服务器间通过ssh使用密钥对实现无密码登录solaris,redhat,linux

yuhuohu

受flutter的启发，把bigadmin上的文档完善并简化一下,非常简单。

E文原址：http://www.sun.com/bigadmin/content/submitted/ssh_setting.html

关键词：ssh 密钥 无密码登录 信任关系

                                以下做法在solaris 10 u5,redhat as 5.0上测试通过。2008.07.24更新.

【概述】

如果你（A机）想无密码ssh登录别的机器（B机），只需要完成3个步骤:

• A机生成密钥对
• 把公钥传给B机
• B机对A机的公钥授权

哥们，看帖要推荐啊，点这里


hosta和hostb都必须同步完成以下操作,以hosta为例

提示：如果没有.ssh目录可用ssh命令远程登录一下任意机器再退出即可，或者手工创建一个:
mkdir .ssh;chmod 755 .ssh

注意，如果按下列步骤完成后，ssh依然需要输入密码，那么请设置.ssh目录权限为755，authorized_keys*的权限为600

================================================================
1、创建密钥对，两台都做
[root@hosta /]# who am i
root     pts/1        2008-04-30 12:08 (172.16.10.220)
[root@hosta /]# cd ~/.ssh  ----------------------没有这个目录的话，你随便ssh登录一下其他机器，就有了
[root@hosta .ssh]# ssh-keygen -t dsa
Generating public/private dsa key pair.
Enter file in which to save the key (/root/.ssh/id_dsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_dsa.                              -------私钥名一定要叫id_dsa
Your public key has been saved in /root/.ssh/id_dsa.pub.
The key fingerprint is:
0a:13:25:19:a2:59:2c:b1:49:e6:62:90:57:07:e5:f7 root@hosta

passphrase(密钥保护) 保留为空，否则使用ssh时将要求输入passphrase(密钥保护)

2、发布公钥和获取公钥
[root@hosta .ssh]# scp id_dsa.pub hostb:/root/.ssh/hosta.key.pub
root@hostb's password:
id_dsa.pub                                            100%  600     0.6KB/s   00:00   
[root@hosta .ssh]# scp hostb:/root/.ssh/id_dsa.pub /root/.ssh/hostb.key.pub
root@hostb's password:
id_dsa.pub                                            100%  600     0.6KB/s   00:00   

3、对公钥授权两台都做
[root@hostb .ssh]# cat hosta.key.pub >>authorized_keys2                 -----对A机公钥授权,A机用私钥来登录B机
[root@hostb .ssh]# cat id_dsa.pub >>authorized_keys2                      -----可选项，本机登录本机，可不配置

如果是ssh v1版本，比如solaris 9，就使用authorized_keys文件

4、使用密钥对登录
[root@hosta .ssh]# ssh hostb
Last login: Sun Apr 27 00:04:49 2008 from 172.16.10.220

已经不用输入密码:" />:" />lol

[root@hostb ~]# exit
logout
Connection to hostb closed.

5、查看日志
[root@hosta .ssh]# more /var/log/secure
Apr 27 10:26:47 hosta sshd[9309]: Accepted password for root from 172.16.10.220 port 239
5 ssh2
Apr 27 10:26:47 hosta sshd[9309]: pam_unix(sshd:session): session opened for user root b
y (uid=0)
Apr 27 10:41:51 hosta sshd[12195]: Accepted password for root from 172.16.10.220 port 24
08 ssh2
Apr 27 10:41:51 hosta sshd[12195]: pam_unix(sshd:session): session opened for user root
by (uid=0)
Apr 27 12:42:15 hosta sshd[3331]: pam_unix(sshd:session): session closed for user root
Apr 27 13:08:32 hosta sshd[26563]: Accepted password for root from 172.16.10.2 port 4324
7 ssh2
Apr 27 13:08:32 hosta sshd[26563]: pam_unix(sshd:session): session opened for user root
by (uid=0)
Apr 27 13:08:33 hosta sshd[26563]: pam_unix(sshd:session): session closed for user root
Apr 27 13:08:52 hosta sshd[26607]: Accepted password for root from 172.16.10.2 port 4324
8 ssh2
Apr 27 13:08:52 hosta sshd[26607]: pam_unix(sshd:session): session opened for user root
by (uid=0)
Apr 27 13:08:52 hosta sshd[26607]: pam_unix(sshd:session): session closed for user root
Apr 27 13:09:15 hosta sshd[26658]: Accepted password for root from 172.16.10.2 port 4324
9 ssh2
Apr 27 13:09:15 hosta sshd[26658]: pam_unix(sshd:session): session opened for user root
by (uid=0)
Apr 27 13:09:15 hosta sshd[26658]: pam_unix(sshd:session): session closed for user root
Apr 27 13:09:25 hosta sshd[26689]: Accepted password for root from 172.16.10.2 port 4325
0 ssh2
Apr 27 13:09:25 hosta sshd[26689]: pam_unix(sshd:session): session opened for user root
by (uid=0)
Apr 27 13:09:25 hosta sshd[26689]: pam_unix(sshd:session): session closed for user root
Apr 27 13:51:27 hosta sshd[29770]: Accepted password for root from 172.16.10.220 port 4248 ssh2
Apr 27 13:51:27 hosta sshd[29770]: pam_unix(sshd:session): session opened for user root by (uid=0)
Apr 27 13:53:54 hosta sshd[29770]: pam_unix(sshd:session): session closed for user root
Apr 27 15:13:48 hosta sshd[9309]: pam_unix(sshd:session): session closed for user root
Apr 27 15:22:20 hosta sshd[12195]: pam_unix(sshd:session): session closed for user root
Apr 27 23:37:48 hosta sshd[7798]: Accepted password for root from 172.16.10.220 port 4948 ssh2
Apr 27 23:37:48 hosta sshd[7798]: pam_unix(sshd:session): session opened for user root by (uid=0)
Apr 28 04:30:58 hosta sshd[7798]: pam_unix(sshd:session): session closed for user root
Apr 30 12:08:32 hosta sshd[15039]: Accepted password for root from 172.16.10.220 port 1637 ssh2
Apr 30 12:08:32 hosta sshd[15039]: pam_unix(sshd:session): session opened for user root by (uid=0)
Apr 30 12:11:05 hosta useradd[15282]: new group: name=mysql, GID=503
Apr 30 12:11:05 hosta useradd[15282]: new user: name=mysql, UID=503, GID=503, home=/home/mysql, shell=/bin/bash
Apr 30 12:22:18 hosta sshd[16164]: Accepted password for root from 172.16.10.2 port 47224 ssh2
Apr 30 12:22:18 hosta sshd[16164]: pam_unix(sshd:session): session opened for user root by (uid=0)
Apr 30 12:22:18 hosta sshd[16164]: pam_unix(sshd:session): session closed for user root

