1 /*
2  * Copyright (C) 2016 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 _EEDATA_H_
18 #define _EEDATA_H_
19 
20 #include <stdbool.h>
21 #include <stdint.h>
22 
23 /*
24  * EEDATA allows storage of data in a persistent area that survives reboots and OS updates.
25  * Each data piece has a name and stores 0..EE_DATA_LEN_MAX bytes of data. The name is a
26  * non-zero number in the range 0..EE_DATA_NAME_MAX - 1. All names below EE_DATA_FIRST_USER
27  * are reserved for OS purposes and are not accessible using the external-app-visible API.
28  * To store an EEDATA item, use eeDataSet(). Setting the buffer to NULL will delete an
29  * existing item and not replace it. Otherwise an item is replaced. Return value is success
30  * (deleting a non-existent item always suceeds). You can use eeDataGet() to get items. It
31  * will return true if an item exists. If called with buf set to NULL and szP not NULL,
32  * *szP will be filled with its size. Else if buf and szP are both not NULL, up to *szP
33  * bytes will be stored into buf, and *szP will be updated with the number of bytes written.
34  * True is returned if the data item exists at all, else false is. For encryption keys, we
35  * [ab]use eeDataGetAllVersions to get all keys (as each has the same name).
36  */
37 
38 
39 
40 #define EE_DATA_NAME_MAX   0x000FFFFF
41 #define EE_DATA_LEN_MAX    0x00000FFF //in bytes
42 #define EE_DATA_FIRST_USER 0x00000100
43 
44 
45 bool eeDataGet(uint32_t name, void *buf, uint32_t *szP);
46 bool eeDataSet(uint32_t name, const void *buf, uint32_t len);
47 
48 //allow getting old "versions". Set state to NULL initially, call till you get NULL as return value
49 void *eeDataGetAllVersions(uint32_t name, void *buf, uint32_t *szP, void **stateP);
50 bool eeDataEraseOldVersion(uint32_t name, void *addr); // addr is non-NULL address returned by call to eeDataGetAllVersions
51 
52 //predefined key types
53 
54 #define EE_DATA_NAME_ENCR_KEY            1
55 
56 
57 
58 #endif
59 
60