1package eu.siacs.conversations.crypto;
2
3import android.util.Log;
4import android.util.Pair;
5
6import org.bouncycastle.asn1.ASN1Primitive;
7import org.bouncycastle.asn1.DERIA5String;
8import org.bouncycastle.asn1.DERTaggedObject;
9import org.bouncycastle.asn1.DERUTF8String;
10import org.bouncycastle.asn1.DLSequence;
11import org.bouncycastle.asn1.x500.RDN;
12import org.bouncycastle.asn1.x500.X500Name;
13import org.bouncycastle.asn1.x500.style.BCStyle;
14import org.bouncycastle.asn1.x500.style.IETFUtils;
15import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
16
17import java.io.IOException;
18import java.security.cert.Certificate;
19import java.security.cert.X509Certificate;
20import java.util.ArrayList;
21import java.util.Collection;
22import java.util.List;
23
24import javax.net.ssl.HostnameVerifier;
25import javax.net.ssl.SSLSession;
26
27public class XmppDomainVerifier implements HostnameVerifier {
28
29 private static final String LOGTAG = "XmppDomainVerifier";
30
31 private final String SRVName = "1.3.6.1.5.5.7.8.7";
32 private final String xmppAddr = "1.3.6.1.5.5.7.8.5";
33
34 @Override
35 public boolean verify(String domain, SSLSession sslSession) {
36 try {
37 Certificate[] chain = sslSession.getPeerCertificates();
38 if (chain.length == 0 || !(chain[0] instanceof X509Certificate)) {
39 return false;
40 }
41 X509Certificate certificate = (X509Certificate) chain[0];
42 Collection<List<?>> alternativeNames = certificate.getSubjectAlternativeNames();
43 List<String> xmppAddrs = new ArrayList<>();
44 List<String> srvNames = new ArrayList<>();
45 List<String> domains = new ArrayList<>();
46 if (alternativeNames != null) {
47 for (List<?> san : alternativeNames) {
48 Integer type = (Integer) san.get(0);
49 if (type == 0) {
50 Pair<String, String> otherName = parseOtherName((byte[]) san.get(1));
51 if (otherName != null) {
52 switch (otherName.first) {
53 case SRVName:
54 srvNames.add(otherName.second);
55 break;
56 case xmppAddr:
57 xmppAddrs.add(otherName.second);
58 break;
59 default:
60 Log.d(LOGTAG, "oid: " + otherName.first + " value: " + otherName.second);
61 }
62 }
63 } else if (type == 2) {
64 Object value = san.get(1);
65 if (value instanceof String) {
66 domains.add((String) value);
67 }
68 }
69 }
70 }
71 if (srvNames.size() == 0 && xmppAddrs.size() == 0 && domains.size() == 0) {
72 X500Name x500name = new JcaX509CertificateHolder(certificate).getSubject();
73 RDN[] rdns = x500name.getRDNs(BCStyle.CN);
74 for (int i = 0; i < rdns.length; ++i) {
75 domains.add(IETFUtils.valueToString(x500name.getRDNs(BCStyle.CN)[i].getFirst().getValue()));
76 }
77 }
78 Log.d(LOGTAG, "searching for " + domain + " in srvNames: " + srvNames + " xmppAddrs: " + xmppAddrs + " domains:" + domains);
79 return xmppAddrs.contains(domain) || srvNames.contains("_xmpp-client." + domain) || matchDomain(domain, domains);
80 } catch (Exception e) {
81 return false;
82 }
83 }
84
85 private static Pair<String, String> parseOtherName(byte[] otherName) {
86 try {
87 ASN1Primitive asn1Primitive = ASN1Primitive.fromByteArray(otherName);
88 if (asn1Primitive instanceof DERTaggedObject) {
89 ASN1Primitive inner = ((DERTaggedObject) asn1Primitive).getObject();
90 if (inner instanceof DLSequence) {
91 DLSequence sequence = (DLSequence) inner;
92 if (sequence.size() >= 2 && sequence.getObjectAt(1) instanceof DERTaggedObject) {
93 String oid = sequence.getObjectAt(0).toString();
94 ASN1Primitive value = ((DERTaggedObject) sequence.getObjectAt(1)).getObject();
95 if (value instanceof DERUTF8String) {
96 return new Pair<>(oid, ((DERUTF8String) value).getString());
97 } else if (value instanceof DERIA5String) {
98 return new Pair<>(oid, ((DERIA5String) value).getString());
99 }
100 }
101 }
102 }
103 return null;
104 } catch (IOException e) {
105 return null;
106 }
107 }
108
109 private static boolean matchDomain(String needle, List<String> haystack) {
110 for (String entry : haystack) {
111 if (entry.startsWith("*.")) {
112 int i = needle.indexOf('.');
113 Log.d(LOGTAG, "comparing " + needle.substring(i) + " and " + entry.substring(1));
114 if (i != -1 && needle.substring(i).equals(entry.substring(1))) {
115 Log.d(LOGTAG, "domain " + needle + " matched " + entry);
116 return true;
117 }
118 } else {
119 if (entry.equals(needle)) {
120 Log.d(LOGTAG, "domain " + needle + " matched " + entry);
121 return true;
122 }
123 }
124 }
125 return false;
126 }
127}