【java】关于怎么使用Kerberos的一个小问题

首先Kerberos机制我明白点，就是客户端连接服务段的时候，需要两个文件
name.keytab
krb5.conf
这俩文件是怎么来的？
（项目是一个同事操作的，Kerberos不是完全懂，原理看了些，说是Kerberos服务器会去数据库查白名单，然后给ticket）
我有一个疑问就是，比如我现在要写一个项目，连的服务端有Kerberos验证，我怎么获取这两个文件，或者说怎么去认证，不会是我去找运维，然后和他说“你给我加一下白名单，给我俩文件”？？？？

不好意思我有点菜，这个地方真不懂，那俩文件是同时给我的说我用就行了，其他的不知道，求指导或者资料

学习参考资料
记住，如果用华为的fusioninght平台，zookeeper包要用华为自己的，要不然验证会不通过，血的教训。
1.kerberos认证原理
2.kerberos安装和常用命令并与cdh集成

以下是我的学习收获
1.想要获得认证有两种途径
第一种：通过kinit admin，输入用户密码，这种是通过shell命令
第二种：通过krb5.conf和keytab文件，这种一般是通过程序获得认证，代码如下init（）、login（）方法加在需要连接服务器某个服务（比如zookepeer）程序之前运行

private static void login() throws IOException {
if (User.isHBaseSecurityEnabled(conf)) {
String userdir = System.getProperty("user.dir") + File.separator + "conf" + File.separator;
userName = "admin";
userKeytabFile = userdir + "user.keytab";
krb5File = userdir + "krb5.conf";

  /*
   * if need to connect zk, please provide jaas info about zk. of course,
   * you can do it as below:
   * System.setProperty("java.security.auth.login.config", confDirPath +
   * "jaas.conf"); but the demo can help you more : Note: if this process
   * will connect more than one zk cluster, the demo may be not proper. you
   * can contact us for more help
   */
        // System.out.println();
        LoginUtil.setJaasConf(ZOOKEEPER_DEFAULT_LOGIN_CONTEXT_NAME, userName, userKeytabFile);
        LoginUtil.setZookeeperServerPrincipal(ZOOKEEPER_SERVER_PRINCIPAL_KEY,
                ZOOKEEPER_DEFAULT_SERVER_PRINCIPAL);
        LoginUtil.login(userName, userKeytabFile, krb5File, conf);


    }
}

private static void init() throws IOException {
    // Default load from conf directory
    conf = HBaseConfiguration.create();
    String userdir = System.getProperty("user.dir") + File.separator + "conf" + File.separator;
    conf.addResource(new Path(userdir + "core-site-dev.xml"));
    conf.addResource(new Path(userdir + "hdfs-site-dev.xml"));
    conf.addResource(new Path(userdir + "hbase-site-dev.xml"));
    conf.addResource(new Path(userdir + "hive-site-dev.xml"));


}

还有一个LoginUtil.java类

package cn.tongdun.datacompute.biz.suppport;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.authentication.util.KerberosUtil;
import org.apache.log4j.Logger;

import javax.security.auth.login.AppConfigurationEntry;
import javax.security.auth.login.AppConfigurationEntry.LoginModuleControlFlag;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class LoginUtil {

private static final Logger LOG = Logger.getLogger(LoginUtil.class);

private static final String JAVA_SECURITY_KRB5_CONF_KEY = "java.security.krb5.conf";

private static final String LOGIN_FAILED_CAUSE_PASSWORD_WRONG = "(wrong password) keytab file and user not match, you can kinit -k -t keytab user in client server to check";

private static final String LOGIN_FAILED_CAUSE_TIME_WRONG = "(clock skew) time of local server and remote server not match, please check ntp to remote server";

private static final String LOGIN_FAILED_CAUSE_AES256_WRONG = "(aes256 not support) aes256 not support by default jdk/jre, need copy local_policy.jar and US_export_policy.jar from remote server in path /opt/huawei/Bigdata/jdk/jre/lib/security";

private static final String LOGIN_FAILED_CAUSE_PRINCIPAL_WRONG = "(no rule) principal format not support by default, need add property hadoop.security.auth_to_local(in core-site.xml) value RULE:[1:$1] RULE:[2:$1]";

private static final String LOGIN_FAILED_CAUSE_TIME_OUT = "(time out) can not connect to kdc server or there is fire wall in the network";

private static final boolean IS_IBM_JDK = System.getProperty("java.vendor").contains("IBM");
private static final boolean IS_WINDOWS_OS = System.getProperty("os.name").toLowerCase()
.contains("windows");

public synchronized static void login(String userPrincipal, String userKeytabPath,
String krb5ConfPath, Configuration conf) throws IOException {
// 1.check input parameters
if ((userPrincipal == null) || (userPrincipal.length() <= 0)) {
LOG.error("input userPrincipal is invalid.");
throw new IOException("input userPrincipal is invalid.");
}

if ((userKeytabPath == null) || (userKeytabPath.length() <= 0)) {
  LOG.error("input userKeytabPath is invalid.");
  throw new IOException("input userKeytabPath is invalid.");
}

if ((krb5ConfPath == null) || (krb5ConfPath.length() <= 0)) {
  LOG.error("input krb5ConfPath is invalid.");
  throw new IOException("input krb5ConfPath is invalid.");
}

if ((conf == null)) {
  LOG.error("input conf is invalid.");
  throw new IOException("input conf is invalid.");
}

