Replace <<-13 by >>13. Leave old code in #ifdef BUGGY_CODE_BW_COMPAT.

diff --git a/Modules/rotormodule.c b/Modules/rotormodule.c
index 71bac909a683496fc0f551340bb5d0b085635122..f01c5fe3f86b5b10f5732f4536c5e921b180562e 100644 (file)
--- a/Modules/rotormodule.c
+++ b/Modules/rotormodule.c
@@ -158,11 +158,26 @@ char *key;
        int i;
        int len=strlen(key);
        for (i=0;i<len;i++) {
+#ifdef BUGGY_CODE_BW_COMPAT
+               /* This is the code as it was originally released.
+                  It causes warnings on many systems and can generate
+                  different results as well.  If you have files
+                  encrypted using an older version you may want to
+                  #define BUGGY_CODE_BW_COMPAT so as to be able to
+                  decrypt them... */
                k1 = (((k1<<3 | k1<<-13) + key[i]) & 65535);
                k2 = (((k2<<3 | k2<<-13) ^ key[i]) & 65535);
                k3 = (((k3<<3 | k3<<-13) - key[i]) & 65535);
                k4 = ((key[i] - (k4<<3 | k4<<-13)) & 65535);
                k5 = (((k5<<3 | k5<<-13) ^ ~key[i]) & 65535);
+#else
+               /* This code should be more portable */
+               k1 = (((k1<<3 | k1>>13) + key[i]) & 65535);
+               k2 = (((k2<<3 | k2>>13) ^ key[i]) & 65535);
+               k3 = (((k3<<3 | k3>>13) - key[i]) & 65535);
+               k4 = ((key[i] - (k4<<3 | k4>>13)) & 65535);
+               k5 = (((k5<<3 | k5>>13) ^ ~key[i]) & 65535);
+#endif
        }
        r->key[0] = (short)k1;
        r->key[1] = (short)(k2|1);