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path: root/drivers/staging/vt6655/rc4.c
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Diffstat (limited to 'drivers/staging/vt6655/rc4.c')
-rw-r--r--drivers/staging/vt6655/rc4.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/staging/vt6655/rc4.c b/drivers/staging/vt6655/rc4.c
new file mode 100644
index 00000000000..0345e3247f4
--- /dev/null
+++ b/drivers/staging/vt6655/rc4.c
@@ -0,0 +1,86 @@
+/*
+ * File: rc4.c
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Purpose:
+ *
+ * Functions:
+ *
+ * Revision History:
+ *
+ * Author: Kyle Hsu
+ *
+ * Date: Sep 4, 2002
+ *
+ */
+
+#if !defined(__RC4_H__)
+#include "rc4.h"
+#endif
+
+VOID rc4_init(PRC4Ext pRC4, PBYTE pbyKey, UINT cbKey_len)
+{
+ UINT ust1, ust2;
+ UINT keyindex;
+ UINT stateindex;
+ PBYTE pbyst;
+ UINT idx;
+
+ pbyst = pRC4->abystate;
+ pRC4->ux = 0;
+ pRC4->uy = 0;
+ for (idx = 0; idx < 256; idx++)
+ pbyst[idx] = (BYTE)idx;
+ keyindex = 0;
+ stateindex = 0;
+ for (idx = 0; idx < 256; idx++) {
+ ust1 = pbyst[idx];
+ stateindex = (stateindex + pbyKey[keyindex] + ust1) & 0xff;
+ ust2 = pbyst[stateindex];
+ pbyst[stateindex] = (BYTE)ust1;
+ pbyst[idx] = (BYTE)ust2;
+ if (++keyindex >= cbKey_len)
+ keyindex = 0;
+ }
+}
+
+UINT rc4_byte(PRC4Ext pRC4)
+{
+ UINT ux;
+ UINT uy;
+ UINT ustx, usty;
+ PBYTE pbyst;
+
+ pbyst = pRC4->abystate;
+ ux = (pRC4->ux + 1) & 0xff;
+ ustx = pbyst[ux];
+ uy = (ustx + pRC4->uy) & 0xff;
+ usty = pbyst[uy];
+ pRC4->ux = ux;
+ pRC4->uy = uy;
+ pbyst[uy] = (BYTE)ustx;
+ pbyst[ux] = (BYTE)usty;
+
+ return pbyst[(ustx + usty) & 0xff];
+}
+
+VOID rc4_encrypt(PRC4Ext pRC4, PBYTE pbyDest,
+ PBYTE pbySrc, UINT cbData_len)
+{
+ UINT ii;
+ for (ii = 0; ii < cbData_len; ii++)
+ pbyDest[ii] = (BYTE)(pbySrc[ii] ^ rc4_byte(pRC4));
+}