/* $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;

  }

}