1// Copyright 2011 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package net
6
7import (
8	"encoding/hex"
9	"reflect"
10	"testing"
11)
12
13func TestDNSParseSRVReply(t *testing.T) {
14	data, err := hex.DecodeString(dnsSRVReply)
15	if err != nil {
16		t.Fatal(err)
17	}
18	msg := new(dnsMsg)
19	ok := msg.Unpack(data)
20	if !ok {
21		t.Fatal("unpacking packet failed")
22	}
23	msg.String() // exercise this code path
24	if g, e := len(msg.answer), 5; g != e {
25		t.Errorf("len(msg.answer) = %d; want %d", g, e)
26	}
27	for idx, rr := range msg.answer {
28		if g, e := rr.Header().Rrtype, uint16(dnsTypeSRV); g != e {
29			t.Errorf("rr[%d].Header().Rrtype = %d; want %d", idx, g, e)
30		}
31		if _, ok := rr.(*dnsRR_SRV); !ok {
32			t.Errorf("answer[%d] = %T; want *dnsRR_SRV", idx, rr)
33		}
34	}
35	for _, name := range [...]string{
36		"_xmpp-server._tcp.google.com.",
37		"_XMPP-Server._TCP.Google.COM.",
38		"_XMPP-SERVER._TCP.GOOGLE.COM.",
39	} {
40		_, addrs, err := answer(name, "foo:53", msg, uint16(dnsTypeSRV))
41		if err != nil {
42			t.Error(err)
43		}
44		if g, e := len(addrs), 5; g != e {
45			t.Errorf("len(addrs) = %d; want %d", g, e)
46			t.Logf("addrs = %#v", addrs)
47		}
48	}
49	// repack and unpack.
50	data2, ok := msg.Pack()
51	msg2 := new(dnsMsg)
52	msg2.Unpack(data2)
53	switch {
54	case !ok:
55		t.Error("failed to repack message")
56	case !reflect.DeepEqual(msg, msg2):
57		t.Error("repacked message differs from original")
58	}
59}
60
61func TestDNSParseCorruptSRVReply(t *testing.T) {
62	data, err := hex.DecodeString(dnsSRVCorruptReply)
63	if err != nil {
64		t.Fatal(err)
65	}
66	msg := new(dnsMsg)
67	ok := msg.Unpack(data)
68	if !ok {
69		t.Fatal("unpacking packet failed")
70	}
71	msg.String() // exercise this code path
72	if g, e := len(msg.answer), 5; g != e {
73		t.Errorf("len(msg.answer) = %d; want %d", g, e)
74	}
75	for idx, rr := range msg.answer {
76		if g, e := rr.Header().Rrtype, uint16(dnsTypeSRV); g != e {
77			t.Errorf("rr[%d].Header().Rrtype = %d; want %d", idx, g, e)
78		}
79		if idx == 4 {
80			if _, ok := rr.(*dnsRR_Header); !ok {
81				t.Errorf("answer[%d] = %T; want *dnsRR_Header", idx, rr)
82			}
83		} else {
84			if _, ok := rr.(*dnsRR_SRV); !ok {
85				t.Errorf("answer[%d] = %T; want *dnsRR_SRV", idx, rr)
86			}
87		}
88	}
89	_, addrs, err := answer("_xmpp-server._tcp.google.com.", "foo:53", msg, uint16(dnsTypeSRV))
90	if err != nil {
91		t.Fatalf("answer: %v", err)
92	}
93	if g, e := len(addrs), 4; g != e {
94		t.Errorf("len(addrs) = %d; want %d", g, e)
95		t.Logf("addrs = %#v", addrs)
96	}
97}
98
99func TestDNSParseTXTReply(t *testing.T) {
100	expectedTxt1 := "v=spf1 redirect=_spf.google.com"
101	expectedTxt2 := "v=spf1 ip4:69.63.179.25 ip4:69.63.178.128/25 ip4:69.63.184.0/25 " +
102		"ip4:66.220.144.128/25 ip4:66.220.155.0/24 " +
103		"ip4:69.171.232.0/25 ip4:66.220.157.0/25 " +
104		"ip4:69.171.244.0/24 mx -all"
105
106	replies := []string{dnsTXTReply1, dnsTXTReply2}
107	expectedTxts := []string{expectedTxt1, expectedTxt2}
108
109	for i := range replies {
110		data, err := hex.DecodeString(replies[i])
111		if err != nil {
112			t.Fatal(err)
113		}
114
115		msg := new(dnsMsg)
116		ok := msg.Unpack(data)
117		if !ok {
118			t.Errorf("test %d: unpacking packet failed", i)
119			continue
120		}
121
122		if len(msg.answer) != 1 {
123			t.Errorf("test %d: len(rr.answer) = %d; want 1", i, len(msg.answer))
124			continue
125		}
126
127		rr := msg.answer[0]
128		rrTXT, ok := rr.(*dnsRR_TXT)
129		if !ok {
130			t.Errorf("test %d: answer[0] = %T; want *dnsRR_TXT", i, rr)