// 2.check file exsits
File userKeytabFile = new File(userKeytabPath);
if (!userKeytabFile.exists()) {
  LOG.error("userKeytabFile(" + userKeytabFile.getAbsolutePath() + ") does not exsit.");
  throw new IOException("userKeytabFile(" + userKeytabFile.getAbsolutePath()
      + ") does not exsit.");
}
if (!userKeytabFile.isFile()) {
  LOG.error("userKeytabFile(" + userKeytabFile.getAbsolutePath() + ") is not a file.");
  throw new IOException("userKeytabFile(" + userKeytabFile.getAbsolutePath()
      + ") is not a file.");
}

File krb5ConfFile = new File(krb5ConfPath);
if (!krb5ConfFile.exists()) {
  LOG.error("krb5ConfFile(" + krb5ConfFile.getAbsolutePath() + ") does not exsit.");
  throw new IOException("krb5ConfFile(" + krb5ConfFile.getAbsolutePath() + ") does not exsit.");
}
if (!krb5ConfFile.isFile()) {
  LOG.error("krb5ConfFile(" + krb5ConfFile.getAbsolutePath() + ") is not a file.");
  throw new IOException("krb5ConfFile(" + krb5ConfFile.getAbsolutePath() + ") is not a file.");
}

// 3.set and check krb5config
setKrb5Config(krb5ConfFile.getAbsolutePath());
setConfiguration(conf);

// 4.login and check for hadoop
loginHadoop(userPrincipal, userKeytabFile.getAbsolutePath());

LOG.info("Login success!!!!!!!!!!!!!!");

}

private static void setConfiguration(Configuration conf) throws IOException {
UserGroupInformation.setConfiguration(conf);
}

private static boolean checkNeedLogin(String principal) throws IOException {
if (!UserGroupInformation.isSecurityEnabled()) {
LOG.error("UserGroupInformation is not SecurityEnabled, please check if core-site.xml exists in classpath.");
throw new IOException(
"UserGroupInformation is not SecurityEnabled, please check if core-site.xml exists in classpath.");
}
UserGroupInformation currentUser = UserGroupInformation.getCurrentUser();
if ((currentUser != null) && (currentUser.hasKerberosCredentials())) {
if (checkCurrentUserCorrect(principal)) {
LOG.info("current user is " + currentUser + "has logined.");
if (!currentUser.isFromKeytab()) {
LOG.error("current user is not from keytab.");
throw new IOException("current user is not from keytab.");
}
return false;
} else {
LOG.error("current user is "
+ currentUser
+ "has logined. please check your enviroment , especially when it used IBM JDK or kerberos for OS count login!!");
throw new IOException("current user is " + currentUser
+ " has logined. And please check your enviroment!!");
}
}

return true;

}

private static void setKrb5Config(String krb5ConfFile) throws IOException {
System.setProperty(JAVA_SECURITY_KRB5_CONF_KEY, krb5ConfFile);
String ret = System.getProperty(JAVA_SECURITY_KRB5_CONF_KEY);
if (ret == null) {
LOG.error(JAVA_SECURITY_KRB5_CONF_KEY + " is null.");
throw new IOException(JAVA_SECURITY_KRB5_CONF_KEY + " is null.");
}
if (!ret.equals(krb5ConfFile)) {
LOG.error(JAVA_SECURITY_KRB5_CONF_KEY + " is " + ret + " is not " + krb5ConfFile + ".");
throw new IOException(JAVA_SECURITY_KRB5_CONF_KEY + " is " + ret + " is not " + krb5ConfFile
+ ".");
}
}

public static void setJaasConf(String loginContextName, String principal, String keytabFile)
throws IOException {
if ((loginContextName == null) || (loginContextName.length() <= 0)) {
LOG.error("input loginContextName is invalid.");
throw new IOException("input loginContextName is invalid.");
}

if ((principal == null) || (principal.length() <= 0)) {
  LOG.error("input principal is invalid.");
  throw new IOException("input principal is invalid.");
}

if ((keytabFile == null) || (keytabFile.length() <= 0)) {
  LOG.error("input keytabFile is invalid.");
  throw new IOException("input keytabFile is invalid.");
}

