/* $OpenBSD: tb_asnmth.c,v 1.6 2017/01/29 17:49:23 beck Exp $ */

/* ====================================================================

 * Copyright (c) 2006 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 <string.h>

#include <openssl/err.h>

#include "eng_int.h"

#include "asn1_locl.h"

#include <openssl/evp.h>

/* If this symbol is defined then ENGINE_get_pkey_asn1_meth_engine(), the

 * function that is used by EVP to hook in pkey_asn1_meth code and cache

 * defaults (etc), will display brief debugging summaries to stderr with the

 * 'nid'. */

/* #define ENGINE_PKEY_ASN1_METH_DEBUG */

static ENGINE_TABLE *pkey_asn1_meth_table = NULL;

void

ENGINE_unregister_pkey_asn1_meths(ENGINE *e)

{

  engine_table_unregister(&pkey_asn1_meth_table, e);

}

static void

engine_unregister_all_pkey_asn1_meths(void)

{

  engine_table_cleanup(&pkey_asn1_meth_table);

}

int

ENGINE_register_pkey_asn1_meths(ENGINE *e)

{

  if (e->pkey_asn1_meths) {

    const int *nids;

    int num_nids = e->pkey_asn1_meths(e, NULL, &nids, 0);

    if (num_nids > 0)

      return engine_table_register(&pkey_asn1_meth_table,

          engine_unregister_all_pkey_asn1_meths, e, nids,

          num_nids, 0);

  }

  return 1;

}

void

ENGINE_register_all_pkey_asn1_meths(void)

{

  ENGINE *e;

  for (e = ENGINE_get_first(); e; e = ENGINE_get_next(e))

    ENGINE_register_pkey_asn1_meths(e);

}

int

ENGINE_set_default_pkey_asn1_meths(ENGINE *e)

{

  if (e->pkey_asn1_meths) {

    const int *nids;

    int num_nids = e->pkey_asn1_meths(e, NULL, &nids, 0);

    if (num_nids > 0)

      return engine_table_register(&pkey_asn1_meth_table,

          engine_unregister_all_pkey_asn1_meths, e, nids,

          num_nids, 1);

  }

  return 1;

}

/* Exposed API function to get a functional reference from the implementation

 * table (ie. try to get a functional reference from the tabled structural

 * references) for a given pkey_asn1_meth 'nid' */

ENGINE *

ENGINE_get_pkey_asn1_meth_engine(int nid)

{

  return engine_table_select(&pkey_asn1_meth_table, nid);

}

/* Obtains a pkey_asn1_meth implementation from an ENGINE functional reference */

const EVP_PKEY_ASN1_METHOD *

ENGINE_get_pkey_asn1_meth(ENGINE *e, int nid)

{

  EVP_PKEY_ASN1_METHOD *ret;

  ENGINE_PKEY_ASN1_METHS_PTR fn = ENGINE_get_pkey_asn1_meths(e);

  if (!fn || !fn(e, &ret, NULL, nid)) {

    ENGINEerror(ENGINE_R_UNIMPLEMENTED_PUBLIC_KEY_METHOD);

    return NULL;

  }

  return ret;

}

/* Gets the pkey_asn1_meth callback from an ENGINE structure */

ENGINE_PKEY_ASN1_METHS_PTR

ENGINE_get_pkey_asn1_meths(const ENGINE *e)

{

  return e->pkey_asn1_meths;

}

/* Sets the pkey_asn1_meth callback in an ENGINE structure */

int

ENGINE_set_pkey_asn1_meths(ENGINE *e, ENGINE_PKEY_ASN1_METHS_PTR f)

{

  e->pkey_asn1_meths = f;

  return 1;

}

/* Internal function to free up EVP_PKEY_ASN1_METHOD structures before an

 * ENGINE is destroyed

 */

void

engine_pkey_asn1_meths_free(ENGINE *e)

{

  int i;

  EVP_PKEY_ASN1_METHOD *pkm;

  if (e->pkey_asn1_meths) {

    const int *pknids;

    int npknids;

    npknids = e->pkey_asn1_meths(e, NULL, &pknids, 0);

    for (i = 0; i < npknids; i++) {

      if (e->pkey_asn1_meths(e, &pkm, NULL, pknids[i])) {

        EVP_PKEY_asn1_free(pkm);

      }

    }

  }

}

/* Find a method based on a string. This does a linear search through

 * all implemented algorithms. This is OK in practice because only

 * a small number of algorithms are likely to be implemented in an engine

 * and it is not used for speed critical operations.

 */

const EVP_PKEY_ASN1_METHOD *

ENGINE_get_pkey_asn1_meth_str(ENGINE *e, const char *str, int len)

{

  int i, nidcount;

  const int *nids;

  EVP_PKEY_ASN1_METHOD *ameth;

  if (!e->pkey_asn1_meths)

    return NULL;

  if (len == -1)

    len = strlen(str);

  nidcount = e->pkey_asn1_meths(e, NULL, &nids, 0);

  for (i = 0; i < nidcount; i++) {

    e->pkey_asn1_meths(e, &ameth, NULL, nids[i]);

    if (((int)strlen(ameth->pem_str) == len) &&

        !strncasecmp(ameth->pem_str, str, len))

      return ameth;

  }

  return NULL;

}

typedef struct {

  ENGINE *e;

  const EVP_PKEY_ASN1_METHOD *ameth;

  const char *str;

  int len;

} ENGINE_FIND_STR;

static void

look_str_cb(int nid, STACK_OF(ENGINE) *sk, ENGINE *def, void *arg)

{

  ENGINE_FIND_STR *lk = arg;

  int i;

  if (lk->ameth)

    return;

  for (i = 0; i < sk_ENGINE_num(sk); i++) {

    ENGINE *e = sk_ENGINE_value(sk, i);

    EVP_PKEY_ASN1_METHOD *ameth;

    e->pkey_asn1_meths(e, &ameth, NULL, nid);

    if (((int)strlen(ameth->pem_str) == lk->len) &&

        !strncasecmp(ameth->pem_str, lk->str, lk->len)) {

      lk->e = e;

      lk->ameth = ameth;

      return;

    }

  }

}

const EVP_PKEY_ASN1_METHOD *

ENGINE_pkey_asn1_find_str(ENGINE **pe, const char *str, int len)

{

  ENGINE_FIND_STR fstr;

  fstr.e = NULL;

  fstr.ameth = NULL;

  fstr.str = str;

  fstr.len = len;

  CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);

  engine_table_doall(pkey_asn1_meth_table, look_str_cb, &fstr);

  /* If found obtain a structural reference to engine */

  if (fstr.e) {

    fstr.e->struct_ref++;

    engine_ref_debug(fstr.e, 0, 1)

  }

  *pe = fstr.e;

  CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);

  return fstr.ameth;

}