/*

 * Copyright 2006-2018 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 "e_os.h"

#include "eng_local.h"

#include <openssl/evp.h>

#include "crypto/asn1.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)) {

        ENGINEerr(ENGINE_F_ENGINE_GET_PKEY_ASN1_METH,

                  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 (ameth != NULL

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

            && strncasecmp(ameth->pem_str, str, len) == 0)

            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 (ameth != NULL

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

                && strncasecmp(ameth->pem_str, lk->str, lk->len) == 0) {

            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;

    if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) {

        ENGINEerr(ENGINE_F_ENGINE_PKEY_ASN1_FIND_STR, ERR_R_MALLOC_FAILURE);

        return NULL;

    }

    CRYPTO_THREAD_write_lock(global_engine_lock);

    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_THREAD_unlock(global_engine_lock);

    return fstr.ameth;

}