File userKeytabFile = new File(keytabFile);
if (!userKeytabFile.exists()) {
  LOG.error("userKeytabFile(" + userKeytabFile.getAbsolutePath() + ") does not exsit.");
  throw new IOException("userKeytabFile(" + userKeytabFile.getAbsolutePath()
      + ") does not exsit.");
}

javax.security.auth.login.Configuration.setConfiguration(new JaasConfiguration(
    loginContextName, principal, userKeytabFile.getAbsolutePath()));

javax.security.auth.login.Configuration conf = javax.security.auth.login.Configuration
    .getConfiguration();
if (!(conf instanceof JaasConfiguration)) {
  LOG.error("javax.security.auth.login.Configuration is not JaasConfiguration.");
  throw new IOException("javax.security.auth.login.Configuration is not JaasConfiguration.");
}

AppConfigurationEntry[] entrys = conf.getAppConfigurationEntry(loginContextName);
if (entrys == null) {
  LOG.error("javax.security.auth.login.Configuration has no AppConfigurationEntry named "
      + loginContextName + ".");
  throw new IOException(
      "javax.security.auth.login.Configuration has no AppConfigurationEntry named "
          + loginContextName + ".");
}

boolean checkPrincipal = false;
boolean checkKeytab = false;
for (int i = 0; i < entrys.length; i++) {
  if (entrys[i].getOptions().get("principal").equals(principal)) {
    checkPrincipal = true;
  }

  if (IS_IBM_JDK) {
    if (entrys[i].getOptions().get("useKeytab").equals(keytabFile)) {
      checkKeytab = true;
    }
  } else {
    if (entrys[i].getOptions().get("keyTab").equals(keytabFile)) {
      checkKeytab = true;
    }
  }

}

if (!checkPrincipal) {
  LOG.error("AppConfigurationEntry named " + loginContextName
      + " does not have principal value of " + principal + ".");
  throw new IOException("AppConfigurationEntry named " + loginContextName
      + " does not have principal value of " + principal + ".");
}

if (!checkKeytab) {
  LOG.error("AppConfigurationEntry named " + loginContextName
      + " does not have keyTab value of " + keytabFile + ".");
  throw new IOException("AppConfigurationEntry named " + loginContextName
      + " does not have keyTab value of " + keytabFile + ".");
}

}

public static void setZookeeperServerPrincipal(String zkServerPrincipalKey,
String zkServerPrincipal) throws IOException {
System.setProperty(zkServerPrincipalKey, zkServerPrincipal);
String ret = System.getProperty(zkServerPrincipalKey);
if (ret == null) {
LOG.error(zkServerPrincipalKey + " is null.");
throw new IOException(zkServerPrincipalKey + " is null.");
}
if (!ret.equals(zkServerPrincipal)) {
LOG.error(zkServerPrincipalKey + " is " + ret + " is not " + zkServerPrincipal + ".");
throw new IOException(zkServerPrincipalKey + " is " + ret + " is not " + zkServerPrincipal
+ ".");
}
}

private static void loginHadoop(String principal, String keytabFile) throws IOException {
try {
UserGroupInformation.loginUserFromKeytab(principal, keytabFile);
} catch (IOException e) {
LOG.error("login failed with " + principal + " and " + keytabFile + ".");
LOG.error("perhaps cause 1 is " + LOGIN_FAILED_CAUSE_PASSWORD_WRONG + ".");
LOG.error("perhaps cause 2 is " + LOGIN_FAILED_CAUSE_TIME_WRONG + ".");
LOG.error("perhaps cause 3 is " + LOGIN_FAILED_CAUSE_AES256_WRONG + ".");
LOG.error("perhaps cause 4 is " + LOGIN_FAILED_CAUSE_PRINCIPAL_WRONG + ".");
LOG.error("perhaps cause 5 is " + LOGIN_FAILED_CAUSE_TIME_OUT + ".");

  throw e;
}

}

private static void checkAuthenticateOverKrb() throws IOException {
UserGroupInformation loginUser = UserGroupInformation.getLoginUser();
UserGroupInformation currentUser = UserGroupInformation.getCurrentUser();
if (loginUser == null) {
LOG.error("current user is " + currentUser + ", but loginUser is null.");
throw new IOException("current user is " + currentUser + ", but loginUser is null.");
}
if (!loginUser.equals(currentUser)) {
LOG.error("current user is " + currentUser + ", but loginUser is " + loginUser + ".");
throw new IOException("current user is " + currentUser + ", but loginUser is " + loginUser
+ ".");
}
if (!loginUser.hasKerberosCredentials()) {
LOG.error("current user is " + currentUser + " has no Kerberos Credentials.");
throw new IOException("current user is " + currentUser + " has no Kerberos Credentials.");
}
if (!UserGroupInformation.isLoginKeytabBased()) {
LOG.error("current user is " + currentUser + " is not Login Keytab Based.");
throw new IOException("current user is " + currentUser + " is not Login Keytab Based.");
}
}

private static boolean checkCurrentUserCorrect(String principal) throws IOException {
UserGroupInformation ugi = UserGroupInformation.getCurrentUser();
if (ugi == null) {
LOG.error("current user still null.");
throw new IOException("current user still null.");
}

