Java Code Examples for sun.security.krb5.Config#refresh()

public static void main(String[] args) throws Exception {

        OneKDC kdc = new OneKDC(null);

        KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
                "ticket_lifetime = 10s",
                "renew_lifetime = 11s");
        Config.refresh();

        KerberosTicket ticket = Context
                .fromUserPass(OneKDC.USER, OneKDC.PASS, false).s()
                .getPrivateCredentials(KerberosTicket.class).iterator().next();

        System.out.println(ticket);
        Asserts.assertTrue(ticket.getRenewTill() != null, ticket.toString());

        Thread.sleep(2000);

        ticket.refresh();
        System.out.println(ticket);
        Asserts.assertTrue(ticket.getRenewTill() == null, ticket.toString());

        Thread.sleep(2000);
        ticket.refresh();
        System.out.println(ticket);
    }
 

public static void main(String[] args) throws Exception {

        OneKDC kdc = new OneKDC(null);
        kdc.writeJAASConf();

        KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
                "default_tkt_enctypes=des-cbc-md5",
                "default_tgs_enctypes=des-cbc-md5",
                "permitted_enctypes=des-cbc-md5");
        Config.refresh();

        try {
            Context.fromJAAS("client");
            throw new Exception("What?");
        } catch (LoginException le) {
            // This is OK
        }
    }
 

public static void main(String[] args) throws Exception {
    Path base = Paths.get("krb5.conf");
    Path include = Paths.get("included.conf");
    String baseConf = "include " + include.toAbsolutePath().toString()
            + "\n[x]\na = b\n";
    String includeConf = "[y]\nc = d\n";
    Files.write(include, includeConf.getBytes());
    Files.write(base, baseConf.getBytes());

    System.setProperty("java.security.krb5.conf", base.toString());
    Config.refresh();

    if (!Objects.equals(Config.getInstance().get("x", "a"), "b")) {
        throw new Exception("Failed");
    }
}
 

static void checkLogin(
        String s1,      // ticket_lifetime in krb5.conf, null if none
        String s2,      // renew_lifetime in krb5.conf, null if none
        int t1, int t2  // expected lifetimes, -1 of unexpected
            ) throws Exception {
    KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
            s1 != null ? ("ticket_lifetime = " + s1) : "",
            s2 != null ? ("renew_lifetime = " + s2) : "");
    Config.refresh();

    Context c;
    c = Context.fromJAAS("client");

    Set<KerberosTicket> tickets =
            c.s().getPrivateCredentials(KerberosTicket.class);
    if (tickets.size() != 1) {
        throw new Exception();
    }
    KerberosTicket ticket = tickets.iterator().next();

    checkRough(ticket.getEndTime(), t1);
    checkRough(ticket.getRenewTill(), t2);
}
 

public static void main(String[] args)
        throws Exception {

    System.setProperty("sun.security.krb5.debug", "true");

    OneKDC kdc = new OneKDC(null);
    kdc.writeJAASConf();

    // Two styles of kdc_timeout setting. One global, one realm-specific.
    if (args[0].equals("UDP")) {
        KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
                "kdc_timeout = 10s");
    } else {
        kdc.addConf("kdc_timeout = 10s");
        KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
                "udp_preference_limit = 1");
    }
    Config.refresh();

    ByteArrayOutputStream bo = new ByteArrayOutputStream();
    PrintStream oldout = System.out;
    System.setOut(new PrintStream(bo));
    Context.fromUserPass(OneKDC.USER, OneKDC.PASS, false);
    System.setOut(oldout);

    for (String line: new String(bo.toByteArray()).split("\n")) {
        if (line.contains(">>> KDCCommunication")) {
            if (!line.contains(args[0]) || !line.contains("timeout=10000")) {
                throw new Exception("No " + args[0] + " in: " + line);
            }
        }
    }
}
 

public static void main(String[] args) throws Exception {
    System.setProperty("java.security.krb5.conf",
            System.getProperty("test.src", ".") + "/kdc_default_options.conf");
    Config.refresh();
    KDCOptions options = new KDCOptions();
    if (!options.get(KDCOptions.FORWARDABLE) ||
            !options.get(KDCOptions.PROXIABLE) ||
            !options.get(KDCOptions.RENEWABLE_OK)) {
        throw new Exception(options.toString());
    }
}
 

public static void main(String[] args) throws Exception {
    File f = new File(
            System.getProperty("test.src", "."), "unreachable.krb5.conf");
    System.setProperty("java.security.krb5.conf", f.getPath());
    Config.refresh();

