1/*
2 * Copyright 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#ifndef SYSTEM_KEYMASTER_ECIES_KEM_H_
18#define SYSTEM_KEYMASTER_ECIES_KEM_H_
19
20#include "kem.h"
21
22#include <UniquePtr.h>
23#include <openssl/ec.h>
24
25#include <keymaster/authorization_set.h>
26
27#include "hkdf.h"
28#include "key_exchange.h"
29
30namespace keymaster {
31
32/**
33 * EciesKem is an implementation of the key encapsulation mechanism ECIES-KEM described in
34 * ISO 18033-2 (http://www.shoup.net/iso/std6.pdf, http://www.shoup.net/papers/iso-2_1.pdf).
35 */
36class EciesKem : public Kem {
37  public:
38    virtual ~EciesKem() override {}
39    EciesKem(const AuthorizationSet& kem_description, keymaster_error_t* error);
40
41    /* Kem interface. */
42    bool Encrypt(const Buffer& peer_public_value, Buffer* output_clear_key,
43                 Buffer* output_encrypted_key) override;
44    bool Encrypt(const uint8_t* peer_public_value, size_t peer_public_value_len,
45                 Buffer* output_clear_key, Buffer* output_encrypted_key) override;
46
47    bool Decrypt(EC_KEY* private_key, const Buffer& encrypted_key, Buffer* output_key) override;
48    bool Decrypt(EC_KEY* private_key, const uint8_t* encrypted_key, size_t encrypted_key_len,
49                 Buffer* output_key) override;
50
51  private:
52    UniquePtr<KeyExchange> key_exchange_;
53    UniquePtr<Rfc5869Sha256Kdf> kdf_;
54    bool single_hash_mode_;
55    uint32_t key_bytes_to_generate_;
56    keymaster_ec_curve_t curve_;
57};
58
59}  // namespace keymaster
60
61#endif  // SYSTEM_KEYMASTER_ECIES_KEM_H_
62