freebsd-dev/contrib/openpam/lib/libpam/pam_get_user.c

136 lines
4.3 KiB
C

/*-
* Copyright (c) 2002-2003 Networks Associates Technology, Inc.
* Copyright (c) 2004-2011 Dag-Erling Smørgrav
* All rights reserved.
*
* This software was developed for the FreeBSD Project by ThinkSec AS and
* Network Associates Laboratories, the Security Research Division of
* Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: pam_get_user.c 455 2011-10-29 18:31:11Z des $
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <sys/param.h>
#include <stdlib.h>
#include <security/pam_appl.h>
#include <security/openpam.h>
#include "openpam_impl.h"
static const char user_prompt[] = "Login:";
/*
* XSSO 4.2.1
* XSSO 6 page 52
*
* Retrieve user name
*/
int
pam_get_user(pam_handle_t *pamh,
const char **user,
const char *prompt)
{
char prompt_buf[1024];
size_t prompt_size;
const void *promptp;
char *resp;
int r;
ENTER();
if (pamh == NULL || user == NULL)
RETURNC(PAM_SYSTEM_ERR);
r = pam_get_item(pamh, PAM_USER, (const void **)user);
if (r == PAM_SUCCESS && *user != NULL)
RETURNC(PAM_SUCCESS);
/* pam policy overrides the module's choice */
if ((promptp = openpam_get_option(pamh, "user_prompt")) != NULL)
prompt = promptp;
/* no prompt provided, see if there is one tucked away somewhere */
if (prompt == NULL)
if (pam_get_item(pamh, PAM_USER_PROMPT, &promptp) &&
promptp != NULL)
prompt = promptp;
/* fall back to hardcoded default */
if (prompt == NULL)
prompt = user_prompt;
/* expand */
prompt_size = sizeof prompt_buf;
r = openpam_subst(pamh, prompt_buf, &prompt_size, prompt);
if (r == PAM_SUCCESS && prompt_size <= sizeof prompt_buf)
prompt = prompt_buf;
r = pam_prompt(pamh, PAM_PROMPT_ECHO_ON, &resp, "%s", prompt);
if (r != PAM_SUCCESS)
RETURNC(r);
r = pam_set_item(pamh, PAM_USER, resp);
FREE(resp);
if (r != PAM_SUCCESS)
RETURNC(r);
r = pam_get_item(pamh, PAM_USER, (const void **)user);
RETURNC(r);
}
/*
* Error codes:
*
* =pam_get_item
* =pam_prompt
* =pam_set_item
* !PAM_SYMBOL_ERR
*/
/**
* The =pam_get_user function returns the name of the target user, as
* specified to =pam_start.
* If no user was specified, nor set using =pam_set_item, =pam_get_user
* will prompt for a user name.
* Either way, a pointer to the user name is stored in the location
* pointed to by the =user argument.
*
* The =prompt argument specifies a prompt to use if no user name is
* cached.
* If it is =NULL, the =PAM_USER_PROMPT item will be used.
* If that item is also =NULL, a hardcoded default prompt will be used.
* Either way, the prompt is expanded using =openpam_subst before it is
* passed to the conversation function.
*
* If =pam_get_user is called from a module and the ;user_prompt option is
* set in the policy file, the value of that option takes precedence over
* both the =prompt argument and the =PAM_USER_PROMPT item.
*
* >pam_get_item
* >pam_get_authtok
* >openpam_subst
*/