diff --git a/library/arc4.c b/library/arc4.c
new file mode 100644
index 0000000..d226c07
--- /dev/null
+++ b/library/arc4.c
@@ -0,0 +1,158 @@
+/*
+ *  An implementation of the ARCFOUR algorithm
+ *
+ *  Copyright (C) 2006-2007  Christophe Devine
+ *
+ *  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.
+ */
+/*
+ *  The ARCFOUR algorithm was publicly disclosed on 94/09.
+ *
+ *  http://groups.google.com/group/sci.crypt/msg/10a300c9d21afca0
+ */
+
+#include "xyssl/config.h"
+
+#if defined(XYSSL_ARC4_C)
+
+#include "xyssl/arc4.h"
+
+/*
+ * ARC4 key schedule
+ */
+void arc4_setup( arc4_context *ctx, unsigned char *key, int keylen )
+{
+    int i, j, k, a;
+    unsigned char *m;
+
+    ctx->x = 0;
+    ctx->y = 0;
+    m = ctx->m;
+
+    for( i = 0; i < 256; i++ )
+        m[i] = (unsigned char) i;
+
+    j = k = 0;
+
+    for( i = 0; i < 256; i++, k++ )
+    {
+        if( k >= keylen ) k = 0;
+
+        a = m[i];
+        j = ( j + a + key[k] ) & 0xFF;
+        m[i] = m[j];
+        m[j] = (unsigned char) a;
+    }
+}
+
+/*
+ * ARC4 cipher function
+ */
+void arc4_crypt( arc4_context *ctx, unsigned char *buf, int buflen )
+{
+    int i, x, y, a, b;
+    unsigned char *m;
+
+    x = ctx->x;
+    y = ctx->y;
+    m = ctx->m;
+
+    for( i = 0; i < buflen; i++ )
+    {
+        x = ( x + 1 ) & 0xFF; a = m[x];
+        y = ( y + a ) & 0xFF; b = m[y];
+
+        m[x] = (unsigned char) b;
+        m[y] = (unsigned char) a;
+
+        buf[i] = (unsigned char)
+            ( buf[i] ^ m[(unsigned char)( a + b )] );
+    }
+
+    ctx->x = x;
+    ctx->y = y;
+}
+
+#if defined(XYSSL_SELF_TEST)
+
+#include <string.h>
+#include <stdio.h>
+
+/*
+ * ARC4 tests vectors as posted by Eric Rescorla in sep. 1994:
+ *
+ * http://groups.google.com/group/comp.security.misc/msg/10a300c9d21afca0
+ */
+static const unsigned char arc4_test_key[3][8] =
+{
+    { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+    { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
+};
+
+static const unsigned char arc4_test_pt[3][8] =
+{
+    { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
+    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
+};
+
+static const unsigned char arc4_test_ct[3][8] =
+{
+    { 0x75, 0xB7, 0x87, 0x80, 0x99, 0xE0, 0xC5, 0x96 },
+    { 0x74, 0x94, 0xC2, 0xE7, 0x10, 0x4B, 0x08, 0x79 },
+    { 0xDE, 0x18, 0x89, 0x41, 0xA3, 0x37, 0x5D, 0x3A }
+};
+
+/*
+ * Checkup routine
+ */
+int arc4_self_test( int verbose )
+{
+    int i;
+    unsigned char buf[8];
+    arc4_context ctx;
+
+    for( i = 0; i < 3; i++ )
+    {
+        if( verbose != 0 )
+            printf( "  ARC4 test #%d: ", i + 1 );
+
+        memcpy( buf, arc4_test_pt[i], 8 );
+
+        arc4_setup( &ctx, (unsigned char *) arc4_test_key[i], 8 );
+        arc4_crypt( &ctx, buf, 8 );
+
+        if( memcmp( buf, arc4_test_ct[i], 8 ) != 0 )
+        {
+            if( verbose != 0 )
+                printf( "failed\n" );
+
+            return( 1 );
+        }
+
+        if( verbose != 0 )
+            printf( "passed\n" );
+    }
+
+    if( verbose != 0 )
+        printf( "\n" );
+
+    return( 0 );
+}
+
+#endif
+
+#endif