NAME
pam_get_authtok - get authentication token
SYNOPSIS
#include <security/pam_ext.h>
int pam_get_authtok(pam_handle_t *pamh, int item, const char **authtok,
const char *prompt);
int pam_get_authtok_noverify(pam_handle_t *pamh, const char **authtok,
const char *prompt);
int pam_get_authtok_verify(pam_handle_t *pamh, const char **authtok,
const char *prompt);
DESCRIPTION
The pam_get_authtok function returns the cached authentication token,
or prompts the user if no token is currently cached. It is intended for
internal use by Linux-PAM and PAM service modules. Upon successful
return, authtok contains a pointer to the value of the authentication
token. Note, this is a pointer to the actual data and should not be
free()'ed or over-written!
The prompt argument specifies a prompt to use if no token is cached. If
a NULL pointer is given, pam_get_authtok uses pre-defined prompts.
The following values are supported for item:
PAM_AUTHTOK
Returns the current authentication token. Called from
pam_sm_chauthtok(3) pam_get_authtok will ask the user to confirm
the new token by retyping it. If a prompt was specified, "Retype"
will be used as prefix.
PAM_OLDAUTHTOK
Returns the previous authentication token when changing
authentication tokens.
The pam_get_authtok_noverify function can only be used for changing the
password (from pam_sm_chauthtok(3)). It returns the cached
authentication token, or prompts the user if no token is currently
cached. The difference to pam_get_authtok is, that this function does
not ask a second time for the password to verify it. Upon successful
return, authtok contains a pointer to the value of the authentication
token. Note, this is a pointer to the actual data and should not be
free()'ed or over-written!
The pam_get_authtok_verify function can only be used to verify a
password for mistypes gotten by pam_get_authtok_noverify(3). This
function asks a second time for the password and verify it with the
password provided by authtok argument. In case of an error, the value
of authtok is undefined. Else this argument will point to the actual
data and should not be free()'ed or over-written!
OPTIONS
pam_get_authtok honours the following module options:
try_first_pass
Before prompting the user for their password, the module first
tries the previous stacked module's password in case that satisfies
this module as well.
use_first_pass
The argument use_first_pass forces the module to use a previous
stacked modules password and will never prompt the user - if no
password is available or the password is not appropriate, the user
will be denied access.
use_authtok
When password changing enforce the module to set the new token to
the one provided by a previously stacked password module. If no
token is available token changing will fail.
authtok_type=XXX
The default action is for the module to use the following prompts
when requesting passwords: "New UNIX password: " and "Retype UNIX
password: ". The example word UNIX can be replaced with this
option, by default it is empty.
RETURN VALUES
PAM_AUTH_ERR
Authentication token could not be retrieved.
PAM_AUTHTOK_ERR
New authentication could not be retrieved.
PAM_SUCCESS
Authentication token was successfully retrieved.
PAM_SYSTEM_ERR
No space for an authentication token was provided.
PAM_TRY_AGAIN
New authentication tokens mismatch.
SEE ALSO
pam(8)
STANDARDS
The pam_get_authtok function is a Linux-PAM extensions.