查询是否安装telnet
# rpm -qa | grep telnet
telnet-server-0.17-31.EL4.5
telnet-0.17-31.EL4.5
打开telnet服务
修改设置文件/etc/xinetd.d/telnet中disable字段改为no。
启动服务#ntsysv或#service xinetd restart。
创建登陆用户
因为不能直接root telnet登陆,所以创建一个登陆用户.安转完成后可以把该用户删除
useradd opensshinstall
(删除用户及/home/sshinstall目录 userdel -r sshinstall 删除这个用户的组groupdel sshinstall)
安装源文件在/usr/local/src目录下
zlib和openssl安装在/usr/local目录下
安装zlib-1.2.5
#tar -zxvf zlib-1.2.5.tar.gz
#cd zlib-1.2.5
#./configure --prefix=/usr/local/zlib-1.2.5 -share
#make
#make test
#make install
cp libz.a /usr/local/zlib-1.2.5/lib
cp libz.so.1.2.5 /usr/local/zlib-1.2.5/lib
cd /usr/local/zlib-1.2.5/lib; chmod u=rw,go=r libz.a
cp zlib.3 /usr/local/zlib-1.2.5/share/man/man3
chmod 644 /usr/local/zlib-1.2.5/share/man/man3/zlib.3
cp zlib.pc /usr/local/zlib-1.2.5/lib/pkgconfig
chmod 644 /usr/local/zlib-1.2.5/lib/pkgconfig/zlib.pc
cp zlib.h zconf.h /usr/local/zlib-1.2.5/include
chmod 644 /usr/local/zlib-1.2.5/include/zlib.h /usr/local/zlib-1.2.5/include/zconf.h
#vi /etc/ld.so.conf 配置库文件搜索路径
include ld.so.conf.d/*.conf
##add 2010.7.7
/usr/local/zlib-1.2.5/lib
##add end
#ldconfig -v 刷新缓存文件/etc/ld.so.cache
#ln -s /usr/local/zlib-1.2.5 /usr/local/zlib
安装openssl
#cd /usr/local/src
#tar zxvf openssl-1.0.0a.tar.gz
#cd openssl-1.0.0a
#./config shared zlib-dynamic --prefix=/usr/local/openssl-1.0.0a --with-zlib-lib=/usr/local/zlib-1.2.5/lib --with-zlib-include=/usr/local/zlib-1.2.5/include
#make
#make test （这一步是进行 SSL 加密协议的完整测试，如果出现错误就要一定先找出原因，否则一味继续可能导致 SSH 不能使用！）
#make install
#vi /etc/ld.so.conf 配置库文件搜索路径
############################################
## add below line to ld.so.conf
/usr/local/openssl-1.0.0a/lib 64位OS 没有生成lib目录，是lib64目录
############################################
#ldconfig -v 刷新缓存文件/etc/ld.so.cache
#ln -s /usr/local/openssl-1.0.0a /usr/local/openssl
vi /etc/profile
###########################################
(add to end of the file)
PATH=/usr/local/openssl/bin:$PATH
export PATH
###########################################
退出，再登录，查看openssl的版本号，以验正是否安装正确
#openssl version -a
OpenSSL 1.0.0a 1 Jun 2010
built on: Wed Jul 7 17:08:07 CST 2010
platform. linux-x86_64
options: bn(64,64) rc4(1x,char) des(idx,cisc,16,int) idea(int) blowfish(idx)
compiler: gcc -fPIC -DOPENSSL_PIC -DZLIB_SHARED -DZLIB -DOPENSSL_THREADS -D_REENTRANT -DDSO_DLFCN -DHAVE_DLFCN_H -m64 -DL_ENDIAN -DTERMIO -O3 -Wall -DMD32_REG_T=int -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DMD5_ASM -DAES_ASM -DWHIRLPOOL_ASM
OPENSSLDIR: "/usr/local/openssl-1.0.0a/ssl"
停止并卸载Openssh
1.停止OpenSSH服务
#service sshd stop
2. 查询并卸载openssh
# rpm -qa | grep openssh
openssh-3.9p1-8.RHEL4.24
openssh-askpass-3.9p1-8.RHEL4.24
openssh-clients-3.9p1-8.RHEL4.24
openssh-server-3.9p1-8.RHEL4.24
openssh-askpass-gnome-3.9p1-8.RHEL4.24
#rpm -e openssh-3.9p1-8.RHEL4.24 --nodeps
#rpm -e openssh-clients-3.9p1-8.RHEL4.24 --nodeps
警告/etc/ssh/ssh_config 已存为 /etc/ssh/ssh_config.rpmsave
#rpm -e openssh-askpass-3.9p1-8.RHEL4.24
#rpm -e openssh-server-3.9p1-8.RHEL4.24 --nodeps
#rpm -e openssh-askpass-gnome-3.9p1-8.RHEL4.24
cd /usr/local/src
tar zxvf openssh-5.5p1.tar.gz
