OpenSolaris_b135/lib/pam_modules/krb5/krb5_password.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <kadm5/admin.h>
#include <krb5.h>
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_impl.h>
#include <syslog.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <pwd.h>
#include <libintl.h>
#include <netdb.h>
#include "utils.h"
#include "krb5_repository.h"
extern int attempt_krb5_auth(pam_handle_t *, krb5_module_data_t *, char *,
char **, boolean_t);
extern int krb5_verifypw(char *, char *, int);
static void display_msg(pam_handle_t *, int, char *);
static void display_msgs(pam_handle_t *, int, int,
char msgs[][PAM_MAX_MSG_SIZE]);
static int krb5_changepw(pam_handle_t *, char *, char *, char *, int);
/*
* set_ccname()
*
* set KRB5CCNAME shell var
*/
static void
set_ccname(
pam_handle_t *pamh,
krb5_module_data_t *kmd,
int login_result,
int debug)
{
int result;
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): password: finalize"
" ccname env, login_result =%d, env ='%s'",
login_result, kmd->env ? kmd->env : "<null>");
if (kmd->env) {
if (login_result == PAM_SUCCESS) {
/*
* Put ccname into the pamh so that login
* apps can pick this up when they run
* pam_getenvlist().
*/
if ((result = pam_putenv(pamh, kmd->env))
!= PAM_SUCCESS) {
/* should not happen but... */
__pam_log(LOG_AUTH | LOG_ERR,
"PAM-KRB5 (password):"
" pam_putenv failed: result: %d",
result);
goto cleanupccname;
}
} else {
cleanupccname:
/* for lack of a Solaris unputenv() */
krb5_unsetenv(KRB5_ENV_CCNAME);
free(kmd->env);
kmd->env = NULL;
}
}
}
/*
* get_set_creds()
*
* do a krb5 login to get and set krb5 creds (needed after a pw change
* on pw expire on login)
*/
static void
get_set_creds(
pam_handle_t *pamh,
krb5_module_data_t *kmd,
char *user,
char *newpass,
int debug)
{
int login_result;
if (!kmd || kmd->age_status != PAM_NEW_AUTHTOK_REQD)
return;
/*
* if pw has expired, get/set krb5 creds ala auth mod
*
* pwchange verified user sufficiently, so don't request strict
* tgt verification (will cause rcache perm issues possibly anyways)
*/
login_result = attempt_krb5_auth(pamh, kmd, user, &newpass, 0);
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): get_set_creds: login_result= %d",
login_result);
/*
* the krb5 login should not fail, but if so,
* warn the user they have to kinit(1)
*/
if (login_result != PAM_SUCCESS) {
display_msg(pamh, PAM_TEXT_INFO,
dgettext(TEXT_DOMAIN,
"Warning: "
"Could not cache Kerberos"
" credentials, please run "
"kinit(1) or re-login\n"));
}
set_ccname(pamh, kmd, login_result, debug);
}
/*
* This is the PAM Kerberos Password Change module
*
*/
int
pam_sm_chauthtok(
pam_handle_t *pamh,
int flags,
int argc,
const char **argv)
{
char *user;
int err, result = PAM_AUTHTOK_ERR;
char *newpass = NULL;
char *oldpass = NULL;
int i;
int debug = 0;
uid_t pw_uid;
krb5_module_data_t *kmd = NULL;
pam_repository_t *rep_data = NULL;
for (i = 0; i < argc; i++) {
if (strcmp(argv[i], "debug") == 0)
debug = 1;
else
__pam_log(LOG_AUTH | LOG_ERR,
"PAM-KRB5 (password): illegal option %s",
argv[i]);
}
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): start: flags = %x",
flags);
(void) pam_get_item(pamh, PAM_REPOSITORY, (void **)&rep_data);
if (rep_data != NULL) {
if (strcmp(rep_data->type, KRB5_REPOSITORY_NAME) != 0) {
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (auth): wrong"
"repository found (%s), returning "
"PAM_IGNORE", rep_data->type);
return (PAM_IGNORE);
}
}
if (flags & PAM_PRELIM_CHECK) {
/* Nothing to do here */
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): prelim check");
return (PAM_IGNORE);
}
/* make sure PAM framework is telling us to update passwords */
if (!(flags & PAM_UPDATE_AUTHTOK)) {
__pam_log(LOG_AUTH | LOG_ERR,
"PAM-KRB5 (password): bad flags: %d",
flags);
return (PAM_SYSTEM_ERR);
}
if ((err = pam_get_data(pamh, KRB5_DATA, (const void **)&kmd))
!= PAM_SUCCESS) {
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): get mod data failed %d",
err);
kmd = NULL;
}
if (flags & PAM_CHANGE_EXPIRED_AUTHTOK) {
/* let's make sure we know the krb5 pw has expired */
