XmppDomainVerifier.java

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