middleware/file: proper support for wildcard (#323)

Add support for wildcard records, while taking care of wildcard-cnames and DNSSEC. Add enough tests to check all the corner cases.
2025-11-18 18:02:16 -05:00 · 2016-10-08 15:22:31 +01:00
parent b44d82839f
commit e43384b501
13 changed files with 437 additions and 187 deletions
--- a/middleware/file/dnssex_test.go
+++ b/middleware/file/dnssex_test.go
@@ -0,0 +1,145 @@
+package file
+
+const dbDnssexNLSigned = `
+; File written on Tue Mar 29 21:02:24 2016
+; dnssec_signzone version 9.10.3-P4-Ubuntu
+dnssex.nl.		1800	IN SOA	linode.atoom.net. miek.miek.nl. (
+					1459281744 ; serial
+					14400      ; refresh (4 hours)
+					3600       ; retry (1 hour)
+					604800     ; expire (1 week)
+					14400      ; minimum (4 hours)
+					)
+			1800	RRSIG	SOA 8 2 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					CA/Y3m9hCOiKC/8ieSOv8SeP964BUdG/8MC3
+					WtKljUosK9Z9bBGrVizDjjqgq++lyH8BZJcT
+					aabAsERs4xj5PRtcxicwQXZACX5VYjXHQeZm
+					CyytFU5wq2gcXSmvUH86zZzftx3RGPvn1aOo
+					TlcvoC3iF8fYUCpROlUS0YR8Cdw= )
+			1800	NS	omval.tednet.nl.
+			1800	NS	linode.atoom.net.
+			1800	NS	ns-ext.nlnetlabs.nl.
+			1800	RRSIG	NS 8 2 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					dLIeEvP86jj5nd3orv9bH7hTvkblF4Na0sbl
+					k6fJA6ha+FPN1d6Pig3NNEEVQ/+wlOp/JTs2
+					v07L7roEEUCbBprI8gMSld2gFDwNLW3DAB4M
+					WD/oayYdAnumekcLzhgvWixTABjWAGRTGQsP
+					sVDFXsGMf9TGGC9FEomgkCVeNC0= )
+			1800	A	139.162.196.78
+			1800	RRSIG	A 8 2 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					LKJKLzPiSEDWOLAag2YpfD5EJCuDcEAJu+FZ
+					Xy+4VyOv9YvRHCTL4vbrevOo5+XymY2RxU1q
+					j+6leR/Fe7nlreSj2wzAAk2bIYn4m6r7hqeO
+					aKZsUFfpX8cNcFtGEywfHndCPELbRxFeEziP
+					utqHFLPNMX5nYCpS28w4oJ5sAnM= )
+			1800	TXT	"Doing It Safe Is Better"
+			1800	RRSIG	TXT 8 2 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					f6S+DUfJK1UYdOb3AHgUXzFTTtu+yLp/Fv7S
+					Hv0CAGhXAVw+nBbK719igFvBtObS33WKwzxD
+					1pQNMaJcS6zeevtD+4PKB1KDC4fyJffeEZT6
+					E30jGR8Y29/xA+Fa4lqDNnj9zP3b8TiABCle
+					ascY5abkgWCALLocFAzFJQ/27YQ= )
+			1800	AAAA	2a01:7e00::f03c:91ff:fef1:6735
+			1800	RRSIG	AAAA 8 2 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					PWcPSawEUBAfCuv0liEOQ8RYe7tfNW4rubIJ
+					LE+dbrub1DUer3cWrDoCYFtOufvcbkYJQ2CQ
+					AGjJmAQ5J2aqYDOPMrKa615V0KT3ifbZJcGC
+					gkIic4U/EXjaQpRoLdDzR9MyVXOmbA6sKYzj
+					ju1cNkLqM8D7Uunjl4pIr6rdSFo= )
+			14400	NSEC	*.dnssex.nl. A NS SOA TXT AAAA RRSIG NSEC DNSKEY
+			14400	RRSIG	NSEC 8 2 14400 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					oIvM6JZIlNc1aNKGTxv58ApSnDr1nDPPgnD9
+					9oJZRIn7eb5WnpeDz2H3z5+x6Bhlp5hJJaUp
+					KJ3Ss6Jg/IDnrmIvKmgq6L6gHj1Y1IiHmmU8
+					VeZTRzdTsDx/27OsN23roIvsytjveNSEMfIm
+					iLZ23x5kg1kBdJ9p3xjYHm5lR+8= )
+			1800	DNSKEY	256 3 8 (
+					AwEAAazSO6uvLPEVknDA8yxjFe8nnAMU7txp
+					wb19k55hQ81WV3G4bpBM1NdN6sbYHrkXaTNx
+					2bQWAkvX6pz0XFx3z/MPhW+vkakIWFYpyQ7R
+					AT5LIJfToVfiCDiyhhF0zVobKBInO9eoGjd9
+					BAW3TUt+LmNAO/Ak5D5BX7R3CuA7v9k7
+					) ; ZSK; alg = RSASHA256; key id = 14460
+			1800	DNSKEY	257 3 8 (
+					AwEAAbyeaV9zg0IqdtgYoqK5jJ239anzwG2i
+					gvH1DxSazLyaoNvEkCIvPgMLW/JWfy7Z1mQp
+					SMy9DtzL5pzRyQgw7kIeXLbi6jufUFd9pxN+
+					xnzKLf9mY5AcnGToTrbSL+jnMT67wG+c34+Q
+					PeVfucHNUePBxsbz2+4xbXiViSQyCQGv
+					) ; KSK; alg = RSASHA256; key id = 18772
+			1800	RRSIG	DNSKEY 8 2 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					cFSFtJE+DBGNxb52AweFaVHBe5Ue5MDpqNdC
