月份：2017年7月

1、导入客户端密钥

$> vi ~/.ssh/authorized_keys #没有就新建
（复制客户端 ~/.ssh/id_rsa.pub 保存文件）
$> chmod 700 ~/.ssh/authorized_keys

2、禁止使用密码登录

$> vi /etc/ssh/sshd_config
修改为： PasswordAuthentication No 

3、修改默认端口

$> vi /etc/ssh/sshd_config
修改为： Port 11233
$> service sshd restart

4、开放端口防火墙权限

$> iptables -I INPUT 4 -p tcp -m state --state NEW -m tcp --dport 11233  -j ACCEPT
$> service iptables save

校验方式：客户端链接方式：

$> ssh [email protected] -p 11233

配置密钥可使用户免密ssh方式登录服务器。

配置方法：

生成密钥对

$ ssh-keygen

此处可选择生成密钥的文件路径，默认为~/.ssh/id_rsa
密码为可选。

拷贝公钥到服务器

方式一：

$ ssh-copy-id -i ~/.ssh/id_rsa.pub xxx@host

方式二：

手动拷贝id_rsa.pub到服务器上，并收到添加认证文件。

$ cat id_rsa.pub >> ~/.ssh/authorized_keys

服务器配置

配置服务器上/etc/ssh/sshd_config文件，修改以下配置项

RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile  .ssh/authorized_keys

修改后，重启sshd服务，根据不同的系统使用相应命令

登录

直接登录

$ ssh user@host

如果配置成功，则不需要密码直接登录。

问题

配置成功后，仍提示密码输入

主要原因在于服务器上认证文件及所在目录的权限问题

详情排查步骤可查看文章配置ssh公钥登录提示还是输入密码

解决方法：

$ chmod 755 ~/home/xxxuser

使用ssh客户端（如：putty）连接Linux服务器，可能会等待10-30秒才有提示输入密码。严重影响工作效率。登录很慢，登录上去后速度正常，这种情况主要有两种可能的原因：

1、 DNS反向解析问题

OpenSSH在用户登录的时候会验证IP，它根据用户的IP使用反向DNS找到主机名，再使用DNS找到IP地址，最后匹配一下登录的IP是否合法。如果客户机的IP没有域名，或者DNS服务器很慢或不通，那么登录就会很花时间。

解决办法：在目标服务器上修改sshd服务器端配置,并重启sshd

vi /etc/ssh/sshd_config
UseDNS no

2、 关闭ssh的gssapi认证

用ssh -v user@server 可以看到登录时有如下信息：

debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure. Minor code may provide more information

注：ssh -vvv user@server 可以看到更细的debug信息

解决办法：

修改sshd服务器端配置

vi /etc/ssh/ssh_config
GSSAPIAuthentication no

可以使用ssh -o GSSAPIAuthentication=no user@server登录

GSSAPI ( Generic Security Services Application Programming Interface) 是一套类似Kerberos 5的通用网络安全系统接口。该接口是对各种不同的客户端服务器安全机制的封装，以消除安全接口的不同，降低编程难度。但该接口在目标机器无域名解析时会有 问题

使用strace查看后发现，ssh在验证完key之后，进行authentication gssapi-with-mic，此时先去连接DNS服务器，在这之后会进行其他操作

