pam_modules/unix_account/unix_acct.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) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
 */


#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_impl.h>
#include <syslog.h>
#include <pwd.h>
#include <shadow.h>
#include <lastlog.h>
#include <ctype.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <libintl.h>
#include <signal.h>
#include <thread.h>
#include <synch.h>
#include <errno.h>
#include <time.h>
#include <string.h>
#include <crypt.h>
#include <assert.h>
#include <deflt.h>
#include <libintl.h>
#include <passwdutil.h>

#define LASTLOG     "/var/adm/lastlog"
#define LOGINADMIN  "/etc/default/login"
#define UNIX_AUTH_DATA      "SUNW-UNIX-AUTH-DATA"
#define UNIX_AUTHTOK_DATA   "SUNW-UNIX-AUTHTOK-DATA"

/*
 * Function Declarations
 */
extern void     setusershell();
extern int      _nfssys(int, void *);

typedef struct _unix_authtok_data_ {
    int age_status;
}unix_authtok_data;

/*ARGSUSED*/
static void
unix_cleanup(
    pam_handle_t *pamh,
    void *data,
    int pam_status)
{
    free((unix_authtok_data *)data);
}

/*
 * check_for_login_inactivity   - Check for login inactivity
 *
 */

static int
check_for_login_inactivity(
    uid_t       pw_uid,
    struct  spwd    *shpwd)
{
    int     fdl;
    struct lastlog  ll;
    int     retval;
    offset_t    offset;

    offset = (offset_t)pw_uid * (offset_t)sizeof (struct lastlog);

    if ((fdl = open(LASTLOG, O_RDWR|O_CREAT, 0444)) >= 0) {
        /*
         * Read the last login (ll) time
         */
        if (llseek(fdl, offset, SEEK_SET) != offset) {
            __pam_log(LOG_AUTH | LOG_ERR,
                "pam_unix_acct: pam_sm_acct_mgmt: "
                "can't obtain last login info on uid %d "
                "(uid too large)", pw_uid);
            (void) close(fdl);
            return (0);
        }

        retval = read(fdl, (char *)&ll, sizeof (ll));

        /* Check for login inactivity */

        if ((shpwd->sp_inact > 0) && (retval == sizeof (ll)) &&
            ll.ll_time) {
            /*
             * account inactive too long.
             * and no update password set
             * and no last pwd change date in shadow file
             * and last pwd change more than inactive time
             * then account inactive too long and no access.
             */
            if (((time_t)((ll.ll_time / DAY) + shpwd->sp_inact)
                < DAY_NOW) &&
                (shpwd->sp_lstchg != 0) &&
                (shpwd->sp_lstchg != -1) &&
                ((shpwd->sp_lstchg + shpwd->sp_inact) < DAY_NOW)) {
                /*
                 * Account inactive for too long
                 */
                (void) close(fdl);
                return (1);
            }
        }

        (void) close(fdl);
    }
    return (0);
}

/*
 * new_password_check()
 *
 * check to see if the user needs to change their password
 */

static int
new_password_check(shpwd, flags)
    struct  spwd    *shpwd;
    int         flags;
{
    time_t  now  = DAY_NOW;

    /*
     * We want to make sure that we change the password only if
     * passwords are required for the system, the user does not
     * have a password, AND the user's NULL password can be changed
     * according to its password aging information
     */

    if ((flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) {
        if (shpwd->sp_pwdp[0] == '\0') {
            if (((shpwd->sp_max == -1) ||
                ((time_t)shpwd->sp_lstchg > now) ||
                ((now >= (time_t)(shpwd->sp_lstchg +
                            shpwd->sp_min)) &&
                (shpwd->sp_max >= shpwd->sp_min)))) {
                    return (PAM_NEW_AUTHTOK_REQD);
            }
        }
    }
    return (PAM_SUCCESS);
}

/*
 * perform_passwd_aging_check
 *      - Check for password exipration.
 */
static  int
perform_passwd_aging_check(
    pam_handle_t *pamh,
    struct  spwd    *shpwd,
    int flags)
{
    time_t  now = DAY_NOW;
    int idledays = -1;
    char    *ptr;
    char    messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];
    void    *defp;


    if ((defp = defopen_r(LOGINADMIN)) != NULL) {
        if ((ptr = defread_r("IDLEWEEKS=", defp)) != NULL)
            idledays = 7 * atoi(ptr);
        defclose_r(defp);
    }