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): kmd age status %d",
kmd ? kmd->age_status : -99);
if (!kmd || kmd->age_status != PAM_NEW_AUTHTOK_REQD)
return (PAM_IGNORE);
}
(void) pam_get_item(pamh, PAM_USER, (void **)&user);
if (user == NULL || *user == '\0') {
__pam_log(LOG_AUTH | LOG_ERR,
"PAM-KRB5 (password): username is empty");
return (PAM_USER_UNKNOWN);
}
if (!get_pw_uid(user, &pw_uid)) {
__pam_log(LOG_AUTH | LOG_ERR,
"PAM-KRB5 (password): can't get uid for %s", user);
return (PAM_USER_UNKNOWN);
}
/*
* if root key exists in the keytab, it's a random key so no
* need to prompt for pw and we just return IGNORE
*/
if ((strcmp(user, ROOT_UNAME) == 0) &&
key_in_keytab(user, debug)) {
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): "
"key for '%s' in keytab, returning IGNORE", user);
result = PAM_IGNORE;
goto out;
}
(void) pam_get_item(pamh, PAM_AUTHTOK, (void **)&newpass);
/*
* If the preauth type done didn't use a passwd just ignore the error.
*/
if (newpass == NULL)
if (kmd && kmd->preauth_type == KRB_PKINIT)
return (PAM_IGNORE);
else
return (PAM_SYSTEM_ERR);
(void) pam_get_item(pamh, PAM_OLDAUTHTOK, (void **)&oldpass);
if (oldpass == NULL)
if (kmd && kmd->preauth_type == KRB_PKINIT)
return (PAM_IGNORE);
else
return (PAM_SYSTEM_ERR);
result = krb5_verifypw(user, oldpass, debug);
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): verifypw %d", result);
/*
* If it's a bad password or general failure, we are done.
*/
if (result != 0) {
/*
* if the preauth type done didn't use a passwd just ignore the
* error.
*/
if (kmd && kmd->preauth_type == KRB_PKINIT)
return (PAM_IGNORE);
if (result == 2)
display_msg(pamh, PAM_ERROR_MSG, dgettext(TEXT_DOMAIN,
"Old Kerberos password incorrect\n"));
return (PAM_AUTHTOK_ERR);
}
/*
* If the old password verifies try to change it regardless of the
* preauth type and do not ignore the error.
*/
result = krb5_changepw(pamh, user, oldpass, newpass, debug);
if (result == PAM_SUCCESS) {
display_msg(pamh, PAM_TEXT_INFO, dgettext(TEXT_DOMAIN,
"Kerberos password successfully changed\n"));
get_set_creds(pamh, kmd, user, newpass, debug);
}
out:
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): out: returns %d",
result);
return (result);
}
int
krb5_verifypw(
char *princ_str,
char *old_password,
int debug)
{
kadm5_ret_t code;
krb5_principal princ = 0;
char admin_realm[1024];
char kprinc[2*MAXHOSTNAMELEN];
char *cpw_service;
void *server_handle;
krb5_context context;
kadm5_config_params params;
(void) memset((char *)¶ms, 0, sizeof (params));
if (code = krb5_init_secure_context(&context)) {
return (6);
}
if ((code = get_kmd_kuser(context, (const char *)princ_str, kprinc,
2*MAXHOSTNAMELEN)) != 0) {
return (code);
}
/* Need to get a krb5_principal struct */
code = krb5_parse_name(context, kprinc, &princ);
if (code != 0)
return (6);
if (strlen(old_password) == 0) {
krb5_free_principal(context, princ);
return (5);
}
(void) strlcpy(admin_realm,
krb5_princ_realm(context, princ)->data,
sizeof (admin_realm));
params.mask |= KADM5_CONFIG_REALM;
params.realm = admin_realm;
if (kadm5_get_cpw_host_srv_name(context, admin_realm, &cpw_service)) {
__pam_log(LOG_AUTH | LOG_ERR,
"PAM-KRB5 (password): unable to get host based "
"service name for realm %s\n",
admin_realm);
krb5_free_principal(context, princ);
return (3);
}
code = kadm5_init_with_password(kprinc, old_password, cpw_service,
¶ms, KADM5_STRUCT_VERSION,
KADM5_API_VERSION_2, NULL,
&server_handle);
if (code != 0) {
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5: krb5_verifypw: init_with_pw"
" failed: (%s)", error_message(code));
krb5_free_principal(context, princ);
return ((code == KADM5_BAD_PASSWORD) ? 2 : 3);
}
krb5_free_principal(context, princ);
(void) kadm5_destroy(server_handle);
return (0);
}
/*
* Function: krb5_changepw
*
* Purpose: Initialize and call lower level routines to change a password
*
* Arguments:
*
* princ_str principal name to use, optional
* old_password old password
* new_password new password
*
* Returns:
* exit status of PAM_SUCCESS for success
* else returns PAM failure
*
* Requires:
* Passwords cannot be more than 255 characters long.
