/*

 * Copyright 2002-2019 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include "internal/cryptlib.h"

#include <stdio.h>

#include <ctype.h>

#include <openssl/crypto.h>

#include "internal/conf.h"

#include "internal/dso.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, const char *name, const 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(const char *name);

static int module_init(CONF_MODULE *pmod, const char *name, const char *value,

                       const CONF *cnf);

static CONF_MODULE *module_load_dso(const CONF *cnf, const char *name,

                                    const char *value);

/* 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 == NULL)

        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)

        OPENSSL_free(file);

    NCONF_free(conf);

    if (flags & CONF_MFLAGS_IGNORE_RETURN_CODES)

        return 1;

    return ret;

}

static int module_run(const CONF *cnf, const char *name, const 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);

    if (!md) {

        if (!(flags & CONF_MFLAGS_SILENT)) {

            CONFerr(CONF_F_MODULE_RUN, CONF_R_UNKNOWN_MODULE_NAME);

            ERR_add_error_data(2, "module=", name);

        }

        return -1;

    }

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

    if (ret <= 0) {

        if (!(flags & CONF_MFLAGS_SILENT)) {

            char rcode[DECIMAL_SIZE(ret) + 1];

            CONFerr(CONF_F_MODULE_RUN, CONF_R_MODULE_INITIALIZATION_ERROR);

            BIO_snprintf(rcode, sizeof(rcode), "%-8d", ret);

            ERR_add_error_data(6, "module=", name, ", value=", value,

                               ", retcode=", rcode);

        }

    }

    return ret;

}

/* Load a module from a DSO */

static CONF_MODULE *module_load_dso(const CONF *cnf,

                                    const char *name, const char *value)

{

    DSO *dso = NULL;

    conf_init_func *ifunc;

    conf_finish_func *ffunc;

    const 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:

    DSO_free(dso);

    CONFerr(CONF_F_MODULE_LOAD_DSO, errcode);

    ERR_add_error_data(4, "module=", name, ", path=", 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 (supported_modules == NULL)

        supported_modules = sk_CONF_MODULE_new_null();

    if (supported_modules == NULL)

        return NULL;

    if ((tmod = OPENSSL_zalloc(sizeof(*tmod))) == NULL) {

        CONFerr(CONF_F_MODULE_ADD, ERR_R_MALLOC_FAILURE);

        return NULL;

    }

    tmod->dso = dso;

    tmod->name = OPENSSL_strdup(name);

    tmod->init = ifunc;

    tmod->finish = ffunc;

    if (tmod->name == NULL) {

        OPENSSL_free(tmod);

        return NULL;

    }

    if (!sk_CONF_MODULE_push(supported_modules, tmod)) {

        OPENSSL_free(tmod->name);

        OPENSSL_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(const 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) == 0)

            return tmod;

    }

    return NULL;

}

/* initialize a module */

static int module_init(CONF_MODULE *pmod, const char *name, const char *value,

                       const CONF *cnf)

{

    int ret = 1;

    int init_called = 0;

    CONF_IMODULE *imod = NULL;

    /* Otherwise add initialized module to list */

    imod = OPENSSL_malloc(sizeof(*imod));

    if (imod == NULL)

        goto err;

    imod->pmod = pmod;

    imod->name = OPENSSL_strdup(name);

    imod->value = OPENSSL_strdup(value);

    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) {

            CONFerr(CONF_F_MODULE_INIT, ERR_R_MALLOC_FAILURE);

            goto err;

        }

    }

    if (!sk_CONF_IMODULE_push(initialized_modules, imod)) {

        CONFerr(CONF_F_MODULE_INIT, 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) {

        OPENSSL_free(imod->name);

        OPENSSL_free(imod->value);

        OPENSSL_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)

{

    DSO_free(md->dso);

    OPENSSL_free(md->name);

    OPENSSL_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)

        return;

    if (imod->pmod->finish)

        imod->pmod->finish(imod);

    imod->pmod->links--;

    OPENSSL_free(imod->name);

    OPENSSL_free(imod->value);

    OPENSSL_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_int(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, *sep = "";

    int len;

    if ((file = ossl_safe_getenv("OPENSSL_CONF")) != NULL)

        return OPENSSL_strdup(file);

    len = strlen(X509_get_default_cert_area());

#ifndef OPENSSL_SYS_VMS

    len++;

    sep = "/";

#endif

    len += strlen(OPENSSL_CONF);

    file = OPENSSL_malloc(len + 1);

    if (file == NULL)

        return NULL;

    BIO_snprintf(file, len + 1, "%s%s%s", X509_get_default_cert_area(),

                 sep, OPENSSL_CONF);

    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) {

        CONFerr(CONF_F_CONF_PARSE_LIST, 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;

    }

}