pam_sm_authenticate(3)

pam_sm_authenticate3

Pam service function for user authentication

Usage

#include <security/pam_modules.h>

int pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv);

Overview

The pam_sm_authenticate function is the service module's implementation of the pam_authenticate(3) interface.

This function performs the task of authenticating the user.

Valid flags, which may be logically OR'd with PAM_SILENT, are:

PAM_SILENT

Do not emit any messages.

PAM_DISALLOW_NULL_AUTHTOK

Return PAM_AUTH_ERR if the database of authentication tokens for this authentication mechanism has a NULL entry for the user. Without this flag, such a NULL token will lead to a success without the user being prompted.

Return values

PAM_AUTH_ERR

Authentication failure.

PAM_CRED_INSUFFICIENT

For some reason the application does not have sufficient credentials to authenticate the user.

PAM_AUTHINFO_UNAVAIL

The modules were not able to access the authentication information. This might be due to a network or hardware failure etc.

PAM_SUCCESS

The authentication token was successfully updated.

PAM_USER_UNKNOWN

The supplied username is not known to the authentication service.

PAM_MAXTRIES

One or more of the authentication modules has reached its limit of tries authenticating the user. Do not try again.

Releases

10 releases since Debian 5.0 (Lenny); the text changed 8 times.

  1. 5.0
  2. 6.0
  3. 7
  4. 8–9
  5. 10
  6. 11
  7. 12
  8. 13
  9. Arch

From pam 1.7.3-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.