#define kSecTokenLoginDomain CFSTR("com.apple.security.tokenlogin")
-static CFStringRef cfDataToHex(CFDataRef bin)
+static CFStringRef CF_RETURNS_RETAINED cfDataToHex(CFDataRef bin)
{
size_t len = CFDataGetLength(bin) * 2;
CFMutableStringRef str = CFStringCreateMutable(NULL, len);