keys: yk: Implement ChallengeResponseKey for YubiKey

* Implement a YubiKey challenge response class.  One object will be
  created for each challenge response key available.

Signed-off-by: Kyle Manna <kyle@kylemanna.com>

src/keys/YkChallengeResponseKey.cpp

@@ -0,0 +1,72 @@
+/*
+*  Copyright (C) 2014 Kyle Manna <kyle@kylemanna.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 <QFile>
+#include <QXmlStreamReader>
+
+#include "core/Tools.h"
+#include "crypto/CryptoHash.h"
+#include "crypto/Random.h"
+
+#include "keys/YkChallengeResponseKey.h"
+#include "keys/drivers/YubiKey.h"
+
+YkChallengeResponseKey::YkChallengeResponseKey(int slot,
+                                               bool blocking)
+    : m_slot(slot),
+      m_blocking(blocking)
+{
+}
+
+QByteArray YkChallengeResponseKey::rawKey() const
+{
+    return m_key;
+}
+
+YkChallengeResponseKey* YkChallengeResponseKey::clone() const
+{
+    return new YkChallengeResponseKey(*this);
+}
+
+
+/** Assumes yubikey()->init() was called */
+bool YkChallengeResponseKey::challenge(const QByteArray& chal)
+{
+    if (YubiKey::instance()->challenge(m_slot, true, chal, m_key) != YubiKey::ERROR) {
+        return true;
+    }
+
+    return false;
+}
+
+QString YkChallengeResponseKey::getName() const
+{
+    unsigned int serial;
+    QString fmt("YubiKey[%1] Challenge Response - Slot %2 - %3");
+
+    YubiKey::instance()->getSerial(serial);
+
+    return fmt.arg(QString::number(serial),
+                   QString::number(m_slot),
+                   (m_blocking) ? "Press" : "Passive");
+}
+
+bool YkChallengeResponseKey::isBlocking() const
+{
+    return m_blocking;
+}