pam_modules/authtok_store/authtok_store.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 (c) 2004, 2011, Oracle and/or its affiliates. All rights reserved.
 */


#include <sys/types.h>
#include <sys/varargs.h>
#include <string.h>
#include <syslog.h>
#include <stdlib.h>

#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_impl.h>

#include <user_attr.h>
#include <secdb.h>

#include <libintl.h>

#include <passwdutil.h>
#include <shadow.h>

/*PRINTFLIKE3*/
static void
error(int nowarn, pam_handle_t *pamh, char *fmt, ...)
{
    va_list ap;
    char messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];

    va_start(ap, fmt);
    (void) vsnprintf(messages[0], sizeof (messages[0]), fmt, ap);
    if (nowarn == 0)
        (void) __pam_display_msg(pamh, PAM_ERROR_MSG, 1, messages,
            NULL);
    va_end(ap);
}

/*PRINTFLIKE3*/
static void
info(int nowarn, pam_handle_t *pamh, char *fmt, ...)
{
    va_list ap;
    char messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];

    va_start(ap, fmt);
    (void) vsnprintf(messages[0], sizeof (messages[0]), fmt, ap);
    if (nowarn == 0)
        (void) __pam_display_msg(pamh, PAM_TEXT_INFO, 1, messages,
            NULL);
    va_end(ap);
}

#if defined(ENABLE_AGING)
/*
 * test if authtok is aged.
 * returns 1 if it is, 0 otherwise
 */
static int
authtok_is_aged(pam_handle_t *pamh)
{
    unix_authtok_data *status;

    if (pam_get_data(pamh, UNIX_AUTHTOK_DATA,
        (const void **)status) != PAM_SUCCESS)
        return (0);

    return (status->age_status == PAM_NEW_AUTHTOK_REQD)
}
#endif

int
pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
    int i;
    int debug = 0;
    int nowarn = 0;
    attrlist l;
    pwu_repository_t *pwu_rep;
    char *user;
    char *oldpw;
    char *newpw;
    char *service;
    struct pam_repository *auth_rep;
    int res;
    int updated_reps = 0;
    int server_policy = 0;
    userattr_t *ue;

    for (i = 0; i < argc; i++) {
        if (strcmp(argv[i], "debug") == 0)
            debug = 1;
        else if (strcmp(argv[i], "nowarn") == 0)
            nowarn = 1;
        else if (strcmp(argv[i], "server_policy") == 0)
            server_policy = 1;
    }

    if ((flags & PAM_PRELIM_CHECK) != 0)
        return (PAM_IGNORE);

    if ((flags & PAM_UPDATE_AUTHTOK) == 0)
        return (PAM_SYSTEM_ERR);

    if ((flags & PAM_SILENT) != 0)
        nowarn = 1;

    if (debug)
        syslog(LOG_DEBUG, "pam_authtok_store: storing authtok");

#if defined(ENABLE_AGING)
    if ((flags & PAM_CHANGE_EXPIRED_AUTHTOK) && !authtok_is_aged(pamh)) {
        syslog(LOG_DEBUG, "pam_authtok_store: System password young");
        return (PAM_IGNORE);
    }
#endif

    res = pam_get_item(pamh, PAM_SERVICE, (void **)&service);
    if (res != PAM_SUCCESS) {
        syslog(LOG_ERR, "pam_authtok_store: error getting SERVICE");
        return (PAM_SYSTEM_ERR);
    }

    res = pam_get_item(pamh, PAM_USER, (void **)&user);
    if (res != PAM_SUCCESS) {
        syslog(LOG_ERR, "pam_authtok_store: error getting USER");
        return (PAM_SYSTEM_ERR);
    }

    /*
     * If the PAM_USER who's password is being changed is a role
     * with roleauth=user then we ignore it because those accounts
     * should not have a UNIX password.  We can't return a failure
     * though because the account may have other creds (eg kerberos)
     * that should be getting updated in the PAM stack for password.
     * We also warn the user and tell them what to do to resolve it.
     */
    if (user == NULL || *user == '\0') {
        syslog(LOG_ERR, "pam_authtok_store: username is empty");
        return (PAM_USER_UNKNOWN);
    } else if ((ue = getusernam(user)) != NULL) {
        char *utype, *ra;

        utype = kva_match((kva_t *)ue->attr, USERATTR_TYPE_KW);
        ra = kva_match((kva_t  *)ue->attr, USERATTR_ROLE_AUTH_KW);
        if (utype != NULL && strcmp(utype, USERATTR_TYPE_ROLE) == 0 &&
            ra != NULL && strcmp(ra, USERATTR_ROLE_AUTH_USER) == 0) {
            info(nowarn, pamh, dgettext(TEXT_DOMAIN,
                "%s: Role '%s' has roleauth=user. "
                "UNIX password updates are ignored."),
                service, user);
            return (PAM_IGNORE);
        }
    }

    res = pam_get_item(pamh, PAM_OLDAUTHTOK, (void **)&oldpw);
    if (res != PAM_SUCCESS) {
        syslog(LOG_ERR, "pam_authtok_store: error getting OLDAUTHTOK");
        return (PAM_SYSTEM_ERR);
    }

