| // |
| // Copyright (C) 2011 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| |
| #include "shill/crypto_rot47.h" |
| |
| using std::string; |
| |
| namespace shill { |
| |
| const char CryptoROT47::kID[] = "rot47"; |
| |
| CryptoROT47::CryptoROT47() {} |
| |
| string CryptoROT47::GetID() { |
| return kID; |
| } |
| |
| bool CryptoROT47::Encrypt(const string& plaintext, string* ciphertext) { |
| const int kRotSize = 94; |
| const int kRotHalf = kRotSize / 2; |
| const char kRotMin = '!'; |
| const char kRotMax = kRotMin + kRotSize - 1; |
| |
| *ciphertext = plaintext; |
| for (auto& ch : *ciphertext) { |
| if (ch < kRotMin || ch > kRotMax) { |
| continue; |
| } |
| int rot = ch + kRotHalf; |
| ch = (rot > kRotMax) ? rot - kRotSize : rot; |
| } |
| return true; |
| } |
| |
| bool CryptoROT47::Decrypt(const string& ciphertext, string* plaintext) { |
| // ROT47 is self-reciprocal. |
| return Encrypt(ciphertext, plaintext); |
| } |
| |
| } // namespace shill |