3 files changed, 21 insertions, 2 deletions
diff --git a/avahi-core/domain-util.c b/avahi-core/domain-util.c
index 0d6ba14..7f562db 100644
--- a/avahi-core/domain-util.c
+++ b/avahi-core/domain-util.c
@@ -237,4 +237,18 @@ uint8_t avahi_count_canonical_labels(const char* input){
     }
 
     return count;
-}
-\ No newline at end of file
+}
+
+/* reference keytag generator from RFC 4034 */
+/* invoke with avahi_keytag(<rdata>, <rdlength>); */
+uint16_t avahi_keytag(uint8_t key[], uint16_t keysize){
+    uint32_t ac;
+    int i;
+
+    for (ac = 0, i = 0; i < keysize; ++i)
+        ac += (i & 1) ? key[i] : key[i] << 8;
+
+    ac += (ac >> 16) & 0xFFFF;
+
+    return ac & 0xFFFF;
+   }
diff --git a/avahi-core/domain-util.h b/avahi-core/domain-util.h
index c3e3579..2e4cf3d 100644
--- a/avahi-core/domain-util.h
+++ b/avahi-core/domain-util.h
@@ -48,6 +48,9 @@ unsigned char * avahi_c_to_canonical_string(const char* input);
 /** returns the number of labels in a canonical DNS domain */
 uint8_t avahi_count_canonical_labels(const char* input);
 
+/* reference keytag generator from RFC 4034 */
+uint16_t avahi_keytag(uint8_t key[], uint16_t keysize)
+
 AVAHI_C_DECL_END
 
 #endif
diff --git a/avahi-core/rr.h b/avahi-core/rr.h
index fc6a0e6..2437ef2 100644
--- a/avahi-core/rr.h
+++ b/avahi-core/rr.h
@@ -52,7 +52,9 @@ enum {
 /**DNSSEC protocol constants */
 
 enum {
-    AVAHI_DNSSEC_PROTO = 0x3
+    AVAHI_DNSSEC_PROTO = 0x3,
+    AVAHI_DNSSEC_VALIDITY = 30,
+    AVAHI_DNSSEC_TIME_DRIFT = 3600
 };
 
 /** DNS record classes, see RFC 1035, in addition to those defined in defs.h */