关于云计算:修复-K8s-SSLTLS-漏洞CVE20162183指南

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作者:老 Z,中电信数智科技有限公司山东分公司运维架构师,云原生爱好者,目前专一于云原生运维,云原生畛域技术栈波及 Kubernetes、KubeSphere、DevOps、OpenStack、Ansible 等。

前言

测试服务器配置

主机名 IP CPU 内存 系统盘 数据盘 用处
zdeops-master 192.168.9.9 2 4 40 200 Ansible 运维管制节点
ks-k8s-master-0 192.168.9.91 4 16 40 200+200 KubeSphere/k8s-master/k8s-worker
ks-k8s-master-1 192.168.9.92 4 16 40 200+200 KubeSphere/k8s-master/k8s-worker
ks-k8s-master-2 192.168.9.93 4 16 40 200+200 KubeSphere/k8s-master/k8s-worker
storage-node-0 192.168.9.95 2 8 40 200+200 ElasticSearch/GlusterFS
storage-node-0 192.168.9.96 2 8 40 200+200 ElasticSearch/GlusterFS
storage-node-0 192.168.9.97 2 8 40 200+200 ElasticSearch/GlusterFS
harbor 192.168.9.89 2 8 40 200 Harbor
共计 8 22 84 320 2800

测试环境波及软件版本信息

  • 操作系统:CentOS-7.9-x86_64
  • Ansible:2.8.20
  • KubeSphere:3.3.0
  • Kubernetes:v1.24.1
  • GlusterFS:9.5.1
  • ElasticSearch:7.17.5
  • Harbor:2.5.1

简介

生产环境 KubeSphere 3.3.0 部署的 Kubernetes 集群在平安评估的时候发现安全漏洞,其中一项破绽提醒 SSL/TLS 协定信息泄露破绽 (CVE-2016-2183)

本文详细描述了破绽产生起因、破绽修复计划、破绽修复的操作流程以及注意事项。

破绽信息及修复计划

破绽详细信息

破绽报告中波及破绽 SSL/TLS 协定信息泄露破绽 (CVE-2016-2183) 的具体信息如下:

破绽剖析

  1. 剖析破绽报告信息,咱们发现破绽波及以下端口和服务:
端口号 服务
2379/2380 Etcd
6443 kube-apiserver
10250 kubelet
10257 kube-controller
10259 kube-scheduler
  1. 在破绽节点 (任意 Master 节点) 查看、确认端口号对应的服务:
# ETCD
[root@ks-k8s-master-0 ~]# ss -ntlup | grep Etcd | grep -v "127.0.0.1"
tcp    LISTEN     0      128    192.168.9.91:2379                  *:*                   users:(("Etcd",pid=1341,fd=7))
tcp    LISTEN     0      128    192.168.9.91:2380                  *:*                   users:(("Etcd",pid=1341,fd=5))

# kube-apiserver
[root@ks-k8s-master-0 ~]# ss -ntlup | grep 6443
tcp    LISTEN     0      128    [::]:6443               [::]:*                   users:(("kube-apiserver",pid=1743,fd=7))

# kubelet
[root@ks-k8s-master-0 ~]# ss -ntlup | grep 10250
tcp    LISTEN     0      128    [::]:10250              [::]:*                   users:(("kubelet",pid=1430,fd=24))

# kube-controller
[root@ks-k8s-master-0 ~]# ss -ntlup | grep 10257
tcp    LISTEN     0      128    [::]:10257              [::]:*                   users:(("kube-controller",pid=19623,fd=7))

# kube-scheduler
[root@ks-k8s-master-0 ~]# ss -ntlup | grep 10259
tcp    LISTEN     0      128    [::]:10259              [::]:*                   users:(("kube-scheduler",pid=1727,fd=7))
  1. 破绽起因:

相干服务配置文件里应用了 IDEA、DES 和 3DES 等算法。

  1. 利用测试工具验证破绽:

能够应用 Nmap 或是 openssl 进行验证,本文重点介绍 Nmap 的验证形式。

留神:openssl 的形式输入太多且不好直观判断,有趣味的能够参考命令 openssl s_client -connect 192.168.9.91:10257 -cipher "DES:3DES"