+					TIneUnEhP2m+vK4zJ/TraK0WdQFpsX63pod8
+					PZ9y03vHUfewivyonCCBD3DcNdoU9subhN22
+					tez9Ct8Z5/9E4RAz7orXal4M1VUEhRcXSEH8
+					SJW20mfVsqJAiKqqNeGB/pAj23I= )
+			1800	RRSIG	DNSKEY 8 2 1800 (
+					20160428190224 20160329190224 18772 dnssex.nl.
+					oiiwo/7NYacePqohEp50261elhm6Dieh4j2S
+					VZGAHU5gqLIQeW9CxKJKtSCkBVgUo4cvO4Rn
+					2tzArAuclDvBrMXRIoct8u7f96moeFE+x5FI
+					DYqICiV6k449ljj9o4t/5G7q2CRsEfxZKpTI
+					A/L0+uDk0RwVVzL45+TnilcsmZs= )
+*.dnssex.nl.		1800	IN TXT	"Doing It Safe Is Better"
+			1800	RRSIG	TXT 8 2 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					FUZSTyvZfeuuOpCmNzVKOfITRHJ6/ygjmnnb
+					XGBxVUyQjoLuYXwD5XqZWGw4iKH6QeSDfGCx
+					4MPqA4qQmW7Wwth7mat9yMfA4+p2sO84bysl
+					7/BG9+W2G+q1uQiM9bX9V42P2X/XuW5Y/t9Y
+					8u1sljQ7D8WwS6naH/vbaJxnDBw= )
+			14400	NSEC	a.dnssex.nl. TXT RRSIG NSEC
+			14400	RRSIG	NSEC 8 2 14400 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					os6INm6q2eXknD5z8TpfbK00uxVbQefMvHcR
+					/RNX/kh0xXvzAaaDOV+Ge/Ko+2dXnKP+J1LY
+					G9ffXNpdbaQy5ygzH5F041GJst4566GdG/jt
+					7Z7vLHYxEBTpZfxo+PLsXQXH3VTemZyuWyDf
+					qJzafXJVH1F0nDrcXmMlR6jlBHA= )
+www.dnssex.nl.		1800	IN CNAME a.dnssex.nl.
+			1800	RRSIG	CNAME 8 3 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					Omv42q/uVvdNsWQoSrQ6m6w6U7r7Abga7uF4
+					25b3gZlse0C+WyMyGFMGUbapQm7azvBpreeo
+					uKJHjzd+ufoG+Oul6vU9vyoj+ejgHzGLGbJQ
+					HftfP+UqP5SWvAaipP/LULTWKPuiBcLDLiBI
+					PGTfsq0DB6R+qCDTV0fNnkgxEBQ= )
+			14400	NSEC	dnssex.nl. CNAME RRSIG NSEC
+			14400	RRSIG	NSEC 8 3 14400 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					TBN3ddfZW+kC84/g3QlNNJMeLZoyCalPQylt
+					KXXLPGuxfGpl3RYRY8KaHbP+5a8MnHjqjuMB
+					Lofb7yKMFxpSzMh8E36vnOqry1mvkSakNj9y
+					9jM8PwDjcpYUwn/ql76MsmNgEV5CLeQ7lyH4
+					AOrL79yOSQVI3JHJIjKSiz88iSw= )
+a.dnssex.nl.		1800	IN A	139.162.196.78
+			1800	RRSIG	A 8 3 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					OXHpFj9nSpKi5yA/ULH7MOpGAWfyJ2yC/2xa
+					Pw0fqSY4QvcRt+V3adcFA4H9+P1b32GpxEjB
+					lXmCJID+H4lYkhUR4r4IOZBVtKG2SJEBZXip
+					pH00UkOIBiXxbGzfX8VL04v2G/YxUgLW57kA
+					aknaeTOkJsO20Y+8wmR9EtzaRFI= )
+			1800	AAAA	2a01:7e00::f03c:91ff:fef1:6735
+			1800	RRSIG	AAAA 8 3 1800 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					jrepc/VnRzJypnrG0WDEqaAr3HMjWrPxJNX0
+					86gbFjZG07QxBmrA1rj0jM9YEWTjjyWb2tT7
+					lQhzKDYX/0XdOVUeeOM4FoSks80V+pWR8fvj
+					AZ5HmX69g36tLosMDKNR4lXcrpv89QovG4Hr
+					/r58fxEKEFJqrLDjMo6aOrg+uKA= )
+			14400	NSEC	www.dnssex.nl. A AAAA RRSIG NSEC
+			14400	RRSIG	NSEC 8 3 14400 (
+					20160428190224 20160329190224 14460 dnssex.nl.
+					S+UM62wXRNNFN3QDWK5YFWUbHBXC4aqaqinZ
+					A2ZDeC+IQgyw7vazPz7cLI5T0YXXks0HTMlr
+					soEjKnnRZsqSO9EuUavPNE1hh11Jjm0fB+5+
+					+Uro0EmA5Dhgc0Z2VpbXVQEhNDf/pI1gem15
+					RffN2tBYNykZn4Has2ySgRaaRYQ= )`
--- a/middleware/file/lookup.go
+++ b/middleware/file/lookup.go
@@ -44,7 +44,7 @@ func (z *Zone) Lookup(qname string, qtype uint16, do bool) ([]dns.RR, []dns.RR,
 		glue := []dns.RR{}
 		for _, ns := range rrs {
 			if dns.IsSubDomain(ns.Header().Name, ns.(*dns.NS).Ns) {
-				// even with Do, this should be unsigned.
+				// Even with Do, this should be unsigned.
 				elem, res := z.Tree.SearchGlue(ns.(*dns.NS).Ns)
 				if res == tree.Found {
 					glue = append(glue, elem.Types(dns.TypeAAAA)...)
@@ -55,21 +55,22 @@ func (z *Zone) Lookup(qname string, qtype uint16, do bool) ([]dns.RR, []dns.RR,
 		return nil, rrs, glue, Delegation
 	}