    // If PortUnreachableException is not received, the login will consume
    // about 3*3*30 seconds and the test will timeout.
    try {
        Context.fromUserPass("name", "pass".toCharArray(), true);
    } catch (LoginException le) {
        // This is OK
    }
}
 

public static void main(String[] args) throws Exception {

        W83 x = new W83();

        // Cannot use OneKDC. kinit command cannot resolve
        // hostname kdc.rabbit.hole
        KDC kdc = new KDC(OneKDC.REALM, "127.0.0.1", 0, true);
        kdc.addPrincipal(OneKDC.USER, OneKDC.PASS);
        kdc.addPrincipalRandKey("krbtgt/" + OneKDC.REALM);
        KDC.saveConfig(OneKDC.KRB5_CONF, kdc);
        System.setProperty("java.security.krb5.conf", OneKDC.KRB5_CONF);
        Config.refresh();

        kdc.writeKtab(OneKDC.KTAB);

        KeyTab ktab = KeyTab.getInstance(OneKDC.KTAB);
        for (int etype: EType.getBuiltInDefaults()) {
            if (etype != EncryptedData.ETYPE_ARCFOUR_HMAC) {
                ktab.deleteEntries(new PrincipalName(OneKDC.USER), etype, -1);
            }
        }
        ktab.save();

        if (System.getProperty("6932525") != null) {
            // For 6932525 and 6951366, make sure the etypes sent in 2nd AS-REQ
            // is not restricted to that of preauth
            kdc.setOption(KDC.Option.ONLY_RC4_TGT, true);
        }
        if (System.getProperty("6959292") != null) {
            // For 6959292, make sure that when etype for enc-part in 2nd AS-REQ
            // is different from that of preauth, client can still decrypt it
            kdc.setOption(KDC.Option.RC4_FIRST_PREAUTH, true);
        }
        x.go();
    }
 

/**
 * Sets and checks.
 *
 * @param u dns_lookup_XXX value set, none if null
 * @param f dns_fallback value set, none if null
 * @param r expected useDNS_Realm
 * @param k expected useDNS_KDC
 */
static void check(String u, String f, boolean r, boolean k)
        throws Exception {

    try (PrintStream ps =
            new PrintStream(new FileOutputStream("dnsfallback.conf"))) {
        ps.println("[libdefaults]\n");
        if (u != null) {
            ps.println("dns_lookup_realm=" + u);
            ps.println("dns_lookup_kdc=" + u);
        }
        if (f != null) {
            ps.println("dns_fallback=" + f);
        }
    }

    System.setProperty("java.security.krb5.conf", "dnsfallback.conf");
    Config.refresh();
    System.out.println("Testing " + u + ", " + f + ", " + r + ", " + k);

    if (!useDNS_Realm.invoke(Config.getInstance()).equals(r)) {
        throw new Exception("useDNS_Realm Fail");
    }

    if (!useDNS_KDC.invoke(Config.getInstance()).equals(k)) {
        throw new Exception("useDNS_KDC Fail");
    }
}
 

public static void main(String[] args) throws Exception {
    File f = new File(
            System.getProperty("test.src", "."), "unreachable.krb5.conf");
    System.setProperty("java.security.krb5.conf", f.getPath());
    Config.refresh();

    // If PortUnreachableException is not received, the login will consume
    // about 3*3*30 seconds and the test will timeout.
    try {
        Context.fromUserPass("name", "pass".toCharArray(), true);
    } catch (LoginException le) {
        // This is OK
    }
}
 

/**
 * Creates the KDC and starts it.
 * @param etype Encryption type, null if not specified
 * @throws java.lang.Exception if there's anything wrong
 */
public OneKDC(String etype) throws Exception {
    super(REALM, KDCHOST, 0, true);
    addPrincipal(USER, PASS);
    addPrincipal(USER2, PASS2);
    addPrincipalRandKey("krbtgt/" + REALM);
    addPrincipalRandKey(SERVER);
    addPrincipalRandKey(BACKEND);

