/* $OpenBSD: conf_mod.c,v 1.27 2017/01/29 17:49:22 beck Exp $ */
/* Written by Stephen Henson (steve@openssl.org) for the OpenSSL
 * project 2001.
 */
/* ====================================================================
 * Copyright (c) 2001 The OpenSSL Project.  All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <openssl/conf.h>
#include <openssl/crypto.h>
#include <openssl/dso.h>
#include <openssl/err.h>
#include <openssl/x509.h>

#define DSO_mod_init_name "OPENSSL_init"
#define DSO_mod_finish_name "OPENSSL_finish"

/* This structure contains a data about supported modules.
 * entries in this table correspond to either dynamic or
 * static modules.
 */

struct conf_module_st {
        /* DSO of this module or NULL if static */
        DSO *dso;
        /* Name of the module */
        char *name;
        /* Init function */
        conf_init_func *init;
        /* Finish function */
        conf_finish_func *finish;
        /* Number of successfully initialized modules */
        int links;
        void *usr_data;
};


/* This structure contains information about modules that have been
 * successfully initialized. There may be more than one entry for a
 * given module.
 */

struct conf_imodule_st {
        CONF_MODULE *pmod;
        char *name;
        char *value;
        unsigned long flags;
        void *usr_data;
};

static STACK_OF(CONF_MODULE) *supported_modules = NULL;
static STACK_OF(CONF_IMODULE) *initialized_modules = NULL;

static void module_free(CONF_MODULE *md);
static void module_finish(CONF_IMODULE *imod);
static int module_run(const CONF *cnf, char *name, char *value,
    unsigned long flags);
static CONF_MODULE *module_add(DSO *dso, const char *name,
    conf_init_func *ifunc, conf_finish_func *ffunc);
static CONF_MODULE *module_find(char *name);
static int module_init(CONF_MODULE *pmod, char *name, char *value,
    const CONF *cnf);
static CONF_MODULE *module_load_dso(const CONF *cnf, char *name, char *value,
    unsigned long flags);

/* Main function: load modules from a CONF structure */

int
CONF_modules_load(const CONF *cnf, const char *appname, unsigned long flags)
{
        STACK_OF(CONF_VALUE) *values;
        CONF_VALUE *vl;
        char *vsection = NULL;

        int ret, i;

        if (!cnf)
                return 1;

        if (appname)
                vsection = NCONF_get_string(cnf, NULL, appname);

        if (!appname || (!vsection && (flags & CONF_MFLAGS_DEFAULT_SECTION)))
                vsection = NCONF_get_string(cnf, NULL, "openssl_conf");

        if (!vsection) {
                ERR_clear_error();
                return 1;
        }

        values = NCONF_get_section(cnf, vsection);

        if (!values)
                return 0;

        for (i = 0; i < sk_CONF_VALUE_num(values); i++) {
                vl = sk_CONF_VALUE_value(values, i);
                ret = module_run(cnf, vl->name, vl->value, flags);
                if (ret <= 0)
                        if (!(flags & CONF_MFLAGS_IGNORE_ERRORS))
                                return ret;
        }

        return 1;
}

int
CONF_modules_load_file(const char *filename, const char *appname,
    unsigned long flags)
{
        char *file = NULL;
        CONF *conf = NULL;
        int ret = 0;
        conf = NCONF_new(NULL);
        if (!conf)
                goto err;

        if (filename == NULL) {
                file = CONF_get1_default_config_file();
                if (!file)
                        goto err;
        } else
                file = (char *)filename;

        if (NCONF_load(conf, file, NULL) <= 0) {
                if ((flags & CONF_MFLAGS_IGNORE_MISSING_FILE) &&
                    (ERR_GET_REASON(ERR_peek_last_error()) ==
                    CONF_R_NO_SUCH_FILE)) {
                        ERR_clear_error();
                        ret = 1;
                }
                goto err;
        }

        ret = CONF_modules_load(conf, appname, flags);

err:
        if (filename == NULL)
                free(file);
        NCONF_free(conf);

        return ret;
}

static int
module_run(const CONF *cnf, char *name, char *value, unsigned long flags)
{
        CONF_MODULE *md;
        int ret;

        md = module_find(name);

