handle zero terminated strings better in UTF8 checks.

the final zero is not valid UTF8.
Control characters are not valid UTF8.
Limit the allowed UTF8 length to where the trailing zero is located

diff --git a/src/lib/util/print.c b/src/lib/util/print.c
index 374756dd3ab609e935ea99b8b898bab8a4b7e982..a330feb5d1b1b959df09a68bd46f90192ce74af4 100644 (file)
--- a/src/lib/util/print.c
+++ b/src/lib/util/print.c
@@ -40,7 +40,17 @@ inline size_t fr_utf8_char(uint8_t const *str, ssize_t inlen)
 {
        if (inlen == 0) return 0;
 
-       if (inlen < 0) inlen = 4;       /* longest char */
+       if (inlen < 0) {
+               if (*str < 0x20) return 0; /* end of string, or control characters. */
+
+               /*
+                *      The trailing zero can occur at any point in
+                *      the next 4 characters.
+                */
+               for (inlen = 1; inlen <= 4; inlen++) {
+                       if (!str[inlen]) break;
+               }
+       }
 
        if (*str <= 0x7f) return 1;     /* 1 */