在任意节点装置测试工具 Nmap,并执行测试命令。

谬误的姿态,仅用于阐明抉择 Nmap 版本很重要,实际操作中不要执行。

# 用 CentOS 默认源装置 nmap
yum install nmap

# 执行针对 2379 端口的 ssl-enum-ciphers 检测
nmap --script ssl-enum-ciphers -p 2379 192.168.9.91

# 后果输入如下
Starting Nmap 6.40 (http://nmap.org) at 2023-02-13 14:14 CST
Nmap scan report for ks-k8s-master-0 (192.168.9.91)
Host is up (0.00013s latency).
PORT     STATE SERVICE
2379/tcp open  unknown

Nmap done: 1 IP address (1 host up) scanned in 0.30 seconds

留神: 剖析输入的后果发现并没有任何正告信息。起因是 Nmap 版本过低,须要 7.x 以上才能够。

正确的姿态,理论执行的操作:

# 从 Nmap 官网,下载安装新版软件包
rpm -Uvh https://nmap.org/dist/nmap-7.93-1.x86_64.rpm

# 执行针对 2379 端口的 ssl-enum-ciphers 检测
# nmap -sV --script ssl-enum-ciphers -p 2379 192.168.9.91 (该命令输入更为具体也更加耗时,为节俭篇幅应用上面简略输入的模式)
nmap --script ssl-enum-ciphers -p 2379 192.168.9.91

# 输入后果如下
Starting Nmap 7.93 (https://nmap.org) at 2023-02-13 17:28 CST
Nmap scan report for ks-k8s-master-0 (192.168.9.91)
Host is up (0.00013s latency).

PORT     STATE SERVICE
2379/tcp open  Etcd-client
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA (ecdh_x25519) - C
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
|       TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
|       TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
|     compressors:
|       NULL
|     cipher preference: client
|     warnings:
|       64-bit block cipher 3DES vulnerable to SWEET32 attack
|_  least strength: C

Nmap done: 1 IP address (1 host up) scanned in 0.66 seconds

# 执行针对 2380 端口的 ssl-enum-ciphers 检测
nmap --script ssl-enum-ciphers -p 2380 192.168.9.91

# 输入后果如下
Starting Nmap 7.93 (https://nmap.org) at 2023-02-13 17:28 CST
Nmap scan report for ks-k8s-master-0 (192.168.9.91)
Host is up (0.00014s latency).

PORT     STATE SERVICE
2380/tcp open  Etcd-server
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA (ecdh_x25519) - C
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
|       TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
|       TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
|     compressors:
|       NULL
|     cipher preference: client
|     warnings:
|       64-bit block cipher 3DES vulnerable to SWEET32 attack
|_  least strength: C

Nmap done: 1 IP address (1 host up) scanned in 0.64 seconds

# 执行针对 6443 端口的 ssl-enum-ciphers 检测(10250/10257/10259 端口扫描后果雷同)nmap --script ssl-enum-ciphers -p 6443 192.168.9.91

# 输入后果如下
Starting Nmap 7.93 (https://nmap.org) at 2023-02-13 17:29 CST
Nmap scan report for ks-k8s-master-0 (192.168.9.91)
Host is up (0.00014s latency).

PORT     STATE SERVICE
6443/tcp open  sun-sr-https
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (secp256r1) - A
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
|       TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
|       TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA (secp256r1) - C
|       TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
|     compressors:
|       NULL
|     cipher preference: server
|     warnings:
|       64-bit block cipher 3DES vulnerable to SWEET32 attack
|   TLSv1.3:
|     ciphers:
|       TLS_AKE_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
|       TLS_AKE_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
|       TLS_AKE_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
|     cipher preference: server
|_  least strength: C

Nmap done: 1 IP address (1 host up) scanned in 0.66 seconds

留神:扫描后果中重点关注 warnings64-bit block cipher 3DES vulnerable to SWEET32 attack

破绽修复计划

破绽扫描报告中提到的修复计划并不适用于 Etcd、Kubernetes 相干服务。

针对于 Etcd、Kubernetes 等服务无效的修复伎俩是批改服务配置文件,禁用 3DES 相干的加密配置。

Cipher Suites 配置参数的抉择,能够参考 ETCD 官网文档或是 IBM 公有云文档,网上搜到的很多配置都是参考的 IBM 的文档,想省事的能够拿来即用。

对于配置参数的最终抉择,我采纳了最笨的办法,即把扫描后果列出的 Cipher 值拼接起来。因为不分明影响范畴,所以激进的采纳了在原有配置根底上删除 3DES 相干的配置。

