我们在让 Kerberos/AD 身份验证与 Spring webapp 一起工作时遇到问题，我认为问题与 Kerberos 票证和 Active Directory 域功能级别的加密类型有关。

基本设置是:

• Tomcat 7
• Java 1.6 (29)
• window 服务器 2008 R2
• Spring 3.0
• 此处详细介绍了 Spring Security Kerberos/Spnego 扩展 M2:http://blog.springsource.com/2009/09/28/spring-security-kerberos/

我有一个环境，其中 Active Directory 域功能级别为 Windows Server 2003，并且一切正常，客户端在登录域时按预期进行身份验证。使用 kerbtray 检查此环境中的票证，我可以看到它们都具有票证加密类型和 key 加密类型“RSADSI RC4-HMAC”。

我有一个功能级别为 Windows Server 2008 的新域，这是身份验证不起作用的地方。尝试验证票证时返回的应用程序错误是:

Kerberos validation not successful...

Caused by: GSSException: Failure unspecified at GSS-API level (Mechanism level: Checksum failed)
    at sun.security.jgss.krb5.Krb5Context.acceptSecContext(Unknown Source)
    at sun.security.jgss.GSSContextImpl.acceptSecContext(Unknown Source)
    at sun.security.jgss.GSSContextImpl.acceptSecContext(Unknown Source)
    at sun.security.jgss.spnego.SpNegoContext.GSS_acceptSecContext(Unknown Source)
    at sun.security.jgss.spnego.SpNegoContext.acceptSecContext(Unknown Source)
    at sun.security.jgss.GSSContextImpl.acceptSecContext(Unknown Source)
    at sun.security.jgss.GSSContextImpl.acceptSecContext(Unknown Source)
    at org.springframework.security.extensions.kerberos.SunJaasKerberosTicketValidator$KerberosValidateAction.run(SunJaasKerberosTicketValidator.java:146)
    at org.springframework.security.extensions.kerberos.SunJaasKerberosTicketValidator$KerberosValidateAction.run(SunJaasKerberosTicketValidator.java:136)
    ... 34 more
Caused by: KrbException: Checksum failed
    at sun.security.krb5.internal.crypto.ArcFourHmacEType.decrypt(Unknown Source)
    at sun.security.krb5.internal.crypto.ArcFourHmacEType.decrypt(Unknown Source)
    at sun.security.krb5.EncryptedData.decrypt(Unknown Source)
    at sun.security.krb5.KrbApReq.authenticate(Unknown Source)
    at sun.security.krb5.KrbApReq.<init>(Unknown Source)
    at sun.security.jgss.krb5.InitSecContextToken.<init>(Unknown Source)
    ... 43 more
Caused by: java.security.GeneralSecurityException: Checksum failed
    at sun.security.krb5.internal.crypto.dk.ArcFourCrypto.decrypt(Unknown Source)
    at sun.security.krb5.internal.crypto.ArcFourHmac.decrypt(Unknown Source)

堆栈跟踪显示“ArcfourCrypto.decrypt”，因此可能将 Kerberos 票据视为 RC4-HMAC。再次使用 kerbtray 检查票证，这次在客户端上有 2 张票证用于域:krbtgt/.COM。两张票都有 key 加密类型 RSADS1 RC4-HMAC，一张也有此票加密类型，但另一张有“Kerberos AES256-CTS-HMAC-SHA1-96”。

我不确定这是否是问题的原因，但这是我在两种环境中能够找到的唯一可以解释身份验证异常的差异。我试过更改 AD 加密策略，尝试过 IE 和 Firefox，以及我能想到的几乎所有其他方法，但没有任何效果。

解决此问题的任何帮助将不胜感激。我更愿意在 Java 端修复它，因为我可能不能对生产 AD 设置说太多。

最佳答案

问题似乎出在 key 表中。有一些 Action 序列导致某些特定的 key 表文件状态: (A) keytab 适用于 Java 但不适用于 k5start/kinit； (B) keytab 不适用于 Java，但适用于 k5start/kinit； (C) keytab 与它们一起工作。

允许检查 Java 是否可以使用 key 表文件进行身份验证的简短 Java 代码:

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import javax.security.auth.Subject;

import com.sun.security.auth.module.Krb5LoginModule;