131			continue
132		}
133
134		if rrTXT.Txt != expectedTxts[i] {
135			t.Errorf("test %d: Txt = %s; want %s", i, rrTXT.Txt, expectedTxts[i])
136		}
137	}
138}
139
140func TestDNSParseTXTCorruptDataLengthReply(t *testing.T) {
141	replies := []string{dnsTXTCorruptDataLengthReply1, dnsTXTCorruptDataLengthReply2}
142
143	for i := range replies {
144		data, err := hex.DecodeString(replies[i])
145		if err != nil {
146			t.Fatal(err)
147		}
148
149		msg := new(dnsMsg)
150		ok := msg.Unpack(data)
151		if ok {
152			t.Errorf("test %d: expected to fail on unpacking corrupt packet", i)
153		}
154	}
155}
156
157func TestDNSParseTXTCorruptTXTLengthReply(t *testing.T) {
158	replies := []string{dnsTXTCorruptTXTLengthReply1, dnsTXTCorruptTXTLengthReply2}
159
160	for i := range replies {
161		data, err := hex.DecodeString(replies[i])
162		if err != nil {
163			t.Fatal(err)
164		}
165
166		msg := new(dnsMsg)
167		ok := msg.Unpack(data)
168		// Unpacking should succeed, but we should just get the header.
169		if !ok {
170			t.Errorf("test %d: unpacking packet failed", i)
171			continue
172		}
173
174		if len(msg.answer) != 1 {
175			t.Errorf("test %d: len(rr.answer) = %d; want 1", i, len(msg.answer))
176			continue
177		}
178
179		rr := msg.answer[0]
180		if _, justHeader := rr.(*dnsRR_Header); !justHeader {
181			t.Errorf("test %d: rr = %T; expected *dnsRR_Header", i, rr)
182		}
183	}
184}
185
186// Valid DNS SRV reply
187const dnsSRVReply = "0901818000010005000000000c5f786d70702d736572766572045f74637006676f6f67" +
188	"6c6503636f6d0000210001c00c002100010000012c00210014000014950c786d70702d" +
189	"73657276657234016c06676f6f676c6503636f6d00c00c002100010000012c00210014" +
190	"000014950c786d70702d73657276657232016c06676f6f676c6503636f6d00c00c0021" +
191	"00010000012c00210014000014950c786d70702d73657276657233016c06676f6f676c" +
192	"6503636f6d00c00c002100010000012c00200005000014950b786d70702d7365727665" +
193	"72016c06676f6f676c6503636f6d00c00c002100010000012c00210014000014950c78" +
194	"6d70702d73657276657231016c06676f6f676c6503636f6d00"
195
196// Corrupt DNS SRV reply, with its final RR having a bogus length
197// (perhaps it was truncated, or it's malicious) The mutation is the
198// capital "FF" below, instead of the proper "21".
199const dnsSRVCorruptReply = "0901818000010005000000000c5f786d70702d736572766572045f74637006676f6f67" +
200	"6c6503636f6d0000210001c00c002100010000012c00210014000014950c786d70702d" +
201	"73657276657234016c06676f6f676c6503636f6d00c00c002100010000012c00210014" +
202	"000014950c786d70702d73657276657232016c06676f6f676c6503636f6d00c00c0021" +
203	"00010000012c00210014000014950c786d70702d73657276657233016c06676f6f676c" +
204	"6503636f6d00c00c002100010000012c00200005000014950b786d70702d7365727665" +
205	"72016c06676f6f676c6503636f6d00c00c002100010000012c00FF0014000014950c78" +
206	"6d70702d73657276657231016c06676f6f676c6503636f6d00"
207
208// TXT reply with one <character-string>
209const dnsTXTReply1 = "b3458180000100010004000505676d61696c03636f6d0000100001c00c001000010000012c00" +
210	"201f763d737066312072656469726563743d5f7370662e676f6f676c652e636f6dc00" +
211	"c0002000100025d4c000d036e733406676f6f676c65c012c00c0002000100025d4c00" +
212	"06036e7331c057c00c0002000100025d4c0006036e7333c057c00c0002000100025d4" +
213	"c0006036e7332c057c06c00010001000248b50004d8ef200ac09000010001000248b5" +
214	"0004d8ef220ac07e00010001000248b50004d8ef240ac05300010001000248b50004d" +
215	"8ef260a0000291000000000000000"
216
217// TXT reply with more than one <character-string>.
