NSEC3: reject records with a zero length hash field

diff --git a/lib/dns/rdata/generic/nsec3_50.c b/lib/dns/rdata/generic/nsec3_50.c
index 95d04213ba39c1b19e2191f2e2d5d2805fd521a6..f9f356a576413c13f06f626e212a4665b85fd3f3 100644 (file)
--- a/lib/dns/rdata/generic/nsec3_50.c
+++ b/lib/dns/rdata/generic/nsec3_50.c
@@ -212,7 +212,7 @@ fromwire_nsec3(ARGS_FROMWIRE) {
        hashlen = sr.base[0];
        isc_region_consume(&sr, 1);
 
-       if (sr.length < hashlen) {
+       if (hashlen < 1 || sr.length < hashlen) {
                RETERR(DNS_R_FORMERR);
        }
        isc_region_consume(&sr, hashlen);