DNSSEC: do top-down search for limit of secure delegation.

CHANGELOG

@@ -31,7 +31,16 @@ version 2.73
 	    request for certain domains, before the correct answer can
             arrive. Thanks to Glen Huang for the patch.
 	
+	    Revisit the part of DNSSEC validation which determines if an 
+	    unsigned answer is legit, or is in some part of the DNS 
+	    tree which should be signed. Dnsmasq now works from the 
+	    DNS root downward looking for the limit of signed 
+	    delegations, rather than working bottom up. This is 
+	    both more correct, and less likely to trip over broken 
+	    nameservers in the unsigned parts of the DNS tree 
+	    which don't respond well to DNSSEC queries.
 
+	
 version 2.72
             Add ra-advrouter mode, for RFC-3775 mobile IPv6 support.
 

src/dnsmasq.h

@@ -569,8 +569,9 @@ struct hostsfile {
 #define STAT_SECURE_WILDCARD    7
 #define STAT_NO_SIG             8
 #define STAT_NO_DS              9
-#define STAT_NEED_DS_NEG       10
-#define STAT_CHASE_CNAME       11
+#define STAT_NO_NS             10
+#define STAT_NEED_DS_NEG       11
+#define STAT_CHASE_CNAME       12
 
 #define FREC_NOREBIND           1
 #define FREC_CHECKING_DISABLED  2
@@ -604,7 +605,9 @@ struct frec {
 #ifdef HAVE_DNSSEC 
   int class, work_counter;
   struct blockdata *stash; /* Saved reply, whilst we validate */
-  size_t stash_len;
+  struct blockdata *orig_domain; /* domain of original query, whilst
+				    we're seeing is if in unsigned domain */
+  size_t stash_len, name_start, name_len;
   struct frec *dependent; /* Query awaiting internally-generated DNSKEY or DS query */
   struct frec *blocking_query; /* Query which is blocking us. */
 #endif
@@ -1126,7 +1129,7 @@ int in_zone(struct auth_zone *zone, char *name, char **cut);
 size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, int class, int type, union mysockaddr *addr);
 int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t n, char *name, char *keyname, int class);
 int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class);
-int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class, int *neganswer);
+int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class, int *neganswer, int *nons);
 int dnssec_chase_cname(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname);
 int dnskey_keytag(int alg, int flags, unsigned char *rdata, int rdlen);
 size_t filter_rrsigs(struct dns_header *header, size_t plen);

src/dnssec.c

@@ -875,8 +875,7 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
 /* The DNS packet is expected to contain the answer to a DNSKEY query.
    Put all DNSKEYs in the answer which are valid into the cache.
    return codes:
-         STAT_INSECURE No DNSKEYs in reply.
-	 STAT_SECURE   At least one valid DNSKEY found and in cache.
+         STAT_SECURE   At least one valid DNSKEY found and in cache.
 	 STAT_BOGUS    No DNSKEYs found, which  can be validated with DS,
 	               or self-sign for DNSKEY RRset is not valid, bad packet.
 	 STAT_NEED_DS  DS records to validate a key not found, name in keyname 
@@ -896,11 +895,8 @@ int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, ch
   GETSHORT(qtype, p);
   GETSHORT(qclass, p);
   
-  if (qtype != T_DNSKEY || qclass != class)
+  if (qtype != T_DNSKEY || qclass != class || ntohs(header->ancount) == 0)
     return STAT_BOGUS;
-  
-  if (ntohs(header->ancount) == 0)
-    return STAT_INSECURE;
 
   /* See if we have cached a DS record which validates this key */
   if (!(crecp = cache_find_by_name(NULL, name, now, F_DS)))
@@ -1103,17 +1099,17 @@ int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, ch
 /* The DNS packet is expected to contain the answer to a DS query
    Put all DSs in the answer which are valid into the cache.
    return codes:
-   STAT_INSECURE    no DS in reply or not signed.
    STAT_SECURE      At least one valid DS found and in cache.
    STAT_NO_DS       It's proved there's no DS here.
-   STAT_BOGUS       At least one DS found, which fails validation, bad packet.
+   STAT_NO_NS       It's proved there's no DS _or_ NS here.
+   STAT_BOGUS       no DS in reply or not signed, fails validation, bad packet.
    STAT_NEED_DNSKEY DNSKEY records to validate a DS not found, name in keyname
 */
 