String defaultRealm = null;
try {
  defaultRealm = KerberosUtil.getDefaultRealm();
} catch (Exception e) {
  LOG.warn("getDefaultRealm failed.");
  throw new IOException(e);
}

if ((defaultRealm != null) && (defaultRealm.length() > 0)) {
  StringBuilder realm = new StringBuilder();
  StringBuilder principalWithRealm = new StringBuilder();
  realm.append("@").append(defaultRealm);
  if (!principal.endsWith(realm.toString())) {
    principalWithRealm.append(principal).append(realm);
    principal = principalWithRealm.toString();
  }
}

return principal.equals(ugi.getUserName());

}

/**

• copy from hbase zkutil 0.94&0.98 A JAAS configuration that defines the

• login modules that we want to use for login.
  */
  private static class JaasConfiguration extends javax.security.auth.login.Configuration {
  private static final Map BASIC_JAAS_OPTIONS = new HashMap();
  static {
  String jaasEnvVar = System.getenv("HBASE_JAAS_DEBUG");
  if (jaasEnvVar != null && "true".equalsIgnoreCase(jaasEnvVar)) {
  BASIC_JAAS_OPTIONS.put("debug", "true");
  }
  }

  private static final Map KEYTAB_KERBEROS_OPTIONS = new HashMap();
  static {
  if (IS_IBM_JDK) {
  KEYTAB_KERBEROS_OPTIONS.put("credsType", "both");
  } else {
  KEYTAB_KERBEROS_OPTIONS.put("useKeyTab", "true");
  KEYTAB_KERBEROS_OPTIONS.put("useTicketCache", "false");
  KEYTAB_KERBEROS_OPTIONS.put("doNotPrompt", "true");
  KEYTAB_KERBEROS_OPTIONS.put("storeKey", "true");
  }

  KEYTAB_KERBEROS_OPTIONS.putAll(BASIC_JAAS_OPTIONS);
  }

  private static final AppConfigurationEntry KEYTAB_KERBEROS_LOGIN = new AppConfigurationEntry(
  KerberosUtil.getKrb5LoginModuleName(), LoginModuleControlFlag.REQUIRED,
  KEYTAB_KERBEROS_OPTIONS);

  private static final AppConfigurationEntry[] KEYTAB_KERBEROS_CONF = new AppConfigurationEntry[] { KEYTAB_KERBEROS_LOGIN };

  private javax.security.auth.login.Configuration baseConfig;

  private final String loginContextName;

  private final boolean useTicketCache;

  private final String keytabFile;

  private final String principal;

  public JaasConfiguration(String loginContextName, String principal, String keytabFile)
  throws IOException {
  this(loginContextName, principal, keytabFile, keytabFile == null || keytabFile.length() == 0);
  }

  private JaasConfiguration(String loginContextName, String principal, String keytabFile,
  boolean useTicketCache) throws IOException {
  try {
  this.baseConfig = javax.security.auth.login.Configuration.getConfiguration();
  } catch (SecurityException e) {
  this.baseConfig = null;
  }
  this.loginContextName = loginContextName;
  this.useTicketCache = useTicketCache;
  this.keytabFile = keytabFile;
  this.principal = principal;

  initKerberosOption();
  LOG.info("JaasConfiguration loginContextName=" + loginContextName + " principal=" + principal
  + " useTicketCache=" + useTicketCache + " keytabFile=" + keytabFile);
  }

  private void initKerberosOption() throws IOException {
  if (!useTicketCache) {
  if (IS_IBM_JDK) {
  KEYTAB_KERBEROS_OPTIONS.put("useKeytab", keytabFile);
  } else {
  KEYTAB_KERBEROS_OPTIONS.put("keyTab", keytabFile);
  KEYTAB_KERBEROS_OPTIONS.put("useKeyTab", "true");
  KEYTAB_KERBEROS_OPTIONS.put("useTicketCache", useTicketCache ? "true" : "false");
  }
  }
  KEYTAB_KERBEROS_OPTIONS.put("principal", principal);
  }

  public AppConfigurationEntry[] getAppConfigurationEntry(String appName) {
  if (loginContextName.equals(appName)) {
  return KEYTAB_KERBEROS_CONF;
  }
  if (baseConfig != null)
  return baseConfig.getAppConfigurationEntry(appName);
  return (null);
  }
  }
  }