    String extraConfig = "";
    if (etype != null) {
        extraConfig += "default_tkt_enctypes=" + etype
                + "\ndefault_tgs_enctypes=" + etype;
        if (etype.startsWith("des")) {
            extraConfig += "\nallow_weak_crypto = true";
        }
    }
    KDC.saveConfig(KRB5_CONF, this,
            "forwardable = true",
            "default_keytab_name = " + KTAB,
            extraConfig);
    System.setProperty("java.security.krb5.conf", KRB5_CONF);
    // Whatever krb5.conf had been loaded before, we reload ours now.
    Config.refresh();

    writeKtab(KTAB);
    Security.setProperty("auth.login.defaultCallbackHandler",
            "OneKDC$CallbackForClient");
}
 

public static void main(String[] args) throws Exception {
    File f = new File(
            System.getProperty("test.src", "."), "unreachable.krb5.conf");
    System.setProperty("java.security.krb5.conf", f.getPath());
    Config.refresh();

    // If PortUnreachableException is not received, the login will consume
    // about 3*3*30 seconds and the test will timeout.
    try {
        Context.fromUserPass("name", "pass".toCharArray(), true);
    } catch (LoginException le) {
        // This is OK
    }
}
 

public static void main(String[] args)
        throws Exception {

    System.setProperty("sun.security.krb5.debug", "true");

    OneKDC kdc = new OneKDC(null);
    kdc.writeJAASConf();

    // Two styles of kdc_timeout setting. One global, one realm-specific.
    if (args[0].equals("UDP")) {
        KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
                "kdc_timeout = 10s");
    } else {
        kdc.addConf("kdc_timeout = 10s");
        KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
                "udp_preference_limit = 1");
    }
    Config.refresh();

    ByteArrayOutputStream bo = new ByteArrayOutputStream();
    PrintStream oldout = System.out;
    System.setOut(new PrintStream(bo));
    Context.fromUserPass(OneKDC.USER, OneKDC.PASS, false);
    System.setOut(oldout);

    for (String line: new String(bo.toByteArray()).split("\n")) {
        if (line.contains(">>> KDCCommunication")) {
            if (!line.contains(args[0]) || !line.contains("timeout=10000")) {
                throw new Exception("No " + args[0] + " in: " + line);
            }
        }
    }
}
 

public static void main(String[] args)
        throws Exception {

    OneKDC kdc = new OneKDC(null);
    kdc.writeJAASConf();

    String extraLine;
    switch (args[0]) {
        case "1": extraLine = "noaddresses = false"; break;
        case "2": extraLine = "noaddresses = true"; break;
        default: extraLine = ""; break;
    }

    KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
            extraLine);
    Config.refresh();

    Context c = Context.fromUserPass(OneKDC.USER, OneKDC.PASS, false);
    Set<KerberosTicket> tickets =
            c.s().getPrivateCredentials(KerberosTicket.class);

    if (tickets.isEmpty()) throw new Exception();
    KerberosTicket ticket = tickets.iterator().next();
    InetAddress[] addresses = ticket.getClientAddresses();

    switch (args[0]) {
        case "1":
            if (addresses == null || addresses.length == 0) {
                throw new Exception("No addresses");
            }
            if (ticket.getServer().getNameType()
                    != KerberosPrincipal.KRB_NT_SRV_INST) {
                throw new Exception(
                        "Wrong type: " + ticket.getServer().getNameType());
            }
            break;
        default:
            if (addresses != null && addresses.length != 0) {
                throw new Exception("See addresses");
            }
            break;
    }
}
 

/**
 * Writes a krb5.conf file.
 * @param max max_retries, -1 if not set
 * @param to kdc_timeout, -1 if not set
 * @param ports where KDCs listen on
 */
static void writeConf(int max, int to, int... ports) throws Exception {

    // content of krb5.conf
    String conf = "";

    // Extra settings in [libdefaults]
    String inDefaults = "";

    // Extra settings in [realms]
    String inRealm = "";

