From 556b463a79594c4a90e12237d6d5212d460f41d1 Mon Sep 17 00:00:00 2001
From: Stefan Suhren <suhren.stefan@fh-swf.de>
Date: Tue, 5 May 2015 15:32:05 +0200
Subject: Add the best self written RC4 algo and use it for encryption

---
 src/crypt/cryptrc4.cpp | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

(limited to 'src/crypt/cryptrc4.cpp')

diff --git a/src/crypt/cryptrc4.cpp b/src/crypt/cryptrc4.cpp
index 701525d..88806c8 100644
--- a/src/crypt/cryptrc4.cpp
+++ b/src/crypt/cryptrc4.cpp
@@ -1,5 +1,14 @@
 #include "cryptrc4.h"
 
+void swap(RC4_INT &a, RC4_INT &b)
+{
+    RC4_INT tmp;
+
+    tmp = a;
+    a = b;
+    b = tmp;
+}
+
 CryptRc4::CryptRc4()
 {
 
@@ -10,10 +19,47 @@ void CryptRc4::rc4SetKey(QByteArray key)
     RC4_set_key(&m_rc4Key, key.length(), (const unsigned char *) key.data());
 }
 
+void CryptRc4::rc4SetKeyOwn(QByteArray key)
+{
+    m_rc4Key.x = 0;
+    m_rc4Key.y = 0;
+
+    for(RC4_INT i = 0; i < 256; i++)
+    {
+       m_rc4Key.data[i] = i;
+    }
+    RC4_INT j = 0;
+    for(RC4_INT i = 0; i < 256; i++)
+    {
+        j = (j + m_rc4Key.data[i] + key[i % key.length()]) % 256;
+        swap(m_rc4Key.data[i], m_rc4Key.data[j]);
+    }
+}
+
 QByteArray CryptRc4::rc4Run(QByteArray clear)
 {
     QByteArray crypt(clear);
-    RC4(&m_rc4Key, clear.length(), (const unsigned char *) clear.data(), (unsigned char *) crypt.data());
+    RC4(&m_rc4Key, clear.length(), (const unsigned char *) clear.data(),
+        (unsigned char *) crypt.data());
+    return crypt;
+}
+
+QByteArray CryptRc4::rc4RunOwn(QByteArray clear)
+{
+    QByteArray crypt(clear);
+
+    RC4_INT i = 0;
+    RC4_INT j = 0;
+    for(int k = 0; k < crypt.length(); k++)
+    {
+        i = (i + 1) % 256;
+        j = (j + m_rc4Key.data[i]) % 256;
+
+        swap(m_rc4Key.data[i], m_rc4Key.data[j]);
+
+        crypt[k] = crypt[k] ^ m_rc4Key.data[(m_rc4Key.data[i] + m_rc4Key.data[j]) % 256];
+    }
+
     return crypt;
 }
 
-- 
cgit v1.2.3-70-g09d2