Pluggable Authentication Module (PAM) Submethod
Pluggable Authentication Module is an authentication framework used in Unix systems. In SSH Tectia, support for PAM is enabled as a submethod of Keyboard-Interactive authentication.
When PAM is used, SSH Tectia Server (M) transfers the control of authentication to the PAM library, which will then load the modules specified in the PAM configuration file. Finally, the PAM library tells SSH Tectia Server (M) whether or not the authentication was successful. SSH Tectia Server (M) is not aware of the details of the actual authentication method employed by PAM. Only the final result is of interest.
To enable PAM support, include the following lines in the
/etc/ssh2/sshd2_config file on the server:
Include the following line in the
/etc/ssh2/ssh2_config file on the client:
The PAM configuration settings are located either in
/etc/ or in
/etc/pam.d/sshd2. The modules are usually either in the
/lib/security directory or in the
/usr/lib/security directory. Currently, SSH Tectia Server (M) supports PAM on Linux and on Solaris 2.6 or later.
There must be at least one
account, and one
session module in the configuration file. Otherwise the connection will be refused. Also, modules which require
PAM_TTY will not work because TTY allocation is done in SSH Tectia Server (M) after the authentication.
See Section Keyboard-Interactive Authentication for more information on Keyboard-Interactive authentication.
Note: SSH Communications Security does not provide technical support on how to configure PAM. Our support only covers SSH Tectia applications.
The following are examples of different PAM configurations.
PAM on Red Hat Linux
/etc/pam.d/sshd2 file on Red Hat Linux:
auth required /lib/security/pam_pwdb.so shadow nullok
auth required /lib/security/pam_nologin.so
account required /lib/security/pam_pwdb.so
password required /lib/security/pam_cracklib.so
password required /lib/security/pam_pwdb.so shadow nullok use_authtok
session required /lib/security/pam_pwdb.so
On SUSE LINUX, the configuration is otherwise the same but
pam_unix.so is used instead of
PAM on Sun Solaris
/etc/pam.conf entry on Solaris:
sshd2 auth required /usr/lib/security/pam_unix.so debug
sshd2 account required /usr/lib/security/pam_unix.so debug
sshd2 password required /usr/lib/security/pam_unix.so debug
sshd2 session required /usr/lib/security/pam_unix.so debug
PAM Used with LDAP on Red Hat Linux
The following is an example on how to configure PAM to use LDAP authentication on a Red Hat 9 machine. Before trying this setup, verify that PAM works for local accounts.
In the file
/etc/pam.d/sshd2, add the following:
auth required /lib/security/pam_ldap.so
account required /lib/security/pam_ldap.so
password required /lib/security/pam_ldap.so
session required /lib/security/pam_ldap.so
In the file
/etc/nsswitch.conf, add the following:
passwd: files ldap
shadow: files ldap
group: files ldap
In the file
/etc/ldap.conf, add the following:
This is just an example and needs to be modified according to your LDAP server configuration.