Add TOTP support

2 files changed, 204 insertions, 0 deletions

diff --git a/src/totp/totp.cpp b/src/totp/totp.cpp
new file mode 100644
index 000000000..45e98d38d
--- /dev/null
+++ b/src/totp/totp.cpp
@@ -0,0 +1,170 @@
+/*
+ *  Copyright (C) 2017 Weslly Honorato <weslly@protonmail.com>
+ *
+ *  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 2 or (at your option)
+ *  version 3 of the License.
+ *
+ *  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 "totp.h"
+#include <cmath>
+#include <QtEndian>
+#include <QRegExp>
+#include <QDateTime>
+#include <QCryptographicHash>
+#include <QMessageAuthenticationCode>
+#include <QUrl>
+#include <QUrlQuery>
+
+
+const quint8 QTotp::defaultStep = 30;
+const quint8 QTotp::defaultDigits = 6;
+
+QTotp::QTotp()
+{
+}
+
+QString QTotp::parseOtpString(QString key, quint8 &digits, quint8 &step)
+{
+    QUrl url(key);
+
+    QString seed;
+    uint q_digits, q_step;
+
+    // Default OTP url format
+    if (url.isValid() && url.scheme() == "otpauth") {
+        QUrlQuery query(url);
+
+        seed = query.queryItemValue("secret");
+
+        q_digits = query.queryItemValue("digits").toUInt();
+        if (q_digits == 6 || q_digits == 8) {
+            digits = q_digits;
+        }
+
+        q_step = query.queryItemValue("period").toUInt();
+        if (q_step > 0 && q_step <= 60) {
+            step = q_step;
+        }
+
+
+    } else {
+        // Compatibility with "KeeOtp" plugin string format
+        QRegExp rx("key=(.+)", Qt::CaseInsensitive, QRegExp::RegExp);
+
+        if (rx.exactMatch(key)) {
+            QUrlQuery query(key);
+
+            seed = query.queryItemValue("key");
+            q_digits = query.queryItemValue("size").toUInt();
+            if (q_digits == 6 || q_digits == 8) {
+                digits = q_digits;
+            }
+
+            q_step = query.queryItemValue("step").toUInt();
+            if (q_step > 0 && q_step <= 60) {
+                step = q_step;
+            }
+
+        } else {
+            seed = key;
+        }
+    }
+
+    if (digits == 0) {
+        digits = defaultDigits;
+    }
+
+    if (step == 0) {
+        step = defaultStep;
+    }
+
+    return seed;
+}
+
+
+QByteArray QTotp::base32_decode(const QByteArray encoded)
+{
+    // Base32 implementation
+    // Copyright 2010 Google Inc.
+    // Author: Markus Gutschke
+    // Licensed under the Apache License, Version 2.0
+
+    QByteArray result;
+
+    int buffer = 0;
+    int bitsLeft = 0;
+
+    for (char ch : encoded) {
+        if (ch == 0 || ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n' || ch == '-' || ch == '=') {
+            continue;
+        }
+
+        buffer <<= 5;
+
+        // Deal with commonly mistyped characters
+        if (ch == '0') {
+            ch = 'O';
+        } else if (ch == '1') {
+            ch = 'L';
+        } else if (ch == '8') {
+            ch = 'B';
+        }
+
+        // Look up one base32 digit
+        if ((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z')) {
+            ch = (ch & 0x1F) - 1;
+        } else if (ch >= '2' && ch <= '7') {
+            ch -= '2' - 26;
+        } else {
+            return QByteArray();
+        }
+
+        buffer |= ch;
+        bitsLeft += 5;
+
+        if (bitsLeft >= 8) {
+            result.append(static_cast<char> (buffer >> (bitsLeft - 8)));
+            bitsLeft -= 8;
+        }
+    }
+
+    return result;
+}
+
+
+QString QTotp::generateTotp(const QByteArray key, quint64 time, const quint8 numDigits = defaultDigits, const quint8 step = defaultStep)
+{
+    quint64 current = qToBigEndian(time / step);
+
+    QByteArray secret = QTotp::base32_decode(key);
+    if (secret.isEmpty()) {
+        return "Invalid TOTP secret key";
+    }
+
+    QMessageAuthenticationCode code(QCryptographicHash::Sha1);
+    code.setKey(secret);
+    code.addData(QByteArray(reinterpret_cast<char*>(&current), sizeof(current)));
+    QByteArray hmac = code.result();
+
+    int offset = (hmac[hmac.length() - 1] & 0xf);
+    int binary =
+            ((hmac[offset] & 0x7f) << 24)
+            | ((hmac[offset + 1] & 0xff) << 16)
+            | ((hmac[offset + 2] & 0xff) << 8)
+            | (hmac[offset + 3] & 0xff);
+
+    quint32 digitsPower = pow(10, numDigits);
+
+    quint64 password = binary % digitsPower;
+    return QString("%1").arg(password, numDigits, 10, QChar('0'));
+}
diff --git a/src/totp/totp.h b/src/totp/totp.h
new file mode 100644
index 000000000..8d7e86744
--- /dev/null
+++ b/src/totp/totp.h
@@ -0,0 +1,34 @@
+/*
+ *  Copyright (C) 2017 Weslly Honorato <weslly@protonmail.com>
+ *
+ *  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 2 or (at your option)
+ *  version 3 of the License.
+ *
+ *  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/>.
+ */
+
+#ifndef QTOTP_H
+#define QTOTP_H
+
+#include <QtCore/qglobal.h>
+
+class QTotp
+{
+public:
+    QTotp();
+    static QString parseOtpString(QString rawSecret, quint8 &digits, quint8 &step);
+    static QByteArray base32_decode(const QByteArray encoded);
+    static QString generateTotp(const QByteArray key, quint64 time, const quint8 numDigits, const quint8 step);
+    static const quint8 defaultStep;
+    static const quint8 defaultDigits;
+};
+
+#endif // QTOTP_H