/**
 * This is simple Java program that tests ability to authenticate 
 * with Kerberos using the JDK implementation.
 * 
 * The program uses no libraries but JDK itself.
 */
public class Krb {

  private void loginImpl(final String propertiesFileName) throws Exception {
    System.out.println("NB: system property to specify the krb5 config: [java.security.krb5.conf]");
    //System.setProperty("java.security.krb5.conf", "/etc/krb5.conf");

    System.out.println(System.getProperty("java.version"));

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

    final Subject subject = new Subject();

    final Krb5LoginModule krb5LoginModule = new Krb5LoginModule();
    final Map<String,String> optionMap = new HashMap<String,String>();

    if (propertiesFileName == null) {
      //optionMap.put("ticketCache", "/tmp/krb5cc_1000");
      optionMap.put("keyTab", "/etc/krb5.keytab");
      optionMap.put("principal", "foo"); // default realm

      optionMap.put("doNotPrompt", "true");
      optionMap.put("refreshKrb5Config", "true");
      optionMap.put("useTicketCache", "true");
      optionMap.put("renewTGT", "true");
      optionMap.put("useKeyTab", "true");
      optionMap.put("storeKey", "true");
      optionMap.put("isInitiator", "true");
    } else {
      File f = new File(propertiesFileName);
      System.out.println("======= loading property file ["+f.getAbsolutePath()+"]");
      Properties p = new Properties();
      InputStream is = new FileInputStream(f);
      try {
        p.load(is);
      } finally {
        is.close();
      }
      optionMap.putAll((Map)p);
    }
    optionMap.put("debug", "true"); // switch on debug of the Java implementation

    krb5LoginModule.initialize(subject, null, new HashMap<String,String>(), optionMap);

    boolean loginOk = krb5LoginModule.login();
    System.out.println("======= login:  " + loginOk);

    boolean commitOk = krb5LoginModule.commit();
    System.out.println("======= commit: " + commitOk);

    System.out.println("======= Subject: " + subject);
  }

  public static void main(String[] args) throws Exception {
    System.out.println("A property file with the login context can be specified as the 1st and the only paramater.");
    final Krb krb = new Krb();
    krb.loginImpl(args.length == 0 ? null : args[0]);
  }
}

，以及要使用的属性文件:

#ticketCache=/tmp/krb5cc_1000
keyTab=/etc/krb5.keytab
principal=foo

doNotPrompt=true
refreshKrb5Config=true
useTicketCache=true
renewTGT=true
useKeyTab=true
storeKey=true
isInitiator=true

(下面我们假设krb/kdc安装和配置正确，数据库是用kdb5_util创建的。每个命令序列的起始状态是:删除keytab文件，删除token缓存，删除用户“foo”数据库。)

以下操作序列导致 keytab 状态 (A):

$ echo -e "foo\nfoo" | kadmin.local -q "addprinc foo"
$ echo -e "foo\nfoo" | kadmin.local -q "ktadd foo"
$ java -cp . Krb ./krb5.properties 
# Now java auth okay, but the following command fails:
$ k5start foo
Kerberos initialization for foo@EXAMPLE.COM
Password for foo@EXAMPLE.COM: 
k5start: error getting credentials: Decrypt integrity check failed
$

以下操作序列导致 keytab 状态 (B):

$ echo -e "foo\nfoo" | kadmin.local -q "addprinc foo"
$ echo -e "foo\nfoo" | kadmin.local -q "ktadd foo"
$ echo -e "foo\nfoo" | kadmin.local -q "cpw foo"
$ java -cp . Krb ./krb5.properties 
A property file with the login context can be specified as the 1st and the only paramater.
NB: system property to specify the krb5 config: [java.security.krb5.conf]
1.6.0_33
======= loading property file [/tmp/krb-test/yhadoop-common/./krb5.properties]
Debug is  true storeKey true useTicketCache true useKeyTab true doNotPrompt true ticketCache is null isInitiator true KeyTab is /etc/krb5.keytab refreshKrb5Config is true principal is foo tryFirstPass is false useFirstPass is false storePass is false clearPass is false
Refreshing Kerberos configuration
Config name: /etc/krb5.conf
>>> KdcAccessibility: reset
>>> KdcAccessibility: reset
Acquire TGT from Cache
>>>KinitOptions cache name is /tmp/krb5cc_0
Principal is foo@EXAMPLE.COM
null credentials from Ticket Cache
>>> KeyTabInputStream, readName(): EXAMPLE.COM
>>> KeyTabInputStream, readName(): foo
>>> KeyTab: load() entry length: 49; type: 23
Added key: 23version: 3
Ordering keys wrt default_tkt_enctypes list
default etypes for default_tkt_enctypes: 23.
0: EncryptionKey: keyType=23 kvno=3 keyValue (hex dump)=
0000: 5F 7F 9B 42 BB 02 51 81   32 05 1D 7B C0 9F 19 C0  _..B..Q.2.......