    // We will randomly put extra settings only in [libdefaults],
    // or in [realms] but with different values in [libdefaults],
    // to prove that settings in [realms] override those in [libdefaults].
    Random r = new Random();

    if (max > 0) {
        if (r.nextBoolean()) {
            inDefaults += "max_retries = " + max + "\n";
        } else {
            inRealm += "   max_retries = " + max + "\n";
            inDefaults += "max_retries = " + (max + 1) + "\n";
        }
    }

    if (to > 0) {
        if (r.nextBoolean()) {
            inDefaults += "kdc_timeout = " + to + "\n";
        } else {
            inRealm += "   kdc_timeout = " + to + "\n";
            inDefaults += "kdc_timeout = " + (to + 1) + "\n";
        }
    }

    if (udp) {
        if (r.nextBoolean()) {
            inDefaults += "udp_preference_limit = 10000\n";
        } else if (r.nextBoolean()) {
            inRealm += "   udp_preference_limit = 10000\n";
            inDefaults += "udp_preference_limit = 1\n";
        } // else no settings means UDP
    } else {
        if (r.nextBoolean()) {
            inDefaults += "udp_preference_limit = 1\n";
        } else {
            inRealm += "   udp_preference_limit = 1\n";
            inDefaults += "udp_preference_limit = 10000\n";
        }
    }

    conf = "[libdefaults]\n" +
            "default_realm = " + OneKDC.REALM + "\n" +
            inDefaults +
            "\n" +
            "[realms]\n" +
            OneKDC.REALM + " = {\n";

    for (int port : ports) {
        conf += "   kdc = " + OneKDC.KDCHOST + ":" + port + "\n" +
                inRealm;
    }

    conf += "}\n";

    Files.write(Paths.get("alternative-krb5.conf"), conf.getBytes());
    Config.refresh();
}
 

/**
 * @param args boolean if the program should succeed
 */
public static void main(String[] args)
        throws Exception {

    // Create and start the KDCs. Here we have 3 realms: R1, R2 and R3.
    // R1 is trusted by R2, and R2 trusted by R3.
    KDC kdc1 = KDC.create("R1");
    kdc1.setOption(KDC.Option.OK_AS_DELEGATE,
            System.getProperty("test.kdc.policy.ok-as-delegate"));
    kdc1.addPrincipal("dummy", "bogus".toCharArray());
    kdc1.addPrincipalRandKey("krbtgt/R1");
    kdc1.addPrincipal("krbtgt/R2@R1", "r1->r2".toCharArray());

    KDC kdc2 = KDC.create("R2");
    kdc2.setOption(KDC.Option.OK_AS_DELEGATE,
            System.getProperty("test.kdc.policy.ok-as-delegate"));
    kdc2.addPrincipalRandKey("krbtgt/R2");
    kdc2.addPrincipal("krbtgt/R2@R1", "r1->r2".toCharArray());
    kdc2.addPrincipal("krbtgt/R3@R2", "r2->r3".toCharArray());

    KDC kdc3 = KDC.create("R3");
    kdc3.setOption(KDC.Option.OK_AS_DELEGATE,
            System.getProperty("test.kdc.policy.ok-as-delegate"));
    kdc3.addPrincipalRandKey("krbtgt/R3");
    kdc3.addPrincipal("krbtgt/R3@R2", "r2->r3".toCharArray());
    kdc3.addPrincipalRandKey("host/host.r3.local");

    KDC.saveConfig("krb5-localkdc.conf", kdc1, kdc2, kdc3,
            "forwardable=true",
            "[capaths]",
            "R1 = {",
            "    R2 = .",
            "    R3 = R2",
            "}",
            "[domain_realm]",
            ".r3.local=R3"
            );

    System.setProperty("java.security.krb5.conf", "krb5-localkdc.conf");
    kdc3.writeKtab("localkdc.ktab");

    FileOutputStream fos = new FileOutputStream("jaas-localkdc.conf");

    // Defines the client and server on R1 and R3 respectively.
    fos.write(("com.sun.security.jgss.krb5.initiate {\n" +
            "    com.sun.security.auth.module.Krb5LoginModule\n" +
            "    required\n" +
            "    principal=dummy\n" +
            "    doNotPrompt=false\n" +
            "    useTicketCache=false\n" +
            "    ;\n};\n" +
            "com.sun.security.jgss.krb5.accept {\n" +
            "    com.sun.security.auth.module.Krb5LoginModule required\n" +
            "    principal=\"host/host.r3.local@R3\"\n" +
            "    useKeyTab=true\n" +
            "    keyTab=localkdc.ktab\n" +
            "    isInitiator=false\n" +
            "    storeKey=true;\n};\n" +
            "\n").getBytes());
    fos.close();

