Bugfixes

Rev: src/modules/_Crypto/lib/rc4.c:1.3

src/modules/_Crypto/lib/rc4.c

@@ -5,48 +5,39 @@
 #include "crypto_types.h"
 #include <rc4.h>
 
-#define SWAP(a,b) (a ^= b, b ^= a, a ^= b)
-
-#if 0
-void rc4_init(struct rc4_ctx *ctx)
-{
-  int i;
-  for (i = 0; i < 256; i++)
-    ctx->S[i] = i;
-  ctx->i = ctx->j = 0;
-}
-#endif
+#define SWAP(a,b) do { int _t = a; a = b; b = _t; } while(0)
 
 void rc4_set_key(struct rc4_ctx *ctx, const unsigned INT8 *key, INT32 len)
 {
-  register unsigned i, j;
+  register unsigned INT8 i, j; /* Depends on the eight-bitness of these variables. */
   INT32 k;
 
   /* Initialize context */
-  for (i = 0; i < 256; i++)
-    ctx->S[i] = i;
+  i = 0;
+  do ctx->S[i] = i; while (++i);
 
   /* Expand key */
-  for (i = j = k = 0; i < 256; i++)
-    {
+  i = j = k = 0;
+  do {
     j += ctx->S[i] + key[k];
     SWAP(ctx->S[i], ctx->S[j]);
     k = (k+1) % len; /* Repeat key if needed */
-    }
-  ctx->j = j; ctx->i = 0;
+  } while(++i);
+  
+  ctx->i = ctx->j = 0;
 }
 
 void rc4_crypt(struct rc4_ctx *ctx, unsigned INT8 *dest, const unsigned INT8 *src, INT32 len)
 {
-  register unsigned INT8 i,j; /* Depends on the 8-bitness of these variables */
+  register unsigned INT8 i, j; /* Depends on the eight-bitness of these variables */
 
   i = ctx->i; j = ctx->j;
   while(len--)
     {
-      i = (i + 1);
-      j = (j + ctx->S[i]);
+      i++;
+      j += ctx->S[i];
       SWAP(ctx->S[i], ctx->S[j]);
-      *dest++ = *src++ ^ ctx->S[ (ctx->S[i] + ctx->S[j]) ];
+      *dest++ = *src++ ^ ctx->S[ (ctx->S[i] + ctx->S[j]) & 0xff ];
     }
   ctx->i = i; ctx->j = j;
 }