principal's key obtained from the keytab
Acquire TGT using AS Exchange
default etypes for default_tkt_enctypes: 23.
>>> KrbAsReq calling createMessage
>>> KrbAsReq in createMessage
>>> KrbKdcReq send: kdc=localhost UDP:88, timeout=30000, number of retries =3, #bytes=128
>>> KDCCommunication: kdc=localhost UDP:88, timeout=30000,Attempt =1, #bytes=128
>>> KrbKdcReq send: #bytes read=611
>>> KrbKdcReq send: #bytes read=611
>>> KdcAccessibility: remove localhost:88
>>> EType: sun.security.krb5.internal.crypto.ArcFourHmacEType
Checksum failed !
                [Krb5LoginModule] authentication failed 
Checksum failed
Exception in thread "main" javax.security.auth.login.LoginException: Checksum failed
        at com.sun.security.auth.module.Krb5LoginModule.attemptAuthentication(Krb5LoginModule.java:696)
        at com.sun.security.auth.module.Krb5LoginModule.login(Krb5LoginModule.java:542)
        at Krb.loginImpl(Krb.java:65)
        at Krb.main(Krb.java:77)
Caused by: KrbException: Checksum failed
        at sun.security.krb5.internal.crypto.ArcFourHmacEType.decrypt(ArcFourHmacEType.java:85)
        at sun.security.krb5.internal.crypto.ArcFourHmacEType.decrypt(ArcFourHmacEType.java:77)
        at sun.security.krb5.EncryptedData.decrypt(EncryptedData.java:168)
        at sun.security.krb5.KrbAsRep.<init>(KrbAsRep.java:87)
        at sun.security.krb5.KrbAsReq.getReply(KrbAsReq.java:446)
        at sun.security.krb5.Credentials.sendASRequest(Credentials.java:401)
        at sun.security.krb5.Credentials.acquireTGT(Credentials.java:350)
        at com.sun.security.auth.module.Krb5LoginModule.attemptAuthentication(Krb5LoginModule.java:672)
        ... 3 more
Caused by: java.security.GeneralSecurityException: Checksum failed
        at sun.security.krb5.internal.crypto.dk.ArcFourCrypto.decrypt(ArcFourCrypto.java:388)
        at sun.security.krb5.internal.crypto.ArcFourHmac.decrypt(ArcFourHmac.java:74)
        at sun.security.krb5.internal.crypto.ArcFourHmacEType.decrypt(ArcFourHmacEType.java:83)
        ... 10 more
$

但是“k5start foo”和“kinit foo”在此状态下都可以。

下面的 Action 序列会导致状态 (C):

$ echo -e "foo\nfoo" | kadmin.local -q "addprinc foo"
$ ktutil 
ktutil:  addent -password -p foo -k 1 -e rc4-hmac
Password for foo@EXAMPLE.COM: 
ktutil:  wkt /etc/krb5.keytab
ktutil:  q

之后 k5start/kinit 和 java 验证都给出了肯定的结果。

环境:

yum list krb5-appl-servers krb5-libs krb5-server krb5-workstation kstart pam_krb5 
...
Installed Packages
krb5-libs.x86_64                                                                            1.9-33.el6_3.3                                                                      @updates
krb5-server.x86_64                                                                          1.9-33.el6_3.3                                                                      @updates
krb5-workstation.x86_64                                                                     1.9-33.el6_3.3                                                                      @updates
kstart.x86_64                                                                               4.1-2.el6                                                                           @epel   
...
$ cat /etc/redhat-release 
CentOS release 6.3 (Final)
$ java -version
java version "1.6.0_33"
Java(TM) SE Runtime Environment (build 1.6.0_33-b03)
Java HotSpot(TM) 64-Bit Server VM (build 20.8-b03, mixed mode)

在 Java 7 中也观察到了相同的行为。 在 Ubuntu precise (12.04.1 LTS) 上也观察到相同的行为，使用 MIT 的 kerberos 5-1.10.3 从源代码分发编译。

关于java - 校验和失败 : Kerberos/Spring/Active Directory (2008)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/8509087/