    Security.setProperty("auth.login.defaultCallbackHandler",
            "OkAsDelegateXRealm");

    System.setProperty("java.security.auth.login.config", "jaas-localkdc.conf");

    Config.refresh();

    Context c = Context.fromJAAS("com.sun.security.jgss.krb5.initiate");
    Context s = Context.fromJAAS("com.sun.security.jgss.krb5.accept");

    // Test twice. The frist time the whole cross realm process is tried,
    // the second time the cached service ticket is used. This is to make sure
    // the behaviors are the same, especailly for the case when one of the
    // cross-realm TGTs does not have OK-AS-DELEGATE on.

    for (int i=0; i<2; i++) {
        c.startAsClient("[email protected]", GSSUtil.GSS_KRB5_MECH_OID);
        s.startAsServer(GSSUtil.GSS_KRB5_MECH_OID);
        c.x().requestDelegPolicy(true);

        Context.handshake(c, s);
        boolean succeed = true;
        try {
            s.x().getDelegCred();
        } catch (GSSException gsse) {
            succeed = false;
        }
        if (succeed != Boolean.parseBoolean(args[0])) {
            throw new Exception("Test fail at round #" + i);
        }
    }
}
 

void go(
        boolean forwardable,
        boolean requestDelegState,
        boolean requestDelegPolicyState,
        boolean delegState,
        boolean delegPolicyState,
        boolean delegated
        ) throws Exception {
    OneKDC kdc = new OneKDC(null);
    kdc.setOption(KDC.Option.OK_AS_DELEGATE,
            System.getProperty("test.kdc.policy.ok-as-delegate"));
    kdc.writeJAASConf();
    if (!forwardable) {
        // The default OneKDC always includes "forwardable = true"
        // in krb5.conf, override it.
        KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
                "default_keytab_name = " + OneKDC.KTAB);
        Config.refresh();
    }

    Context c, s;
    c = Context.fromJAAS("client");
    s = Context.fromJAAS("com.sun.security.jgss.krb5.accept");

    Oid mech = GSSUtil.GSS_KRB5_MECH_OID;
    if (System.getProperty("test.spnego") != null) {
        mech = GSSUtil.GSS_SPNEGO_MECH_OID;
    }
    c.startAsClient(OneKDC.SERVER, mech);
    ExtendedGSSContext cx = (ExtendedGSSContext)c.x();
    cx.requestCredDeleg(requestDelegState);
    cx.requestDelegPolicy(requestDelegPolicyState);
    s.startAsServer(mech);
    ExtendedGSSContext sx = (ExtendedGSSContext)s.x();

    Context.handshake(c, s);

    if (cx.getCredDelegState() != delegState) {
        throw new Exception("Initiator cred state error");
    }
    if (sx.getCredDelegState() != delegState) {
        throw new Exception("Acceptor cred state error");
    }
    if (cx.getDelegPolicyState() != delegPolicyState) {
        throw new Exception("Initiator cred policy state error");
    }

    GSSCredential cred = null;
    try {
        cred = s.x().getDelegCred();
    } catch (GSSException e) {
        // leave cred as null
    }

    if (delegated != (cred != null)) {
        throw new Exception("get cred error");
    }
}
 

public static void main(String[] args)
        throws Exception {

    KDC k1 = KDC.create("R1");
    k1.addPrincipal("u1", "hello".toCharArray());
    k1.addPrincipalRandKey("krbtgt/R1");
    k1.addPrincipalRandKey("host/same.host");

    KDC k2 = KDC.create("R2");
    k2.addPrincipal("u2", "hello".toCharArray());
    k2.addPrincipalRandKey("krbtgt/R2");
    k2.addPrincipalRandKey("host/same.host");

    System.setProperty("java.security.krb5.conf", "krb5.conf");

    // R1 is the default realm now
    KDC.saveConfig("krb5.conf", k1, k2);
    Config.refresh();

    k1.writeKtab("ktab1");
    k2.writeKtab("ktab2");

