source: openpam/trunk/lib/libpam/openpam_dispatch.c @ 935

/*-
 * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
 * Copyright (c) 2004-2017 Dag-Erling Smørgrav
 * All rights reserved.
 *
 * This software was developed for the FreeBSD Project by ThinkSec AS and
 * Network Associates Laboratories, the Security Research Division of
 * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
 * ("CBOSS"), as part of the DARPA CHATS research program.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: openpam_dispatch.c 935 2017-04-26 21:04:10Z des $
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <sys/param.h>

#include <stdint.h>

#include <security/pam_appl.h>

#include "openpam_impl.h"

#if !defined(OPENPAM_RELAX_CHECKS)
static void openpam_check_error_code(int, int);
#else
#define openpam_check_error_code(a, b)
#endif /* !defined(OPENPAM_RELAX_CHECKS) */

/*
 * OpenPAM internal
 *
 * Execute a module chain
 */

int
openpam_dispatch(pam_handle_t *pamh,
        int primitive,
        int flags)
{
        pam_chain_t *chain;
        int err, fail, nsuccess, r;
        int debug;

        ENTER();

        /* prevent recursion */
        if (pamh->current != NULL) {
                openpam_log(PAM_LOG_ERROR,
                    "%s() called while %s::%s() is in progress",
                    pam_func_name[primitive],
                    pamh->current->module->path,
                    pam_sm_func_name[pamh->primitive]);
                RETURNC(PAM_ABORT);
        }

        /* pick a chain */
        switch (primitive) {
        case PAM_SM_AUTHENTICATE:
        case PAM_SM_SETCRED:
                chain = pamh->chains[PAM_AUTH];
                break;
        case PAM_SM_ACCT_MGMT:
                chain = pamh->chains[PAM_ACCOUNT];
                break;
        case PAM_SM_OPEN_SESSION:
        case PAM_SM_CLOSE_SESSION:
                chain = pamh->chains[PAM_SESSION];
                break;
        case PAM_SM_CHAUTHTOK:
                chain = pamh->chains[PAM_PASSWORD];
                break;
        default:
                RETURNC(PAM_SYSTEM_ERR);
        }

        /* execute */
        err = PAM_SUCCESS;
        fail = nsuccess = 0;
        for (; chain != NULL; chain = chain->next) {
                if (chain->module->func[primitive] == NULL) {
                        openpam_log(PAM_LOG_ERROR, "%s: no %s()",
                            chain->module->path, pam_sm_func_name[primitive]);
                        r = PAM_SYMBOL_ERR;
                } else {
                        pamh->primitive = primitive;
                        pamh->current = chain;
                        debug = (openpam_get_option(pamh, "debug") != NULL);
                        if (debug)
                                ++openpam_debug;
                        openpam_log(PAM_LOG_LIBDEBUG, "calling %s() in %s",
                            pam_sm_func_name[primitive], chain->module->path);
                        r = (chain->module->func[primitive])(pamh, flags,
                            chain->optc, (const char **)(intptr_t)chain->optv);
                        pamh->current = NULL;
                        openpam_log(PAM_LOG_LIBDEBUG, "%s: %s(): %s",
                            chain->module->path, pam_sm_func_name[primitive],
                            pam_strerror(pamh, r));
                        if (debug)
                                --openpam_debug;
                }

                if (r == PAM_IGNORE)
                        continue;
                if (r == PAM_SUCCESS) {
                        ++nsuccess;
                        /*
                         * For pam_setcred() and pam_chauthtok() with the
                         * PAM_PRELIM_CHECK flag, treat "sufficient" as
                         * "optional".
                         */
                        if ((chain->flag == PAM_SUFFICIENT ||
                            chain->flag == PAM_BINDING) && !fail &&
                            primitive != PAM_SM_SETCRED &&
                            !(primitive == PAM_SM_CHAUTHTOK &&
                                (flags & PAM_PRELIM_CHECK)))
                                break;
                        continue;
                }

                openpam_check_error_code(primitive, r);

                /*
                 * Record the return code from the first module to
                 * fail.  If a required module fails, record the
                 * return code from the first required module to fail.
                 */
                if (err == PAM_SUCCESS)
                        err = r;
                if ((chain->flag == PAM_REQUIRED ||
                    chain->flag == PAM_BINDING) && !fail) {
                        openpam_log(PAM_LOG_LIBDEBUG, "required module failed");
                        fail = 1;
                        err = r;
                }

                /*
                 * If a requisite module fails, terminate the chain
                 * immediately.
                 */
                if (chain->flag == PAM_REQUISITE) {
                        openpam_log(PAM_LOG_LIBDEBUG, "requisite module failed");
                        fail = 1;
                        break;
                }
        }

        if (!fail && err != PAM_NEW_AUTHTOK_REQD)
                err = PAM_SUCCESS;

        /*
         * Require the chain to be non-empty, and at least one module
         * in the chain to be successful, so that we don't fail open.
         */
        if (err == PAM_SUCCESS && nsuccess < 1) {
                openpam_log(PAM_LOG_ERROR,
                    "all modules were unsuccessful for %s()",
                    pam_sm_func_name[primitive]);
                err = PAM_SYSTEM_ERR;
        }

        RETURNC(err);
}

#if !defined(OPENPAM_RELAX_CHECKS)
static void
openpam_check_error_code(int primitive, int r)
{
        /* common error codes */
        if (r == PAM_SUCCESS ||
            r == PAM_SYSTEM_ERR ||
            r == PAM_SERVICE_ERR ||
            r == PAM_BUF_ERR ||
            r == PAM_CONV_ERR ||
            r == PAM_PERM_DENIED ||
            r == PAM_ABORT)
                return;

        /* specific error codes */
        switch (primitive) {
        case PAM_SM_AUTHENTICATE:
                if (r == PAM_AUTH_ERR ||
                    r == PAM_CRED_INSUFFICIENT ||
                    r == PAM_AUTHINFO_UNAVAIL ||
                    r == PAM_USER_UNKNOWN ||
                    r == PAM_MAXTRIES)
                        return;
                break;
        case PAM_SM_SETCRED:
                if (r == PAM_CRED_UNAVAIL ||
                    r == PAM_CRED_EXPIRED ||
                    r == PAM_USER_UNKNOWN ||
                    r == PAM_CRED_ERR)
                        return;
                break;
        case PAM_SM_ACCT_MGMT:
                if (r == PAM_USER_UNKNOWN ||
                    r == PAM_AUTH_ERR ||
                    r == PAM_NEW_AUTHTOK_REQD ||
                    r == PAM_ACCT_EXPIRED)
                        return;
                break;
        case PAM_SM_OPEN_SESSION:
        case PAM_SM_CLOSE_SESSION:
                if (r == PAM_SESSION_ERR)
                        return;
                break;
        case PAM_SM_CHAUTHTOK:
                if (r == PAM_PERM_DENIED ||
                    r == PAM_AUTHTOK_ERR ||
                    r == PAM_AUTHTOK_RECOVERY_ERR ||
                    r == PAM_AUTHTOK_LOCK_BUSY ||
                    r == PAM_AUTHTOK_DISABLE_AGING ||
                    r == PAM_TRY_AGAIN)
                        return;
                break;
        }

        openpam_log(PAM_LOG_ERROR, "%s(): unexpected return value %d",
            pam_sm_func_name[primitive], r);
}
#endif /* !defined(OPENPAM_RELAX_CHECKS) */

/*
 * NODOC
 *
 * Error codes:
 */