6、查看ssh的详细操作记录(ssh -v, scp -v or sftp -v ...)
[root@hosta .ssh]# scp -v /root/install.log hostb:/root
Executing: program /usr/bin/ssh host hostb, user (unspecified), command scp -v -t /root
OpenSSH_4.3p2, OpenSSL 0.9.8b 04 May 2006
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to hostb [172.16.10.2] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_dsa type 2
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3
debug1: match: OpenSSH_4.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.3
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'hostb' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:2
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure.  Minor code may provide more information
No credentials cache found

debug1: Unspecified GSS failure.  Minor code may provide more information
No credentials cache found

debug1: Unspecified GSS failure.  Minor code may provide more information
No credentials cache found

debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/identity
debug1: Trying private key: /root/.ssh/id_rsa
debug1: Offering public key: /root/.ssh/id_dsa
debug1: Server accepts key: pkalg ssh-dss blen 433
debug1: read PEM private key done: type DSA
debug1: Authentication succeeded (publickey).
debug1: channel 0: new [client-session]
debug1: Entering interactive session.
debug1: Sending environment.
debug1: Sending env LANG = zh_CN.GB18030
debug1: Sending command: scp -v -t /root
Sending file modes: C0644 35582 install.log
Sink: C0644 35582 install.log
install.log                                                             100%   35KB  34.8KB/s   00:00   
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug1: channel 0: free: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
debug1: Transferred: stdin 0, stdout 0, stderr 0 bytes in 0.2 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0
debug1: Exit status 0

[ 本帖最后由 yuhuohu 于 2009-7-4 20:29 编辑 ]

flutter

呵呵，向斑斑致敬，这么快就整理出来了，网上的帖子都是缺少第2步，第3步用的也是SSH1的文件，导致很多人不成功，包括偶。

   斑斑为大家开路铺石，值得敬佩。

steedz

呵呵，这个我也经常做，补充一些：
不只是root用户，如果两个联网的主机，test1用户在主机A1上，另一台主机A2，要想实现test1登陆A2时不用敲密码直接登陆，即建立信任关系:
在A1上使用test1用户键入：ssh-keygen -t dsa
然后：scp /home/test1/.ssh/id_dsa.pub  A2_ip_address:/home/test1/.ssh/id_dsa.pub_bak
最后在A2上：cd /home/test1/.ssh
cat id_dsa.pub_bak >>  authorized_keys
就OK了。
当然A2上的用户不一定非要test1，其它的也可以，但是相同用户比较多见。

flutter

LZ上，你这个办法好象不行了，网上的帖子都跟你写的一样，可就是通过不了，需要密码的，我看了N个帖子，都跟你写的一样，后来看了SUN文章，才发现多了第2步，第3步的文件也不一样了，SSH1和SSH2的文件不一样了。

steedz

我在Solaris10上经常做，没有问题呀，可以的。

nicsky

不错，Solaris10   ok..............

风之幻想

收藏了.顶.

emcc-83

环境：hosta访问hostb不用密码
配置前，请先确定此用户可以使用密码登录远程主机！

以下操作在hosta上完成
1、创建密钥对
[root@hosta /]# who am i

[root@hosta /]# cd ~/.ssh
[root@hosta .ssh]# ssh-keygen -t dsa #使用DSA算法，当然你可以可以使用RSA

一路回车

注意：passphrase(密钥保护) 保留为空，否则使用ssh时将要求输入passphrase(密钥保护)

2、发布公钥

[root@hosta .ssh]# scp id_dsa.pub hostb:/root/.ssh/hosta.key.pub #发布公钥到主机B上

以下操作在hostb上完成
3、对公钥授权
[root@hostb .ssh]# cat hosta.key.pub >> authorized_keys2

切记：chmod 600 authorized_keys2

如果是ssh v1版本,就使用authorized_keys文件

4、使用密钥对登录
[root@hosta .ssh]# ssh hostb

已经不用输入密码了：）

ps：在配置过程中如果出现问题，请查看/var/log/secure

想要hostb能访问hosta 在对应机器上再做一遍上面的步骤就可以啦！

openth

好像，在哪文件里，写入主机名、用户名后。用SSH，就不用密码了。但，要求，服务器必须有这个用户名。具体是哪个文件里，呵呵。忘了。

tech11

如果要几台主机都能不要密码登录到一台主机，就是说这台机器上要保留几台机器的公钥，authorized_keys2文件怎么命名啊？可以authorized_keys3..4..5 这样排下去吗？