 int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class)
 {
   unsigned char *p = (unsigned char *)(header+1);
-  int qtype, qclass, val, i, neganswer;
+  int qtype, qclass, val, i, neganswer, nons;
 
   if (ntohs(header->qdcount) != 1 ||
       !(p = skip_name(p, header, plen, 4)))
@@ -1125,32 +1121,39 @@ int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char
   if (qtype != T_DS || qclass != class)
     val = STAT_BOGUS;
   else
-    val = dnssec_validate_reply(now, header, plen, name, keyname, NULL, &neganswer);
-
-  if (val == STAT_NO_SIG)
-    val = STAT_INSECURE;
+    val = dnssec_validate_reply(now, header, plen, name, keyname, NULL, &neganswer, &nons);
+  /* Note dnssec_validate_reply() will have cached positive answers */
+  
+  if (val == STAT_NO_SIG || val == STAT_INSECURE)
+    val = STAT_BOGUS;
   
   p = (unsigned char *)(header+1);
   extract_name(header, plen, &p, name, 1, 4);
   p += 4; /* qtype, qclass */
   
   if (!(p = skip_section(p, ntohs(header->ancount), header, plen)))
-    return STAT_BOGUS;
+    val = STAT_BOGUS;
   
   if (val == STAT_BOGUS)
-    log_query(F_UPSTREAM, name, NULL, "BOGUS DS");
-  
-  if ((val == STAT_SECURE || val == STAT_INSECURE) && neganswer)
     {
-      int rdlen, flags = F_FORWARD | F_DS | F_NEG;
+      log_query(F_UPSTREAM, name, NULL, "BOGUS DS");
+      return STAT_BOGUS;
+    }
+
+  /* By here, the answer is proved secure, and a positive answer has been cached. */
+  if (val == STAT_SECURE && neganswer)
+    {
+      int rdlen, flags = F_FORWARD | F_DS | F_NEG | F_DNSSECOK;
       unsigned long ttl, minttl = ULONG_MAX;
       struct all_addr a;
 
       if (RCODE(header) == NXDOMAIN)
 	flags |= F_NXDOMAIN;
       
-      if (val == STAT_SECURE)
-	flags |= F_DNSSECOK;
+      /* We only cache validated DS records, DNSSECOK flag hijacked 
+	 to store presence/absence of NS. */
+      if (nons)
+	flags &= ~F_DNSSECOK;
       
       for (i = ntohs(header->nscount); i != 0; i--)
 	{
@@ -1196,10 +1199,12 @@ int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char
 	  a.addr.dnssec.class = class;
 	  cache_insert(name, &a, now, ttl, flags);
 	  
-	  cache_end_insert(); 
+	  cache_end_insert();  
+	  
+	  log_query(F_UPSTREAM, name, NULL, nons ? "no delegation" : "no DS");
 	}
 
-      return (val == STAT_SECURE) ? STAT_NO_DS : STAT_INSECURE; 
+      return nons ? STAT_NO_NS : STAT_NO_DS; 
     }
 
   return val;
@@ -1323,12 +1328,15 @@ static int find_nsec_records(struct dns_header *header, size_t plen, unsigned ch
 }
 
 static int prove_non_existence_nsec(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count,
-				    char *workspace1, char *workspace2, char *name, int type)
+				    char *workspace1, char *workspace2, char *name, int type, int *nons)
 {
   int i, rc, rdlen;
   unsigned char *p, *psave;
   int offset = (type & 0xff) >> 3;
   int mask = 0x80 >> (type & 0x07);
+
+  if (nons)
+    *nons = 0;
   
   /* Find NSEC record that proves name doesn't exist */
   for (i = 0; i < nsec_count; i++)
@@ -1355,6 +1363,10 @@ static int prove_non_existence_nsec(struct dns_header *header, size_t plen, unsi
 	  rdlen -= p - psave;
 	  /* rdlen is now length of type map, and p points to it */
 	  
