- Changed libgb assembly and added libcryptal (implementation of cryptoalgorithms from Brad Conte).

- Changed build libgb.
- Added memory.h for compatibility.

git-svn-id: svn://kolibrios.org@8367 a494cfbc-eb01-0410-851d-a64ba20cac60

programs/develop/ktcc/trunk/lib/libcryptal/arcfour.c

@@ -0,0 +1,47 @@
+/*********************************************************************
+* Filename:   arcfour.c
+* Author:     Brad Conte (brad AT bradconte.com)
+* Copyright:
+* Disclaimer: This code is presented "as is" without any guarantees.
+* Details:    Implementation of the ARCFOUR encryption algorithm.
+              Algorithm specification can be found here:
+               * http://en.wikipedia.org/wiki/RC4
+*********************************************************************/
+
+/*************************** HEADER FILES ***************************/
+#include <stdlib.h>
+#include <cryptal/arcfour.h>
+
+/*********************** FUNCTION DEFINITIONS ***********************/
+void arcfour_key_setup(BYTE state[], const BYTE key[], int len)
+{
+	int i, j;
+	BYTE t;
+
+	for (i = 0; i < 256; ++i)
+		state[i] = i;
+	for (i = 0, j = 0; i < 256; ++i) {
+		j = (j + state[i] + key[i % len]) % 256;
+		t = state[i];
+		state[i] = state[j];
+		state[j] = t;
+	}
+}
+
+// This does not hold state between calls. It always generates the
+// stream starting from the first  output byte.
+void arcfour_generate_stream(BYTE state[], BYTE out[], size_t len)
+{
+	int i, j;
+	size_t idx;
+	BYTE t;
+
+	for (idx = 0, i = 0, j = 0; idx < len; ++idx)  {
+		i = (i + 1) % 256;
+		j = (j + state[i]) % 256;
+		t = state[i];
+		state[i] = state[j];
+		state[j] = t;
+		out[idx] = state[(state[i] + state[j]) % 256];
+	}
+}