JSch 无法通过 Kerberos 密钥表文件进行连接

Question

我构建了一个Java应用程序，它通过ssh运行一个命令。在第一次尝试中，我通过用户名和密码进行了身份验证，一切都很好。

现在我想使用Kerberos keytab文件进行身份验证，但这会产生问题！

这里有几个词对我的配置：

• KDC服务器：my-server.de
• 领域名称：MYREALM.DE
• Keytab用户名：keytabuser
• KDC=服务器：在CentOS 7上运行
• 我的客户端：具有所有默认配置的Windows 8.1 (x64)，已安装Kerberos for Windows
• 我在客户端上的用户名：Daniel
• kinit -kt ...似乎工作正常，所以keytab文件也应该可以

到目前为止，我只有以下代码片段：

public static void main(String[] args) {
String host = "my-server.de";
String user = "keytabuser";
String  command = "ls -l";
JSch jsch = new JSch();
jsch.setLogger(new MyLogger());
System.setProperty("java.security.krb5.conf", "C:\ProgramData\MIT\Kerberos5\krb5.ini");
System.setProperty("java.security.auth.login.config", "C:\ProgramData\MIT\Kerberos5\jaas.conf");
System.setProperty("javax.security.auth.useSubjectCredsOnly", "false");
//to enable kerberos debugging mode
System.setProperty("sun.security.krb5.debug", "true");
try {
Session session = jsch.getSession(user, host, 22);
Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");
config.put("PreferredAuthentications", "gssapi-with-mic");
session.setConfig(config);
session.connect(20000);
Channel channel = session.openChannel("exec");
... // Do the commands
channel.disconnect();
session.disconnect();
System.out.println("DONE");
} catch (JSchException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

这是我的jaas.conf文件：

com.sun.security.jgss.krb5.initiate {
com.sun.security.auth.module.Krb5LoginModule required
doNotPrompt=true
principal="[e-mail]"
useKeyTab=true
keyTab="C:ProgramDataMITKerberos5keytabuser.keytab"
storeKey=true;
};

这里是我的krb5.ini文件：

[libdefaults]
default_realm = MYREALM.DE
[realms]
MYREALM.DE = {
admin_server = my-server.de
kdc = my-server.de
}

当我运行这个应用程序时，我得到以下输出：

更新：在新的jsch依赖项0.1.54之后的新控制台输出

INFO: Connecting to my-server.de port 22
INFO: Connection established
INFO: Remote version string: SSH-2.0-OpenSSH_6.6.1
INFO: Local version string: SSH-2.0-JSCH-0.1.54
INFO: CheckCiphers: aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,arcfour,arcfour128,arcfour256
INFO: aes256-ctr is not available.
INFO: aes192-ctr is not available.
INFO: aes256-cbc is not available.
INFO: aes192-cbc is not available.
INFO: CheckKexes: diffie-hellman-group14-sha1,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521
INFO: CheckSignatures: ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
INFO: SSH_MSG_KEXINIT sent
INFO: SSH_MSG_KEXINIT received
INFO: kex: server: [e-mail],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
INFO: kex: server: ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519
INFO: kex: server: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,[e-mail],[e-mail],[e-mail],aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[e-mail]
INFO: kex: server: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,[e-mail],[e-mail],[e-mail],aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[e-mail]
INFO: kex: server: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-md5,hmac-sha1,[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[e-mail],hmac-sha1-96,hmac-md5-96
INFO: kex: server: [e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],[e-mail],hmac-md5,hmac-sha1,[e-mail],[e-mail],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[e-mail],hmac-sha1-96,hmac-md5-96
INFO: kex: server: none,[e-mail]
INFO: kex: server: none,[e-mail]
INFO: kex: server: 
INFO: kex: server: 
INFO: kex: client: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
INFO: kex: client: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
INFO: kex: client: aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc
INFO: kex: client: aes128-ctr,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc
INFO: kex: client: hmac-md5,hmac-sha1,hmac-sha2-256,hmac-sha1-96,hmac-md5-96
INFO: kex: client: hmac-md5,hmac-sha1,hmac-sha2-256,hmac-sha1-96,hmac-md5-96
INFO: kex: client: none
INFO: kex: client: none
INFO: kex: client: 
INFO: kex: client: 
INFO: kex: server->client aes128-ctr hmac-md5 none
INFO: kex: client->server aes128-ctr hmac-md5 none
INFO: SSH_MSG_KEX_ECDH_INIT sent
INFO: expecting SSH_MSG_KEX_ECDH_REPLY
INFO: ssh_rsa_verify: signature true
WARN: Permanently added 'my-server.de' (RSA) to the list of known hosts.
INFO: SSH_MSG_NEWKEYS sent
INFO: SSH_MSG_NEWKEYS received
INFO: SSH_MSG_SERVICE_REQUEST sent
INFO: SSH_MSG_SERVICE_ACCEPT received
INFO: Authentications that can continue: gssapi-with-mic
INFO: Next authentication method: gssapi-with-mic
INFO: Disconnecting from my-server.de port 22
com.jcraft.jsch.JSchException: Auth fail
at com.jcraft.jsch.Session.connect(Session.java:519)
at kerberos.JschKerberos.main(JschKerberos.java:49)

我的配置有问题吗？本地(用户、域等)和远程之间是否存在某些条件？

Answer 1

我终于找到了解决方案！这是sshd服务缺少的服务密钥选项卡！某些服务主体不是由Kerberos服务器自动生成的。因此，这必须由kadmin手动完成，因为sshd服务还必须根据Kerberos进行身份验证！这是由host/fqdn@REALM主体完成的。

这里的重要信息："主机"是一个固定的字符串(！)，我总是用我的OpenSSH服务器机器的主机名来代替它。。。因此，只有"fqdn"one_answers"REALM.COM"必须替换为您的数据

• 有关更多信息(德语)，请参阅此部分：http://www.pks.mpg.de/~mueller/docs/suse1030/opensuse-manual_de/manual/sec.kerbadmin.hostprinc.html
• 这也显示了步骤(英文)：http://www.microhowto.info/howto/create_a_host_principal_using_mit_kerberos.html

所以这些是我完成应用程序的必要步骤：

1. 在OpenSSH服务器的/etc/ssh/sshd_conf配置文件中设置GSSAPIAuthentication yes
2. 在ssh客户端的/etc/ssh/ssh_conf配置文件中设置Host * [...] GSSAPIAuthentication yes
3. 检查客户端上的jaas.conf和krb5.conf(或.ini)文件的设置是否正确(请参阅上面问题部分的代码块)
4. 在Kerberos服务器上，打开kadmin.local并键入ktadd host/my-server.de
5. 可选：添加用户主体(如果还不存在)：ktadd keytabuser
6. 制作kinit keytabuser(带密码)或kinit -kt /path/to/file.keytab keytabuser(普通Kerberos命令)
7. 检查用户是否通过klist进行身份验证
8. 通过控制台ssh [e-mail]直接运行应用程序或ssh
9. 您应该使用缓存的票证登录

当然，用户keytabuser必须是ssh服务器机器上的用户！