initial commitHEADmain

1 files changed, 50 insertions, 0 deletions

diff --git a/crypt.c b/crypt.c
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+++ b/crypt.c
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+/*
+ * LOKI3
+ *
+ * [ crypt.c ]
+ *
+ *  1996/7 Guild Corporation Worldwide      [daemon9]
+ */
+
+#include "loki.h"
+#include "crypt.h"
+
+#ifdef WEAK_CRYPTO
+/*
+ *  Simple XOR obfuscation.
+ *
+ *  ( Syko was right -- the following didn't work under certain compilation
+ *  environments...  Never write code in which the order of evaluation defines
+ *  the result.  See K&R page 53, at the bottom... )
+ *
+ *  if (!m) while (i < bs) t[i] ^= t[i++ +1];
+ *  else
+ *  {
+ *      i = bs;
+ *      while (i) t[i - 1] ^= t[i--];
+ *  }
+ *
+ */
+void blur(int m, int bs, uint8_t *t) {
+    int i = 0;
+
+    if (!m) { /* Encrypt */
+        while (i < bs) {
+            t[i] ^= t[i + 1];
+            i++;
+        }
+    } else { /* Decrypt */
+        i = bs;
+        while (i) {
+            t[i - 1] ^= t[i];
+            i--;
+        }
+    }
+}
+#endif /* WEAK_CRYPTO */
+
+#ifdef NO_CRYPTO
+void blur(int m, int bs, uint8_t *t){}
+#endif /* NO_CRYPTO */
+
+/* EOF */