        /* Module not found: try to load DSO */
        if (!md && !(flags & CONF_MFLAGS_NO_DSO))
                md = module_load_dso(cnf, name, value, flags);

        if (!md) {
                if (!(flags & CONF_MFLAGS_SILENT)) {
                        CONFerror(CONF_R_UNKNOWN_MODULE_NAME);
                        ERR_asprintf_error_data("module=%s", name);
                }
                return -1;
        }

        ret = module_init(md, name, value, cnf);

        if (ret <= 0) {
                if (!(flags & CONF_MFLAGS_SILENT)) {
                        CONFerror(CONF_R_MODULE_INITIALIZATION_ERROR);
                        ERR_asprintf_error_data
                            ("module=%s, value=%s, retcode=%-8d",
                            name, value, ret);
                }
        }

        return ret;
}

/* Load a module from a DSO */
static CONF_MODULE *
module_load_dso(const CONF *cnf, char *name, char *value, unsigned long flags)
{
        DSO *dso = NULL;
        conf_init_func *ifunc;
        conf_finish_func *ffunc;
        char *path = NULL;
        int errcode = 0;
        CONF_MODULE *md;

        /* Look for alternative path in module section */
        path = NCONF_get_string(cnf, value, "path");
        if (!path) {
                ERR_clear_error();
                path = name;
        }
        dso = DSO_load(NULL, path, NULL, 0);
        if (!dso) {
                errcode = CONF_R_ERROR_LOADING_DSO;
                goto err;
        }
        ifunc = (conf_init_func *)DSO_bind_func(dso, DSO_mod_init_name);
        if (!ifunc) {
                errcode = CONF_R_MISSING_INIT_FUNCTION;
                goto err;
        }
        ffunc = (conf_finish_func *)DSO_bind_func(dso, DSO_mod_finish_name);
        /* All OK, add module */
        md = module_add(dso, name, ifunc, ffunc);

        if (!md)
                goto err;

        return md;

err:
        if (dso)
                DSO_free(dso);
        CONFerror(errcode);
        ERR_asprintf_error_data("module=%s, path=%s", name, path);
        return NULL;
}

/* add module to list */
static CONF_MODULE *
module_add(DSO *dso, const char *name, conf_init_func *ifunc,
    conf_finish_func *ffunc)
{
        CONF_MODULE *tmod = NULL;

        if (name == NULL)
                return NULL;
        if (supported_modules == NULL)
                supported_modules = sk_CONF_MODULE_new_null();
        if (supported_modules == NULL)
                return NULL;
        tmod = malloc(sizeof(CONF_MODULE));
        if (tmod == NULL)
                return NULL;

        tmod->dso = dso;
        tmod->name = strdup(name);
        tmod->init = ifunc;
        tmod->finish = ffunc;
        tmod->links = 0;

        if (!sk_CONF_MODULE_push(supported_modules, tmod)) {
                free(tmod);
                return NULL;
        }

        return tmod;
}

/* Find a module from the list. We allow module names of the
 * form modname.XXXX to just search for modname to allow the
 * same module to be initialized more than once.
 */

static CONF_MODULE *
module_find(char *name)
{
        CONF_MODULE *tmod;
        int i, nchar;
        char *p;

        p = strrchr(name, '.');

        if (p)
                nchar = p - name;
        else
                nchar = strlen(name);

        for (i = 0; i < sk_CONF_MODULE_num(supported_modules); i++) {
                tmod = sk_CONF_MODULE_value(supported_modules, i);
                if (!strncmp(tmod->name, name, nchar))
                        return tmod;
        }

        return NULL;
}

/* initialize a module */
static int
module_init(CONF_MODULE *pmod, char *name, char *value, const CONF *cnf)
{
        int ret = 1;
        int init_called = 0;
        CONF_IMODULE *imod = NULL;

        /* Otherwise add initialized module to list */
        imod = malloc(sizeof(CONF_IMODULE));
        if (!imod)
                goto err;

        imod->pmod = pmod;
        imod->name = name ? strdup(name) : NULL;
        imod->value = value ? strdup(value) : NULL;
        imod->usr_data = NULL;

        if (!imod->name || !imod->value)
                goto memerr;

        /* Try to initialize module */
        if (pmod->init) {
                ret = pmod->init(imod, cnf);
                init_called = 1;
                /* Error occurred, exit */
                if (ret <= 0)
                        goto err;
        }

        if (initialized_modules == NULL) {
                initialized_modules = sk_CONF_IMODULE_new_null();
                if (!initialized_modules) {
                        CONFerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
        }

        if (!sk_CONF_IMODULE_push(initialized_modules, imod)) {
                CONFerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        pmod->links++;

        return ret;

err:
        /* We've started the module so we'd better finish it */
        if (pmod->finish && init_called)
                pmod->finish(imod);

memerr:
        if (imod) {
                free(imod->name);
                free(imod->value);
                free(imod);
        }

        return -1;
}

/* Unload any dynamic modules that have a link count of zero:
 * i.e. have no active initialized modules. If 'all' is set
 * then all modules are unloaded including static ones.
 */

void
CONF_modules_unload(int all)
{
        int i;
        CONF_MODULE *md;