+	  /* If we can prove that there's no NS record, return that information. */
+	  if (nons && rdlen >= 2 && p[0] == 0 && (p[2] & (0x80 >> T_NS)) == 0)
+	    *nons = 1;
+	  
 	  while (rdlen >= 2)
 	    {
 	      if (!CHECK_LEN(header, p, plen, rdlen))
@@ -1456,7 +1468,7 @@ static int base32_decode(char *in, unsigned char *out)
 }
 
 static int check_nsec3_coverage(struct dns_header *header, size_t plen, int digest_len, unsigned char *digest, int type,
-				char *workspace1, char *workspace2, unsigned char **nsecs, int nsec_count)
+				char *workspace1, char *workspace2, unsigned char **nsecs, int nsec_count, int *nons)
 {
   int i, hash_len, salt_len, base32_len, rdlen;
   unsigned char *p, *psave;
@@ -1497,6 +1509,10 @@ static int check_nsec3_coverage(struct dns_header *header, size_t plen, int dige
 		if (!CHECK_LEN(header, p, plen, rdlen))
 		  return 0;
 		
+		/* If we can prove that there's no NS record, return that information. */
+		if (nons && rdlen >= 2 && p[0] == 0 && (p[2] & (0x80 >> T_NS)) == 0)
+		  *nons = 1;
+		
 		while (rdlen >= 2)
 		  {
 		    if (p[0] == type >> 8)
@@ -1533,13 +1549,16 @@ static int check_nsec3_coverage(struct dns_header *header, size_t plen, int dige
 }
 
 static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count,
-				     char *workspace1, char *workspace2, char *name, int type, char *wildname)
+				     char *workspace1, char *workspace2, char *name, int type, char *wildname, int *nons)
 {
   unsigned char *salt, *p, *digest;
   int digest_len, i, iterations, salt_len, base32_len, algo = 0;
   struct nettle_hash const *hash;
   char *closest_encloser, *next_closest, *wildcard;
- 
+  
+  if (nons)
+    *nons = 0;
+  
   /* Look though the NSEC3 records to find the first one with 
      an algorithm we support (currently only algo == 1).
 
@@ -1612,7 +1631,7 @@ static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, uns
   if ((digest_len = hash_name(name, &digest, hash, salt, salt_len, iterations)) == 0)
     return STAT_BOGUS;
   
-  if (check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count))
+  if (check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, nons))
     return STAT_SECURE;
 
   /* Can't find an NSEC3 which covers the name directly, we need the "closest encloser NSEC3" 
@@ -1657,7 +1676,7 @@ static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, uns
   if ((digest_len = hash_name(next_closest, &digest, hash, salt, salt_len, iterations)) == 0)
     return STAT_BOGUS;
 
-  if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count))
+  if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, NULL))
     return STAT_BOGUS;
   
   /* Finally, check that there's no seat of wildcard synthesis */
@@ -1672,7 +1691,7 @@ static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, uns
       if ((digest_len = hash_name(wildcard, &digest, hash, salt, salt_len, iterations)) == 0)
 	return STAT_BOGUS;
       
-      if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count))
+      if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, NULL))
 	return STAT_BOGUS;
     }
   
@@ -1681,7 +1700,8 @@ static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, uns
     
 /* Validate all the RRsets in the answer and authority sections of the reply (4035:3.2.3) */
 /* Returns are the same as validate_rrset, plus the class if the missing key is in *class */
-int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class, int *neganswer)
+int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, 
+			  int *class, int *neganswer, int *nons)
 {
   unsigned char *ans_start, *qname, *p1, *p2, **nsecs;
   int type1, class1, rdlen1, type2, class2, rdlen2, qclass, qtype;
@@ -1811,10 +1831,11 @@ int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, ch
 		    return STAT_BOGUS; /* No NSECs or bad packet */
 		  
 		  if (nsec_type == T_NSEC)
-		    rc = prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1);
+		    rc = prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1, NULL);
 		  else
-		    rc = prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1, wildname);
-
+		    rc = prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, 
+						   keyname, name, type1, wildname, NULL);
+		  
 		  if (rc != STAT_SECURE)
 		    return rc;
 		} 
@@ -1937,9 +1958,9 @@ int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, ch
     return STAT_BOGUS;
   
   if (nsec_type == T_NSEC)
-    return prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype);
+    return prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype, nons);
   else
-    return prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype, NULL);
+    return prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype, NULL, nons);
 }
 
 /* Chase the CNAME chain in the packet until the first record which _doesn't validate.