cd openssh-5.5p1
./configure --prefix=/usr --sysconfdir=/etc/ssh --with-pam --with-ssl-dir=/usr/local/openssl-1.0.0a --with-md5-passwords --mandir=/usr/share/man --with-zlib=/usr/local/zlib-1.2.5
#make
#make install
#
将sshd加入启动服务:
进入ssh安装解压目录
#cp ./contrib/redhat/sshd.init /etc/init.d/sshd
#chmod +x /etc/init.d/sshd
#chkconfig --add sshd
最后，启动 SSH 服务使修改生效：
# service sshd start
重启后确认一下当前的 OpenSSH 和 OpenSSL 是否正确：
# ssh -v
如果看到了新的版本号就没问题啦！
关闭telnet服务
修改设置文件/etc/xinetd.d/telnet中disable字段改为yes。
启动服务#ntsysv或#service xinetd restart。
注意问题
1.在安装openssh, ./configure 时，报下面错误：
configure: error: PAM headers not found
运行# rpm -qa | grep pam
pam_smb-1.1.7-5
pam_ccreds-1-3
pam_passwdqc-0.7.5-2
pam-0.77-66.17
pam_krb5-2.1.8-1
spamassassin-3.0.6-1.el4
发现有 pam-0.77-66.17，从网上找到 pam-devel-0.77-66.17.i386.rpm，
运行rpm -ivh pam-devel-0.77-66.17.i386.rpm后，./configure正常
版本号0.77-66.17必须一样。
2.在安装openssh时,configure报错:
./configure --prefix=/usr --sysconfdir=/etc/ssh --with-pam --with-zlib --with-ssl-dir=/usr/include/openssl --with-md5-passwords --mandir=/usr/share/man
.....
configure: error: *** zlib too old - check config.log ***
Your reported zlib version has known security problems. It's possible your
vendor has fixed these problems without changing the version number. If you
are sure this is the case, you can disable the check by running
"./configure --without-zlib-version-check".
If you are in doubt, upgrade zlib to version 1.2.3 or greater.
See http://www.gzip.org/zlib/ for details.
因此需要升级zlib.
3.如果操作系统是64位的，openssl-1.0.0a只生成了lib64，没有生成lib目录。openssh configure时，还是连接的老版本的openssl,郁闷。
4. ./configure显示信息：
./configure --prefix=/usr --sysconfdir=/etc/ssh --with-pam --with-ssl-dir=/usr/local/openssl-1.0.0a --with-md5-passwords --mandir=/usr/share/man --with-zlib=/usr/local/zlib-1.2.5
显示信息：
OpenSSH has been configured with the following options:
User binaries: /usr/bin
System binaries: /usr/sbin
Configuration files: /etc/ssh
Askpass program: /usr/libexec/ssh-askpass
Manual pages: /usr/share/man/manX
PID file: /var/run
Privilege separation chroot path: /var/empty
sshd default user PATH: /usr/bin:/bin:/usr/sbin:/sbin
Manpage format: doc
PAM support: yes
OSF SIA support: no
KerberosV support: no
SELinux support: no
Smartcard support:
S/KEY support: no
TCP Wrappers support: no
MD5 password support: yes
libedit support: no
Solaris process contract support: no
IP address in $DISPLAY hack: no
Translate v4 in v6 hack: yes
BSD Auth support: no
Random number source: OpenSSL internal ONLY
Host: i686-pc-linux-gnu
Compiler: gcc
Compiler flags: -g -O2 -Wall -Wpointer-arith -Wuninitialized -Wsign-compare -Wformat-security -fno-builtin-memset -std=gnu99
Preprocessor flags: -I/usr/local/openssl-1.0.0a/include -I/usr/local/zlib-1.2.5/include
Linker flags: -L/usr/local/openssl-1.0.0a/lib -L/usr/local/zlib-1.2.5/lib
Libraries: -lresolv -lcrypto -ldl -lutil -lz -lnsl -lcrypt
+for sshd: -lpam
PAM is enabled. You may need to install a PAM control file
for sshd, otherwise password authentication may fail.
Example PAM control files can be found in the contrib/
subdirectory