在 Oracle® Solaris 11.2 中管理 Kerberos 和其他验证服务

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更新时间: 2014 年 9 月
 
 

对 Kerberos 服务使用 DTrace

Kerberos 机制支持多种 DTrace 探测器来解码各种协议消息。有关列表,请参见Appendix A, 用于 Kerberos 的 DTrace 探测器。相对于其他协议检查器,DTrace 探测器具有明显优势,因为 DTrace 可让特权用户轻松查看未加密的 Kerberos 数据和应用程序数据。

以下示例指明了可以使用 Kerberos DTrace 探测器查看的信息。

示例 8-1  使用 DTrace 跟踪 Kerberos 消息

以下脚本使用 DTrace 探测器来显示有关系统收发的 Kerberos 消息的详细信息。请注意,所显示的字段基于分配给 krb_message-recvkrb_message-send 探测器的结构。有关更多信息,请参见Kerberos DTrace 探测器的定义

kerberos$target:::krb_message-recv
{
    printf("<- krb message recved: %s\n", args[0]->krb_message_type);
    printf("<- krb message remote addr: %s\n", args[1]->kconn_remote);
    printf("<- krb message ports: local %d remote %d\n",
            args[1]->kconn_localport, args[1]->kconn_remoteport);
    printf("<- krb message protocol: %s transport: %s\n",
            args[1]->kconn_protocol, args[1]->kconn_type);
}

kerberos$target:::krb_message-send
{
    printf("-> krb message sent: %s\n", args[0]->krb_message_type);
    printf("-> krb message remote addr: %s\n", args[1]->kconn_remote);
    printf("-> krb message ports: local %d remote %d\n",
            args[1]->kconn_localport, args[1]->kconn_remoteport);
    printf("-> krb message protocol: %s transport: %s\n",
            args[1]->kconn_protocol, args[1]->kconn_type);
    printf("\n");
}

kerberos$target:::krb_error-read
{
    printf("<- krb error code: %s\n", args[1]->kerror_error_code);
    printf("<- krb error client: %s server: %s\n", args[1]->kerror_client,
            args[1]->kerror_server);
    printf("<- krb error e-text: %s\n", args[1]->kerror_e_text);
    printf("\n");
}

可以从命令行中调用前一个脚本,也可以通过 krb5kdc 守护进程调用。以下示例显示了如何从命令行中调用名为 krb-dtrace.d 的脚本。该命令将促使 Kerberos 收发消息。请注意,必须指定 LD_NOLAZYLOAD=1 来强制装入包含 Kerberos DTrace 探测器的 Kerberos mech_krb5.so 库。

# LD_NOLAZYLOAD=1 dtrace -s ./krb\-dtrace.d -c kinit
dtrace: script './krb-dtrace' matched 4 probes
kinit: Client 'root@DEV.ORACLE.COM' not found in Kerberos database while g
etting initial credentials
dtrace: pid 3750 has exited
 CPU     ID                    FUNCTION:NAME
   2  74782 k5_trace_message_send:krb_message-send -> krb message sent: KR
B_AS_REQ(10)
-> krb message remote addr: 10.229.168.163
-> krb message ports: local 62029 remote 88
-> krb message protocol: ipv4 transport: udp


   2  74781 k5_trace_message_recv:krb_message-recv <- krb message recved:
KRB_ERROR(30)
<- krb message remote addr: 10.229.168.163
<- krb message ports: local 62029 remote 88
<- krb message protocol: ipv4 transport: udp

   2  74776     krb5_rd_error:krb_error-read <- krb error code: KDC_ERR_C_
PRINCIPAL_UNKNOWN(6)
<- krb error client: root@DEV.ORACLE.COM server: krbtgt/DEV.ORACLE.COM@DEV
.ORACLE.COM
<- krb error e-text: CLIENT_NOT_FOUND

要通过 krb5kdc 守护进程使用该脚本,必须启用 svc:/network/security/krb5kdc:default 服务并使其联机。请注意,以下命令不使用 LD_NOLAZYLOAD=1,因为 mech_krb5.so 库将装入 krb5kdc 守护进程。