-	rrs := elem.Types(dns.TypeCNAME)
+	rrs := elem.Types(dns.TypeCNAME, qname)
 	if len(rrs) > 0 { // should only ever be 1 actually; TODO(miek) check for this?
 		return z.lookupCNAME(rrs, qtype, do)
 	}

-	rrs = elem.Types(qtype)
+	rrs = elem.Types(qtype, qname)
 	if len(rrs) == 0 {
 		return z.noData(elem, do)
 	}

 	if do {
-		sigs := elem.Types(dns.TypeRRSIG)
+		sigs := elem.Types(dns.TypeRRSIG, qname)
 		sigs = signatureForSubType(sigs, qtype)
 		rrs = append(rrs, sigs...)
 	}
+
 	return rrs, nil, nil, Success
 }

@@ -156,6 +157,7 @@ func (z *Zone) lookupCNAME(rrs []dns.RR, qtype uint16, do bool) ([]dns.RR, []dns
 	if elem == nil {
 		return rrs, nil, nil, Success
 	}
+
 	targets := cnameForType(elem.All(), qtype)
 	if do {
 		sigs := elem.Types(dns.TypeRRSIG)
--- a/middleware/file/tree/elem.go
+++ b/middleware/file/tree/elem.go
@@ -4,7 +4,8 @@ import "github.com/miekg/dns"