*
* Modifies:
*
* Changes the principal's password.
*
*/
static int
krb5_changepw(
pam_handle_t *pamh,
char *princ_str,
char *old_password,
char *new_password,
int debug)
{
kadm5_ret_t code;
krb5_principal princ = 0;
char msg_ret[1024], admin_realm[1024];
char kprinc[2*MAXHOSTNAMELEN];
char *cpw_service;
void *server_handle;
krb5_context context;
kadm5_config_params params;
(void) memset((char *)¶ms, 0, sizeof (params));
if (krb5_init_secure_context(&context) != 0)
return (PAM_SYSTEM_ERR);
if ((code = get_kmd_kuser(context, (const char *)princ_str, kprinc,
2*MAXHOSTNAMELEN)) != 0) {
return (code);
}
/* Need to get a krb5_principal struct */
code = krb5_parse_name(context, kprinc, &princ);
if (code != 0)
return (PAM_SYSTEM_ERR);
if (strlen(old_password) == 0) {
krb5_free_principal(context, princ);
return (PAM_AUTHTOK_ERR);
}
(void) snprintf(admin_realm, sizeof (admin_realm), "%s",
krb5_princ_realm(context, princ)->data);
params.mask |= KADM5_CONFIG_REALM;
params.realm = admin_realm;
if (kadm5_get_cpw_host_srv_name(context, admin_realm, &cpw_service)) {
__pam_log(LOG_AUTH | LOG_ERR,
"PAM-KRB5 (password):unable to get host based "
"service name for realm %s\n",
admin_realm);
return (PAM_SYSTEM_ERR);
}
code = kadm5_init_with_password(kprinc, old_password, cpw_service,
¶ms, KADM5_STRUCT_VERSION,
KADM5_API_VERSION_2, NULL,
&server_handle);
free(cpw_service);
if (code != 0) {
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): changepw: "
"init_with_pw failed: (%s)", error_message(code));
krb5_free_principal(context, princ);
return ((code == KADM5_BAD_PASSWORD) ?
PAM_AUTHTOK_ERR : PAM_SYSTEM_ERR);
}
code = kadm5_chpass_principal_util(server_handle, princ,
new_password,
NULL /* don't need pw back */,
msg_ret,
sizeof (msg_ret));
if (code) {
char msgs[2][PAM_MAX_MSG_SIZE];
(void) snprintf(msgs[0], PAM_MAX_MSG_SIZE, "%s",
dgettext(TEXT_DOMAIN,
"Kerberos password not changed: "));
(void) snprintf(msgs[1], PAM_MAX_MSG_SIZE, "%s", msg_ret);
display_msgs(pamh, PAM_ERROR_MSG, 2, msgs);
}
krb5_free_principal(context, princ);
(void) kadm5_destroy(server_handle);
if (debug)
__pam_log(LOG_AUTH | LOG_DEBUG,
"PAM-KRB5 (password): changepw: end %d", code);
if (code != 0)
return (PAM_AUTHTOK_ERR);
return (PAM_SUCCESS);
}
static void
display_msgs(pam_handle_t *pamh,
int msg_style, int nmsg, char msgs[][PAM_MAX_MSG_SIZE])
{
(void) __pam_display_msg(pamh, msg_style, nmsg, msgs, NULL);
}
static void
display_msg(pam_handle_t *pamh, int msg_style, char *msg)
{
char pam_msg[1][PAM_MAX_MSG_SIZE];
(void) snprintf(pam_msg[0], PAM_MAX_MSG_SIZE, "%s", msg);
display_msgs(pamh, msg_style, 1, pam_msg);
}