1 files changed, 11 insertions, 9 deletions

diff --git a/ot_hex.c b/ot_hex.c
index 17dd1ef..9581951 100644
--- a/ot_hex.c
+++ b/ot_hex.c
@@ -10,16 +10,18 @@
 /* Opentracker */
 #include "ot_hex.h"
 
-static int fromhex(unsigned char c) {
-  if (c >= '0' && c <= '9')
-    return c - '0';
-  c |= 0x20; /* fold upper case onto lower, digits are already handled */
-  if (c >= 'a' && c <= 'f')
-    return c - 'a' + 10;
+int hex_value(int c) {
+  unsigned char u = (unsigned char)c;
+
+  if (u >= '0' && u <= '9')
+    return u - '0';
+  u |= 0x20; /* fold upper case onto lower, digits are already handled */
+  if (u >= 'a' && u <= 'f')
+    return u - 'a' + 10;
   return -1;
 }
 
-int hex_isdigit(int c) { return fromhex((unsigned char)c) >= 0; }
+int hex_isdigit(int c) { return hex_value(c) >= 0; }
 
 char *hex_fromhash(char *dest, const uint8_t *hash) {
   static const char digits[] = "0123456789ABCDEF";
@@ -43,9 +45,9 @@ int hex_tohash(ot_hash hash, const char *src) {
 
     /* Tested one character at a time so that a string ending early stops us
        at its terminator rather than one byte past it */
-    if ((high = fromhex((unsigned char)src[2 * i])) < 0)
+    if ((high = hex_value((unsigned char)src[2 * i])) < 0)
       return 0;
-    if ((low = fromhex((unsigned char)src[2 * i + 1])) < 0)
+    if ((low = hex_value((unsigned char)src[2 * i + 1])) < 0)
       return 0;
 
     decoded[i] = (uint8_t)((high << 4) | low);