1//
2// Copyright (C) 2012 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 "shill/crypto_provider.h"
18
19#include <memory>
20
21#include <base/strings/string_util.h>
22
23#include "shill/crypto_des_cbc.h"
24#include "shill/crypto_rot47.h"
25#include "shill/logging.h"
26
27using std::string;
28
29namespace shill {
30
31const char CryptoProvider::kKeyMatterFile[] = "/var/lib/whitelist/owner.key";
32
33CryptoProvider::CryptoProvider()
34    : key_matter_file_(kKeyMatterFile) {}
35
36void CryptoProvider::Init() {
37  cryptos_.clear();
38
39  // Register the crypto modules in priority order -- highest priority first.
40  std::unique_ptr<CryptoDESCBC> des_cbc(new CryptoDESCBC());
41  if (des_cbc->LoadKeyMatter(key_matter_file_)) {
42    cryptos_.push_back(des_cbc.release());
43  }
44  cryptos_.push_back(new CryptoROT47());
45}
46
47string CryptoProvider::Encrypt(const string& plaintext) {
48  for (auto crypto : cryptos_) {
49    string ciphertext;
50    if (crypto->Encrypt(plaintext, &ciphertext)) {
51      const string prefix = crypto->GetID() + ":";
52      return prefix + ciphertext;
53    }
54  }
55  LOG(WARNING) << "Unable to encrypt text, returning as is.";
56  return plaintext;
57}
58
59string CryptoProvider::Decrypt(const string& ciphertext) {
60  for (auto crypto : cryptos_) {
61    const string prefix = crypto->GetID() + ":";
62    if (base::StartsWith(ciphertext, prefix, base::CompareCase::SENSITIVE)) {
63      string to_decrypt = ciphertext;
64      to_decrypt.erase(0, prefix.size());
65      string plaintext;
66      if (!crypto->Decrypt(to_decrypt, &plaintext)) {
67        LOG(WARNING) << "Crypto module " << crypto->GetID()
68                     << " failed to decrypt.";
69      }
70      return plaintext;
71    }
72  }
73  LOG(WARNING) << "Unable to decrypt text, returning as is.";
74  return ciphertext;
75}
76
77}  // namespace shill
78