    res = pam_get_item(pamh, PAM_AUTHTOK, (void **)&newpw);
    if (res != PAM_SUCCESS || newpw == NULL) {
        /*
         * A module on the stack has removed PAM_AUTHTOK. We fail
         */
        return (PAM_SYSTEM_ERR);
    }

    l.data.val_s = newpw;
    /*
     * If the server_policy option is specified,
     * use the special attribute, ATTR_PASSWD_SERVER_POLICY,
     * to tell the update routine for each repository
     * to perform the necessary special operations.
     * For now, only the LDAP routine treats this attribute
     * differently that ATTR_PASSWD. It will skip the
     * crypting of the password before storing it in the LDAP
     * server. NIS, and FILES will handle ATTR_PASSWD_SERVER_POLICY
     * the same as ATTR_PASSWD.
     */
    if (server_policy)
        l.type = ATTR_PASSWD_SERVER_POLICY;
    else
        l.type = ATTR_PASSWD;
    l.next = NULL;

    res = pam_get_item(pamh, PAM_REPOSITORY, (void **)&auth_rep);
    if (res != PAM_SUCCESS) {
        syslog(LOG_ERR, "pam_authtok_store: error getting repository");
        return (PAM_SYSTEM_ERR);
    }

    if (auth_rep == NULL) {
        pwu_rep = PWU_DEFAULT_REP;
    } else {
        if ((pwu_rep = calloc(1, sizeof (*pwu_rep))) == NULL)
            return (PAM_BUF_ERR);
        pwu_rep->type = auth_rep->type;
        pwu_rep->scope = auth_rep->scope;
        pwu_rep->scope_len = auth_rep->scope_len;
    }

    res = __set_authtoken_attr(user, oldpw, pwu_rep, &l, &updated_reps);

    if (pwu_rep != PWU_DEFAULT_REP)
        free(pwu_rep);
    /*
     * now map the various passwdutil return states to user messages
     * and PAM return codes.
     */
    switch (res) {
    case PWU_SUCCESS:
        for (i = 1; i <= REP_LAST; i <<= 1) {
            if ((updated_reps & i) == 0)
                continue;
            info(nowarn, pamh, dgettext(TEXT_DOMAIN,
                "%s: password successfully changed for %s"),
                service, user);
        }
        res = PAM_SUCCESS;
        break;
    case PWU_BUSY:
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: Password database busy. Try again later."),
            service);
        res = PAM_AUTHTOK_LOCK_BUSY;
        break;
    case PWU_STAT_FAILED:
        syslog(LOG_ERR, "%s: stat of password file failed", service);
        res = PAM_AUTHTOK_ERR;
        break;
    case PWU_OPEN_FAILED:
    case PWU_WRITE_FAILED:
    case PWU_CLOSE_FAILED:
    case PWU_UPDATE_FAILED:
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: Unexpected failure. Password database unchanged."),
            service);
        res = PAM_SYSTEM_ERR;
        break;
    case PWU_NOT_FOUND:
        /* Different error if repository was explicitly specified */
        if (auth_rep != NULL) {
            error(nowarn, pamh, dgettext(TEXT_DOMAIN,
                "%s: System error: no %s password for %s."),
                service, auth_rep->type, user);
        } else {
            error(nowarn, pamh, dgettext(TEXT_DOMAIN,
                "%s: %s does not exist."), service, user);
        }
        res = PAM_USER_UNKNOWN;
        break;
    case PWU_NOMEM:
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: Internal memory allocation failure."), service);
        res = PAM_BUF_ERR;
        break;
    case PWU_SERVER_ERROR:
        res = PAM_SYSTEM_ERR;
        break;
    case PWU_SYSTEM_ERROR:
        res = PAM_SYSTEM_ERR;
        break;
    case PWU_DENIED:
        res = PAM_PERM_DENIED;
        break;
    case PWU_NO_CHANGE:
        /*
         * we're not changing anything.
         */
        info(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: Password information unchanged."), service);
        res = PAM_SUCCESS;
        break;
    case PWU_REPOSITORY_ERROR:
        syslog(LOG_NOTICE, "pam_authtok_store: detected "
            "unsupported configuration in /etc/nsswitch.conf.");
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: System error: repository out of range."), service);
        res = PAM_SYSTEM_ERR;
        break;
    case PWU_PWD_TOO_SHORT:
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: Password too short."), service);
        res = PAM_AUTHTOK_ERR;
        break;
    case PWU_PWD_INVALID:
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: Invalid password syntax."), service);
        res = PAM_AUTHTOK_ERR;
        break;
    case PWU_PWD_IN_HISTORY:
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: Reuse of old passwords not "
            "allowed, the new password is in the history list."),
            service);
        res = PAM_AUTHTOK_ERR;
        break;
    case PWU_CHANGE_NOT_ALLOWED:
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: You may not change "
            "this password."), service);
        res = PAM_PERM_DENIED;
        break;
    case PWU_WITHIN_MIN_AGE:
        error(nowarn, pamh, dgettext(TEXT_DOMAIN,
            "%s: Password can not be changed yet, "
            "not enough time has passed."), service);
        res = PAM_PERM_DENIED;
        break;
    default:
        res = PAM_SYSTEM_ERR;
        break;
    }

    return (res);
}