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	@Override
 31	public boolean verify(String domain, SSLSession sslSession) {
 32		try {
 33			Certificate[] chain = sslSession.getPeerCertificates();
 34			if (chain.length == 0 || !(chain[0] instanceof X509Certificate)) {
 35				return false;
 36			}
 37			X509Certificate certificate = (X509Certificate) chain[0];
 38			Collection<List<?>> alternativeNames = certificate.getSubjectAlternativeNames();
 39			List<String> xmppAddrs = new ArrayList<>();
 40			List<String> srvNames = new ArrayList<>();
 41			List<String> domains = new ArrayList<>();
 42			if (alternativeNames != null) {
 43				for(List<?> san : alternativeNames) {
 44					Integer type = (Integer) san.get(0);
 45					if (type == 0) {
 46						try {
 47							ASN1Primitive asn1Primitive = ASN1Primitive.fromByteArray((byte[]) san.get(1));
 48							if (asn1Primitive instanceof  DERTaggedObject) {
 49								ASN1Primitive inner = ((DERTaggedObject) asn1Primitive).getObject();
 50								if (inner instanceof  DLSequence) {
 51									DLSequence sequence = (DLSequence) inner;
 52									if (sequence.size() >= 2 && sequence.getObjectAt(1) instanceof DERTaggedObject) {
 53										String oid = sequence.getObjectAt(0).toString();
 54										ASN1Primitive value  = ((DERTaggedObject) sequence.getObjectAt(1)).getObject();
 55										switch (oid) {
 56											case "1.3.6.1.5.5.7.8.5":
 57												if (value instanceof DERUTF8String) {
 58													xmppAddrs.add(((DERUTF8String) value).getString());
 59												} else if (value instanceof DERIA5String) {
 60													xmppAddrs.add(((DERIA5String) value).getString());
 61												}
 62												break;
 63											case "1.3.6.1.5.5.7.8.7":
 64												if (value instanceof DERUTF8String) {
 65													srvNames.add(((DERUTF8String) value).getString());
 66												} else if (value instanceof DERIA5String) {
 67													srvNames.add(((DERIA5String) value).getString());
 68												}
 69												break;
 70											default:
 71												Log.d(LOGTAG,"value was of type:"+value.getClass().getName()+ " oid was:"+oid);
 72										}
 73									}
 74								}
 75							}
 76						} catch (IOException e) {
 77							//ignored
 78						}
 79					} else if (type == 2) {
 80						Object value = san.get(1);
 81						if (value instanceof String) {
 82							domains.add((String) value);
 83						}
 84					}
 85				}
 86			}
 87			if (srvNames.size() == 0 && xmppAddrs.size() == 0 && domains.size() == 0) {
 88				X500Name x500name = new JcaX509CertificateHolder(certificate).getSubject();
 89				RDN[] rdns = x500name.getRDNs(BCStyle.CN);
 90				for(int i = 0; i < rdns.length; ++i) {
 91					domains.add(IETFUtils.valueToString(x500name.getRDNs(BCStyle.CN)[i].getFirst().getValue()));
 92				}
 93			}
 94			Log.d(LOGTAG, "searching for " + domain + " in srvNames: " + srvNames + " xmppAddrs: " + xmppAddrs + " domains:" + domains);
 95			return xmppAddrs.contains(domain) || srvNames.contains("_xmpp-client."+domain) || matchDomain(domain, domains);
 96		} catch (Exception e) {
 97			return false;
 98		}
 99	}
100
101	private boolean matchDomain(String needle, List<String> haystack) {
102		for(String entry : haystack) {
103			if (entry.startsWith("*.")) {
104				int i = needle.indexOf('.');
105				Log.d(LOGTAG,"comparing "+needle.substring(i)+ " and "+entry.substring(1));
106				if (i != -1 && needle.substring(i).equals(entry.substring(1))) {
107					Log.d(LOGTAG,"domain "+needle+" matched "+entry);
108					return true;
109				}
110			} else {
111				if (entry.equals(needle)) {
112					Log.d(LOGTAG,"domain "+needle+" matched "+entry);
113					return true;
114				}
115			}
116		}
117		return false;
118	}
119}