上面的内容整顿了 Cipher Suites 配置参数的可参考配置。

  1. 原始扫描后果中的 Cipher Suites 配置:
- TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
- TLS_RSA_WITH_3DES_EDE_CBC_SHA
- TLS_RSA_WITH_AES_128_CBC_SHA
- TLS_RSA_WITH_AES_128_GCM_SHA256
- TLS_RSA_WITH_AES_256_CBC_SHA
- TLS_RSA_WITH_AES_256_GCM_SHA384
  1. 原始扫描后果去掉 3DES 的 Cipher Suites 配置:
- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
- TLS_RSA_WITH_AES_128_CBC_SHA
- TLS_RSA_WITH_AES_128_GCM_SHA256
- TLS_RSA_WITH_AES_256_CBC_SHA
- TLS_RSA_WITH_AES_256_GCM_SHA384

应用该计划时必须 严格依照以下程序配置,我在测试时发现程序不统一会导致 Etcd 服务重复重启。

ETCD_CIPHER_SUITES=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA

尽管 CIPHER 配置一样,然而在应用上面的程序时,Etcd 服务重复重启,我排查了良久也没确定根因。也可能是我写的有问题,然而比对屡次也没发现异常,只能临时是认为是程序造成的。

ETCD_CIPHER_SUITES=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_256_GCM_SHA384

留神:只有 Etcd 服务受到程序的影响,kube 相干组件程序不同也没发现异常。

  1. IBM 相干文档中的 Cipher Suites 配置:

网上搜到的参考文档使用率最高的配置。理论测试也的确好用,服务都能失常启动,没有发现 Etcd 一直重启的景象。如果没有非凡需要,能够采纳该计划,毕竟抉择越少出安全漏洞的几率也越小。

- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

破绽修复

倡议应用以下程序修复破绽:

  • Etcd
  • kube-apiserver
  • kube-controller
  • kube-scheduler
  • kubelet

下面的操作流程中,重点是将 Etcd 的修复重启放在最后面执行。因为 kube 等组件的运行依赖于 Etcd,我在验证时最初降级的 Etcd,当 Etcd 启动失败后(重复重启),其余服务因为无奈连贯 Etcd,造成服务异样进行。所以先确保 Etcd 运行失常再去修复其余组件。

本文所有操作仅演示了一个节点的操作方法,多节点存在破绽时请按组件顺次执行,先修复实现一个组件,确认无误后再去修复另一个组件。

以下操作是我实战验证过的教训,仅供参考,生产环境请肯定要充沛验证、测试后再执行!

修复 Etcd

  1. 编辑 Etcd 配置文件 /etc/Etcd.env

KubeSpere 3.3.0 采纳二进制的形式部署的 Etcd,相干配置文件蕴含 /etc/systemd/system/Etcd.service/etc/Etcd.env,参数配置保留在 /etc/Etcd.env

# 在文件最初减少配置(用 cat 命令主动配置)
cat >> /etc/Etcd.env << "EOF"

# TLS CIPHER SUITES settings
ETCD_CIPHER_SUITES=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA
EOF
  1. 重启 Etcd 服务:
# 重启服务
systemctl restart Etcd

# 验证服务已启动
ss -ntlup | grep Etcd

# 正确的后果如下
tcp    LISTEN     129    128    192.168.9.91:2379                  *:*                   users:(("Etcd",pid=40160,fd=7))
tcp    LISTEN     0      128    127.0.0.1:2379                  *:*                   users:(("Etcd",pid=40160,fd=6))
tcp    LISTEN     0      128    192.168.9.91:2380                  *:*                   users:(("Etcd",pid=40160,fd=5))

# 继续观测 确保服务没有重复重启
watch -n 1 -d 'ss -ntlup | grep Etcd'

留神:如果是多节点模式,肯定要所有节点都批改完配置文件,而后,所有节点同时重启 Etcd 服务。重启过程中会造成 Etcd 服务中断,生产环境审慎操作。

  1. 验证破绽是否修复:
# 执行扫描命令
nmap --script ssl-enum-ciphers -p 2379 192.168.9.91

# 输入后果如下
Starting Nmap 7.93 (https://nmap.org) at 2023-02-14 17:48 CST
Nmap scan report for ks-k8s-master-0 (192.168.9.91)
Host is up (0.00015s latency).

