/*
 # Copyright (c) 2009 - OpenSLX Project, Computer Center University of Freiburg
 #
 # This program is free software distributed under the GPL version 2.
 # See http://openslx.org/COPYING
 #
 # If you have any feedback please consult http://openslx.org/feedback and
 # send your suggestions, praise, or complaints to feedback@openslx.org
 #
 # General information about OpenSLX can be found at http://openslx.org/
 # -----------------------------------------------------------------------------
 # src/util/CertManager.cpp
 #    - Manage SSL certificates
 #    - provide access by name
 # -----------------------------------------------------------------------------
 */

#define CERTSTORAGE ".config/openslx/pvs2/"

#include "certmanager.h"
#include "../../shared/util.h"
// Remove in future - see comment in util.h
#undef errorOccurred

#include <QHash>
#include <QDir>
#include <QDebug>
#include <QFileInfo>
#include <QMessageBox>
#include <QProcess>
#include <QCoreApplication>

namespace CertManager
{
static QHash<QString, QSslCertificate> _certs;
static QHash<QString, QSslKey> _keys;

static void generateFiles(QString& key, QString& cert);
static bool loadFiles(QString& keyFile, QString& certFile, QSslKey &key, QSslCertificate &cert);

bool getPrivateKeyAndCert(const QString &name, QSslKey &key, QSslCertificate &cert)
{
	if (_keys.contains(name)) {
		key = _keys[name];
		cert = _certs[name];
		return true;
	}
	QString certDir = QDir::homePath().append("/").append(CERTSTORAGE);
	if (!QDir::root().mkpath(certDir)) {
		certDir = QString("/tmp/") + QString::number(slxrand()) + "-" + QString::number(slxrand()) + "/";
		QDir::root().mkpath(certDir);
	}
	QString certFile = certDir.append(name);
	QString keyFile = certFile;
	keyFile.append(".rsa");
	certFile.append(".crt");
	//
	if (!loadFiles(keyFile, certFile, key, cert)) {
		generateFiles(keyFile, certFile);
		if (!loadFiles(keyFile, certFile, key, cert)) {
			qDebug() << "error while creating cert and key files";
			return false;
		}
	}
	_certs.insert(name, cert);
	_keys.insert(name, key);
	return true;
}

void fatal()
{
	QMessageBox::critical(nullptr, QObject::tr("OpenSSL error", "CertManager"),
			QObject::tr("Could not generate certificates for secure connections.\n"
			"PVS will not work.\n\n"
			"Press OK to quit.", "CertManager"));
	QCoreApplication::exit(1);
}

static bool loadFiles(QString& keyFile, QString& certFile, QSslKey &key, QSslCertificate &cert)
{
	QFileInfo keyInfo(keyFile);
	QFileInfo certInfo(certFile);
	if (keyInfo.exists() && certInfo.exists()) {
		// Both files exist, see if they're valid and return
		QFile kf(keyFile);
		kf.open(QFile::ReadOnly);
		key = QSslKey(&kf, QSsl::Rsa, QSsl::Pem, QSsl::PrivateKey);
		QList<QSslCertificate> certlist = QSslCertificate::fromPath(certFile);
		if (!key.isNull() && !certlist.empty()) {
			cert = certlist.first();
			if (!cert.isNull()) {
				return true;
			}
		}
	}
	return false;
}

static void generateFiles(QString& key, QString& cert)
{
	QProcess p;
	QFile::remove(key);
	QFile::remove(cert);
	p.setProcessChannelMode(QProcess::ForwardedChannels);
	p.start(QStringLiteral("openssl"), {
		"req", "-x509", "-nodes", "-days", "5000", "-newkey", "rsa:4096",
		"-subj", "/C=DE/ST=BaWue/L=Freiburg/CN=openslx.org",
		"-keyout", key, "-out", cert
	});
	p.waitForFinished();
	p.start(QStringLiteral("chmod"), { "0600", key, cert });
	p.waitForFinished(500);
}

}