src/forward.c

@@ -26,8 +26,9 @@ static void free_frec(struct frec *f);
 #ifdef HAVE_DNSSEC
 static int tcp_key_recurse(time_t now, int status, struct dns_header *header, size_t n, 
 			   int class, char *name, char *keyname, struct server *server, int *keycount);
-static int do_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class);
-static int send_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname);
+static int do_check_sign(struct frec *forward, int status, time_t now, char *name, char *keyname);
+static int send_check_sign(struct frec *forward, time_t now, struct dns_header *header, size_t plen, 
+			   char *name, char *keyname);
 #endif
 
 
@@ -815,18 +816,22 @@ void reply_query(int fd, int family, time_t now)
 	  else if (forward->flags & FREC_DS_QUERY)
 	    {
 	      status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
-	      if (status == STAT_NO_DS)
-		status = STAT_INSECURE;
+	      if (status == STAT_NO_DS || status == STAT_NO_NS)
+		status = STAT_BOGUS;
 	    }
 	  else if (forward->flags & FREC_CHECK_NOSIGN)
-	    status = do_check_sign(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
+	    {
+	      status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
+	      if (status != STAT_NEED_KEY)
+		status = do_check_sign(forward, status, now, daemon->namebuff, daemon->keyname);
+	    }
 	  else
 	    {
-	      status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL);
+	      status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL, NULL);
 	      if (status == STAT_NO_SIG)
 		{
 		  if (option_bool(OPT_DNSSEC_NO_SIGN))
-		    status = send_check_sign(now, header, n, daemon->namebuff, daemon->keyname);
+		    status = send_check_sign(forward, now, header, n, daemon->namebuff, daemon->keyname);
 		  else
 		    status = STAT_INSECURE;
 		}
@@ -861,6 +866,7 @@ void reply_query(int fd, int family, time_t now)
 		  new->blocking_query = NULL;
 		  new->sentto = server;
 		  new->rfd4 = NULL;
+		  new->orig_domain = NULL;
 #ifdef HAVE_IPV6
 		  new->rfd6 = NULL;
 #endif
@@ -889,7 +895,9 @@ void reply_query(int fd, int family, time_t now)
 		  new->new_id = get_id();
 		  header->id = htons(new->new_id);
 		  /* Save query for retransmission */
-		  new->stash = blockdata_alloc((char *)header, nn);
+		  if (!(new->stash = blockdata_alloc((char *)header, nn)))
+		    return;
+		      
 		  new->stash_len = nn;
 		  
 		  /* Don't resend this. */
@@ -946,18 +954,22 @@ void reply_query(int fd, int family, time_t now)
 		  else if (forward->flags & FREC_DS_QUERY)
 		    {
 		      status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
-		      if (status == STAT_NO_DS)
-			status = STAT_INSECURE;
+		      if (status == STAT_NO_DS || status == STAT_NO_NS)
+			status = STAT_BOGUS;
 		    }
 		  else if (forward->flags & FREC_CHECK_NOSIGN)
-		    status = do_check_sign(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
+		    {
+		      status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
+		      if (status != STAT_NEED_KEY)
+			status = do_check_sign(forward, status, now, daemon->namebuff, daemon->keyname);
+		    }
 		  else
 		    {
-		      status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL);	
+		      status = dnssec_validate_reply(now, header, n, daemon->namebuff, daemon->keyname, &forward->class, NULL, NULL);	
 		      if (status == STAT_NO_SIG)
 			{
 			  if (option_bool(OPT_DNSSEC_NO_SIGN))
-			    status = send_check_sign(now, header, n, daemon->namebuff, daemon->keyname);
+			    status = send_check_sign(forward, now, header, n, daemon->namebuff, daemon->keyname);
 			  else
 			    status = STAT_INSECURE;
 			}
@@ -1319,70 +1331,80 @@ void receive_query(struct listener *listen, time_t now)
 /* UDP: we've got an unsigned answer, return STAT_INSECURE if we can prove there's no DS
    and therefore the answer shouldn't be signed, or STAT_BOGUS if it should be, or 
    STAT_NEED_DS_NEG and keyname if we need to do the query. */
-static int send_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname)
+static int send_check_sign(struct frec *forward, time_t now, struct dns_header *header, size_t plen, 
+			   char *name, char *keyname)
 {
-  struct crec *crecp;
-  char *name_start = name;
   int status = dnssec_chase_cname(now, header, plen, name, keyname);
   
   if (status != STAT_INSECURE)
     return status;
 
