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#define _XOPEN_SOURCE
/* #include <pwd.h> */
#include <netdb.h>
#include <shadow.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>
#include <string.h>
#ifndef MAXHOSTNAMELEN
# define MAXHOSTNAMELEN 256
#endif
#define PAM_SM_AUTH
#define PAM_SM_ACCOUNT
#define PAM_PASSWORD
#ifndef __linux__
#include <login_cap.h>
#endif
#include <security/pam_modules.h>
#include <security/pam_appl.h>
#include <security/pam_mod_misc.h>
/*
* User authentication
*/
PAM_EXTERN int
pam_sm_authenticate(pam_handle_t *pamh, int flags,
int argc , const char **argv ) {
#ifndef __linux__
login_cap_t *lc;
#endif
struct spwd *pwd;
const char *pass, *crypt_pass, *user;
int pam_err;
/* identify user */
if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) {
PAM_LOG("Authenticating as self.");
pwd = getspnam(getlogin());
} else {
if ((pam_err = pam_get_user(pamh, &user, NULL)) != PAM_SUCCESS) {
PAM_ERROR("Authenticating with uname [%s] failed.", user);
return (pam_err);
}
pwd = getspnam(user);
}
PAM_LOG("Authenticating user: [%s]", user);
/* get password */
if (pwd != NULL) {
PAM_LOG("Doing real authentication");
pass = pwd->sp_pwdp;
if (pass[0] == '\0') {
if (!(flags & PAM_DISALLOW_NULL_AUTHTOK) &&
openpam_get_option(pamh, PAM_OPT_NULLOK)){
PAM_ERROR("Authentication failed. Empty passwd not allowed.");
return (PAM_SUCCESS);
}
pass = "*";
}
#ifndef __linux__
lc = login_getpwclass(pwd);
#endif
} else {
PAM_LOG("Doing dummy authentication.");
pass = "*";
#ifndef __linux__
lc = login_getpwclass(NULL);
#endif
}
#ifndef __linux__
prompt = login_getcapstr(lc, "passwd_prompt", NULL, NULL);
pam_err = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, prompt);
login_close(lc);
#else
pam_err = pam_get_authtok(pamh, PAM_AUTHTOK, (const char **) &pass, NULL);
#endif
PAM_LOG("Got password for user [%s]", user);
if (pam_err == PAM_CONV_ERR)
return (pam_err);
if (pam_err != PAM_SUCCESS)
return (PAM_AUTH_ERR);
/* check shadow */
crypt_pass = crypt(pass, pwd->sp_pwdp);
if ( strcmp(crypt_pass, pwd->sp_pwdp) != 0 ) {
PAM_ERROR("Wrong password. Authentication failed.");
pam_err = PAM_AUTH_ERR;
} else {
PAM_LOG("Authentication completed succesfully.");
pam_err = PAM_SUCCESS;
}
return (pam_err);
}
PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh , int flags ,
int argc , const char *argv[] ) {
/*
* This functions takes care of renewing/initializing
* user credentials as well as gid/uids. Someday, it
* will be completed. For now, it's not very urgent.
*/
return (PAM_SUCCESS);
}
/*
* Account Management
*/
PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags ,
int argc , const char *argv[] ) {
#ifndef __linux__
login_cap_t *lc;
#endif
struct spwd *pwd;
int pam_err;
const char *user;
time_t curtime;
#ifndef __linux__
const void *rhost, *tty;
char rhostip[MAXHOSTNAMELEN] = "";
#endif
/* Sanity checks for uname,pwd,tty,host etc */
pam_err = pam_get_user(pamh, &user, NULL);
if (pam_err != PAM_SUCCESS)
return (pam_err);
if (user == NULL || (pwd = getspnam(user)) == NULL)
return (PAM_SERVICE_ERR);
#ifndef __linux__
/*
* tty/host info are provided by login classes
* and cannot be used out of the box under Linux
* for sanity checking (BSD only). May need to
* be ported/rewritten to work on Linux as well.
* Time will tell...