 // Elem is an element in the tree.
 type Elem struct {
-	m map[uint16][]dns.RR
+	m    map[uint16][]dns.RR
+	name string // owner name
 }

 // newElem returns a new elem.
@@ -14,13 +15,20 @@ func newElem(rr dns.RR) *Elem {
 	return &e
 }

-// Types returns the RRs with type qtype from e.
-func (e *Elem) Types(qtype uint16) []dns.RR {
-	if rrs, ok := e.m[qtype]; ok {
-		return rrs
+// Types returns the RRs with type qtype from e. If qname is given (only the
+// first one is used), the RR are copied and the owner is replaced with qname[0].
+func (e *Elem) Types(qtype uint16, qname ...string) []dns.RR {
+	rrs := e.m[qtype]
+
+	if rrs != nil && len(qname) > 0 {
+		copied := make([]dns.RR, len(rrs))
+		for i := range rrs {
+			copied[i] = dns.Copy(rrs[i])
+			copied[i].Header().Name = qname[0]
+		}
+		return copied
 	}
-	// nodata
-	return nil
+	return rrs
 }

 // All returns all RRs from e, regardless of type.
@@ -34,12 +42,25 @@ func (e *Elem) All() []dns.RR {

 // Name returns the name for this node.
 func (e *Elem) Name() string {
+	if e.name != "" {
+		return e.name
+	}
 	for _, rrs := range e.m {
-		return rrs[0].Header().Name
+		e.name = rrs[0].Header().Name
+		return e.name
 	}
 	return ""
 }

+// Wildcard returns true if this name starts with a wildcard label (*.)
+func (e *Elem) IsWildcard() bool {
+	n := e.Name()
+	if len(n) < 2 {
+		return false
+	}
+	return n[0] == '*' && n[1] == '.'
+}
+
 // Insert inserts rr into e. If rr is equal to existing rrs this is a noop.
 func (e *Elem) Insert(rr dns.RR) {
 	t := rr.Header().Rrtype
--- a/middleware/file/tree/tree.go
+++ b/middleware/file/tree/tree.go
@@ -179,12 +179,22 @@ func (t *Tree) SearchGlue(qname string) (*Elem, Result) {
 }

 // search searches the tree for qname and type. If glue is true the search *does* not
-// spot when hitting NS records, but descends in search of glue. The qtype for this
+// stop when hitting NS records, but descends in search of glue. The qtype for this
 // kind of search can only be AAAA or A.
 func (n *Node) search(qname string, qtype uint16, glue bool) (*Node, Result) {
 	old := n
+
+	var wild *Node
+
 	for n != nil {