[root@192-168-3-40 ~]# ssh -vvv [email protected]  
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013  
debug1: Reading configuration data /etc/ssh/ssh_config  
debug1: Applying options for *  
debug2: ssh_connect: needpriv 0  
debug1: Connecting to 192.168.3.44 [192.168.3.44] port 22.  
debug1: Connection established.  
debug1: permanently_set_uid: 0/0  
debug1: identity file /root/.ssh/identity type -1  
debug1: identity file /root/.ssh/identity-cert type -1  
debug1: identity file /root/.ssh/id_rsa type -1  
debug1: identity file /root/.ssh/id_rsa-cert type -1  
debug1: identity file /root/.ssh/id_dsa type -1  
debug1: identity file /root/.ssh/id_dsa-cert type -1  
debug1: identity file /root/.ssh/id_ecdsa type -1  
debug1: identity file /root/.ssh/id_ecdsa-cert type -1  
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3  
debug1: match: OpenSSH_5.3 pat OpenSSH*  
debug1: Enabling compatibility mode for protocol 2.0  
debug1: Local version string SSH-2.0-OpenSSH_5.3  
debug2: fd 3 setting O_NONBLOCK  
debug1: SSH2_MSG_KEXINIT sent  
debug3: Wrote 960 bytes for a total of 981  
debug1: SSH2_MSG_KEXINIT received  
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1  
debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],ssh-rsa,ssh-dss  
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]  
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]  
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96  
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96  
debug2: kex_parse_kexinit: none,[email protected],zlib  
debug2: kex_parse_kexinit: none,[email protected],zlib  
debug2: kex_parse_kexinit:  
debug2: kex_parse_kexinit:  
debug2: kex_parse_kexinit: first_kex_follows 0  
debug2: kex_parse_kexinit: reserved 0  
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1  
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss  
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]  
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]  
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96  
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96  
debug2: kex_parse_kexinit: none,[email protected]  
debug2: kex_parse_kexinit: none,[email protected]  
debug2: kex_parse_kexinit:  
debug2: kex_parse_kexinit:  
debug2: kex_parse_kexinit: first_kex_follows 0  
debug2: kex_parse_kexinit: reserved 0  
debug2: mac_setup: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none  
debug2: mac_setup: found hmac-md5  
debug1: kex: client->server aes128-ctr hmac-md5 none  
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent  
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP  
debug3: Wrote 24 bytes for a total of 1005  
debug2: dh_gen_key: priv key bits set: 120/256  
debug2: bits set: 506/1024  
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent  
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY  
debug3: Wrote 144 bytes for a total of 1149  
debug3: check_host_in_hostfile: host 192.168.3.44 filename /root/.ssh/known_hosts  
debug3: check_host_in_hostfile: host 192.168.3.44 filename /root/.ssh/known_hosts  
debug3: check_host_in_hostfile: match line 8  
debug1: Host '192.168.3.44' is known and matches the RSA host key.  
debug1: Found key in /root/.ssh/known_hosts:8  
debug2: bits set: 527/1024  
debug1: ssh_rsa_verify: signature correct  
debug2: kex_derive_keys  
debug2: set_newkeys: mode 1  
debug1: SSH2_MSG_NEWKEYS sent  
debug1: expecting SSH2_MSG_NEWKEYS  
debug3: Wrote 16 bytes for a total of 1165  
debug2: set_newkeys: mode 0  
debug1: SSH2_MSG_NEWKEYS received  
debug1: SSH2_MSG_SERVICE_REQUEST sent  
debug3: Wrote 48 bytes for a total of 1213  
debug2: service_accept: ssh-userauth  
debug1: SSH2_MSG_SERVICE_ACCEPT received  
debug2: key: /root/.ssh/identity ((nil))  
debug2: key: /root/.ssh/id_rsa ((nil))  
debug2: key: /root/.ssh/id_dsa ((nil))  
debug2: key: /root/.ssh/id_ecdsa ((nil))  
debug3: Wrote 64 bytes for a total of 1277  
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password  
debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic,password  
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password  
debug3: authmethod_lookup gssapi-keyex  
debug3: remaining preferred: gssapi-with-mic,publickey,keyboard-interactive,password  
debug3: authmethod_is_enabled gssapi-keyex  
debug1: Next authentication method: gssapi-keyex  
debug1: No valid Key exchange context  
debug2: we did not send a packet, disable method  
debug3: authmethod_lookup gssapi-with-mic  
debug3: remaining preferred: publickey,keyboard-interactive,password  
debug3: authmethod_is_enabled gssapi-with-mic  
debug1: Next authentication method: gssapi-with-mic  
debug3: Trying to reverse map address 192.168.3.44.  
debug1: Unspecified GSS failure.  Minor code may provide more information  
Cannot determine realm for numeric host address  

debug1: Unspecified GSS failure.  Minor code may provide more information  
Cannot determine realm for numeric host address  

debug1: Unspecified GSS failure.  Minor code may provide more information  


debug1: Unspecified GSS failure.  Minor code may provide more information  
Cannot determine realm for numeric host address  

debug2: we did not send a packet, disable method  
debug3: authmethod_lookup publickey  
debug3: remaining preferred: keyboard-interactive,password  
debug3: authmethod_is_enabled publickey  
debug1: Next authentication method: publickey  
debug1: Trying private key: /root/.ssh/identity  
debug3: no such identity: /root/.ssh/identity  
debug1: Trying private key: /root/.ssh/id_rsa  
debug3: no such identity: /root/.ssh/id_rsa  
debug1: Trying private key: /root/.ssh/id_dsa  
debug3: no such identity: /root/.ssh/id_dsa  
debug1: Trying private key: /root/.ssh/id_ecdsa  
debug3: no such identity: /root/.ssh/id_ecdsa  
debug2: we did not send a packet, disable method  
debug3: authmethod_lookup password  
debug3: remaining preferred: ,password  
debug3: authmethod_is_enabled password  
debug1: Next authentication method: password  
[email protected]'s password:

