--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcommon/revnibbles.c	Thu Feb 11 23:56:13 2021 +0000
@@ -0,0 +1,34 @@
+/*
+ * This module implements some reversed-nibbles parsing functions.
+ */
+
+#include <sys/types.h>
+
+encode_hex_digit(d)
+	unsigned d;
+{
+	if (d <= 9)
+		return(d + '0');
+	else
+		return(d - 10 + 'A');
+}
+
+decode_reversed_nibbles(bytes, nbytes, dest)
+	u_char *bytes;
+	unsigned nbytes;
+	char *dest;
+{
+	u_char *sp;
+	char *dp;
+	unsigned n, c;
+
+	sp = bytes;
+	dp = dest;
+	for (n = 0; n < nbytes; n++) {
+		c = *sp & 0xF;
+		*dp++ = encode_hex_digit(c);
+		c = *sp >> 4;
+		*dp++ = encode_hex_digit(c);
+		sp++;
+	}
+}