+		// Is this a wildcard that applies to us
+		if n.Elem.IsWildcard() {
+			if dns.IsSubDomain(n.Elem.Name()[2:], qname) {
+				wild = n
+			}
+		}
+
 		switch c := Less(n.Elem, qname); {
 		case c == 0:
 			return n, Found
@@ -200,6 +210,13 @@ func (n *Node) search(qname string, qtype uint16, glue bool) (*Node, Result) {
 			n = n.Right
 		}
 	}
+
+	// If we have seen a wildcard "on-the-way-to-here", we should return this wildcard
+	// instead. This is to be able to have a more specific RR defined *under* the wildcard.
+	if wild != nil {
+		return wild, Found
+	}
+
 	if dns.CountLabel(qname) < dns.CountLabel(old.Elem.Name()) {
 		return n, EmptyNonTerminal
 	}
--- a/middleware/file/wildcard_test.go
+++ b/middleware/file/wildcard_test.go
@@ -19,6 +19,12 @@ var wildcardTestCases = []test.Case{
 			test.TXT(`wild.dnssex.nl.	1800	IN	TXT	"Doing It Safe Is Better"`),
 		},
 	},
+	{
+		Qname: "a.wild.dnssex.nl.", Qtype: dns.TypeTXT,
+		Answer: []dns.RR{
+			test.TXT(`a.wild.dnssex.nl.	1800	IN	TXT	"Doing It Safe Is Better"`),
+		},
+	},
 	{
 		Qname: "wild.dnssex.nl.", Qtype: dns.TypeTXT, Do: true,
 		Answer: []dns.RR{
@@ -27,22 +33,31 @@ var wildcardTestCases = []test.Case{
 		},
 		Extra: []dns.RR{test.OPT(4096, true)},
 	},
-	// nodata reponse
-	/*
-		{
-			Qname: "wild.dnssex.nl.", Qtype: dns.TypeSRV,
-			Answer: []dns.RR{
-				test.TXT(`wild.dnssex.nl.	1800	IN	TXT	"Doing It Safe Is Better"`),
-			},
+	{
+		Qname: "a.wild.dnssex.nl.", Qtype: dns.TypeTXT, Do: true,
+		Answer: []dns.RR{
+			test.RRSIG("a.wild.dnssex.nl.	1800	IN	RRSIG	TXT 8 2 1800 20160428190224 20160329190224 14460 dnssex.nl. FUZSTyvZfeuuOpCm"),
+			test.TXT(`a.wild.dnssex.nl.	1800	IN	TXT	"Doing It Safe Is Better"`),
 		},
-		{
-			Qname: "wild.dnssex.nl.", Qtype: dns.TypeSRV, Do: true,
-			Answer: []dns.RR{
-				test.RRSIG("wild.dnssex.nl.	1800	IN	RRSIG	TXT 8 2 1800 20160428190224 20160329190224 14460 dnssex.nl. FUZSTyvZfeuuOpCm"),
-				test.TXT(`wild.dnssex.nl.	1800	IN	TXT	"Doing It Safe Is Better"`),
-			},
+		Extra: []dns.RR{test.OPT(4096, true)},
+	},
+	// nodata responses
+	{
+		Qname: "wild.dnssex.nl.", Qtype: dns.TypeSRV,
+		Ns: []dns.RR{
+			test.SOA(`dnssex.nl.	1800	IN	SOA	linode.atoom.net. miek.miek.nl. 1459281744 14400 3600 604800 14400`),
 		},
-	*/
+	},
+	{
+		Qname: "wild.dnssex.nl.", Qtype: dns.TypeSRV, Do: true,
+		Ns: []dns.RR{
+			test.NSEC(`*.dnssex.nl.	14400	IN	NSEC	a.dnssex.nl. TXT RRSIG NSEC`),
+			test.RRSIG(`*.dnssex.nl.	14400	IN	RRSIG	NSEC 8 2 14400 20160428190224 20160329190224 14460 dnssex.nl. os6INm6q2eXknD5z8TpfbK00uxVbQefMvHcR/RNX/kh0xXvzAaaDOV+Ge/Ko+2dXnKP+J1LYG9ffXNpdbaQy5ygzH5F041GJst4566GdG/jt7Z7vLHYxEBTpZfxo+PLsXQXH3VTemZyuWyDfqJzafXJVH1F0nDrcXmMlR6jlBHA=`),
+			test.RRSIG(`dnssex.nl.	1800	IN	RRSIG	SOA 8 2 1800 20160428190224 20160329190224 14460 dnssex.nl. CA/Y3m9hCOiKC/8ieSOv8SeP964BUdG/8MC3WtKljUosK9Z9bBGrVizDjjqgq++lyH8BZJcTaabAsERs4xj5PRtcxicwQXZACX5VYjXHQeZmCyytFU5wq2gcXSmvUH86zZzftx3RGPvn1aOoTlcvoC3iF8fYUCpROlUS0YR8Cdw=`),
+			test.SOA(`dnssex.nl.	1800	IN	SOA	linode.atoom.net. miek.miek.nl. 1459281744 14400 3600 604800 14400`),
+		},
+		Extra: []dns.RR{test.OPT(4096, true)},
+	},
 }

 func TestLookupWildcard(t *testing.T) {
@@ -85,146 +100,83 @@ func TestLookupWildcard(t *testing.T) {
 	}
 }

