系统为（rhel6.7）
如果在configure openssh时，如果有参数 –with-pam，会提示：
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
就是如果启用PAM，需要有一个控制文件，按照提示的路径找到redhat/sshd.pam，并复制到/etc/pam.d/sshd，在/etc/ssh/sshd_config中打开UsePAM yes。发现连接服务器被拒绝，关掉就可以登录。
直接修改/etc/pam.d/sshd
#%PAM-1.0 auth required pam_sepermit.so auth include password-auth account required pam_nologin.so account include password-auth password include password-auth # pam_selinux.so close should be the first session rule session required pam_selinux.so close session required pam_loginuid.so # pam_selinux.so open should only be followed by sessions to be executed in the user context session required pam_selinux.so open env_params session optional pam_keyinit.so force revoke session include password-auth
重启sshd，搞定！