Debian Squeeze上不支持使用Kerberos的加密类型NFSv4

Question

我为使用Kerberos的NFSv4设置了一个测试安装，简直要疯了。

机器从LDAP获取用户信息，从Kerberos获取凭据。我可以使用Kerberos帐号登录机器，即基本的Kerberos设置包括PAM正在运行。我可以使用基于主机的访问来设置NFSv4，它运行得也很好。

因此，下一步我将子网掩码更改为“krb5”。

mount -t nfs4 -o sec=krb5 nfs4.mgr:/test mnt
mount.nfs4: access denied by server while mounting nfs4.mgr:/test

给gssd几个-v开关，我在日志中看到了以下内容：

Jan 15 22:00:11 nfs4 rpc.gssd[8116]: handling gssd upcall (/var/lib/nfs/rpc_pipefs/nfs/clntc)
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: handle_gssd_upcall: 'mech=krb5 uid=0 '
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: handling krb5 upcall (/var/lib/nfs/rpc_pipefs/nfs/clntc)
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: process_krb5_upcall: service is '<null>'
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: Full hostname for 'nfs4.mgr' is 'nfs4.mgr'
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: Full hostname for 'nfs4.mgr' is 'nfs4.mgr'
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: Key table entry not found while getting keytab entry for 'root/nfs4.mgr@MGR'
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: Success getting keytab entry for 'nfs/nfs4.mgr@MGR'
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: INFO: Credentials in CC 'FILE:/tmp/krb5cc_machine_MGR' are good until 1358369976
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: INFO: Credentials in CC 'FILE:/tmp/krb5cc_machine_MGR' are good until 1358369976
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: using FILE:/tmp/krb5cc_machine_MGR as credentials cache for machine creds
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: using environment variable to select krb5 ccache FILE:/tmp/krb5cc_machine_MGR
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: creating context using fsuid 0 (save_uid 0)
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: creating tcp client for server nfs4.mgr
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: DEBUG: port already set to 2049
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: creating context with server nfs@nfs4.mgr
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: in authgss_create_default()
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: in authgss_create()
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: authgss_create: name is 0x1bbee10
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: authgss_create: gd->name is 0x1bb46e0
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: in authgss_refresh()
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: struct rpc_gss_sec:
Jan 15 22:00:11 nfs4 rpc.gssd[8116]:      mechanism_OID: { 1 2 134 72 134 247 18 1 2 2 }
Jan 15 22:00:11 nfs4 rpc.gssd[8116]:      qop: 0
Jan 15 22:00:11 nfs4 rpc.gssd[8116]:      service: 1
Jan 15 22:00:11 nfs4 rpc.gssd[8116]:      cred: 0x1bb9ae0
Jan 15 22:00:11 nfs4 rpc.gssd[8116]:      req_flags: 00000002
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: rpcsec_gss: gss_init_sec_context: (major) Unspecified GSS failure.  Minor code may provide more information - (minor) No supported encryption types (config file error?)
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: in authgss_destroy()
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: in authgss_destroy_context()
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: authgss_destroy: freeing name 0x1bb46e0
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: authgss_create_default: freeing name 0x1bbee10
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: WARNING: Failed to create krb5 context for user with uid 0 for server nfs4.mgr
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: WARNING: Failed to create machine krb5 context with credentials cache FILE:/tmp/krb5cc_machine_MGR for server nfs4.mgr
Jan 15 22:00:11 nfs4 rpc.gssd[8116]: WARNING: Machine cache is prematurely expired or corrupted trying to recreate cache for server nfs4.mgr

每次挂载调用都会发生两次。你知道这意味着什么吗？它可能引用哪个配置文件？

谢谢你的帮助。

Answer 1

我相信Debian squeeze中的NFSv4实现仍然是只支持DES的。(这是相当长一段时间内NFSv4实现的一个问题。)但是，所有现代Kerberos实现在默认情况下都不再允许DES，因为它对于良好的安全实践来说太弱了。

至少，您可能需要添加以下内容：

allow_weak_crypto     = true

添加到客户端上/etc/krb5.conf的[libdefaults]部分。您的KDC还需要支持DES服务票证请求。而且，您需要确保NFSv4服务器使用的Kerberos主体只有DES加密类型；如果它有任何其他加密类型，客户机将更喜欢它们(因为它们更强)，但这样服务器就无法理解身份验证。