    /*
     * if (sp_lstchg == 0), the administrator has forced the
     * user to change his/her passwd
     */
    if (shpwd->sp_lstchg == 0)
        return (PAM_NEW_AUTHTOK_REQD);

    /* If password aging is disabled (or min>max), all is well */
    if (shpwd->sp_max < 0 || shpwd->sp_max < shpwd->sp_min)
        return (PAM_SUCCESS);

    /* Password aging is enabled. See if the password has aged */
    if (now < (time_t)(shpwd->sp_lstchg + shpwd->sp_max))
        return (PAM_SUCCESS);

    /* Password has aged. Has it aged more than idledays ? */
    if (idledays < 0)           /* IDLEWEEKS not configured */
        return (PAM_NEW_AUTHTOK_REQD);

    /* idledays is configured */
    if (idledays > 0 && (now < (time_t)(shpwd->sp_lstchg + idledays)))
        return (PAM_NEW_AUTHTOK_REQD);

    /* password has aged more that allowed for by IDLEWEEKS */
    if (!(flags & PAM_SILENT)) {
        (void) strlcpy(messages[0], dgettext(TEXT_DOMAIN,
            "Your password has been expired for too long."),
            sizeof (messages[0]));
        (void) strlcpy(messages[1], dgettext(TEXT_DOMAIN,
            "Please contact the system administrator."),
            sizeof (messages[0]));
        (void) __pam_display_msg(pamh, PAM_ERROR_MSG, 2, messages,
            NULL);
    }
    return (PAM_AUTHTOK_EXPIRED);
}

/*
 * warn_user_passwd_will_expire - warn the user when the password will
 *                    expire.
 */

static void
warn_user_passwd_will_expire(
    pam_handle_t *pamh,
    struct  spwd shpwd)
{
    time_t  now = DAY_NOW;
    char    messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];
    time_t  days;


    if ((shpwd.sp_warn > 0) && (shpwd.sp_max > 0) &&
        (now + shpwd.sp_warn) >= (time_t)(shpwd.sp_lstchg + shpwd.sp_max)) {
        days = (time_t)(shpwd.sp_lstchg + shpwd.sp_max) - now;
        if (days <= 0)
            (void) snprintf(messages[0],
                sizeof (messages[0]),
                dgettext(TEXT_DOMAIN,
                "Your password will expire within 24 hours."));
        else if (days == 1)
            (void) snprintf(messages[0],
                sizeof (messages[0]),
                dgettext(TEXT_DOMAIN,
                "Your password will expire in 1 day."));
        else
            (void) snprintf(messages[0],
                sizeof (messages[0]),
                dgettext(TEXT_DOMAIN,
                "Your password will expire in %d days."),
                (int)days);

        (void) __pam_display_msg(pamh, PAM_TEXT_INFO, 1, messages,
            NULL);
    }
}

/*
 * pam_sm_acct_mgmt -   main account managment routine.
 *            Returns: module error or specific error on failure
 */

int
pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv)
{
    uid_t           pw_uid;
    char            *repository_name = NULL;
    char            *user;
    attrlist        attr_pw[3];
    attrlist        attr_spw[7];
    pwu_repository_t    *pwu_rep = PWU_DEFAULT_REP;
    pwu_repository_t    *auth_rep = NULL;
    int             error = PAM_ACCT_EXPIRED;
    int         result;
    int         i;
    int         debug = 0;
    int         server_policy = 0;
    unix_authtok_data   *status;
    struct  spwd        shpwd = {NULL, NULL,
                    -1, -1, -1, -1, -1, -1, 0};

    for (i = 0; i < argc; i++) {
        if (strcasecmp(argv[i], "debug") == 0)
            debug = 1;
        else if (strcasecmp(argv[i], "server_policy") == 0)
            server_policy = 1;
        else if (strcasecmp(argv[i], "nowarn") == 0) {
            flags = flags | PAM_SILENT;
        } else {
            __pam_log(LOG_AUTH | LOG_ERR,
                "ACCOUNT:pam_sm_acct_mgmt: illegal option %s",
                argv[i]);
        }
    }

    if (debug)
        __pam_log(LOG_AUTH | LOG_DEBUG,
            "pam_unix_account: entering pam_sm_acct_mgmt()");

    if ((error = pam_get_item(pamh, PAM_USER, (void **)&user))
        != PAM_SUCCESS)
        goto out;

    if (user == NULL) {
        error = PAM_USER_UNKNOWN;
        goto out;
    } else
        shpwd.sp_namp = user;

    if ((error = pam_get_item(pamh, PAM_REPOSITORY, (void **)&auth_rep))
        != PAM_SUCCESS)
        goto out;

