使用Java的Kerberos

Question

i am try to login kerberos kdc from Java. But Java is throwing exception. Seems like login is successful but something is stops login. I dont know why ? Someone have solution for this problem? Here is my java system output:

Debug is  true storeKey false useTicketCache true useKeyTab false doNotPrompt false ticketCache is null isInitiator true KeyTab is null refreshKrb5Config is true principal is null tryFirstPass is false useFirstPass is false storePass is false clearPass is false
Refreshing Kerberos configuration
Acquire TGT from Cache
Principal is null
null credentials from Ticket Cache
                [Krb5LoginModule] user entered username: kadirb

principal is kadirb@EXAMPLE.COM
Commit Succeeded

Exception in thread "main" java.lang.Error: GSSException: No valid credentials provided (Mechanism level: Server not found in Kerberos database (7) - LOOKING_UP_SERVER)
        at KerberosTicketRetriever$TicketCreatorAction.run(KerberosTicketRetriever.java:76)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAsPrivileged(Subject.java:473)
        at KerberosTicketRetriever.retrieveTicket(KerberosTicketRetriever.java:179)
        at KerberosTicketRetriever.main(KerberosTicketRetriever.java:188)
Caused by: GSSException: No valid credentials provided (Mechanism level: Server not found in Kerberos database (7) - LOOKING_UP_SERVER)
        at sun.security.jgss.krb5.Krb5Context.initSecContext(Krb5Context.java:710)
        at sun.security.jgss.GSSContextImpl.initSecContext(GSSContextImpl.java:248)
        at sun.security.jgss.GSSContextImpl.initSecContext(GSSContextImpl.java:179)
        at KerberosTicketRetriever$TicketCreatorAction.createTicket(KerberosTicketRetriever.java:105)
        at KerberosTicketRetriever$TicketCreatorAction.run(KerberosTicketRetriever.java:72)
        ... 4 more
Caused by: KrbException: Server not found in Kerberos database (7) - LOOKING_UP_SERVER
        at sun.security.krb5.KrbTgsRep.<init>(KrbTgsRep.java:73)
        at sun.security.krb5.KrbTgsReq.getReply(KrbTgsReq.java:192)
        at sun.security.krb5.KrbTgsReq.sendAndGetCreds(KrbTgsReq.java:203)
        at sun.security.krb5.internal.CredentialsUtil.serviceCreds(CredentialsUtil.java:311)
        at sun.security.krb5.internal.CredentialsUtil.acquireServiceCreds(CredentialsUtil.java:115)
        at sun.security.krb5.Credentials.acquireServiceCreds(Credentials.java:442)
        at sun.security.jgss.krb5.Krb5Context.initSecContext(Krb5Context.java:641)
        ... 8 more
Caused by: KrbException: Identifier doesn't match expected value (906)
        at sun.security.krb5.internal.KDCRep.init(KDCRep.java:143)
        at sun.security.krb5.internal.TGSRep.init(TGSRep.java:66)
        at sun.security.krb5.internal.TGSRep.<init>(TGSRep.java:61)
        at sun.security.krb5.KrbTgsRep.<init>(KrbTgsRep.java:55)
        ... 14 more
Disconnected from the target VM, address: '127.0.0.1:51126', transport: 'socket'

Process finished with exit code 1

And my java code:

import com.sun.security.auth.callback.DialogCallbackHandler;
import org.ietf.jgss.*;
import sun.misc.BASE64Encoder;
import javax.security.auth.Subject;
import javax.security.auth.login.LoginContext;
import javax.security.auth.login.LoginException;
import java.io.*;
import java.security.Principal;
import java.security.PrivilegedAction;
import java.util.Set;

/**
 * Tool to retrieve a kerberos ticket. This one will not be stored in the windows ticket cache.
 */
public final class KerberosTicketRetriever
{
private final static Oid KERB_V5_OID;
private final static Oid KRB5_PRINCIPAL_NAME_OID;

static {
    try
    {
        KERB_V5_OID = new Oid("1.2.840.113554.1.2.2");
        KRB5_PRINCIPAL_NAME_OID = new Oid("1.2.840.113554.1.2.2.1");

    } catch (final GSSException ex)
    {
        throw new Error(ex);
    }
}

/**
 * Not to be instanciated
 */
private KerberosTicketRetriever() {};

/**
 *
 */
private static class TicketCreatorAction implements PrivilegedAction
{
    final String userPrincipal;
    final String applicationPrincipal;

    private StringBuffer outputBuffer;

    /**
     *
     * @param userPrincipal  p.ex. <tt>MuelleHA@MYFIRM.COM</tt>
     * @param applicationPrincipal  p.ex. <tt>HTTP/webserver.myfirm.com</tt>
     */
    private TicketCreatorAction(final String userPrincipal, final String applicationPrincipal)
    {
        this.userPrincipal = userPrincipal;
        this.applicationPrincipal = applicationPrincipal;
    }

    private void setOutputBuffer(final StringBuffer newOutputBuffer)
    {
        outputBuffer = newOutputBuffer;
    }

