1 files changed, 127 insertions, 0 deletions
diff --git a/src/main/java/eu/siacs/conversations/crypto/XmppDomainVerifier.java b/src/main/java/eu/siacs/conversations/crypto/XmppDomainVerifier.java
new file mode 100644
index 00000000..1fca865e
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/crypto/XmppDomainVerifier.java
@@ -0,0 +1,127 @@
+package eu.siacs.conversations.crypto;
+
+import android.util.Log;
+import android.util.Pair;
+
+import org.bouncycastle.asn1.ASN1Primitive;
+import org.bouncycastle.asn1.DERIA5String;
+import org.bouncycastle.asn1.DERTaggedObject;
+import org.bouncycastle.asn1.DERUTF8String;
+import org.bouncycastle.asn1.DLSequence;
+import org.bouncycastle.asn1.x500.RDN;
+import org.bouncycastle.asn1.x500.X500Name;
+import org.bouncycastle.asn1.x500.style.BCStyle;
+import org.bouncycastle.asn1.x500.style.IETFUtils;
+import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
+
+import java.io.IOException;
+import java.security.cert.Certificate;
+import java.security.cert.X509Certificate;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import javax.net.ssl.HostnameVerifier;
+import javax.net.ssl.SSLSession;
+
+public class XmppDomainVerifier implements HostnameVerifier {
+
+	private static final String LOGTAG = "XmppDomainVerifier";
+
+	private final String SRVName = "1.3.6.1.5.5.7.8.7";
+	private final String xmppAddr = "1.3.6.1.5.5.7.8.5";
+
+	@Override
+	public boolean verify(String domain, SSLSession sslSession) {
+		try {
+			Certificate[] chain = sslSession.getPeerCertificates();
+			if (chain.length == 0 || !(chain[0] instanceof X509Certificate)) {
+				return false;
+			}
+			X509Certificate certificate = (X509Certificate) chain[0];
+			Collection<List<?>> alternativeNames = certificate.getSubjectAlternativeNames();
+			List<String> xmppAddrs = new ArrayList<>();
+			List<String> srvNames = new ArrayList<>();
+			List<String> domains = new ArrayList<>();
+			if (alternativeNames != null) {
+				for (List<?> san : alternativeNames) {
+					Integer type = (Integer) san.get(0);
+					if (type == 0) {
+						Pair<String, String> otherName = parseOtherName((byte[]) san.get(1));
+						if (otherName != null) {
+							switch (otherName.first) {
+								case SRVName:
+									srvNames.add(otherName.second);
+									break;
+								case xmppAddr:
+									xmppAddrs.add(otherName.second);
+									break;
+								default:
+									Log.d(LOGTAG, "oid: " + otherName.first + " value: " + otherName.second);
+							}
+						}
+					} else if (type == 2) {
+						Object value = san.get(1);
+						if (value instanceof String) {
+							domains.add((String) value);
+						}
+					}
+				}
+			}
+			if (srvNames.size() == 0 && xmppAddrs.size() == 0 && domains.size() == 0) {
+				X500Name x500name = new JcaX509CertificateHolder(certificate).getSubject();
+				RDN[] rdns = x500name.getRDNs(BCStyle.CN);
+				for (int i = 0; i < rdns.length; ++i) {
+					domains.add(IETFUtils.valueToString(x500name.getRDNs(BCStyle.CN)[i].getFirst().getValue()));
+				}
+			}
+			Log.d(LOGTAG, "searching for " + domain + " in srvNames: " + srvNames + " xmppAddrs: " + xmppAddrs + " domains:" + domains);
+			return xmppAddrs.contains(domain) || srvNames.contains("_xmpp-client." + domain) || matchDomain(domain, domains);
+		} catch (Exception e) {
+			return false;
+		}
+	}
+
+	private static Pair<String, String> parseOtherName(byte[] otherName) {
+		try {
+			ASN1Primitive asn1Primitive = ASN1Primitive.fromByteArray(otherName);
+			if (asn1Primitive instanceof DERTaggedObject) {
+				ASN1Primitive inner = ((DERTaggedObject) asn1Primitive).getObject();
+				if (inner instanceof DLSequence) {
+					DLSequence sequence = (DLSequence) inner;
+					if (sequence.size() >= 2 && sequence.getObjectAt(1) instanceof DERTaggedObject) {
+						String oid = sequence.getObjectAt(0).toString();
+						ASN1Primitive value = ((DERTaggedObject) sequence.getObjectAt(1)).getObject();
+						if (value instanceof DERUTF8String) {
+							return new Pair<>(oid, ((DERUTF8String) value).getString());
+						} else if (value instanceof DERIA5String) {
+							return new Pair<>(oid, ((DERIA5String) value).getString());
+						}
+					}
+				}
+			}
+			return null;
+		} catch (IOException e) {
+			return null;
+		}
+	}
+
+	private static boolean matchDomain(String needle, List<String> haystack) {
+		for (String entry : haystack) {
+			if (entry.startsWith("*.")) {
+				int i = needle.indexOf('.');
+				Log.d(LOGTAG, "comparing " + needle.substring(i) + " and " + entry.substring(1));
+				if (i != -1 && needle.substring(i).equals(entry.substring(1))) {
+					Log.d(LOGTAG, "domain " + needle + " matched " + entry);
+					return true;
+				}
+			} else {
+				if (entry.equals(needle)) {
+					Log.d(LOGTAG, "domain " + needle + " matched " + entry);
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+}