diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index b132d6d..a83252d 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -46,7 +46,7 @@ add_library(${LIBNAME} ${SOURCE})
 target_link_libraries(${LIBNAME}
     PUBLIC Qt5::Core
     PUBLIC Qt5::Network
-    PUBLIC ${BOTAN_LIBRARIES})
+    PRIVATE ${BOTAN_LIBRARIES})
 target_include_directories(${LIBNAME} PRIVATE ${BOTAN_INCLUDE_DIRS})
 
 foreach(LIB Qt5Network Qt5Core ${BOTAN_LIBRARIES})
diff --git a/lib/address.h b/lib/address.h
index 51f4311..e0e1f5d 100644
--- a/lib/address.h
+++ b/lib/address.h
@@ -43,8 +43,8 @@ class QSS_EXPORT Address : public QObject
                      QObject *parent = 0);
 
     Address(const QHostAddress &ip,
-                     const quint16 &p,
-                     QObject *parent = 0);
+            const quint16 &p,
+            QObject *parent = 0);
 
     Address(const Address &o);
     //force the generation of default move constructor
diff --git a/lib/addresstester.h b/lib/addresstester.h
index 1a186d2..adfe231 100644
--- a/lib/addresstester.h
+++ b/lib/addresstester.h
@@ -39,8 +39,8 @@ class QSS_EXPORT AddressTester : public QObject
     Q_OBJECT
 public:
     AddressTester(const QHostAddress &server_address,
-                           const quint16 &server_port,
-                           QObject *parent = 0);
+                  const quint16 &server_port,
+                  QObject *parent = 0);
 
     static const int LAG_TIMEOUT = -1;
     static const int LAG_ERROR = -2;
diff --git a/lib/chacha.h b/lib/chacha.h
index 1b97da4..ac4e2f0 100644
--- a/lib/chacha.h
+++ b/lib/chacha.h
@@ -39,8 +39,8 @@ class ChaCha : public QObject
      * IV length must be 8 or 12
      */
     ChaCha(const QByteArray &_key,
-                    const QByteArray &_iv,
-                    QObject *parent = 0);
+           const QByteArray &_iv,
+           QObject *parent = 0);
 
 public slots:
     //encrypt (or decrypt, same process for ChaCha algorithm) a byte array.
diff --git a/lib/cipher.cpp b/lib/cipher.cpp
index ec7871b..4cd40e6 100644
--- a/lib/cipher.cpp
+++ b/lib/cipher.cpp
@@ -24,12 +24,24 @@
 #include <botan/auto_rng.h>
 #include <botan/key_filt.h>
 #include <botan/lookup.h>
-#include <stdexcept>
+#include <botan/pipe.h>
+#include <botan/version.h>
 #include <QCryptographicHash>
 #include <QMessageAuthenticationCode>
+#include <stdexcept>
 
 using namespace QSS;
 
+#if BOTAN_VERSION_CODE < BOTAN_VERSION_CODE_FOR(1,10,0)
+#error "Botan library is too old."
+#elif BOTAN_VERSION_CODE < BOTAN_VERSION_CODE_FOR(2,0,0)
+typedef Botan::SecureVector<Botan::byte> SecureByteArray;
+#define DataOfSecureByteArray(sba) sba.begin()
+#else
+typedef Botan::secure_vector<Botan::byte> SecureByteArray;
+#define DataOfSecureByteArray(sba) sba.data()
+#endif
+
 Cipher::Cipher(const QByteArray &method,
                const QByteArray &key,
                const QByteArray &iv,
diff --git a/lib/cipher.h b/lib/cipher.h
index 4f08740..ba2c04f 100644
--- a/lib/cipher.h
+++ b/lib/cipher.h
@@ -32,23 +32,15 @@
 #include <array>
 #include <map>
 #include <QObject>
-#include <botan/pipe.h>
-#include <botan/version.h>
 #include "rc4.h"
 #include "chacha.h"
 #include "export.h"
 
