一、Openssh简介

OpenSSH是SSH（Secure SHell）协议的免费开源实现。SSH协议族可以用来进行远程控制， 或在计算机之间传送文件。而实现此功能的传统方式，如telnet(终端仿真协议)、rcp ftp、rlogin、rsh都是极为不安全的，并且会使用明文传送密码。OpenSSH提供了服务端后台程序和客户端工具，用来加密远程控制和文件传输过程中的数据，并由此来代替原来的类似服务。

二、系统环境

1、查看openssl版本

[root@localhost ~]# openssl version

OpenSSL 1.0.2k-fips 26 Jan 2017

2、查看操作系统版本

[root@localhost ~]# cat /etc/redhat-release

CentOS Linux release 7.9.2009 (Core)

3、查看openssh版本

[root@localhost ~]# ssh -V

OpenSSH_7.4p1, OpenSSL 1.0.2k-fips 26 Jan 2017

4、安装编译器

[root@localhost ~]# yum -y install gcc gcc-c++

5、软件下载地址

官方下载地址：http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable

官方下载地址：https://www.openssl.org

官方下载地址：http://www.zlib.net

三、安装zlib

1、下载zlib安装包

[root@localhost ~]# wget http://www.zlib.net/zlib-1.2.13.tar.gz

2、解压

[root@localhost ~]# tar xf zlib-1.2.13.tar.gz

3、编译及安装

[root@localhost ~]# cd zlib-1.2.13

[root@localhost zlib-1.2.13]# ./configure --prefix=/usr/local/zlib

[root@localhost zlib-1.2.13]# make && make install

4、配置动态库

[root@localhost zlib-1.2.13]# echo '/usr/local/zlib/lib' >> /etc/ld.so.conf

[root@localhost zlib-1.2.13]# ldconfig -v

四、安装openssl

1、下载openssl安装包

[root@localhost ~]# wget https://www.openssl.org/source/old/1.1.1/openssl-1.1.1p.tar.gz

2、解压

[root@localhost ~]# tar xf openssl-1.1.1p.tar.gz

3、编译及安装

[root@localhost ~]# cd openssl-1.1.1p

[root@localhost openssl-1.1.1p]# ./config --prefix=/usr/local/openssl -d shared

[root@localhost openssl-1.1.1p]# make && make install

4、配置动态库

[root@localhost openssl-1.1.1p]# echo '/usr/local/openssl/lib' >> /etc/ld.so.conf

[root@localhost openssl-1.1.1p]# ldconfig -v

五、卸载旧版本openssh

1、备份原有文件

[root@localhost openssh-9.0p1]# mv /etc/ssh/sshd_config /etc/ssh/sshd_config.bak

[root@localhost openssh-9.0p1]# mv /usr/sbin/sshd /usr/sbin/sshd.bak

[root@localhost openssh-9.0p1]# mv /usr/bin/ssh /usr/bin/ssh.bak

[root@localhost openssh-9.0p1]# mv /usr/bin/ssh-keygen /usr/bin/ssh-keygen.bak

[root@localhost openssh-9.0p1]# mv /etc/ssh/ssh_host_ecdsa_key.pub /etc/ssh/ssh_host_ecdsa_key.pub.bak

[root@localhost openssh-9.0p1]# mv /usr/bin/openssl /usr/bin/openssl.bak

2、卸载openssh

[root@localhost openssl-1.1.1p]# rpm -qa |grep openssh

openssh-server-7.4p1-21.el7.x86_64

openssh-clients-7.4p1-21.el7.x86_64

openssh-7.4p1-21.el7.x86_64

[root@localhost openssl-1.1.1p]# rpm -qa |grep openssh |xargs rpm -e --nodeps

[root@localhost openssl-1.1.1p]# rpm -qa |grep openssh

查看是否卸载完成，确认没有显示就是卸载成功

六、安装openssh

1、下载openssh安装包

[root@localhost ~]# wget http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-9.0p1.tar.gz

2、解压

[root@localhost ~]# tar xf openssh-9.0p1.tar.gz

3、编译及安装

[root@localhost ~]# cd openssh-9.0p1

[root@localhost openssh-9.0p1]# ./configure --prefix=/usr/local/openssh --with-zlib=/usr/local/zlib --with-ssl-dir=/usr/local/openssl

[root@localhost openssh-9.0p1]# make && make install

4、配置sshd_config文件

[root@localhost openssh-9.0p1]# echo 'UseDNS no' >> /usr/local/openssh/etc/sshd_config

[root@localhost openssh-9.0p1]# echo 'PermitRootLogin yes' >>/usr/local/openssh/etc/sshd_config

[root@localhost openssh-9.0p1]# echo 'PubkeyAuthentication yes' >>/usr/local/openssh/etc/sshd_config

[root@localhost openssh-9.0p1]# echo 'PasswordAuthentication yes' >>/usr/local/openssh/etc/sshd_config

5、拷贝新的配置复制到指定目录

[root@localhost openssh-9.0p1]# cp /usr/local/openssh/etc/sshd_config /etc/ssh/sshd_config

[root@localhost openssh-9.0p1]# cp /usr/local/openssh/sbin/sshd /usr/sbin/sshd

[root@localhost openssh-9.0p1]# cp /usr/local/openssh/bin/ssh /usr/bin/ssh

[root@localhost openssh-9.0p1]# cp /usr/local/openssh/bin/ssh-keygen /usr/bin/ssh-keygen

[root@localhost openssh-9.0p1]# cp /usr/local/openssh/etc/ssh_host_ecdsa_key.pub /etc/ssh/ssh_host_ecdsa_key.pub

[root@localhost openssh-9.0p1]# cp /usr/local/openssl/bin/openssl /usr/bin/openssl

6、配置sshd开机自启动

[root@localhost openssh-9.0p1]# cp -p contrib/redhat/sshd.init /etc/init.d/sshd

[root@localhost openssh-9.0p1]# chkconfig --add sshd

[root@localhost openssh-9.0p1]# chkconfig sshd on

7、重启sshd

[root@localhost openssh-9.0p1]# systemctl restart sshd

[root@localhost openssh-9.0p1]# systemctl status sshd

七、验证

1、验证ssh版本

[root@localhost openssh-9.0p1]# ssh -V

OpenSSH_9.0p1, OpenSSL 1.1.1p 21 Jun 2022

2、重启服务，测试ssh连接

[root@localhost openssh-9.0p1]# reboot

3、xshell连接ssh测试

[D:\~]$ ssh root@172.16.80.198

Connecting to 172.16.80.198:22...

Connection established.

To escape to local shell, press 'Ctrl+Alt+]'.

WARNING! The remote SSH server rejected X11 forwarding request.

Last login: Tue Dec 13 17:23:47 2022 from 172.16.80.84

[root@localhost ~]# ssh -V

OpenSSH_9.0p1, OpenSSL 1.1.1p 21 Jun 2022
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