    // A JAAS config file with 2 Krb5LoginModules, after commit, the
    // subject with have principals and keytabs from both sides
    System.setProperty("java.security.auth.login.config", "jaas.conf");
    File f = new File("jaas.conf");
    FileOutputStream fos = new FileOutputStream(f);
    fos.write((
            "me {\n"
            + "  com.sun.security.auth.module.Krb5LoginModule required"
            + "    isInitiator=true principal=\"host/same.host@R1\""
            + "    useKeyTab=true keyTab=ktab1 storeKey=true;\n"
            + "  com.sun.security.auth.module.Krb5LoginModule required"
            + "    isInitiator=true principal=\"host/same.host@R2\""
            + "    useKeyTab=true keyTab=ktab2 storeKey=true;\n"
            + "};\n"
            ).getBytes());
    fos.close();

    /*
     * This server side context will be able to act as services in both
     * realms. Please note that we still don't support a single instance
     * of server to accept connections from two realms at the same time.
     * Therefore, we must call startAsServer in a given realm to start
     * working there. The same Subject never changes anyway.
     */
    Context s = Context.fromJAAS("me");

    // Default realm still R1
    s.startAsServer("[email protected]", GSSUtil.GSS_KRB5_MECH_OID);
    Context c1 = Context.fromUserPass("u1", "hello".toCharArray(), false);
    c1.startAsClient("[email protected]", GSSUtil.GSS_KRB5_MECH_OID);
    Context.handshake(c1, s);

    KDC.saveConfig("krb5.conf", k2, k1);
    Config.refresh();

    // Default realm now R2
    s.startAsServer("[email protected]", GSSUtil.GSS_KRB5_MECH_OID);
    Context c2 = Context.fromUserPass("u2", "hello".toCharArray(), false);
    c2.startAsClient("[email protected]", GSSUtil.GSS_KRB5_MECH_OID);
    Context.handshake(c2, s);
}
 

public static void main(String[] args)
        throws Exception {

    OneKDC kdc = new OneKDC(null);
    kdc.writeJAASConf();
    KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
            "noaddresses = false",
            "default_keytab_name = " + OneKDC.KTAB);
    Config.refresh();

    Context c = Context.fromJAAS("client");
    Context s = Context.fromJAAS("server");

    c.startAsClient(OneKDC.SERVER, GSSUtil.GSS_KRB5_MECH_OID);
    s.startAsServer(GSSUtil.GSS_KRB5_MECH_OID);

    InetAddress initiator = InetAddress.getLocalHost();
    InetAddress acceptor = InetAddress.getLocalHost();
    switch (args[0]) {
        case "1":
            // no initiator host address available, should be OK
            break;
        case "2":
            // correct initiator host address, still fine
            c.x().setChannelBinding(
                    new ChannelBinding(initiator, acceptor, null));
            s.x().setChannelBinding(
                    new ChannelBinding(initiator, acceptor, null));
            break;
        case "3":
            // incorrect initiator host address, fail
            initiator = InetAddress.getByAddress(new byte[]{1,1,1,1});
            c.x().setChannelBinding(
                    new ChannelBinding(initiator, acceptor, null));
            s.x().setChannelBinding(
                    new ChannelBinding(initiator, acceptor, null));
            break;
    }

    Context.handshake(c, s);
}
 

public static void main(String[] args)
        throws Exception {

    OneKDC kdc = new OneKDC(null);
    kdc.writeJAASConf();
    KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
            "noaddresses = false",
            "default_keytab_name = " + OneKDC.KTAB);
    Config.refresh();

    Context c = Context.fromJAAS("client");
    Context s = Context.fromJAAS("server");

    c.startAsClient(OneKDC.SERVER, GSSUtil.GSS_KRB5_MECH_OID);
    s.startAsServer(GSSUtil.GSS_KRB5_MECH_OID);

    InetAddress initiator = InetAddress.getLocalHost();
    InetAddress acceptor = InetAddress.getLocalHost();
    switch (args[0]) {
        case "1":
            // no initiator host address available, should be OK
            break;
        case "2":
            // correct initiator host address, still fine
            c.x().setChannelBinding(
                    new ChannelBinding(initiator, acceptor, null));
            s.x().setChannelBinding(
                    new ChannelBinding(initiator, acceptor, null));
            break;
        case "3":
            // incorrect initiator host address, fail
            initiator = InetAddress.getByAddress(new byte[]{1,1,1,1});
            c.x().setChannelBinding(
                    new ChannelBinding(initiator, acceptor, null));
            s.x().setChannelBinding(
                    new ChannelBinding(initiator, acceptor, null));
            break;
    }

    Context.handshake(c, s);
}