    /**
     * Only calls {@link #createTicket()}
     * @return <tt>null</tt>
     */
    public Object run()
    {
        try
        {
            createTicket();
        }
        catch (final GSSException  ex)
        {
            throw new Error(ex);
        }

        return null;
    }

    /**
     *
     * @throws GSSException
     */
    private void createTicket () throws GSSException
    {
        final GSSManager manager = GSSManager.getInstance();
        final GSSName clientName = manager.createName(userPrincipal, KRB5_PRINCIPAL_NAME_OID);
        final GSSCredential clientCred = manager.createCredential(clientName,
                8 * 3600,
                KERB_V5_OID,
                GSSCredential.INITIATE_ONLY);

        final GSSName serverName = manager.createName(applicationPrincipal, KRB5_PRINCIPAL_NAME_OID);

        final GSSContext context = manager.createContext(serverName,
                KERB_V5_OID,
                clientCred,
                GSSContext.DEFAULT_LIFETIME);
        context.requestMutualAuth(true);
        context.requestConf(false);
        context.requestInteg(true);

        final byte[] outToken = context.initSecContext(new byte[0], 0, 0);

        if (outputBuffer !=null)
        {
            outputBuffer.append(String.format("Src Name: %s\n", context.getSrcName()));
            outputBuffer.append(String.format("Target  : %s\n", context.getTargName()));
            outputBuffer.append(new BASE64Encoder().encode(outToken));
            outputBuffer.append("\n");
        }

        context.dispose();
    }
}

/**
 *
 * @param realm p.ex. <tt>MYFIRM.COM</tt>
 * @param kdc p.ex. <tt>kerbserver.myfirm.com</tt>
 * @param applicationPrincipal   cf. {@link #TicketCreatorAction(String, String)}
 * @throws GSSException
 * @throws LoginException
 */
static public String retrieveTicket(
        final String realm,
        final String kdc,
        final String applicationPrincipal)
        throws GSSException, LoginException
{

    // create the jass-config-file
    final File jaasConfFile;
    try
    {
        jaasConfFile = File.createTempFile("jaas.conf", null);
        final PrintStream bos = new PrintStream(new FileOutputStream(jaasConfFile));
        bos.print(String.format(
                "Krb5LoginContext { com.sun.security.auth.module.Krb5LoginModule required refreshKrb5Config=true useTicketCache=true debug=true ; };"
        ));
        bos.close();
        jaasConfFile.deleteOnExit();
    }
    catch (final IOException ex)
    {
        throw new IOError(ex);
    }

    // set the properties
    System.setProperty("java.security.krb5.realm", realm);
    System.setProperty("java.security.krb5.kdc", kdc);
    System.setProperty("java.security.auth.login.config",jaasConfFile.getAbsolutePath());

    // get the Subject(), i.e. the current user under Windows
    final Subject subject = new Subject();
    final LoginContext lc = new LoginContext("Krb5LoginContext", subject, new DialogCallbackHandler());
    try {
        lc.login();
    } catch (LoginException e) {
        e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        //e = Client not found in Kerberos database (6) - CLIENT_NOT_FOUND
        System.exit(0);
    }

    // extract our principal
    final Set<Principal> principalSet = subject.getPrincipals();
    if (principalSet.size() != 1)
        throw new AssertionError("No or several principals: " + principalSet);
    final Principal userPrincipal = principalSet.iterator().next();

    // now try to execute the SampleAction as the authenticated Subject
    // action.run() without doAsPrivileged leads to
    //   No valid credentials provided (Mechanism level: Failed to find any Kerberos tgt)
    final TicketCreatorAction action = new TicketCreatorAction(userPrincipal.getName(), applicationPrincipal);
    final StringBuffer outputBuffer = new StringBuffer();
    action.setOutputBuffer(outputBuffer);
    Subject.doAsPrivileged(lc.getSubject(), action, null);

    return outputBuffer.toString();
}

public static void main (final String args[]) throws Throwable
 {
    final String ticket = retrieveTicket("EXAMPLE.COM", "EXAMPLE.COM", "HTTP/webserver.myfirm.com");
    System.out.println(ticket);
 }
}

Answer 1

我没有测试你的代码，但阅读 stacktrace 我相信问题出在 KDC 域上。正如文档所说：

默认领域和该领域的 KDC 在 Kerberos krb5.conf 中指示

krb5.conf 中的 KDC 领域通常是kdc。Fedora 默认安装示例：

[realms]
EXAMPLE.COM = {
kdc = kerberos.example.com
admin_server = kerberos.example.com
}

我似乎很明显您应该kdc使用域名而不是领域名称更改您的域：

final String ticket = retrieveTicket("EXAMPLE.COM", "localhost", "HTTP/webserver.myfirm.com");

您在本地计算机上使用 Kerberos，您可能需要dns_lookup_kdc = false向 krb5.conf添加选项