218// See https://tools.ietf.org/html/rfc1035#section-3.3.14
219const dnsTXTReply2 = "a0a381800001000100020002045f7370660866616365626f6f6b03636f6d0000100001c00c0010000" +
220	"100000e1000af7f763d73706631206970343a36392e36332e3137392e3235206970343a36392e" +
221	"36332e3137382e3132382f3235206970343a36392e36332e3138342e302f3235206970343a363" +
222	"62e3232302e3134342e3132382f3235206970343a36362e3232302e3135352e302f3234206970" +
223	"343a36392e3137312e3233322e302f323520692e70343a36362e3232302e3135372e302f32352" +
224	"06970343a36392e3137312e3234342e302f3234206d78202d616c6cc0110002000100025d1500" +
225	"070161026e73c011c0110002000100025d1500040162c0ecc0ea0001000100025d15000445abe" +
226	"f0cc0fd0001000100025d15000445abff0c"
227
228// DataLength field should be sum of all TXT fields. In this case it's less.
229const dnsTXTCorruptDataLengthReply1 = "a0a381800001000100020002045f7370660866616365626f6f6b03636f6d0000100001c00c0010000" +
230	"100000e1000967f763d73706631206970343a36392e36332e3137392e3235206970343a36392e" +
231	"36332e3137382e3132382f3235206970343a36392e36332e3138342e302f3235206970343a363" +
232	"62e3232302e3134342e3132382f3235206970343a36362e3232302e3135352e302f3234206970" +
233	"343a36392e3137312e3233322e302f323520692e70343a36362e3232302e3135372e302f32352" +
234	"06970343a36392e3137312e3234342e302f3234206d78202d616c6cc0110002000100025d1500" +
235	"070161026e73c011c0110002000100025d1500040162c0ecc0ea0001000100025d15000445abe" +
236	"f0cc0fd0001000100025d15000445abff0c"
237
238// Same as above but DataLength is more than sum of TXT fields.
239const dnsTXTCorruptDataLengthReply2 = "a0a381800001000100020002045f7370660866616365626f6f6b03636f6d0000100001c00c0010000" +
240	"100000e1001227f763d73706631206970343a36392e36332e3137392e3235206970343a36392e" +
241	"36332e3137382e3132382f3235206970343a36392e36332e3138342e302f3235206970343a363" +
242	"62e3232302e3134342e3132382f3235206970343a36362e3232302e3135352e302f3234206970" +
243	"343a36392e3137312e3233322e302f323520692e70343a36362e3232302e3135372e302f32352" +
244	"06970343a36392e3137312e3234342e302f3234206d78202d616c6cc0110002000100025d1500" +
245	"070161026e73c011c0110002000100025d1500040162c0ecc0ea0001000100025d15000445abe" +
246	"f0cc0fd0001000100025d15000445abff0c"
247
248// TXT Length field is less than actual length.
249const dnsTXTCorruptTXTLengthReply1 = "a0a381800001000100020002045f7370660866616365626f6f6b03636f6d0000100001c00c0010000" +
250	"100000e1000af7f763d73706631206970343a36392e36332e3137392e3235206970343a36392e" +
251	"36332e3137382e3132382f3235206970343a36392e36332e3138342e302f3235206970343a363" +
252	"62e3232302e3134342e3132382f3235206970343a36362e3232302e3135352e302f3234206970" +
253	"343a36392e3137312e3233322e302f323520691470343a36362e3232302e3135372e302f32352" +
254	"06970343a36392e3137312e3234342e302f3234206d78202d616c6cc0110002000100025d1500" +
255	"070161026e73c011c0110002000100025d1500040162c0ecc0ea0001000100025d15000445abe" +
256	"f0cc0fd0001000100025d15000445abff0c"
257
258// TXT Length field is more than actual length.
259const dnsTXTCorruptTXTLengthReply2 = "a0a381800001000100020002045f7370660866616365626f6f6b03636f6d0000100001c00c0010000" +
260	"100000e1000af7f763d73706631206970343a36392e36332e3137392e3235206970343a36392e" +
261	"36332e3137382e3132382f3235206970343a36392e36332e3138342e302f3235206970343a363" +
262	"62e3232302e3134342e3132382f3235206970343a36362e3232302e3135352e302f3234206970" +
263	"343a36392e3137312e3233322e302f323520693370343a36362e3232302e3135372e302f32352" +
264	"06970343a36392e3137312e3234342e302f3234206d78202d616c6cc0110002000100025d1500" +
265	"070161026e73c011c0110002000100025d1500040162c0ecc0ea0001000100025d15000445abe" +
266	"f0cc0fd0001000100025d15000445abff0c"
267