initial commit with rc for skalibs-2.0.0.0

1 files changed, 20 insertions, 0 deletions

diff --git a/src/libstdcrypto/rc4.c b/src/libstdcrypto/rc4.c
new file mode 100644
index 0000000..7ead2c6
--- /dev/null
+++ b/src/libstdcrypto/rc4.c
@@ -0,0 +1,20 @@
+/* ISC license. */
+/* Thanks to Thomas Pornin <pornin@bolet.org> */
+
+#include <skalibs/bytestr.h>
+#include <skalibs/rc4.h>
+
+void rc4 (RC4Schedule_ref r, char const *in, char *out, unsigned int n)
+{
+  register unsigned int i = 0 ;
+  for (; i < n ; i++)
+  {
+    register unsigned char t ;
+    r->x = T8(r->x + 1) ;
+    t = r->tab[r->x] ;
+    r->y = T8(r->y + t) ;
+    r->tab[r->x] = r->tab[r->y] ;
+    r->tab[r->y] = t ;
+    out[i] = (unsigned char)in[i] ^ T8(r->tab[r->x] + r->tab[r->y]) ;
+  }
+}