ssh でログイン

ssh でログインできるようにする。

設定を見る

sh-3.2# grep -v '^[     ]*#' /etc/sshd_config





HostKey /etc/apache/server.key




PermitRootLogin no







UsePAM yes

PermitUserEnvironment yes


Subsystem       sftp    /usr/local/libexec/sftp-server
sh-3.2#

ちなみに、grep -v '^[ ]*#' /etc/sshd_config の [ と ] との間はスペースとタブ。
行頭から、スペースかタブかが 0 個以上あって # 、つまりコメントアウトされた行を除く

設定の変更

sh-3.2# cd /etc/
sh-3.2# mv sshd_config{,.orig}
sh-3.2# cp sshd_config{.orig,}
sh-3.2# vi sshd_config
	:
	:
sh-3.2# diff !$.orig !$
diff sshd_config.orig sshd_config
--- sshd_config.orig    Wed Jul 28 20:54:51 2010
+++ sshd_config Wed Oct 13 22:51:24 2010
@@ -20,7 +20,7 @@
 # HostKeys for protocol version 2
 #HostKey /etc/ssh_host_rsa_key
 #HostKey /etc/ssh_host_dsa_key
-HostKey /etc/apache/server.key
+#HostKey /etc/apache/server.key

 # Lifetime and size of ephemeral version 1 server key
 #KeyRegenerationInterval 1h
@@ -35,7 +35,7 @@

 #LoginGraceTime 2m
 #PermitRootLogin yes
-PermitRootLogin no
+PermitRootLogin yes
 #StrictModes yes

 #RSAAuthentication yes
sh-3.2#

ちなみに !$ は、直前のコマンドの最後の引数。
直前のコマンドは vi sshd_config なので、
diff !$.orig !$ は、
diff sshd_config.orig sshd_config と展開される

設定の最読込み

sh-3.2# kill -HUP `cat /var/run/sshd.pid `
sh-3.2#

ssh で接続

sil:~# ssh 192.168.2.204
The authenticity of host '192.168.2.204 (192.168.2.204)' can't be established.
RSA key fingerprint is 6b:7f:f6:3f:ba:08:5c:65:1a:e3:de:03:27:63:6d:68.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.2.204' (RSA) to the list of known hosts.
Password:
Password:
Password:

root にパスワードを付ける

sh-3.2# passwd
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
sh-3.2#

再 ssh

sil:~# ssh 192.168.2.204 root
Password: （上で付けたパスワード）
Password:

再起動

再々 ssh

sil:~# ssh 192.168.2.204 root
Password: （上で付けたパスワード）
Password:

ログを見る

sh-3.2# tail /var/log/messages
	:
	:
Oct 13 22:58:41 LS-VL815 sshd[3124]: pam_listfile(sshd:auth): Refused user root for service sshd
Oct 13 22:58:45 LS-VL815 sshd[3122]: error: PAM: Authentication failure
Oct 13 22:58:45 LS-VL815 sshd[3164]: pam_listfile(sshd:auth): Refused user root for service sshd
sh-3.2#

sshd_config の再修正

sh-3.2# diff -u !$.orig !$
diff -u /etc/sshd_config.orig /etc/sshd_config
--- /etc/sshd_config.orig       Wed Jul 28 20:54:51 2010
+++ /etc/sshd_config    Wed Oct 13 23:01:07 2010
@@ -20,7 +20,7 @@
 # HostKeys for protocol version 2
 #HostKey /etc/ssh_host_rsa_key
 #HostKey /etc/ssh_host_dsa_key
-HostKey /etc/apache/server.key
+#HostKey /etc/apache/server.key

 # Lifetime and size of ephemeral version 1 server key
 #KeyRegenerationInterval 1h
@@ -35,7 +35,7 @@

 #LoginGraceTime 2m
 #PermitRootLogin yes
-PermitRootLogin no
+PermitRootLogin yes
 #StrictModes yes

 #RSAAuthentication yes
@@ -71,7 +71,7 @@
 # Set this to 'yes' to enable PAM authentication (via challenge-response)
 # and session processing. Depending on your PAM configuration, this may
 # bypass the setting of 'PasswordAuthentication'
-UsePAM yes
+UsePAM no

 #AllowTcpForwarding yes
 #GatewayPorts no
sh-3.2# kill -HUP `cat /var/run/sshd.pid `
sh-3.2#

もう一回 ssh

sil:~# ssh 192.168.2.204 root
root@192.168.2.204's password:（上で付けたパスワード）
sh: root: command not found
sil:~# 

sil:~# ssh 192.168.2.204
root@192.168.2.204's password:（上で付けたパスワード）
root@LS-VL815:~#

パスワードを消す

もう一回 ssh

sil:~# ssh 192.168.2.204
root@192.168.2.204's password:
Permission denied, please try again.
root@192.168.2.204's password:

sil:~#

sshd_config の修正

sh-3.2# !diff
diff -u /etc/sshd_config.orig /etc/sshd_config
--- /etc/sshd_config.orig       Wed Jul 28 20:54:51 2010
+++ /etc/sshd_config    Wed Oct 13 23:07:06 2010
@@ -20,7 +20,7 @@
 # HostKeys for protocol version 2
 #HostKey /etc/ssh_host_rsa_key
 #HostKey /etc/ssh_host_dsa_key
-HostKey /etc/apache/server.key
+#HostKey /etc/apache/server.key

 # Lifetime and size of ephemeral version 1 server key
 #KeyRegenerationInterval 1h
@@ -35,7 +35,7 @@

 #LoginGraceTime 2m
 #PermitRootLogin yes
-PermitRootLogin no
+PermitRootLogin yes
 #StrictModes yes

 #RSAAuthentication yes
@@ -55,6 +55,7 @@
 # To disable tunneled clear text passwords, change to no here!
 #PasswordAuthentication yes
 #PermitEmptyPasswords no
+PermitEmptyPasswords yes

 # Change to no to disable s/key passwords
 #ChallengeResponseAuthentication yes
@@ -71,7 +72,7 @@
 # Set this to 'yes' to enable PAM authentication (via challenge-response)
 # and session processing. Depending on your PAM configuration, this may
 # bypass the setting of 'PasswordAuthentication'
-UsePAM yes
+UsePAM no

 #AllowTcpForwarding yes
 #GatewayPorts no
sh-3.2# !kill
kill -HUP `cat /var/run/sshd.pid `
sh-3.2#

今度こそ

sil:~# ssh 192.168.2.204
root@LS-VL815:~#

LS-VL 楽天市場 Amazon