-const dbDnssexNLSigned = `
-; File written on Tue Mar 29 21:02:24 2016
-; dnssec_signzone version 9.10.3-P4-Ubuntu
-dnssex.nl.		1800	IN SOA	linode.atoom.net. miek.miek.nl. (
-					1459281744 ; serial
-					14400      ; refresh (4 hours)
-					3600       ; retry (1 hour)
-					604800     ; expire (1 week)
-					14400      ; minimum (4 hours)
-					)
-			1800	RRSIG	SOA 8 2 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					CA/Y3m9hCOiKC/8ieSOv8SeP964BUdG/8MC3
-					WtKljUosK9Z9bBGrVizDjjqgq++lyH8BZJcT
-					aabAsERs4xj5PRtcxicwQXZACX5VYjXHQeZm
-					CyytFU5wq2gcXSmvUH86zZzftx3RGPvn1aOo
-					TlcvoC3iF8fYUCpROlUS0YR8Cdw= )
-			1800	NS	omval.tednet.nl.
-			1800	NS	linode.atoom.net.
-			1800	NS	ns-ext.nlnetlabs.nl.
-			1800	RRSIG	NS 8 2 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					dLIeEvP86jj5nd3orv9bH7hTvkblF4Na0sbl
-					k6fJA6ha+FPN1d6Pig3NNEEVQ/+wlOp/JTs2
-					v07L7roEEUCbBprI8gMSld2gFDwNLW3DAB4M
-					WD/oayYdAnumekcLzhgvWixTABjWAGRTGQsP
-					sVDFXsGMf9TGGC9FEomgkCVeNC0= )
-			1800	A	139.162.196.78
-			1800	RRSIG	A 8 2 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					LKJKLzPiSEDWOLAag2YpfD5EJCuDcEAJu+FZ
-					Xy+4VyOv9YvRHCTL4vbrevOo5+XymY2RxU1q
-					j+6leR/Fe7nlreSj2wzAAk2bIYn4m6r7hqeO
-					aKZsUFfpX8cNcFtGEywfHndCPELbRxFeEziP
-					utqHFLPNMX5nYCpS28w4oJ5sAnM= )
-			1800	TXT	"Doing It Safe Is Better"
-			1800	RRSIG	TXT 8 2 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					f6S+DUfJK1UYdOb3AHgUXzFTTtu+yLp/Fv7S
-					Hv0CAGhXAVw+nBbK719igFvBtObS33WKwzxD
-					1pQNMaJcS6zeevtD+4PKB1KDC4fyJffeEZT6
-					E30jGR8Y29/xA+Fa4lqDNnj9zP3b8TiABCle
-					ascY5abkgWCALLocFAzFJQ/27YQ= )
-			1800	AAAA	2a01:7e00::f03c:91ff:fef1:6735
-			1800	RRSIG	AAAA 8 2 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					PWcPSawEUBAfCuv0liEOQ8RYe7tfNW4rubIJ
-					LE+dbrub1DUer3cWrDoCYFtOufvcbkYJQ2CQ
-					AGjJmAQ5J2aqYDOPMrKa615V0KT3ifbZJcGC
-					gkIic4U/EXjaQpRoLdDzR9MyVXOmbA6sKYzj
-					ju1cNkLqM8D7Uunjl4pIr6rdSFo= )
-			14400	NSEC	*.dnssex.nl. A NS SOA TXT AAAA RRSIG NSEC DNSKEY
-			14400	RRSIG	NSEC 8 2 14400 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					oIvM6JZIlNc1aNKGTxv58ApSnDr1nDPPgnD9
-					9oJZRIn7eb5WnpeDz2H3z5+x6Bhlp5hJJaUp
-					KJ3Ss6Jg/IDnrmIvKmgq6L6gHj1Y1IiHmmU8
-					VeZTRzdTsDx/27OsN23roIvsytjveNSEMfIm
-					iLZ23x5kg1kBdJ9p3xjYHm5lR+8= )
-			1800	DNSKEY	256 3 8 (
-					AwEAAazSO6uvLPEVknDA8yxjFe8nnAMU7txp
-					wb19k55hQ81WV3G4bpBM1NdN6sbYHrkXaTNx
-					2bQWAkvX6pz0XFx3z/MPhW+vkakIWFYpyQ7R
-					AT5LIJfToVfiCDiyhhF0zVobKBInO9eoGjd9
-					BAW3TUt+LmNAO/Ak5D5BX7R3CuA7v9k7
-					) ; ZSK; alg = RSASHA256; key id = 14460
-			1800	DNSKEY	257 3 8 (
-					AwEAAbyeaV9zg0IqdtgYoqK5jJ239anzwG2i
-					gvH1DxSazLyaoNvEkCIvPgMLW/JWfy7Z1mQp
