【完美升级Openssh】redhat 6.8 x64升级SSH到OpenSSH_7.4p1

# ssh -V
# rpm -qa zlib
# openssl version

# vim /etc/fstab
/mnt/rhel-server-6.8-x86_64-dvd.iso /media/RedHat-6.8-x86_64-DVD iso9660 loop   0   0

# vim /etc/yum.repos.d/rhel-6.8-media.repo

[RedHat-6.8-Media]
name=Red Hat Enterprise Linux $releasever - $basearch -Media
baseurl=file://media/RedHat-6.8-x86_64-DVD
enabled=1
gpgcheck=0
gpgkey=file://media/RedHat-6.8-x86_64-DVD/RPM-GPG-KEY-redhat-release

# mount /media/RedHat-6.8-x86_64-DVD

# yum安装telnet
# yum -y install telnet-server*

# 先关闭防火墙，否则telnet可能无法连接
# service iptables stop
# chkconfig iptables off

# 编译/etc/xinetd.d/telnet，来启动telnet服务
# vim /etc/xinetd.d/telnet
disable值变更：  （yes ----> no）

# 允许root用户通过telnet登录
# mv /etc/securetty /etc/securetty.old 
  
# 启动telnet服务
# service xinetd start 

# 设置telnet服务开机启动              
# chkconfig xinetd on    

# telnet登录验证                
# telnet x.x.x.x
        

# yum  install gcc pam-devel zlib-devel -y

# tar -zxvf zlib-1.2.11.tar.gz
# cd zlib-1.2.11
# ./configure --prefix=/usr
# make
# 注意：此处需要卸载当前zlib（必须按顺序操作，lib64下涉及的模块丢失）
# rpm -e --nodeps zlib
# make install

# 共享库文件注册到系统
# echo ‘/usr/lib‘ >> /etc/ld.so.conf
# 更新共享库cache
# ldconfig                   

# 备份当前的openssl
# mv  /usr/lib64/openssl /usr/lib64/openssl.old
# mv  /usr/bin/openssl  /usr/bin/openssl.old
# mv  /etc/pki/ca-trust/extracted/openssl  /etc/pki/ca-trust/extracted/openssl.old

#如下两个库文件必须先备份，因系统内部分工具（如yum、wget等）依赖此库，而新版OpenSSL不包含这两个库
# cp  /usr/lib64/libcrypto.so.10  /usr/lib64/libcrypto.so.10.old
# cp  /usr/lib64/libssl.so.10  /usr/lib64/libssl.so.10.old

# 卸载但钱openssl
# rpm -qa |grep openssl|xargs -i rpm -e --nodeps {}

# 安装openssl
# tar -zxvf openssl-1.0.2k.tar.gz
# cd openssl-1.0.2k
# 必须加上--shared，否则编译时会因找不到新安装的openssl的类库而报错
# ./config --prefix=/usr/local/ssl --openssldir=/etc/ssl --shared zlib  
# make
# make test                           
# make install
# 验证
# openssl version -a     

# 恢复共享库
# mv  /usr/lib64/libcrypto.so.10.old  /usr/lib64/libcrypto.so.10
# mv  /usr/lib64/libssl.so.10.old  /usr/lib64/libssl.so.10              

# 备份当前openssh
# mv /etc/ssh /etc/ssh.old

# 卸载当前openssh
# 查看已安装的openssh
# rpm -qa | grep openssh

# 删除
# rpm -qa |grep openssh|xargs -i rpm -e --nodeps {}

# openssh安装前环境配置 （要保证这里的命令都能执行正确）
# install  -v -m700 -d /var/lib/sshd
# chown  -v root:sys /var/lib/sshd
# groupadd -g 51 sshd
# useradd  -c ‘sshd PrivSep‘ -d /var/lib/sshd -g sshd -s /bin/false -u 51 sshd

# openssh_7.4p1源码安装
# tar -zxvf openssh-7.4p1.tar.gz
# cd openssh-7.4p1
# 关联的检查配置项要特别注意
# ./configure --prefix=/usr  --sysconfdir=/etc/ssh  --with-md5-passwords  --with-pam  --with-zlib --with-ssl-dir=/usr/local/ssl --with-privsep-path=/var/lib/sshd
# make
# make install

# openssh安装后环境配置
# install -v -m755    contrib/ssh-copy-id /usr/bin
# install -v -m644    contrib/ssh-copy-id.1 /usr/share/man/man1
# install -v -m755 -d /usr/share/doc/openssh-7.4p1
# install -v -m644    INSTALL LICENCE OVERVIEW README* /usr/share/doc/openssh-7.4p1

#验证是否升级成功
# ssh -V   

# 启动openssh服务
# echo ‘X11Forwarding yes‘ >> /etc/ssh/sshd_config
# 配置允许root用户通过ssh登录
# echo "PermitRootLogin yes" >> /etc/ssh/sshd_config  
# cp -p contrib/redhat/sshd.init /etc/init.d/sshd
# chmod +x /etc/init.d/sshd
# chkconfig  --add  sshd
# chkconfig  sshd  on
# chkconfig  --list  sshd
#注意：ssh连接会因重启openssh断开
# service sshd restart
# 此时需要通过telnet登入再执行sshd服务重启命令
# telnet x.x.x.x
# service sshd restart

# 整理操作前备份
# mv /etc/securetty.old /etc/securetty
# chkconfig  xinetd off
# service xinetd stop
#如有必要，可重新开启防火墙
# service iptables start
# chkconfig iptables on

# 如需要还原操作前的ssh配置信息，可直接删除升级后的配置信息（不想修复的，请忽略）
# rm -rf /etc/ssh
# mv /etc/ssh.old /etc/ssh

# （如有必要）最后可以重新配置主机间的ssh互信