        CONF_modules_finish();

        /* unload modules in reverse order */
        for (i = sk_CONF_MODULE_num(supported_modules) - 1; i >= 0; i--) {
                md = sk_CONF_MODULE_value(supported_modules, i);
                /* If static or in use and 'all' not set ignore it */
                if (((md->links > 0) || !md->dso) && !all)
                        continue;
                /* Since we're working in reverse this is OK */
                (void)sk_CONF_MODULE_delete(supported_modules, i);
                module_free(md);
        }
        if (sk_CONF_MODULE_num(supported_modules) == 0) {
                sk_CONF_MODULE_free(supported_modules);
                supported_modules = NULL;
        }
}

/* unload a single module */
static void
module_free(CONF_MODULE *md)
{
        if (md->dso)
                DSO_free(md->dso);
        free(md->name);
        free(md);
}

/* finish and free up all modules instances */

void
CONF_modules_finish(void)
{
        CONF_IMODULE *imod;

        while (sk_CONF_IMODULE_num(initialized_modules) > 0) {
                imod = sk_CONF_IMODULE_pop(initialized_modules);
                module_finish(imod);
        }
        sk_CONF_IMODULE_free(initialized_modules);
        initialized_modules = NULL;
}

/* finish a module instance */

static void
module_finish(CONF_IMODULE *imod)
{
        if (imod->pmod->finish)
                imod->pmod->finish(imod);
        imod->pmod->links--;
        free(imod->name);
        free(imod->value);
        free(imod);
}

/* Add a static module to OpenSSL */

int
CONF_module_add(const char *name, conf_init_func *ifunc,
    conf_finish_func *ffunc)
{
        if (module_add(NULL, name, ifunc, ffunc))
                return 1;
        else
                return 0;
}

void
CONF_modules_free(void)
{
        CONF_modules_finish();
        CONF_modules_unload(1);
}

/* Utility functions */

const char *
CONF_imodule_get_name(const CONF_IMODULE *md)
{
        return md->name;
}

const char *
CONF_imodule_get_value(const CONF_IMODULE *md)
{
        return md->value;
}

void *
CONF_imodule_get_usr_data(const CONF_IMODULE *md)
{
        return md->usr_data;
}

void
CONF_imodule_set_usr_data(CONF_IMODULE *md, void *usr_data)
{
        md->usr_data = usr_data;
}

CONF_MODULE *
CONF_imodule_get_module(const CONF_IMODULE *md)
{
        return md->pmod;
}

unsigned long
CONF_imodule_get_flags(const CONF_IMODULE *md)
{
        return md->flags;
}

void
CONF_imodule_set_flags(CONF_IMODULE *md, unsigned long flags)
{
        md->flags = flags;
}

void *
CONF_module_get_usr_data(CONF_MODULE *pmod)
{
        return pmod->usr_data;
}

void
CONF_module_set_usr_data(CONF_MODULE *pmod, void *usr_data)
{
        pmod->usr_data = usr_data;
}

/* Return default config file name */

char *
CONF_get1_default_config_file(void)
{
        char *file = NULL;

        if (asprintf(&file, "%s/openssl.cnf",
            X509_get_default_cert_area()) == -1)
                return (NULL);
        return file;
}

/* This function takes a list separated by 'sep' and calls the
 * callback function giving the start and length of each member
 * optionally stripping leading and trailing whitespace. This can
 * be used to parse comma separated lists for example.
 */

int
CONF_parse_list(const char *list_, int sep, int nospc,
    int (*list_cb)(const char *elem, int len, void *usr), void *arg)
{
        int ret;
        const char *lstart, *tmpend, *p;

        if (list_ == NULL) {
                CONFerror(CONF_R_LIST_CANNOT_BE_NULL);
                return 0;
        }

        lstart = list_;
        for (;;) {
                if (nospc) {
                        while (*lstart && isspace((unsigned char)*lstart))
                                lstart++;
                }
                p = strchr(lstart, sep);
                if (p == lstart || !*lstart)
                        ret = list_cb(NULL, 0, arg);
                else {
                        if (p)
                                tmpend = p - 1;
                        else
                                tmpend = lstart + strlen(lstart) - 1;
                        if (nospc) {
                                while (isspace((unsigned char)*tmpend))
                                        tmpend--;
                        }
                        ret = list_cb(lstart, tmpend - lstart + 1, arg);
                }
                if (ret <= 0)
                        return ret;
                if (p == NULL)
                        return 1;
                lstart = p + 1;
        }
}