-					SMy9DtzL5pzRyQgw7kIeXLbi6jufUFd9pxN+
-					xnzKLf9mY5AcnGToTrbSL+jnMT67wG+c34+Q
-					PeVfucHNUePBxsbz2+4xbXiViSQyCQGv
-					) ; KSK; alg = RSASHA256; key id = 18772
-			1800	RRSIG	DNSKEY 8 2 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					cFSFtJE+DBGNxb52AweFaVHBe5Ue5MDpqNdC
-					TIneUnEhP2m+vK4zJ/TraK0WdQFpsX63pod8
-					PZ9y03vHUfewivyonCCBD3DcNdoU9subhN22
-					tez9Ct8Z5/9E4RAz7orXal4M1VUEhRcXSEH8
-					SJW20mfVsqJAiKqqNeGB/pAj23I= )
-			1800	RRSIG	DNSKEY 8 2 1800 (
-					20160428190224 20160329190224 18772 dnssex.nl.
-					oiiwo/7NYacePqohEp50261elhm6Dieh4j2S
-					VZGAHU5gqLIQeW9CxKJKtSCkBVgUo4cvO4Rn
-					2tzArAuclDvBrMXRIoct8u7f96moeFE+x5FI
-					DYqICiV6k449ljj9o4t/5G7q2CRsEfxZKpTI
-					A/L0+uDk0RwVVzL45+TnilcsmZs= )
-*.dnssex.nl.		1800	IN TXT	"Doing It Safe Is Better"
-			1800	RRSIG	TXT 8 2 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					FUZSTyvZfeuuOpCmNzVKOfITRHJ6/ygjmnnb
-					XGBxVUyQjoLuYXwD5XqZWGw4iKH6QeSDfGCx
-					4MPqA4qQmW7Wwth7mat9yMfA4+p2sO84bysl
-					7/BG9+W2G+q1uQiM9bX9V42P2X/XuW5Y/t9Y
-					8u1sljQ7D8WwS6naH/vbaJxnDBw= )
-			14400	NSEC	a.dnssex.nl. TXT RRSIG NSEC
-			14400	RRSIG	NSEC 8 2 14400 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					os6INm6q2eXknD5z8TpfbK00uxVbQefMvHcR
-					/RNX/kh0xXvzAaaDOV+Ge/Ko+2dXnKP+J1LY
-					G9ffXNpdbaQy5ygzH5F041GJst4566GdG/jt
-					7Z7vLHYxEBTpZfxo+PLsXQXH3VTemZyuWyDf
-					qJzafXJVH1F0nDrcXmMlR6jlBHA= )
-www.dnssex.nl.		1800	IN CNAME a.dnssex.nl.
-			1800	RRSIG	CNAME 8 3 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					Omv42q/uVvdNsWQoSrQ6m6w6U7r7Abga7uF4
-					25b3gZlse0C+WyMyGFMGUbapQm7azvBpreeo
-					uKJHjzd+ufoG+Oul6vU9vyoj+ejgHzGLGbJQ
-					HftfP+UqP5SWvAaipP/LULTWKPuiBcLDLiBI
-					PGTfsq0DB6R+qCDTV0fNnkgxEBQ= )
-			14400	NSEC	dnssex.nl. CNAME RRSIG NSEC
-			14400	RRSIG	NSEC 8 3 14400 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					TBN3ddfZW+kC84/g3QlNNJMeLZoyCalPQylt
-					KXXLPGuxfGpl3RYRY8KaHbP+5a8MnHjqjuMB
-					Lofb7yKMFxpSzMh8E36vnOqry1mvkSakNj9y
-					9jM8PwDjcpYUwn/ql76MsmNgEV5CLeQ7lyH4
-					AOrL79yOSQVI3JHJIjKSiz88iSw= )
-a.dnssex.nl.		1800	IN A	139.162.196.78
-			1800	RRSIG	A 8 3 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					OXHpFj9nSpKi5yA/ULH7MOpGAWfyJ2yC/2xa
-					Pw0fqSY4QvcRt+V3adcFA4H9+P1b32GpxEjB
-					lXmCJID+H4lYkhUR4r4IOZBVtKG2SJEBZXip
-					pH00UkOIBiXxbGzfX8VL04v2G/YxUgLW57kA
-					aknaeTOkJsO20Y+8wmR9EtzaRFI= )
-			1800	AAAA	2a01:7e00::f03c:91ff:fef1:6735
-			1800	RRSIG	AAAA 8 3 1800 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					jrepc/VnRzJypnrG0WDEqaAr3HMjWrPxJNX0
-					86gbFjZG07QxBmrA1rj0jM9YEWTjjyWb2tT7
-					lQhzKDYX/0XdOVUeeOM4FoSks80V+pWR8fvj
-					AZ5HmX69g36tLosMDKNR4lXcrpv89QovG4Hr