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

    /*
     * First get the password information
     */
    attr_pw[0].type =  ATTR_REP_NAME;   attr_pw[0].next = &attr_pw[1];
    attr_pw[1].type =  ATTR_UID;        attr_pw[1].next = &attr_pw[2];
    attr_pw[2].type =  ATTR_PASSWD;     attr_pw[2].next = NULL;
    result = __get_authtoken_attr(user, pwu_rep, attr_pw);

    if (result == PWU_NOT_FOUND) {
        error = PAM_USER_UNKNOWN;
        goto out;
    } else if (result == PWU_DENIED) {
        error = PAM_PERM_DENIED;
        goto out;
    } else if (result == PWU_NOMEM) {
        error = PAM_BUF_ERR;
        goto out;
    } else if (result != PWU_SUCCESS) {
        error = PAM_SERVICE_ERR;
        goto out;
    } else {
        repository_name = attr_pw[0].data.val_s;
        pw_uid = attr_pw[1].data.val_i;
        shpwd.sp_pwdp = attr_pw[2].data.val_s;
    }

    /*
     * if repository is not files|nis, and user wants server_policy,
     * we don't care about aging and hence return PAM_IGNORE
     */
    if (server_policy &&
        strcmp(repository_name, "files") != 0 &&
        strcmp(repository_name, "nis") != 0) {
        error = PAM_IGNORE;
        goto out;
    }

    /*
     * Now get the aging information
     */
    attr_spw[0].type =  ATTR_LSTCHG;    attr_spw[0].next = &attr_spw[1];
    attr_spw[1].type =  ATTR_MIN;       attr_spw[1].next = &attr_spw[2];
    attr_spw[2].type =  ATTR_MAX;       attr_spw[2].next = &attr_spw[3];
    attr_spw[3].type =  ATTR_WARN;      attr_spw[3].next = &attr_spw[4];
    attr_spw[4].type =  ATTR_INACT;     attr_spw[4].next = &attr_spw[5];
    attr_spw[5].type =  ATTR_EXPIRE;    attr_spw[5].next = &attr_spw[6];
    attr_spw[6].type =  ATTR_FLAG;      attr_spw[6].next = NULL;

    result = __get_authtoken_attr(user, pwu_rep, attr_spw);
    if (result == PWU_SUCCESS) {
        shpwd.sp_lstchg = attr_spw[0].data.val_i;
        shpwd.sp_min = attr_spw[1].data.val_i;
        shpwd.sp_max = attr_spw[2].data.val_i;
        shpwd.sp_warn = attr_spw[3].data.val_i;
        shpwd.sp_inact = attr_spw[4].data.val_i;
        shpwd.sp_expire = attr_spw[5].data.val_i;
        shpwd.sp_flag = attr_spw[6].data.val_i;
    }

    if (debug) {
        char *pw = "Unix PW";

        if (shpwd.sp_pwdp == NULL) {
            pw = "NULL";
        } else if (strncmp(shpwd.sp_pwdp, LOCKSTRING,
            sizeof (LOCKSTRING) - 1) == 0) {
            pw = LOCKSTRING;
        } else if (strcmp(shpwd.sp_pwdp, NOPWDRTR) == 0) {
            pw = NOPWDRTR;
        } else if (strcmp(shpwd.sp_pwdp, UNINITPW) == 0) {
            pw = UNINITPW;
        }

        if (result ==  PWU_DENIED) {
            __pam_log(LOG_AUTH | LOG_DEBUG,
                "pam_unix_account: %s: permission denied "
                "to access password aging information. "
                "Using defaults.", user);
        }