+  /* Store the domain we're trying to check. */
+  forward->name_start = strlen(name);
+  forward->name_len = forward->name_start + 1;
+  if (!(forward->orig_domain = blockdata_alloc(name, forward->name_len)))
+    return STAT_BOGUS;
+  
+  return do_check_sign(forward, 0, now, name, keyname);
+}
+ 
+/* We either have a a reply (header non-NULL, or we need to start by looking in the cache */ 
+static int do_check_sign(struct frec *forward, int status, time_t now, char *name, char *keyname)
+{
+  /* get domain we're checking back from blockdata store, it's stored on the original query. */
+  while (forward->dependent)
+    forward = forward->dependent;
+
+  blockdata_retrieve(forward->orig_domain, forward->name_len, name);
+  
   while (1)
     {
-      crecp = cache_find_by_name(NULL, name_start, now, F_DS);
-      
-      if (crecp && (crecp->flags & F_DNSSECOK))
-	return (crecp->flags & F_NEG) ? STAT_INSECURE : STAT_BOGUS;
-       
-      if (crecp && (crecp->flags & F_NEG) && (name_start = strchr(name_start, '.')))
+      char *p; 
+
+      if (status == 0)
 	{
-	  name_start++; /* chop a label off and try again */
-	  continue;
+	  struct crec *crecp;
+
+	  /* Haven't received answer, see if in cache */
+	  if (!(crecp = cache_find_by_name(NULL, &name[forward->name_start], now, F_DS)))
+	    {
+	      /* put name of DS record we're missing into keyname */
+	      strcpy(keyname, &name[forward->name_start]);
+	      /* and wait for reply to arrive */
+	      return STAT_NEED_DS_NEG;
+	    }
+
+	  /* F_DNSSECOK misused in DS cache records to non-existance of NS record */ 
+	  if (!(crecp->flags & F_NEG))
+	    status = STAT_SECURE;
+	  else if (crecp->flags & F_DNSSECOK)
+	    status = STAT_NO_DS;
+	  else
+	    status = STAT_NO_NS;
 	}
+      
+      /* Have entered non-signed part of DNS tree. */ 
+      if (status == STAT_NO_DS)
+	return STAT_INSECURE;
 
-      /* Reached the root */
-      if (!name_start)
+      if (status == STAT_BOGUS)
 	return STAT_BOGUS;
 
-      strcpy(keyname, name_start);
-      return STAT_NEED_DS_NEG;
-    }
-}
-
-/* Got answer to DS query from send_check_sign, check for proven non-existence, or make the next DS query to try. */
-static int do_check_sign(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class)
-  
-{ 
-  char *name_start;
-  unsigned char *p;
-  int status;
+      /* There's a proven DS record, or we're within a zone, where there doesn't need
+	 to be a DS record. Add a name and try again. 
+	 If we've already tried the whole name, then fail */
 
-  /* In this case only, a SERVFAIL reply allows us to continue up the tree, looking for a 
-     suitable NSEC reply to DS queries. */
-  if (RCODE(header) != SERVFAIL)
-    { 
-      status = dnssec_validate_ds(now, header, plen, name, keyname, class);
+      if (forward->name_start == 0)
+	return STAT_BOGUS;
       
-      if (status != STAT_INSECURE)
-	{
-	  if (status == STAT_NO_DS)
-	    status = STAT_INSECURE;
-	  return status;
-	}
-    }
-  
-  p = (unsigned char *)(header+1);
-  
-  if (extract_name(header, plen, &p, name, 1, 4) &&
-      (name_start = strchr(name, '.')))
-    {
-      name_start++; /* chop a label off and try again */
-      strcpy(keyname, name_start);
-      return STAT_NEED_DS_NEG;
+      for (p = &name[forward->name_start-2]; (*p != '.') && (p != name); p--);
+      
+      if (p != name)
+	p++;
+      
+      forward->name_start = p - name;
+      status = 0; /* force to cache when we iterate. */
     }
-  
-  return STAT_BOGUS;
 }
 
 /* Move toward the root, until we find a signed non-existance of a DS, in which case
@@ -1395,8 +1417,10 @@ static int  tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, s
   unsigned char *packet, *payload;
   u16 *length;
   unsigned char *p = (unsigned char *)(header+1);
-  int status;
-  char *name_start = name;
+  int status, name_len;
+  struct blockdata *block;
+
+  char *name_start;
 