# dtrace -s ./krb\-dtrace.d -p $(pgrep -x krb5kdc)
示例 8-2  使用 DTrace 查看 Kerberos 预验证类型

以下示例显示客户机选择的预验证类型。第一步是创建 DTrace 脚本,如下所示:

cat krbtrace.d
kerberos$target:::krb_message-recv
{
printf("<- krb message recved: %s\n", args[0]->krb_message_type);
printf("<- krb message remote addr: %s\n", args[1]->kconn_remote);
printf("<- krb message ports: local %d remote %d\n",
args[1]->kconn_localport, args[1]->kconn_remoteport);
printf("<- krb message protocol: %s transport: %s\n",
args[1]->kconn_protocol, args[1]->kconn_type);
}

kerberos$target:::krb_message-send
{
printf("-> krb message sent: %s\n", args[0]->krb_message_type);
printf("-> krb message remote addr: %s\n", args[1]->kconn_remote);
printf("-> krb message ports: local %d remote %d\n",
args[1]->kconn_localport, args[1]->kconn_remoteport);
printf("-> krb message protocol: %s transport: %s\n",
args[1]->kconn_protocol, args[1]->kconn_type);
printf("\n");
}

kerberos$target:::krb_kdc_req-make
{
printf("-> krb kdc_req make msg type: %s\n", args[0]->krb_message_type);
printf("-> krb kdc_req make pre-auths: %s\n", args[1]->kdcreq_padata_types);
printf("-> krb kdc_req make auth data: %s\n", args[1]->kdcreq_authorization_data);
printf("-> krb kdc_req make client: %s server: %s\n", args[1]->kdcreq_client,
args[1]->kdcreq_server );
}

kerberos$target:::krb_kdc_req-read
{
/* printf("<- krb kdc_req msg type: %s\n", args[0]->krb_message_type); */
printf("<- krb kdc_req client: %s server: %s\n", args[1]->kdcreq_client,
args[1]->kdcreq_server );
printf("\n");
}

kerberos$target:::krb_kdc_rep-read
{
/* printf("<- krb kdc_rep msg type: %s\n", args[0]->krb_message_type); */
printf("<- krb kdc_rep client: %s server: %s\n", args[1]->kdcrep_client,
args[1]->kdcrep_enc_server );
printf("\n");
}

kerberos$target:::krb_ap_req-make
{
printf("-> krb ap_req make server: %s client: %s\n", args[2]->kticket_server,
args[2]->kticket_enc_client );
}

kerberos$target:::krb_error-read
{
printf("<- krb error code: %s\n", args[1]->kerror_error_code);
printf("<- krb error client: %s server: %s\n", args[1]->kerror_client,
args[1]->kerror_server);
printf("<- krb error e-text: %s\n", args[1]->kerror_e_text);
printf("\n");
}

接下来,以 Kerberos 系统上的某个特权用户的身份执行 krbtrace.d 脚本,方法为键入以下命令:

# LD_BIND_NOW=1 dtrace -qs krbtrace.d -c "kinit -k"
.
.
-> krb kdc_req make pre-auths: FX_COOKIE(133) ENC_TIMESTAMP(2) REQ_ENC_PA_REP(149)