-					/r58fxEKEFJqrLDjMo6aOrg+uKA= )
-			14400	NSEC	www.dnssex.nl. A AAAA RRSIG NSEC
-			14400	RRSIG	NSEC 8 3 14400 (
-					20160428190224 20160329190224 14460 dnssex.nl.
-					S+UM62wXRNNFN3QDWK5YFWUbHBXC4aqaqinZ
-					A2ZDeC+IQgyw7vazPz7cLI5T0YXXks0HTMlr
-					soEjKnnRZsqSO9EuUavPNE1hh11Jjm0fB+5+
-					+Uro0EmA5Dhgc0Z2VpbXVQEhNDf/pI1gem15
-					RffN2tBYNykZn4Has2ySgRaaRYQ= )`
+var wildcardDoubleTestCases = []test.Case{
+	{
+		Qname: "wild.w.example.org.", Qtype: dns.TypeTXT,
+		Answer: []dns.RR{
+			test.TXT(`wild.w.example.org. IN	TXT	"Wildcard"`),
+		},
+	},
+	{
+		Qname: "wild.c.example.org.", Qtype: dns.TypeTXT,
+		Answer: []dns.RR{
+			test.TXT(`wild.c.example.org. IN	TXT	"c Wildcard"`),
+		},
+	},
+	{
+		Qname: "wild.d.example.org.", Qtype: dns.TypeTXT,
+		Answer: []dns.RR{
+			test.TXT(`alias.example.org. IN	TXT	"Wildcard CNAME expansion"`),
+			test.CNAME(`wild.d.example.org. IN	CNAME	alias.example.org`),
+		},
+	},
+	{
+		Qname: "alias.example.org.", Qtype: dns.TypeTXT,
+		Answer: []dns.RR{
+			test.TXT(`alias.example.org. IN	TXT	"Wildcard CNAME expansion"`),
+		},
+	},
+}
+
+func TestLookupDoubleWildcard(t *testing.T) {
+	zone, err := Parse(strings.NewReader(exampleOrg), "example.org.", "stdin")
+	if err != nil {
+		t.Fatalf("expect no error when reading zone, got %q", err)
+	}
+
+	fm := File{Next: test.ErrorHandler(), Zones: Zones{Z: map[string]*Zone{"example.org.": zone}, Names: []string{"example.org."}}}
+	ctx := context.TODO()
+
+	for _, tc := range wildcardDoubleTestCases {
+		m := tc.Msg()
+
+		rec := dnsrecorder.New(&test.ResponseWriter{})
+		_, err := fm.ServeDNS(ctx, rec, m)
+		if err != nil {
+			t.Errorf("expected no error, got %v\n", err)
+			return
+		}
+
+		resp := rec.Msg
+		sort.Sort(test.RRSet(resp.Answer))
+		sort.Sort(test.RRSet(resp.Ns))
+		sort.Sort(test.RRSet(resp.Extra))
+
+		if !test.Header(t, tc, resp) {
+			t.Logf("%v\n", resp)
+			continue
+		}
+		if !test.Section(t, tc, test.Answer, resp.Answer) {
+			t.Logf("%v\n", resp)
+		}
+		if !test.Section(t, tc, test.Ns, resp.Ns) {
+			t.Logf("%v\n", resp)
+		}
+		if !test.Section(t, tc, test.Extra, resp.Extra) {
+			t.Logf("%v\n", resp)
+		}
+	}
+}
+
+const exampleOrg = `; example.org test file
+example.org.		IN	SOA	sns.dns.icann.org. noc.dns.icann.org. 2015082541 7200 3600 1209600 3600
+example.org.		IN	NS	b.iana-servers.net.
+example.org.		IN	NS	a.iana-servers.net.
+example.org.		IN	A	127.0.0.1
+example.org.		IN	A	127.0.0.2
+*.w.example.org.        IN      TXT     "Wildcard"
+a.b.c.w.example.org.    IN      TXT     "Not a wildcard"
+*.c.example.org.        IN      TXT     "c Wildcard"
+*.d.example.org.        IN      CNAME   alias.example.org.
+alias.example.org.      IN      TXT     "Wildcard CNAME expansion"
+`