Imported MaNGOS revision 6767 from http://mangos.svn.sourceforge.net/svnroot/mangos/trunk/

src/shared/Auth/AuthCrypt.cpp

@@ -0,0 +1,81 @@
+/* 
+ * Copyright (C) 2005-2008 MaNGOS <http://getmangos.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 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "AuthCrypt.h"
+#include "Hmac.h"
+
+AuthCrypt::AuthCrypt()
+{
+    _initialized = false;
+}
+
+void AuthCrypt::Init()
+{
+    _send_i = _send_j = _recv_i = _recv_j = 0;
+    _initialized = true;
+}
+
+void AuthCrypt::DecryptRecv(uint8 *data, size_t len)
+{
+    if (!_initialized) return;
+    if (len < CRYPTED_RECV_LEN) return;
+
+    for (size_t t = 0; t < CRYPTED_RECV_LEN; t++)
+    {
+        _recv_i %= _key.size();
+        uint8 x = (data[t] - _recv_j) ^ _key[_recv_i];
+        ++_recv_i;
+        _recv_j = data[t];
+        data[t] = x;
+    }
+}
+
+void AuthCrypt::EncryptSend(uint8 *data, size_t len)
+{
+    if (!_initialized) return;
+    if (len < CRYPTED_SEND_LEN) return;
+
+    for (size_t t = 0; t < CRYPTED_SEND_LEN; t++)
+    {
+        _send_i %= _key.size();
+        uint8 x = (data[t] ^ _key[_send_i]) + _send_j;
+        ++_send_i;
+        data[t] = _send_j = x;
+    }
+}
+
+void AuthCrypt::SetKey(BigNumber *bn)
+{
+    uint8 *key = new uint8[SHA_DIGEST_LENGTH];
+    GenerateKey(key, bn);
+    _key.resize(SHA_DIGEST_LENGTH);
+    std::copy(key, key + SHA_DIGEST_LENGTH, _key.begin());
+    delete key;
+}
+
+AuthCrypt::~AuthCrypt()
+{
+}
+
+void AuthCrypt::GenerateKey(uint8 *key, BigNumber *bn)
+{
+    HmacHash hash;
+    hash.UpdateBigNumber(bn);
+    hash.Finalize();
+    memcpy(key, hash.GetDigest(), SHA_DIGEST_LENGTH);
+}