t enumerated;
111         fingerprint_removed_t removed;
112         fingerprint_acquired_t acquired;
113         fingerprint_authenticated_t authenticated;
114     } data;
115 } fingerprint_msg_t;
116 
117 /* Callback function type */
118 typedef void (*fingerprint_notify_t)(const fingerprint_msg_t *msg);
119 
120 /* Synchronous operation */
121 typedef struct fingerprint_device {
122     /**
123      * Common methods of the fingerprint device. This *must* be the first member
124      * of fingerprint_device as users of this structure will cast a hw_device_t
125      * to fingerprint_device pointer in contexts where it's known
126      * the hw_device_t references a fingerprint_device.
127      */
128     struct hw_device_t common;
129 
130     /*
131      * Client provided callback function to receive notifications.
132      * Do not set by hand, use the function above instead.
133      */
134     fingerprint_notify_t notify;
135 
136     /*
137      * Set notification callback:
138      * Registers a user function that would receive notifications from the HAL
139      * The call will block if the HAL state machine is in busy state until HAL
140      * leaves the busy state.
141      *
142      * Function return: 0 if callback function is successfuly registered
143      *                  or a negative number in case of error, generally from the errno.h set.
144      */
145     int (*set_notify)(struct fingerprint_device *dev, fingerprint_notify_t notify);
146 
147     /*
148      * Fingerprint pre-enroll enroll request:
149      * Generates a unique token to upper layers to indicate the start of an enrollment transaction.
150      * This token will be wrapped by security for verification and passed to enroll() for
151      * verification before enrollment will be allowed. This is to ensure adding a new fingerprint
152      * template was preceded by some kind of credential confirmation (e.g. device password).
153      *
154      * Function return: 0 if function failed
155      *                  otherwise, a uint64_t of token
156      */
157     uint64_t (*pre_enroll)(struct fingerprint_device *dev);
158 
159     /*
160      * Fingerprint enroll request:
161      * Switches the HAL state machine to collect and store a new fingerprint
162      * template. Switches back as soon as enroll is complete
163      * (fingerprint_msg.type == FINGERPRINT_TEMPLATE_ENROLLING &&
164      *  fingerprint_msg.data.enroll.samples_remaining == 0)
165      * or after timeout_sec seconds.
166      * The fingerprint template will be assigned to the group gid. User has a choice
167      * to supply the gid or set it to 0 in which case a unique group id will be generated.
168      *
169      * Function return: 0 if enrollment process can be successfully started
170      *                  or a negative number in case of error, generally from the errno.h set.
171      *                  A notify() function may be called indicating the error condition.
172      */
173     int (*enroll)(struct fingerprint_device *dev, const hw_auth_token_t *hat,
174                     uint32_t gid, uint32_t timeout_sec);
175 
176     /*
177      * Finishes the enroll operation and invalidates the pre_enroll() generated challenge.
178      * This will be called at the end of a multi-finger enrollment session to indicate
179      * that no more fingers will be added.
180      *
181      * Function return: 0 if the request is accepted
182      *                  or a negative number in case of error, generally from the errno.h set.
183      */
184     int (*post_enroll)(struct fingerprint_device *dev);
185 
186     /*
187      * get_authenticator_id:
188      * Returns a token associated with the current fingerprint set. This value will
189      * change whenever a new fingerprint is enrolled, thus creating a new fingerprint
190      * set.
191      *
192      * Function return: current authenticator id or 0 if function failed.
193      */
194     uint64_t (*get_authenticator_id)(struct fingerprint_device *dev);
195 
196     /*
197      * Cancel pending enroll or authenticate, sending FINGERPRINT_ERROR_CANCELED
198      * to all running clients. Switches the HAL state machine back to the idle state.
199      * Unlike enroll_done() doesn't invalidate the pre_enroll() challenge.
200      *
201      * Function return: 0 if cancel request is accepted
202      *                  or a negative number in case of error, generally from the errno.h set.
203      */
204     int (*cancel)(struct fingerprint_device *dev);
205 
206     /*
207      * Enumerate all the fingerprint templates found in the directory set by
208      * set_active_group()
209      * For each template found notify() will be called with:
210      * fingerprint_msg.type == FINGERPRINT_TEMPLATE_ENUMERATED
211      * fingerprint_msg.data.enumerated.finger indicating a template id
212      * fingerprint_msg.data.enumerated.remaining_templates indicating how many more
213      * enumeration messages to expect.
214      *
215      * Function return: 0 if enumerate request is accepted
216      *                  or a negative number in case of error, generally from the errno.h set.
217      */
218     int (*enumerate)(struct fingerprint_device *dev);
219 
220     /*
221      * Fingerprint remove request:
222      * Deletes a fingerprint template.
223      * Works only within the path set by set_active_group().
224      * notify() will be called with details on the template deleted.
225      * fingerprint_msg.type == FINGERPRINT_TEMPLATE_REMOVED and
226      * fingerprint_msg.data.removed.finger indicating the template id removed.
227      *
228      * Function return: 0 if fingerprint template(s) can be successfully deleted
229      *                  or a negative number in case of error, generally from the errno.h set.
230      */
231     int (*remove)(struct fingerprint_device *dev, uint32_t gid, uint32_t fid);
232 
233     /*
234      * Restricts the HAL operation to a set of fingerprints belonging to a
235      * group provided.
236      * The caller must provide a path to a storage location within the user's
237      * data directory.
238      *
239      * Function return: 0 on success
240      *                  or a negative number in case of error, generally from the errno.h set.
241      */
242     int (*set_active_group)(struct fingerprint_device *dev, uint32_t gid,
243                             const char *store_path);
244 
245     /*
246      * Authenticates an operation identifed by operation_id
247      *
248      * Function return: 0 on success
249      *                  or a negative number in case of error, generally from the errno.h set.
250      */
251     int (*authenticate)(struct fingerprint_device *dev, uint64_t operation_id, uint32_t gid);
252 
253     /* Reserved for backward binary compatibility */
254     void *reserved[4];
255 } fingerprint_device_t;
256 
257 typedef struct fingerprint_module {
258     /**
259      * Common methods of the fingerprint module. This *must* be the first member
260      * of fingerprint_module as users of this structure will cast a hw_module_t
261      * to fingerprint_module pointer in contexts where it's known
262      * the hw_module_t references a fingerprint_module.
263      */
264     struct hw_module_t common;
265 } fingerprint_module_t;
266 
267 #endif  /* ANDROID_INCLUDE_HARDWARE_FINGERPRINT_H */
268