1
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forked from blue/squawk
squawk/core/utils/jammer.cpp
2024-12-14 01:53:04 +02:00

95 lines
3.3 KiB
C++

/*
* Squawk messenger.
* Copyright (C) 2019 Yury Gubich <blue@macaw.me>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "jammer.h"
#include <memory>
#include <openssl/evp.h>
#include <openssl/err.h>
struct CipherCtxDeleter {
void operator()(EVP_CIPHER_CTX* ctx) const {
EVP_CIPHER_CTX_free(ctx);
}
};
typedef std::unique_ptr<EVP_CIPHER_CTX, CipherCtxDeleter> CipherCtx;
QString Core::Jammer::encrypt(const QString& plaintext, qint64 key) {
QByteArray encryptedData = process(plaintext.toUtf8(), intToKey(key), true);
return QString::fromUtf8(encryptedData.toHex());
}
QString Core::Jammer::decrypt(const QString& ciphertext, qint64 key) {
QByteArray encryptedData = QByteArray::fromHex(ciphertext.toUtf8());
QByteArray decryptedData = process(encryptedData, intToKey(key), false);
return QString::fromUtf8(decryptedData);
}
std::string Core::Jammer::getOpenSSLErrorString() {
unsigned long errCode = ERR_get_error();
if (errCode == 0) {
return "No OpenSSL error";
}
const char *errMsg = ERR_reason_error_string(errCode);
return errMsg ? std::string(errMsg) : "Unknown OpenSSL error";
}
QByteArray Core::Jammer::process(const QByteArray& input, const QByteArray& key, bool encrypt) {
CipherCtx ctx(EVP_CIPHER_CTX_new());
if (!ctx)
throw std::runtime_error("Failed to create password jammer context");
QByteArray output(input.size() + 16, 0);
int outputLength = 0;
int finalLength = 0;
if (!ctx)
throw std::runtime_error("Failed to create EVP_CIPHER_CTX: " + getOpenSSLErrorString());
if (EVP_CipherInit_ex(ctx.get(), EVP_chacha20(), nullptr, toUChar(key), nullptr, encrypt) != 1)
throw std::runtime_error("EVP_CipherInit_ex failed. " + getOpenSSLErrorString());
if (EVP_CipherUpdate(ctx.get(), toUChar(output), &outputLength, toUChar(input), input.size()) != 1)
throw std::runtime_error("EVP_CipherUpdate failed. " + getOpenSSLErrorString());
if (EVP_CipherFinal_ex(ctx.get(), toUChar(output) + outputLength, &finalLength) != 1)
throw std::runtime_error("EVP_CipherFinal_ex failed. " + getOpenSSLErrorString());
output.resize(outputLength + finalLength);
return output;
}
QByteArray Core::Jammer::intToKey(qint64 key, int keySize) {
QByteArray keyBytes(reinterpret_cast<const char *>(&key), sizeof(key));
while (keyBytes.size() < keySize)
keyBytes.append(keyBytes);
keyBytes.truncate(keySize);
return keyBytes;
}
unsigned char* Core::Jammer::toUChar(QByteArray& data) {
return reinterpret_cast<unsigned char *>(data.data());}
const unsigned char* Core::Jammer::toUChar(const QByteArray& data) {
return reinterpret_cast<const unsigned char *>(data.constData());}