1/*
2 * Copyright 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 SYSTEM_KEYMASTER_AES_KEY_H_
18#define SYSTEM_KEYMASTER_AES_KEY_H_
19
20#include <openssl/aes.h>
21
22#include "symmetric_key.h"
23
24namespace keymaster {
25
26const size_t kMinGcmTagLength = 12 * 8;
27const size_t kMaxGcmTagLength = 16 * 8;
28
29class AesKeyFactory : public SymmetricKeyFactory {
30  public:
31    AesKeyFactory(const KeymasterContext* context) : SymmetricKeyFactory(context) {}
32
33    keymaster_algorithm_t registry_key() const { return KM_ALGORITHM_AES; }
34
35    keymaster_error_t LoadKey(const KeymasterKeyBlob& key_material,
36                              const AuthorizationSet& hw_enforced,
37                              const AuthorizationSet& sw_enforced,
38                              UniquePtr<Key>* key) const override;
39
40    OperationFactory* GetOperationFactory(keymaster_purpose_t purpose) const override;
41
42  private:
43    bool key_size_supported(size_t key_size_bits) const override {
44        return key_size_bits == 128 || key_size_bits == 192 || key_size_bits == 256;
45    }
46    keymaster_error_t validate_algorithm_specific_new_key_params(
47        const AuthorizationSet& key_description) const override;
48};
49
50class AesKey : public SymmetricKey {
51  public:
52    AesKey(const KeymasterKeyBlob& key_material, const AuthorizationSet& hw_enforced,
53           const AuthorizationSet& sw_enforced, keymaster_error_t* error)
54        : SymmetricKey(key_material, hw_enforced, sw_enforced, error) {}
55};
56
57}  // namespace keymaster
58
59#endif  // SYSTEM_KEYMASTER_AES_KEY_H_
60