1 files changed, 26 insertions, 0 deletions
diff --git a/src/libstdcrypto/rc4_init.c b/src/libstdcrypto/rc4_init.c
new file mode 100644
index 0000000..d6f8c20
--- /dev/null
+++ b/src/libstdcrypto/rc4_init.c
@@ -0,0 +1,26 @@
+/* ISC license. */
+/* Thanks to Thomas Pornin <pornin@bolet.org> */
+
+#include <skalibs/bytestr.h>
+#include <skalibs/rc4.h>
+
+void rc4_init (RC4Schedule_ref r, char const *key, unsigned int ksize)
+{
+  register unsigned int i = 0, j = 0 ;
+  register unsigned char c = 0;
+
+  r->x = r->y = 0 ;
+  for (; i < 256 ; i++) r->tab[i] = i ;
+  for (i = 0 ; i < 256 ; i++)
+  {
+    unsigned char t = r->tab[i] ;
+    c = T8(c + (unsigned char)key[j] + t) ;
+    r->tab[i] = r->tab[c] ;
+    r->tab[c] = t ;
+    if (++j == ksize) j = 0 ;
+  }
+  {
+    char tmp[RC4_THROWAWAY] ;
+    rc4(r, tmp, tmp, RC4_THROWAWAY) ;
+  }
+}