*/
pam_err = pam_get_item(pamh, PAM_RHOST, &rhost);
if (pam_err != PAM_SUCCESS)
return (pam_err);
pam_err = pam_get_item(pamh, PAM_TTY, &tty);
if (pam_err != PAM_SUCCESS)
return (pam_err);
#endif
if (*pwd->sp_pwdp == '\0' &&
(flags & PAM_DISALLOW_NULL_AUTHTOK) != 0)
return (PAM_NEW_AUTHTOK_REQD);
#ifndef __linux__
lc = login_getpwclass(pwd);
if (lc == NULL) {
return (PAM_SERVICE_ERR);
}
#endif
/* Check if pw_lstchg or pw_expire is set */
if (pwd->sp_lstchg || pwd->sp_expire)
curtime = time(NULL) / (60 * 60 * 24);
if (pwd->sp_expire) {
if ( (curtime > pwd->sp_expire ) && ( pwd->sp_expire != -1 ) ) {
#ifndef __linux__
login_close(lc);
#endif
return (PAM_ACCT_EXPIRED);
} else if ( ( pwd->sp_expire - curtime < pwd->sp_warn) ) {
// pam_error(pamh, "Warning: your account expires on %s",
// ctime(&pwd->pw_expire));
}
}
if (pwd->sp_lstchg == 0 ) {
return (PAM_NEW_AUTHTOK_REQD);
}
/* check all other possibilities (mostly stolen from pam_tcb) */
if ((curtime > (pwd->sp_lstchg + pwd->sp_max + pwd->sp_inact)) &&
(pwd->sp_max != -1) && (pwd->sp_inact != -1) &&
(pwd->sp_lstchg != 0))
return (PAM_ACCT_EXPIRED);
if (((pwd->sp_lstchg + pwd->sp_max) < curtime) &&
(pwd->sp_max != -1))
return (PAM_ACCT_EXPIRED);
if ((curtime - pwd->sp_lstchg > pwd->sp_max)
&& (curtime - pwd->sp_lstchg > pwd->sp_inact)
&& (curtime - pwd->sp_lstchg > pwd->sp_max + pwd->sp_inact)
&& (pwd->sp_max != -1) && (pwd->sp_inact != -1))
return (PAM_ACCT_EXPIRED);
pam_err = (PAM_SUCCESS);
#ifndef __linux__
/* validate tty/host/time */
if (!auth_hostok(lc, rhost, rhostip) ||
!auth_ttyok(lc, tty) ||
!auth_timeok(lc, time(NULL)))
pam_err = PAM_AUTH_ERR;
login_close(lc);
#endif
return (pam_err);
}
/*
* Password Management
*/
PAM_EXTERN int
pam_sm_chautok(pam_handle_t *pamh, int flags,
int argc, const char *argv[])
{
/*
* NIS support will be left for future implementation.
* This is standard unix passwd changing function.
*/
struct spwd *new_pwd, *old_pwd;
char oldprefix[HASH_PREFIX_SIZE];
const char *user, *old_pass, *new_pass;
char *hashedpwd;
int pam_err;
/* identify user */
if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) {
PAM_LOG("Authenticating as self.");
old_pwd = getspnam(getlogin());
} else {
if ((pam_err = pam_get_user(pamh, &user, NULL)) != PAM_SUCCESS) {
PAM_ERROR("Authenticating with uname [%s] failed.", user);
return (pam_err);
}
old_pwd = getspnam(user);
}
PAM_LOG("Got user: [%s]", user);
if (pwd == NULL) {
PAM_ERROR("User [%s] either has a corrupted passwd entry or \
is not in the selected database");
return (PAM_AUTHTOK_RECOVERY_ERR);
}
/*
* When looking through the LinuxPAM code, I came across this :
*
* ` Various libraries at various times have had bugs related to
* '+' or '-' as the first character of a user name. Don't
* allow them. `
*
* I don't know if the problem is still around but just in case...
*/
if (user == NULL || user[0] == '-' || user[0] == '+' ) {
PAM_ERROR("Bad username [%s]", user);
return (PAM_USER_UNKNOWN);
}
if (flags & PAM_PRELIM_CHECK) {
PAM_LOG("PRELIM round");
if (getuid() == 0 ) {
/* root doesn't need old passwd */
return (pam_set_item(pamh, PAM_OLDAUTHTOK, ""));
}
if ( (pwd->pw_passwd[0] == '\0' ) &&
( openpam_get_option(pamh, PAM_OPT_NULLOK) ) &&
( openpam_get_option(pamh,PAM_DISALLOW_NULL_AUTHTOK)) ) {
/*
* Something funny could happen here since we don't
* ask for a password.
*/
old_pass = "";
}
return (PAM_SUCCESS);
}
PAM_MODULE_ENTRY("pam_unix")
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