一、脚本

在主机上建立sh文件，名称随意，然后在文件中输入以下内容：

#!/bin/sh
DEST_USER=$1
PASSWORD=$2
HOSTS_FILE=$3
if [ $# -ne 3 ]; then
    echo "Usage:"
    echo "$0 remoteUser remotePassword hostsFile"
    exit 1
fi

SSH_DIR=~/.ssh
SCRIPT_PREFIX=./tmp
echo ===========================
# 1. prepare  directory .ssh
mkdir $SSH_DIR
chmod 700 $SSH_DIR

# 2. generat ssh key
TMP_SCRIPT=$SCRIPT_PREFIX.sh
echo  "#!/usr/bin/expect">$TMP_SCRIPT
echo  "spawn ssh-keygen -b 1024 -t rsa">>$TMP_SCRIPT
echo  "expect *key*">>$TMP_SCRIPT
echo  "send r">>$TMP_SCRIPT
if [ -f $SSH_DIR/id_rsa ]; then
    echo  "expect *verwrite*">>$TMP_SCRIPT
    echo  "send yr">>$TMP_SCRIPT
fi
echo  "expect *passphrase*">>$TMP_SCRIPT
echo  "send r">>$TMP_SCRIPT
echo  "expect *again:">>$TMP_SCRIPT
echo  "send r">>$TMP_SCRIPT
echo  "interact">>$TMP_SCRIPT

chmod +x $TMP_SCRIPT

/usr/bin/expect $TMP_SCRIPT
rm $TMP_SCRIPT

# 3. generat file authorized_keys
cat $SSH_DIR/id_rsa.pub>>$SSH_DIR/authorized_keys

# 4. chmod 600 for file authorized_keys
chmod 600 $SSH_DIR/authorized_keys
echo ===========================
# 5. copy all files to other hosts
for ip in $(cat $HOSTS_FILE)  
do
    if [ "x$ip" != "x" ]; then
        echo -------------------------
        TMP_SCRIPT=${SCRIPT_PREFIX}.$ip.sh
        # check known_hosts
        val=`ssh-keygen -F $ip`
        if [ "x$val" == "x" ]; then
            echo "$ip not in $SSH_DIR/known_hosts, need to add"
            val=`ssh-keyscan $ip 2>/dev/null`
            if [ "x$val" == "x" ]; then
                echo "ssh-keyscan $ip failed!"
            else
                echo $val>>$SSH_DIR/known_hosts
            fi
        fi
        echo "copy $SSH_DIR to $ip"

        echo  "#!/usr/bin/expect">$TMP_SCRIPT
        echo  "spawn scp -r  $SSH_DIR $DEST_USER@$ip:~/">>$TMP_SCRIPT
        echo  "expect *assword*">>$TMP_SCRIPT
        echo  "send $PASSWORDr">>$TMP_SCRIPT
        echo  "interact">>$TMP_SCRIPT

        chmod +x $TMP_SCRIPT
        #echo "/usr/bin/expect $TMP_SCRIPT" >$TMP_SCRIPT.do
        #sh $TMP_SCRIPT.do&

        /usr/bin/expect $TMP_SCRIPT
        rm $TMP_SCRIPT
        echo "copy done."                
    fi
done

echo done.

二、建立主机列表文件

新建主机列表文件，一行一个需要建立互信的IP。

示例如下：

192.168.1.2  
192.168.1.3  
192.168.1.4  
192.168.1.5

三、启动程序及参数

运行刚才新建的.sh文件，脚本接受三个参数，远程机器用户名、密码和host文件名（相对路径或绝对路径均可）。

例如：

./auto_auth.sh app app ./hostList.cfg

脚本会生成pub公钥文件，并将公钥拷贝至指定主机。