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

`pam_securetty.so` [ debug ]

### 6.29.1. 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.

### 6.29.2. 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.

### 6.29.3. MODULE TYPES PROVIDED

Only the `auth` module type is provided.

### 6.29.4. 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.

### 6.29.5. EXAMPLES

    auth  required  pam_securetty.so
    auth  required  pam_unix.so

### 6.29.6. AUTHOR

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

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