PORT     STATE SERVICE
2379/tcp open  Etcd-client
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
|       TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
|     compressors:
|       NULL
|     cipher preference: client
|_  least strength: A

Nmap done: 1 IP address (1 host up) scanned in 0.64 seconds

# 为了节俭篇幅,2380 端口扫描残缺输入后果略, 理论后果与 2379 端口统一

# 能够执行过滤输入的扫描命令,如果以下命令返回值为空,阐明破绽修复
nmap --script ssl-enum-ciphers -p 2380 192.168.9.91 | grep SWEET32

修复 kube-apiserver

  1. 编辑 kube-apiserver 配置文件 /etc/kubernetes/manifests/kube-apiserver.yaml
# 新增配置(在原文件 47 行前面减少一行)
- --tls-cipher-suites=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA

# 新增后的成果如下(不截图了,减少了行号显示用来辨别)46     - --tls-cert-file=/etc/kubernetes/pki/apiserver.crt
47     - --tls-private-key-file=/etc/kubernetes/pki/apiserver.key
48     - --tls-cipher-suites=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_        256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA
  1. 重启 kube-apiserver:

不须要手动重启,因为是动态 Pod,Kubernetes 会主动重启。

  1. 验证破绽:
# 执行扫描命令
nmap --script ssl-enum-ciphers -p 6443 192.168.9.91

# 输入后果如下
Starting Nmap 7.93 (https://nmap.org) at 2023-02-14 09:22 CST
Nmap scan report for ks-k8s-master-0 (192.168.9.91)
Host is up (0.00015s latency).

PORT     STATE SERVICE
6443/tcp open  sun-sr-https
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (secp256r1) - A
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
|       TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
|     compressors:
|       NULL
|     cipher preference: server
|   TLSv1.3:
|     ciphers:
|       TLS_AKE_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
|       TLS_AKE_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
|       TLS_AKE_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
|     cipher preference: server
|_  least strength: A

Nmap done: 1 IP address (1 host up) scanned in 0.68 seconds

留神:比照之前的破绽告警信息,扫描后果中曾经不存在 64-bit block cipher 3DES vulnerable to SWEET32 attack,阐明修复胜利。

修复 kube-controller

  1. 编辑 kube-controller 配置文件 /etc/kubernetes/manifests/kube-controller-manager.yaml
# 新增配置(在原文件 33 行前面减少一行)
- --tls-cipher-suites=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA

# 新增后的成果如下(不截图了,减少了行号显示用来辨别)33     - --use-service-account-credentials=true
34     - --tls-cipher-suites=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_        256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA
  1. 重启 kube-controller:

不须要手动重启,因为是动态 Pod,Kubernetes 会主动重启。

  1. 验证破绽:
# 执行残缺扫描命令
nmap --script ssl-enum-ciphers -p 10257 192.168.9.91

# 为了节俭篇幅,残缺输入后果略, 理论后果与 kube-apiserver 的统一

# 能够执行过滤输入的扫描命令,如果以下命令返回值为空,阐明破绽修复
nmap --script ssl-enum-ciphers -p 10257 192.168.9.91 | grep SWEET32

留神:比照之前的破绽告警信息,扫描后果中曾经不存在 64-bit block cipher 3DES vulnerable to SWEET32 attack,阐明修复胜利。

修复 kube-scheduler

  1. 编辑 kube-scheduler 配置文件 /etc/kubernetes/manifests/kube-scheduler.yaml
# 新增配置(在原文件 19 行前面减少一行)
- --tls-cipher-suites=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA

# 新增后的成果如下(不截图了,减少了行号显示用来辨别)19     - --leader-elect=true
20     - --tls-cipher-suites=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_  256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA
  1. 重启 kube-scheduler:

不须要手动重启,因为是动态 Pod,Kubernetes 会主动重启。

  1. 验证破绽:
# 执行残缺扫描命令
nmap --script ssl-enum-ciphers -p 10259 192.168.9.91

# 为了节俭篇幅,残缺输入后果略, 理论后果与 kube-apiserver 的统一

# 能够执行过滤输入的扫描命令,如果以下命令返回值为空,阐明破绽修复
nmap --script ssl-enum-ciphers -p 10259 192.168.9.91 | grep SWEET32

留神:比照之前的破绽告警信息,扫描后果中曾经不存在 64-bit block cipher 3DES vulnerable to SWEET32 attack,阐明修复胜利。

修复 kubelet

  1. 编辑 kubelet 配置文件 /var/lib/kubelet/config.yaml
# 在配置文件最初增加
tlsCipherSuites: [TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_  256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA]

提醒:更多的 cipher suites 配置,请参考 Kubernetes 官网文档。

  1. 重启 kubelet:
systemctl restart kubelet

重启有危险,操作需谨慎!

