1 /*
2  * Copyright (C) 2015 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 #include "operation_table.h"
18 
19 #include <new>
20 
21 #include <openssl/rand.h>
22 
23 #include "openssl_err.h"
24 #include "operation.h"
25 
26 namespace keymaster {
27 
~Entry()28 OperationTable::Entry::~Entry() {
29     delete operation;
30     operation = NULL;
31     handle = 0;
32 }
33 
Add(Operation * operation,keymaster_operation_handle_t * op_handle)34 keymaster_error_t OperationTable::Add(Operation* operation,
35                                       keymaster_operation_handle_t* op_handle) {
36     if (!table_.get()) {
37         table_.reset(new (std::nothrow) Entry[table_size_]);
38         if (!table_.get())
39             return KM_ERROR_MEMORY_ALLOCATION_FAILED;
40     }
41 
42     UniquePtr<Operation> op(operation);
43     if (RAND_bytes(reinterpret_cast<uint8_t*>(op_handle), sizeof(*op_handle)) != 1)
44         return TranslateLastOpenSslError();
45     if (*op_handle == 0) {
46         // Statistically this is vanishingly unlikely, which means if it ever happens in practice,
47         // it indicates a broken RNG.
48         return KM_ERROR_UNKNOWN_ERROR;
49     }
50 
51     for (size_t i = 0; i < table_size_; ++i) {
52         if (table_[i].operation == NULL) {
53             table_[i].operation = op.release();
54             table_[i].handle = *op_handle;
55             return KM_ERROR_OK;
56         }
57     }
58     return KM_ERROR_TOO_MANY_OPERATIONS;
59 }
60 
Find(keymaster_operation_handle_t op_handle)61 Operation* OperationTable::Find(keymaster_operation_handle_t op_handle) {
62     if (op_handle == 0)
63         return NULL;
64 
65     if (!table_.get())
66         return NULL;
67 
68     for (size_t i = 0; i < table_size_; ++i) {
69         if (table_[i].handle == op_handle)
70             return table_[i].operation;
71     }
72     return NULL;
73 }
74 
Delete(keymaster_operation_handle_t op_handle)75 bool OperationTable::Delete(keymaster_operation_handle_t op_handle) {
76     if (!table_.get())
77         return false;
78 
79     for (size_t i = 0; i < table_size_; ++i) {
80         if (table_[i].handle == op_handle) {
81             delete table_[i].operation;
82             table_[i].operation = NULL;
83             table_[i].handle = 0;
84             return true;
85         }
86     }
87     return false;
88 }
89 
90 }  // namespace keymaster
91