6.27. pam_securetty - limit root login to special devices
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## 6.27. pam_securetty - limit root login to special devices

`pam_securetty.so` [ debug ]

### 6.27.1. DESCRIPTION

pam_securetty is a PAM module that allows root logins only if the user is logging in on a "secure" tty, as defined by the listing in the `securetty` file. pam_securetty checks at first, if `/etc/securetty` exists. If not and it was built with vendordir support, it will use `%vendordir%/securetty`. pam_securetty also checks that the `securetty` files are plain files and not world writable. It will also allow root logins on the tty specified with `console=` switch on the kernel command line and on ttys from the `/sys/class/tty/console/active`.

This module has no effect on non-root users and requires that the application fills in the PAM_TTY item correctly.

For canonical usage, should be listed as a required authentication method before any sufficient authentication methods.

### 6.27.2. OPTIONS

`debug`

  Print debug information.

`noconsole`

  Do not automatically allow root logins on the kernel console device, as specified on the kernel command line or by the sys file, if it is not also specified in the `securetty` file.

### 6.27.3. MODULE TYPES PROVIDED

Only the `auth` module type is provided.

### 6.27.4. RETURN VALUES

PAM_SUCCESS

  The user is allowed to continue authentication. Either the user is not root, or the root user is trying to log in on an acceptable device.

PAM_AUTH_ERR

  Authentication is rejected. Either root is attempting to log in via an unacceptable device, or the `securetty` file is world writable or not a normal file.

PAM_BUF_ERR

  Memory buffer error.

PAM_CONV_ERR

  The conversation method supplied by the application failed to obtain the username.

PAM_INCOMPLETE

  The conversation method supplied by the application returned PAM_CONV_AGAIN.

PAM_SERVICE_ERR

  An error occurred while the module was determining the user's name or tty, or the module could not open the `securetty` file.

PAM_USER_UNKNOWN

  The module could not find the user name in the `/etc/passwd` file to verify whether the user had a UID of 0. Therefore, the results of running this module are ignored.

### 6.27.5. EXAMPLES

    auth  required  pam_securetty.so
    auth  required  pam_unix.so

### 6.27.6. AUTHOR

pam_securetty was written by Elliot Lee <sopwith@cuc.edu>.

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