1 files changed, 29 insertions, 0 deletions
diff --git a/generic/keydecode.c b/generic/keydecode.c
new file mode 100644
index 0000000..0ca011e
--- /dev/null
+++ b/generic/keydecode.c
@@ -0,0 +1,29 @@
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+char *
+keydecode(char *key)
+{
+	unsigned int len, half, i, j;
+	char	*newkey;
+
+	if (key == NULL) {
+err:		return (key);
+	}
+	len = strlen(key);
+	half = len / 2;
+	if ((len %2) != 0) goto err; /* len must be even */
+	
+	newkey = malloc(len);
+	
+	/* unpack the old bytes */
+	for (j = 1, i = 0; i < half; i++, j +=2) newkey[j] = key[i];
+
+	/* unpack the even bytes */
+	for (j = 0, i = half; i < len; i++, j +=2)  newkey[j] = key[i];
+
+	memcpy(key, newkey, len);
+	free(newkey);
+	return (key);
+}