  1. 验证破绽:
# 执行残缺扫描命令
nmap --script ssl-enum-ciphers -p 10250 192.168.9.91

# 为了节俭篇幅,残缺输入后果略, 理论后果与 kube-apiserver 的统一

# 能够执行过滤输入的扫描命令,如果以下命令返回值为空,阐明破绽修复
nmap --script ssl-enum-ciphers -p 10250 192.168.9.91 | grep SWEET32

留神:比照之前的破绽告警信息,扫描后果中曾经不存在 64-bit block cipher 3DES vulnerable to SWEET32 attack,阐明修复胜利。

常见问题

Etcd 启动失败

报错信息:

Feb 13 16:17:41 ks-k8s-master-0 Etcd: Etcd Version: 3.4.13
Feb 13 16:17:41 ks-k8s-master-0 Etcd: Git SHA: ae9734ed2
Feb 13 16:17:41 ks-k8s-master-0 Etcd: Go Version: go1.12.17
Feb 13 16:17:41 ks-k8s-master-0 Etcd: Go OS/Arch: linux/amd64
Feb 13 16:17:41 ks-k8s-master-0 Etcd: setting maximum number of CPUs to 4, total number of available CPUs is 4
Feb 13 16:17:41 ks-k8s-master-0 Etcd: the server is already initialized as member before, starting as Etcd member...
Feb 13 16:17:41 ks-k8s-master-0 Etcd: unexpected TLS cipher suite "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256"
Feb 13 16:17:42 ks-k8s-master-0 systemd: Etcd.service: main process exited, code=exited, status=1/FAILURE
Feb 13 16:17:42 ks-k8s-master-0 systemd: Failed to start Etcd.
Feb 13 16:17:42 ks-k8s-master-0 systemd: Unit Etcd.service entered failed state.
Feb 13 16:17:42 ks-k8s-master-0 systemd: Etcd.service failed.

解决方案:

删除配置文件中的 TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 字段,至于起因没有深入研究。

Etcd 服务一直重启

报错信息 (省略掉了一部分):

批改配置文件后,重新启动 Etcd,启动的时候命令执行没有报错。然而,启动后查看 status 有异样,且 /var/log/messages 中有如下信息

Feb 13 16:25:55 ks-k8s-master-0 systemd: Etcd.service holdoff time over, scheduling restart.
Feb 13 16:25:55 ks-k8s-master-0 systemd: Stopped Etcd.
Feb 13 16:25:55 ks-k8s-master-0 systemd: Starting Etcd...
Feb 13 16:25:55 ks-k8s-master-0 Etcd: recognized and used environment variable ETCD_ADVERTISE_CLIENT_URLS=https://192.168.9.91:2379
Feb 13 16:25:55 ks-k8s-master-0 Etcd: [WARNING] Deprecated '--logger=capnslog' flag is set; use '--logger=zap' flag instead
Feb 13 16:25:55 ks-k8s-master-0 Etcd: [WARNING] Deprecated '--logger=capnslog' flag is set; use '--logger=zap' flag instead
Feb 13 16:25:55 ks-k8s-master-0 Etcd: recognized and used environment variable ETCD_AUTO_COMPACTION_RETENTION=8
.....(省略)Feb 13 16:25:58 ks-k8s-master-0 systemd: Started Etcd.
Feb 13 16:25:58 ks-k8s-master-0 Etcd: serving client requests on 192.168.9.91:2379
Feb 13 16:25:58 ks-k8s-master-0 Etcd: serving client requests on 127.0.0.1:2379
Feb 13 16:25:58 ks-k8s-master-0 Etcd: accept tcp 127.0.0.1:2379: use of closed network connection
Feb 13 16:25:58 ks-k8s-master-0 systemd: Etcd.service: main process exited, code=exited, status=1/FAILURE
Feb 13 16:25:58 ks-k8s-master-0 systemd: Unit Etcd.service entered failed state.
Feb 13 16:25:58 ks-k8s-master-0 systemd: Etcd.service failed.

解决方案:

在理论测试中遇到了两种场景都产生了相似下面的报错信息:

第一种,在多节点 Etcd 环境中,须要先批改所有节点的 Etcd 配置文件,而后,同时重启所有节点的 Etcd 服务。

第二种,Etc Cipher 参数程序问题,一直尝试确认了最终程序后(具体配置参考注释),重复重启的问题没有再现。

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