bool Exporter::write(const SecureByteArray &data, const SecureString &pwd)
{
Q_D(Exporter);
Q_ASSERT((data.size() % Crypter::AESBlockSize) == 0);
QByteArray salt = Crypter::generateSalt();
SecureByteArray iv;
SecureByteArray key;
Crypter::makeKeyAndIVFromPassword(pwd.toUtf8(), salt, key, iv);
CryptoPP::CBC_Mode<CryptoPP::AES>::Encryption enc;
enc.SetKeyWithIV(reinterpret_cast<const byte*>(key.constData()), key.size(), reinterpret_cast<const byte*>(iv.constData()));
const int cipherSize = data.size();
QByteArray cipher(cipherSize, static_cast<char>(0));
CryptoPP::ArraySource s(
reinterpret_cast<const byte*>(data.constData()), data.size(),
true,
new CryptoPP::StreamTransformationFilter(
enc,
new CryptoPP::ArraySink(reinterpret_cast<byte*>(cipher.data()), cipher.size()),
CryptoPP::StreamTransformationFilter::NO_PADDING
)
);
Q_UNUSED(s); // just to please the compiler
QFile file(d->filename);
bool opened = file.open(QIODevice::WriteOnly);
if (!opened)
return false;
QByteArray block = salt + cipher;
file.write(PemPreamble.toUtf8());
file.write("\n");
const SecureByteArray &b64 = block.toBase64();
for (int i = 0; i < b64.size(); i += 64) {
file.write(b64.mid(i, qMin(64, b64.size() - i)));
file.write("\n");
}
file.write(PemEpilog.toUtf8());
file.write("\n");
file.close();
return true;
}
SecureByteArray Exporter::read(const SecureString &pwd)
{
Q_D(Exporter);
SecureByteArray plain;
QFile file(d->filename);
bool opened = file.open(QIODevice::ReadOnly);
if (opened) {
static const int MaxLineSize = 64 + 2;
int state = 0;
QByteArray b64;
while (!file.atEnd()) {
char buf[MaxLineSize];
const qint64 bytesRead = file.readLine(buf, MaxLineSize);
const QString line = QByteArray(buf, bytesRead).trimmed();
switch (state) {
case 0:
if (line == PemPreamble) {
state = 1;
}
else {
qWarning() << "bad format";
}
break;
case 1:
if (line != PemEpilog) {
b64.append(line.toUtf8());
}
else {
state = 2;
}
break;
case 2:
// ignore trailing lines
break;
default:
qWarning() << "Oops! Should never have gotten here.";
break;
}
}
file.close();
SecureByteArray iv;
SecureByteArray key;
QByteArray imported = QByteArray::fromBase64(b64);
QByteArray salt = imported.mid(0, Crypter::SaltSize);
QByteArray cipher = imported.mid(Crypter::SaltSize);
Crypter::makeKeyAndIVFromPassword(pwd.toUtf8(), salt, key, iv);
CryptoPP::CBC_Mode<CryptoPP::AES>::Decryption dec;
dec.SetKeyWithIV(reinterpret_cast<const byte*>(key.constData()), key.size(), reinterpret_cast<const byte*>(iv.constData()));
plain = SecureByteArray(cipher.size(), static_cast<char>(0));
CryptoPP::ArraySource s(
reinterpret_cast<const byte*>(cipher.constData()), cipher.size(),
true,
new CryptoPP::StreamTransformationFilter(
dec,
new CryptoPP::ArraySink(reinterpret_cast<byte*>(plain.data()), plain.size()),
CryptoPP::StreamTransformationFilter::NO_PADDING
)
);
Q_UNUSED(s); // just to please the compiler
}
return plain;
}