   /* Get first insecure entry in CNAME chain */
   status = tcp_key_recurse(now, STAT_CHASE_CNAME, header, plen, class, name, keyname, server, keycount);
@@ -1409,95 +1433,113 @@ static int  tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, s
   payload = &packet[2];
   header = (struct dns_header *)payload;
   length = (u16 *)packet;
+
+  /* Stash the name away, since the buffer will be trashed when we recurse */
+  name_len = strlen(name) + 1;
+  name_start = name + name_len - 1;
   
+  if (!(block = blockdata_alloc(name, name_len)))
+    {
+      free(packet);
+      return STAT_BOGUS;
+    }
+
   while (1)
     {
-      unsigned char *newhash, hash[HASH_SIZE];
       unsigned char c1, c2;
-      struct crec *crecp = cache_find_by_name(NULL, name_start, now, F_DS);
- 
+      struct crec *crecp;
+
       if (--(*keycount) == 0)
 	{
 	  free(packet);
+	  blockdata_free(block);
 	  return STAT_BOGUS;    
 	}
-
-      if (crecp && (crecp->flags & F_DNSSECOK))
-	{
-	  free(packet);
-	  return (crecp->flags & F_NEG) ? STAT_INSECURE : STAT_BOGUS;
-	}
       
-      /* If we have cached insecurely that a DS doesn't exist, 
-	 ise that is a hit for where to start looking for the secure one */
-      if (crecp && (crecp->flags & F_NEG) && (name_start = strchr(name_start, '.')))
-	{
-	  name_start++; /* chop a label off and try again */
-	  continue;
-	}
-
-      /* reached the root */
-      if (!name_start)
-	{
-	  free(packet);
-	  return STAT_BOGUS;
+      while (crecp = cache_find_by_name(NULL, name_start, now, F_DS))
+	{      
+	  if ((crecp->flags & F_NEG) && (crecp->flags & F_DNSSECOK))
+	    {
+	      /* Found a secure denial of DS - delegation is indeed insecure */
+	      free(packet);
+	      blockdata_free(block);
+	      return STAT_INSECURE;
+	    }
+      
+	  /* Here, either there's a secure DS, or no NS and no DS, and therefore no delegation.
+	     Add another label and continue. */
+ 
+	  if (name_start == name)
+	    {
+	      free(packet);
+	      blockdata_free(block);
+	      return STAT_BOGUS; /* run out of labels */
+	    }
+	  
+	  name_start -= 2;
+	  while (*name_start != '.' && name_start != name) 
+	    name_start--;
+	  if (name_start != name)
+	    name_start++;
 	}
+      
+      /* Can't find it in the cache, have to send a query */
 
       m = dnssec_generate_query(header, ((char *) header) + 65536, name_start, class, T_DS, &server->addr);
       
-      /* We rely on the question section coming back unchanged, ensure it is with the hash. */
-      if ((newhash = hash_questions(header, (unsigned int)m, name)))
-	{
-	  memcpy(hash, newhash, HASH_SIZE);
+      *length = htons(m);
       
-	  *length = htons(m);
+      if (read_write(server->tcpfd, packet, m + sizeof(u16), 0) &&
+	  read_write(server->tcpfd, &c1, 1, 1) &&
+	  read_write(server->tcpfd, &c2, 1, 1) &&
+	  read_write(server->tcpfd, payload, (c1 << 8) | c2, 1))
+	{
+	  m = (c1 << 8) | c2;
+	  
+	  /* Note this trashes all three name workspaces */
+	  status = tcp_key_recurse(now, STAT_NEED_DS_NEG, header, m, class, name, keyname, server, keycount);
 	  