在输出中显示了预验证类型。有关各种预验证类型的更多信息,请参见 RFC 4120

示例 8-3  使用 DTrace 转储 Kerberos 错误消息
# dtrace -n 'krb_error-make {
printf("\n{");
printf("\n\tctime = %Y", (uint64_t)(args[1]->kerror_ctime * 1000000000));
printf("\n\tcusec = %d", args[1]->kerror_cusec);
printf("\n\tstime = %Y", (uint64_t)(args[1]->kerror_stime * 1000000000));
printf("\n\tsusec = %d", args[1]->kerror_susec);
printf("\n\terror_code = %s", args[1]->kerror_error_code);
printf("\n\tclient = %s", args[1]->kerror_client);
printf("\n\tserver = %s", args[1]->kerror_server);
printf("\n\te_text = %s", args[1]->kerror_e_text);
printf("\n\te_data = %s", "");
printf("\n}");
}'
dtrace: description 'krb_error-make ' matched 1 probe
CPU     ID                    FUNCTION:NAME
0  78307     krb5_mk_error:krb_error-make
{
ctime = 2012 May 10 12:10:20
cusec = 0
stime = 2012 May 10 12:10:20
susec = 319090
error_code = KDC_ERR_C_PRINCIPAL_UNKNOWN(6)
client = testuser@EXAMPLE.COM
server = krbtgt/EXAMPLE.COM@EXAMPLE.COM
e_text = CLIENT_NOT_FOUND
e_data =
}
示例 8-4  使用 DTrace 查看 SSH 服务器的服务票证
# LD_PRELOAD_32=/usr/lib/gss/mech_krb5.so.1 dtrace -q -n '
kerberos$target:::krb_kdc_req-make {
printf("kdcreq_server: %s",args[1]->kdcreq_server);
}' -c "ssh local@four.example.com" -o dtrace.out
Last login: Wed Sep 10 10:10:20 2014
Oracle Solaris 11 X86    July 2014
$ ^D
# cat dtrace.out
kdcreq_server: host/four.example.com@EXAMPLE.COM
示例 8-5  使用 DTrace 查看请求初始 TGT 时不可用的 KDC 的地址和端口
# LD_BIND_NOW=1 dtrace -q -n '
kerberos$target:::krb_message-send {
printf("%s:%d\n",args[1]->kconn_remote, args[1]->kconn_remoteport)
}' -c "kinit local4"

10.10.10.14:88
10.10.10.14:750
10.10.10.14:88
10.10.10.14:750
10.10.10.14:88
10.10.10.14:750
kinit(v5): Cannot contact any KDC for realm 'EXAMPLE.COM'
while getting initial credentials
示例 8-6  使用 DTrace 查看来自 Kerberos 主体的请求
# LD_BIND_NOW=1 dtrace -qs /opt/kdebug/mykdtrace.d \
-c 'kadmin -p kdc/admin -w test123 -q listprincs'
Authenticating as principal kdc/admin with password.
krb kdc_req msg type: KRB_AS_REQ(10)
krb kdc_req make client: kdc/admin@TEST.NET server:
kadmin/interop1.example.com@TEST.NET
krb message sent: KRB_AS_REQ(10)
krb message recved: KRB_ERROR(30)
Err code: KDC_ERR_PREAUTH_REQUIRED(25)
Err msg client: kdc/admin@TEST.NET server: kadmin/interop1.example.com@TEST.NET
Err e-text: NEEDED_PREAUTH
krb kdc_req msg type: KRB_AS_REQ(10)
krb kdc_req make client: kdc/admin@TEST.NET server:
kadmin/interop1.example.com@TEST.NET
krb message sent: KRB_AS_REQ(10)
krb message recved: KRB_AS_REP(11)
kadmin: Database error! Required KADM5 principal missing while
initializing kadmin interface
krb kdc_req msg type: KRB_AS_REQ(10)
krb kdc_req make client: kdc/admin@TEST.NET server:
kadmin/interop2.example.com@TEST.NET
krb message sent: KRB_AS_REQ(10)
krb message recved: KRB_ERROR(30)
Err code: KDC_ERR_S_PRINCIPAL_UNKNOWN(7)
Err msg client: kdc/admin@TEST.NET server: kadmin/interop2.example.com@TEST.NET
Err e-text: SERVER_NOT_FOUND
krb kdc_req msg type: KRB_AS_REQ(10)
krb kdc_req make client: kdc/admin@TEST.NET server:
kadmin/interop2.example.com@TEST.NET

以下脚本用于生成上述输出。

kerberos$target:::krb_message-recv
{
printf("krb message recved: %s\n", args[0]->krb_message_type);
}

kerberos$target:::krb_message-send
{
printf("krb message sent: %s\n", args[0]->krb_message_type);
}

kerberos$target:::krb_kdc_req-make
{
printf("krb kdc_req msg type: %s\n", args[0]->krb_message_type);
printf("krb kdc_req make client: %s server: %s\n", args[1]->kdcreq_client,
args[1]->kdcreq_server );
}

kerberos$target:::krb_ap_req-make
{
printf("krb ap_req make server: %s client: %s\n", args[2]->kticket_server,
args[2]->kticket_enc_client );
}

kerberos$target:::krb_error-read
{
printf("Err code: %s\n", args[1]->kerror_error_code);
printf("Err msg client: %s server: %s\n", args[1]->kerror_client,
args[1]->kerror_server);
printf("Err e-text: %s\n", args[1]->kerror_e_text);
}