        __pam_log(LOG_AUTH | LOG_DEBUG,
            "%s Policy:Unix, pw=%s, lstchg=%d, min=%d, max=%d, "
            "warn=%d, inact=%d, expire=%d",
            user, pw, shpwd.sp_lstchg, shpwd.sp_min, shpwd.sp_max,
            shpwd.sp_warn, shpwd.sp_inact, shpwd.sp_expire);
    }

    if (pwu_rep != PWU_DEFAULT_REP) {
        free(pwu_rep);
        pwu_rep = PWU_DEFAULT_REP;
    }

    if (result == PWU_NOT_FOUND) {
        error = PAM_USER_UNKNOWN;
        goto out;
    } else if (result == PWU_NOMEM) {
        error = PAM_BUF_ERR;
        goto out;
    } else if (result != PWU_SUCCESS && result != PWU_DENIED) {
        error = PAM_SERVICE_ERR;
        goto out;
    }

    /*
     * Check for locked account
     */
    if (shpwd.sp_pwdp != NULL &&
        strncmp(shpwd.sp_pwdp, LOCKSTRING, sizeof (LOCKSTRING) - 1) == 0) {
        char *service;
        char *rhost = NULL;

        (void) pam_get_item(pamh, PAM_SERVICE, (void **)&service);
        (void) pam_get_item(pamh, PAM_RHOST, (void **)&rhost);
        __pam_log(LOG_AUTH | LOG_NOTICE,
            "pam_unix_account: %s attempting to validate locked "
            "account %s from %s",
            service, user,
            (rhost != NULL && *rhost != '\0') ? rhost : "local host");
        error = PAM_PERM_DENIED;
        goto out;
    }

    /*
     * Check for NULL password and, if so, see if such is allowed
     */
    if (shpwd.sp_pwdp[0] == '\0' &&
        (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) {
        char *service;
        char *rhost = NULL;

        (void) pam_get_item(pamh, PAM_SERVICE, (void **)&service);
        (void) pam_get_item(pamh, PAM_RHOST, (void **)&rhost);

        __pam_log(LOG_AUTH | LOG_NOTICE,
            "pam_unix_account: %s: empty password not allowed for "
            "account %s from %s", service, user,
            (rhost != NULL && *rhost != '\0') ? rhost : "local host");
        error = PAM_PERM_DENIED;
        goto out;
    }

    /*
     * Check for account expiration
     */
    if (shpwd.sp_expire > 0 &&
        (time_t)shpwd.sp_expire < DAY_NOW) {
        error = PAM_ACCT_EXPIRED;
        goto out;
    }

    /*
     * Check for excessive login account inactivity
     */
    if (check_for_login_inactivity(pw_uid, &shpwd)) {
        error = PAM_PERM_DENIED;
        goto out;
    }

    /*
     * Check to see if the user needs to change their password
     */
    if (error = new_password_check(&shpwd, flags)) {
        goto out;
    }

    /*
     * Check to make sure password aging information is okay
     */
    if ((error = perform_passwd_aging_check(pamh, &shpwd, flags))
        != PAM_SUCCESS) {
        goto out;
    }

    /*
     * Finally, warn the user if their password is about to expire.
     */
    if (!(flags & PAM_SILENT)) {
        warn_user_passwd_will_expire(pamh, shpwd);
    }

    /*
     * All done, return Success
     */
    error = PAM_SUCCESS;

out:

    {
        int pam_res;
        unix_authtok_data *authtok_data;

        if (debug) {
            __pam_log(LOG_AUTH | LOG_DEBUG,
                "pam_unix_account: %s: %s",
                (user == NULL)?"NULL":user,
                pam_strerror(pamh, error));
        }

        if (repository_name)
            free(repository_name);
        if (pwu_rep != PWU_DEFAULT_REP)
            free(pwu_rep);
        if (shpwd.sp_pwdp) {
            (void) memset(shpwd.sp_pwdp, 0, strlen(shpwd.sp_pwdp));
            free(shpwd.sp_pwdp);
        }

        /* store the password aging status in the pam handle */
        pam_res = pam_get_data(pamh, UNIX_AUTHTOK_DATA,
            (const void **)&authtok_data);

        if ((status = (unix_authtok_data *)calloc(1,
            sizeof (unix_authtok_data))) == NULL) {
            return (PAM_BUF_ERR);
        }

        if (pam_res == PAM_SUCCESS)
            (void) memcpy(status, authtok_data,
                sizeof (unix_authtok_data));

        status->age_status = error;
        if (pam_set_data(pamh, UNIX_AUTHTOK_DATA, status, unix_cleanup)
            != PAM_SUCCESS) {
            free(status);
            return (PAM_SERVICE_ERR);
        }
    }

    return (error);
}