-namespace QSS {
+namespace Botan {
+class Pipe;
+}
 
-#if BOTAN_VERSION_CODE < BOTAN_VERSION_CODE_FOR(1,10,0)
-#error "Botan library is too old."
-#elif BOTAN_VERSION_CODE < BOTAN_VERSION_CODE_FOR(2,0,0)
-typedef Botan::SecureVector<Botan::byte> SecureByteArray;
-#define DataOfSecureByteArray(sba) sba.begin()
-#else
-typedef Botan::secure_vector<Botan::byte> SecureByteArray;
-#define DataOfSecureByteArray(sba) sba.data()
-#endif
+namespace QSS {
 
 class QSS_EXPORT Cipher : public QObject
 {
diff --git a/lib/encryptorprivate.h b/lib/encryptorprivate.h
index 1e7d371..6f5a65e 100644
--- a/lib/encryptorprivate.h
+++ b/lib/encryptorprivate.h
@@ -41,8 +41,8 @@ class QSS_EXPORT EncryptorPrivate : public QObject
      * If the initialisation doesn't succeed, isValid() function return false
      */
     EncryptorPrivate(const QString &method,
-                              const QString &password,
-                              QObject *parent = 0);
+                     const QString &password,
+                     QObject *parent = 0);
 
     //construct an invalid/null instance
     explicit EncryptorPrivate(QObject *parent = 0);
diff --git a/lib/rc4.h b/lib/rc4.h
index d4c86f4..2636e45 100644
--- a/lib/rc4.h
+++ b/lib/rc4.h
@@ -40,8 +40,8 @@ class RC4 : public QObject
     // This class implements so-called RC4-MD5 cipher instead of original RC4
     // _iv is not allowed to be empty!
     RC4(const QByteArray &_key,
-                 const QByteArray &_iv,
-                 QObject *parent = 0);
+        const QByteArray &_iv,
+        QObject *parent = 0);
 
 public slots:
     QByteArray update(const QByteArray &input);
diff --git a/lib/socketstream.h b/lib/socketstream.h
index 424c645..5c068f5 100644
--- a/lib/socketstream.h
+++ b/lib/socketstream.h
@@ -39,8 +39,8 @@ class QSS_EXPORT SocketStream : public QObject
      * vice versa
      */
     SocketStream(QAbstractSocket *a,
-                          QAbstractSocket *b,
-                          QObject *parent = 0);
+                 QAbstractSocket *b,
+                 QObject *parent = 0);
 
 signals:
     void info(const QString &);
diff --git a/lib/tcprelay.h b/lib/tcprelay.h
index af1ded4..0d0f9d8 100644
--- a/lib/tcprelay.h
+++ b/lib/tcprelay.h
@@ -37,13 +37,13 @@ class QSS_EXPORT TcpRelay : public QObject
     Q_OBJECT
 public:
     TcpRelay(QTcpSocket *localSocket,
-                      int timeout,
-                      const Address &server_addr,
-                      const EncryptorPrivate &ep,
-                      const bool &is_local,
-                      const bool &autoBan,
-                      const bool &auth,
-                      QObject *parent = 0);
+             int timeout,
+             const Address &server_addr,
+             const EncryptorPrivate &ep,
+             const bool &is_local,
+             const bool &autoBan,
+             const bool &auth,
+             QObject *parent = 0);
 
     enum STAGE { INIT, ADDR, UDP_ASSOC, DNS, CONNECTING, STREAM, DESTROYED };
 
diff --git a/lib/tcpserver.h b/lib/tcpserver.h
index 78787f3..bc58a23 100644
--- a/lib/tcpserver.h
+++ b/lib/tcpserver.h
@@ -36,12 +36,12 @@ class QSS_EXPORT TcpServer : public QTcpServer
     Q_OBJECT
 public:
     TcpServer(const EncryptorPrivate &ep,
-                       const int &timeout,
-                       const bool &is_local,
-                       const bool &auto_ban,
-                       const bool &auth,
-                       const Address &serverAddress,
-                       QObject *parent = nullptr);
+              const int &timeout,
+              const bool &is_local,
+              const bool &auto_ban,
+              const bool &auth,
+              const Address &serverAddress,
+              QObject *parent = nullptr);
     ~TcpServer();
 
     bool listen(const QHostAddress &address, quint16 port);
diff --git a/lib/udprelay.h b/lib/udprelay.h
index f0fc26d..b5a4850 100644
--- a/lib/udprelay.h
+++ b/lib/udprelay.h
@@ -37,11 +37,11 @@ class QSS_EXPORT UdpRelay : public QObject
     Q_OBJECT
 public:
     UdpRelay(const EncryptorPrivate &ep,
-                      const bool &is_local,
-                      const bool &auto_ban,
-                      const bool &auth,
-                      const Address &serverAddress,
-                      QObject *parent = 0);
+             const bool &is_local,
+             const bool &auto_ban,
+             const bool &auth,
+             const Address &serverAddress,
+             QObject *parent = 0);
 
     void setup(const QHostAddress &localAddr,
                const quint16 &localPort);