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/*
* pam_ftp module
*
* Written by Andrew Morgan <morgan@linux.kernel.org> 1996/3/11
*/
#define PLEASE_ENTER_PASSWORD "Password required for %s."
#define GUEST_LOGIN_PROMPT "Guest login ok, " \
"send your complete e-mail address as password."
/* the following is a password that "can't be correct" */
#define BLOCK_PASSWORD "\177BAD PASSWPRD\177"
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <stdarg.h>
#include <string.h>
#include <security/pam_modules.h>
#include <security/_pam_macros.h>
#include <security/pam_ext.h>
#include "pam_inline.h"
/* argument parsing */
#define PAM_DEBUG_ARG 01
#define PAM_IGNORE_EMAIL 02
#define PAM_NO_ANON 04
static int
_pam_parse(pam_handle_t *pamh, int argc, const char **argv, const char **users)
{
int ctrl=0;
/* step through arguments */
for (ctrl=0; argc-- > 0; ++argv) {
const char *str;
/* generic options */
if (!strcmp(*argv,"debug"))
ctrl |= PAM_DEBUG_ARG;
else if (!strcmp(*argv,"ignore"))
ctrl |= PAM_IGNORE_EMAIL;
else if ((str = pam_str_skip_prefix(*argv, "users=")) != NULL)
*users = str;
else
pam_syslog(pamh, LOG_ERR, "unknown option: %s", *argv);
}
return ctrl;
}
/*
* check if name is in list or default list. place users name in *_user
* return 1 if listed 0 if not.
*/
static int lookup(const char *name, const char *list, char **_user)
{
int anon = 0;
if (list && *list) {
const char *l;
char *list_copy, *x;
char *sptr = NULL;
list_copy = strdup(list);
x = list_copy;
while (list_copy && (l = strtok_r(x, ",", &sptr))) {
x = NULL;
if (!strcmp(name, l)) {
*_user = list_copy;
anon = 1;
break;
}
}
if (*_user != list_copy) {
free(list_copy);
}
} else {
#define MAX_L 2
static const char *l[MAX_L] = { "ftp", "anonymous" };
int i;
for (i=0; i<MAX_L; ++i) {
if (!strcmp(l[i], name)) {
*_user = strdup(l[0]);
anon = 1;
break;
}
}
}
return anon;
}
/* --- authentication management functions (only) --- */
int
pam_sm_authenticate (pam_handle_t *pamh, int flags UNUSED,
int argc, const char **argv)
{
int retval, anon=0, ctrl;
const char *user;
char *anon_user = NULL;
const char *users = NULL;
/*
* this module checks if the user name is ftp or anonymous. If
* this is the case, it can set the PAM_RUSER to the entered email
* address and SUCCEEDS, otherwise it FAILS.
*/
ctrl = _pam_parse(pamh, argc, argv, &users);
retval = pam_get_user(pamh, &user, NULL);
if (retval != PAM_SUCCESS) {
pam_syslog(pamh, LOG_NOTICE, "cannot determine user name: %s",
pam_strerror(pamh, retval));
return PAM_USER_UNKNOWN;
}
if (!(ctrl & PAM_NO_ANON)) {
anon = lookup(user, users, &anon_user);
}
if (anon) {
retval = pam_set_item(pamh, PAM_USER, (const void *)anon_user);
if (retval != PAM_SUCCESS || anon_user == NULL) {
pam_syslog(pamh, LOG_ERR, "user resetting failed");
return PAM_USER_UNKNOWN;
}
free(anon_user);
}
/*
* OK. we require an email address for user or the user's password.
* - build conversation and get their input.
*/
{
char *resp = NULL;
const char *token;
if (!anon)
retval = pam_prompt (pamh, PAM_PROMPT_ECHO_OFF, &resp,
PLEASE_ENTER_PASSWORD, user);
else
retval = pam_prompt (pamh, PAM_PROMPT_ECHO_OFF, &resp,
GUEST_LOGIN_PROMPT);
if (retval != PAM_SUCCESS) {
_pam_overwrite (resp);
_pam_drop (resp);
return ((retval == PAM_CONV_AGAIN)
? PAM_INCOMPLETE:PAM_AUTHINFO_UNAVAIL);
}
if (anon) {
/* XXX: Some effort should be made to verify this email address! */
if (!(ctrl & PAM_IGNORE_EMAIL)) {
char *sptr = NULL;
token = strtok_r(resp, "@", &sptr);
retval = pam_set_item(pamh, PAM_RUSER, token);
if ((token) && (retval == PAM_SUCCESS)) {
token = strtok_r(NULL, "@", &sptr);
retval = pam_set_item(pamh, PAM_RHOST, token);
}
}
/* we are happy to grant anonymous access to the user */
retval = PAM_SUCCESS;
} else {
/*
* we have a password so set AUTHTOK
*/
pam_set_item(pamh, PAM_AUTHTOK, resp);
/*
* this module failed, but the next one might succeed with
* this password.
*/
retval = PAM_AUTH_ERR;
}
/* clean up */
_pam_overwrite(resp);
_pam_drop(resp);
/* success or failure */
return retval;
}
}
int
pam_sm_setcred (pam_handle_t *pamh UNUSED, int flags UNUSED,
int argc UNUSED, const char **argv UNUSED)
{
return PAM_IGNORE;
}
/* end of module definition */
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