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