-	  if (read_write(server->tcpfd, packet, m + sizeof(u16), 0) &&
-	      read_write(server->tcpfd, &c1, 1, 1) &&
-	      read_write(server->tcpfd, &c2, 1, 1) &&
-	      read_write(server->tcpfd, payload, (c1 << 8) | c2, 1))
+	  if (status == STAT_NO_DS)
 	    {
-	      m = (c1 << 8) | c2;
-	      
-	      newhash = hash_questions(header, (unsigned int)m, name);
-	      if (newhash && memcmp(hash, newhash, HASH_SIZE) == 0)
-		{
-		   /* In this case only, a SERVFAIL reply allows us to continue up the tree, looking for a 
-		      suitable NSEC reply to DS queries. */
-		  if (RCODE(header) == SERVFAIL)
-		    status = STAT_INSECURE;
-		  else
-		    /* Note this trashes all three name workspaces */
-		    status = tcp_key_recurse(now, STAT_NEED_DS_NEG, header, m, class, name, keyname, server, keycount);
-		  
-		  /* We've found a DS which proves the bit of the DNS where the
-		     original query is, is unsigned, so the answer is OK, 
-		     if unvalidated. */
-		  if (status == STAT_NO_DS)
-		    {
-		      free(packet);
-		      return STAT_INSECURE;
-		    }
-	      
-		  /* No DS, not got to DNSSEC-land yet, go up. */
-		  if (status == STAT_INSECURE)
-		    {
-		      p = (unsigned char *)(header+1);
-		      
-		      if (extract_name(header, plen, &p, name, 1, 4) &&
-			  (name_start = strchr(name, '.')))
-			{
-			  name_start++; /* chop a label off and try again */
-			  continue;
-			}
-		    }
-		}
+	      /* Found a secure denial of DS - delegation is indeed insecure */
+	      free(packet);
+	      blockdata_free(block);
+	      return STAT_INSECURE;
+	    }
+	  
+	  if (status == STAT_BOGUS)
+	    {
+	      free(packet);
+	      blockdata_free(block);
+	      return STAT_BOGUS;
+	    }
+	  
+	  /* Here, either there's a secure DS, or no NS and no DS, and therefore no delegation.
+	     Add another label and continue. */
+	  
+	  /* Get name we're checking back. */
+	  blockdata_retrieve(block, name_len, name);
+	  
+	  if (name_start == name)
+	    {
+	      free(packet);
+	      blockdata_free(block);
+	      return STAT_BOGUS; /* run out of labels */
 	    }
+	  
+	  name_start -= 2;
+	  while (*name_start != '.' && name_start != name) 
+	    name_start--;
+	  if (name_start != name)
+	    name_start++;
+	}
+      else
+	{
+	  /* IO failure */
+	  free(packet);
+	  blockdata_free(block);
+	  return STAT_BOGUS; /* run out of labels */
 	}
-      
-      free(packet);
-
-      return STAT_BOGUS;
     }
 }
 
@@ -1516,14 +1558,14 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
   else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG)
     {
       new_status = dnssec_validate_ds(now, header, n, name, keyname, class);
-      if (status == STAT_NEED_DS  && new_status == STAT_NO_DS)
-	new_status = STAT_INSECURE;
+      if (status == STAT_NEED_DS && (new_status == STAT_NO_DS || new_status == STAT_NO_NS))
+	new_status = STAT_BOGUS;
     }
   else if (status == STAT_CHASE_CNAME)
     new_status = dnssec_chase_cname(now, header, n, name, keyname);
   else 
     {
-      new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL);
+      new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL, NULL);
       
       if (new_status == STAT_NO_SIG)
 	{
@@ -1576,14 +1618,14 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
 	      else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG)
 		{
 		  new_status = dnssec_validate_ds(now, header, n, name, keyname, class);
-		  if (status == STAT_NEED_DS && new_status == STAT_NO_DS)
-		    new_status = STAT_INSECURE; /* Validated no DS */
+		  if (status == STAT_NEED_DS  && (new_status == STAT_NO_DS || new_status == STAT_NO_NS))
+		    new_status = STAT_BOGUS; /* Validated no DS */
 		}
 	      else if (status == STAT_CHASE_CNAME)
 		new_status = dnssec_chase_cname(now, header, n, name, keyname);
 	      else 
 		{
-		  new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL);
+		  new_status = dnssec_validate_reply(now, header, n, name, keyname, &class, NULL, NULL);
 		  
 		  if (new_status == STAT_NO_SIG)
 		    {
@@ -1961,6 +2003,7 @@ static struct frec *allocate_frec(time_t now)
       f->dependent = NULL;
       f->blocking_query = NULL;
       f->stash = NULL;
+      f->orig_domain = NULL;
 #endif
       daemon->frec_list = f;
     }
@@ -2029,6 +2072,12 @@ static void free_frec(struct frec *f)
       f->stash = NULL;
     }
 
+  if (f->orig_domain)
+    {
+      blockdata_free(f->orig_domain);
+      f->orig_domain = NULL;
+    }
+
   /* Anything we're waiting on is pointless now, too */
   if (f->blocking_query)
     free_frec(f->blocking_query);