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/*
* This program is is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
/**
* $Id$
* @file rlm_pam.c
* @brief Interfaces with the PAM library to allow auth via PAM.
*
* @note This was taken from the hacks that miguel a.l. paraz <map@iphil.net>
* did on radiusd-cistron-1.5.3 and migrated to a separate file.
* That, in fact, was again based on the original stuff from
* Jeph Blaize <jblaize@kiva.net> done in May 1997.
*
* @copyright 2000,2006 The FreeRADIUS server project
* @copyright 1997 Jeph Blaize <jblaize@kiva.net>
* @copyright 1999 miguel a.l. paraz <map@iphil.net>
*/
RCSID("$Id$")
#include <freeradius-devel/radiusd.h>
#include <freeradius-devel/modules.h>
#include "config.h"
#ifdef HAVE_SECURITY_PAM_APPL_H
# include <security/pam_appl.h>
#endif
#ifdef HAVE_PAM_PAM_APPL_H
# include <pam/pam_appl.h>
#endif
#ifdef HAVE_SYSLOG_H
# include <syslog.h>
#endif
typedef struct rlm_pam_t {
char const *pam_auth_name;
} rlm_pam_t;
static const CONF_PARSER module_config[] = {
{ "pam_auth", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_pam_t, pam_auth_name), "radiusd" },
CONF_PARSER_TERMINATOR
};
typedef struct rlm_pam_data_t {
REQUEST *request; //!< The current request.
char const *username; //!< Username to provide to PAM when prompted.
char const *password; //!< Password to provide to PAM when prompted.
bool error; //!< True if pam_conv failed.
} rlm_pam_data_t;
/** Dialogue between RADIUS and PAM modules
*
* Uses PAM's appdata_ptr so it's thread safe, and doesn't
* have any nasty static variables hanging around.
*/
static int pam_conv(int num_msg, struct pam_message const **msg, struct pam_response **resp, void *appdata_ptr)
{
int count;
struct pam_response *reply;
REQUEST *request;
rlm_pam_data_t *pam_config = (rlm_pam_data_t *) appdata_ptr;
request = pam_config->request;
/* strdup(NULL) doesn't work on some platforms */
#define COPY_STRING(s) ((s) ? strdup(s) : NULL)
reply = rad_malloc(num_msg * sizeof(struct pam_response));
memset(reply, 0, num_msg * sizeof(struct pam_response));
for (count = 0; count < num_msg; count++) {
switch (msg[count]->msg_style) {
case PAM_PROMPT_ECHO_ON:
reply[count].resp_retcode = PAM_SUCCESS;
reply[count].resp = COPY_STRING(pam_config->username);
break;
case PAM_PROMPT_ECHO_OFF:
reply[count].resp_retcode = PAM_SUCCESS;
reply[count].resp = COPY_STRING(pam_config->password);
break;
case PAM_TEXT_INFO:
RDEBUG2("%s", msg[count]->msg);
break;
case PAM_ERROR_MSG:
default:
RERROR("PAM conversation failed");
/* Must be an error of some sort... */
for (count = 0; count < num_msg; count++) {
if (msg[count]->msg_style == PAM_ERROR_MSG) RERROR("%s", msg[count]->msg);
if (reply[count].resp) {
/* could be a password, let's be sanitary */
memset(reply[count].resp, 0, strlen(reply[count].resp));
free(reply[count].resp);
}
}
free(reply);
pam_config->error = true;
return PAM_CONV_ERR;
}
}
*resp = reply;
/* PAM frees reply (including reply[].resp) */
return PAM_SUCCESS;
}
/** Check the users password against the standard UNIX password table + PAM.
*
* @note For most flexibility, passing a pamauth type to this function
* allows you to have multiple authentication types (i.e. multiple
* files associated with radius in /etc/pam.d).
*
* @param request The current request.
* @param username User to authenticate.
* @param passwd Password to authenticate with,
* @param pamauth Type of PAM authentication.
* @return 0 on success -1 on failure.
*/
static int do_pam(REQUEST *request, char const *username, char const *passwd, char const *pamauth)
{
pam_handle_t *handle = NULL;
int ret;
rlm_pam_data_t pam_config;
struct pam_conv conv;
/*
* Initialize the structures
*/
conv.conv = pam_conv;
conv.appdata_ptr = &pam_config;
pam_config.request = request;
pam_config.username = username;
pam_config.password = passwd;
pam_config.error = false;
RDEBUG2("Using pamauth string \"%s\" for pam.conf lookup", pamauth);
ret = pam_start(pamauth, username, &conv, &handle);
if (ret != PAM_SUCCESS) {
RERROR("pam_start failed: %s", pam_strerror(handle, ret));
return -1;
}
ret = pam_authenticate(handle, 0);
if (ret != PAM_SUCCESS) {
RERROR("pam_authenticate failed: %s", pam_strerror(handle, ret));
pam_end(handle, ret);
return -1;
}
/*
* FreeBSD 3.x doesn't have account and session management
* functions in PAM, while 4.0 does.
*/
#if !defined(__FreeBSD_version) || (__FreeBSD_version >= 400000)
ret = pam_acct_mgmt(handle, 0);
if (ret != PAM_SUCCESS) {
RERROR("pam_acct_mgmt failed: %s", pam_strerror(handle, ret));
pam_end(handle, ret);
return -1;
}
#endif
RDEBUG2("Authentication succeeded");
pam_end(handle, ret);
return 0;
}
static rlm_rcode_t CC_HINT(nonnull) mod_authenticate(void *instance, REQUEST *request)
{
int ret;
VALUE_PAIR *pair;
rlm_pam_t *data = (rlm_pam_t *) instance;
char const *pam_auth_string = data->pam_auth_name;
/*
* We can only authenticate user requests which HAVE
* a User-Name attribute.
*/
if (!request->username) {
RAUTH("Attribute \"User-Name\" is required for authentication");
return RLM_MODULE_INVALID;
}
/*
* We can only authenticate user requests which HAVE
* a User-Password attribute.
*/
if (!request->password) {
RAUTH("Attribute \"User-Password\" is required for authentication");
return RLM_MODULE_INVALID;
}
/*
* Ensure that we're being passed a plain-text password,
* and not anything else.
*/
if (request->password->da->attr != PW_USER_PASSWORD) {
RAUTH("Attribute \"User-Password\" is required for authentication. Cannot use \"%s\".", request->password->da->name);
return RLM_MODULE_INVALID;
}
/*
* Let the 'users' file over-ride the PAM auth name string,
* for backwards compatibility.
*/
pair = fr_pair_find_by_num(request->config, PW_PAM_AUTH, 0, TAG_ANY);
if (pair) pam_auth_string = pair->vp_strvalue;
ret = do_pam(request, request->username->vp_strvalue, request->password->vp_strvalue, pam_auth_string);
if (ret < 0) return RLM_MODULE_REJECT;
return RLM_MODULE_OK;
}
extern module_t rlm_pam;
module_t rlm_pam = {
.magic = RLM_MODULE_INIT,
.name = "pam",
.type = RLM_TYPE_THREAD_UNSAFE, /* The PAM libraries are not thread-safe */
.inst_size = sizeof(rlm_pam_t),
.config = module_config,
.methods = {
[MOD_AUTHENTICATE] = mod_authenticate
},
};
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