/*

 * Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (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 <openssl/core_names.h>

#include "internal/cryptlib.h"

#include "internal/nelem.h"

#include "crypto/evp.h"

#include "internal/core.h"

#include "internal/provider.h"

#include "evp_local.h"

/*

 * match_type() checks if two EVP_KEYMGMT are matching key types.  This

 * function assumes that the caller has made all the necessary NULL checks.

 */

static int match_type(const EVP_KEYMGMT *keymgmt1, const EVP_KEYMGMT *keymgmt2)

{

    const char *name2 = EVP_KEYMGMT_get0_name(keymgmt2);

    return EVP_KEYMGMT_is_a(keymgmt1, name2);

}

int evp_keymgmt_util_try_import(const OSSL_PARAM params[], void *arg)

{

    struct evp_keymgmt_util_try_import_data_st *data = arg;

    int delete_on_error = 0;

    /* Just in time creation of keydata */

    if (data->keydata == NULL) {

        if ((data->keydata = evp_keymgmt_newdata(data->keymgmt)) == NULL) {

            ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);

            return 0;

        }

        delete_on_error = 1;

    }

    /*

     * It's fine if there was no data to transfer, we just end up with an

     * empty destination key.

     */

    if (params[0].key == NULL)

        return 1;

    if (evp_keymgmt_import(data->keymgmt, data->keydata, data->selection,

                           params))

        return 1;

    if (delete_on_error) {

        evp_keymgmt_freedata(data->keymgmt, data->keydata);

        data->keydata = NULL;

    }

    return 0;

}

int evp_keymgmt_util_assign_pkey(EVP_PKEY *pkey, EVP_KEYMGMT *keymgmt,

                                 void *keydata)

{

    if (pkey == NULL || keymgmt == NULL || keydata == NULL

        || !EVP_PKEY_set_type_by_keymgmt(pkey, keymgmt)) {

        ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);

        return 0;

    }

    pkey->keydata = keydata;

    evp_keymgmt_util_cache_keyinfo(pkey);

    return 1;

}

EVP_PKEY *evp_keymgmt_util_make_pkey(EVP_KEYMGMT *keymgmt, void *keydata)

{

    EVP_PKEY *pkey = NULL;

    if (keymgmt == NULL

        || keydata == NULL

        || (pkey = EVP_PKEY_new()) == NULL

        || !evp_keymgmt_util_assign_pkey(pkey, keymgmt, keydata)) {

        EVP_PKEY_free(pkey);

        return NULL;

    }

    return pkey;

}

int evp_keymgmt_util_export(const EVP_PKEY *pk, int selection,

                            OSSL_CALLBACK *export_cb, void *export_cbarg)

{

    if (pk == NULL || export_cb == NULL)

        return 0;

    return evp_keymgmt_export(pk->keymgmt, pk->keydata, selection,

                              export_cb, export_cbarg);

}

void *evp_keymgmt_util_export_to_provider(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,

                                          int selection)

{

    struct evp_keymgmt_util_try_import_data_st import_data;

    OP_CACHE_ELEM *op;

    /* Export to where? */

    if (keymgmt == NULL)

        return NULL;

    /* If we have an unassigned key, give up */

    if (pk->keydata == NULL)

        return NULL;

    /*

     * If |keymgmt| matches the "origin" |keymgmt|, there is no more to do.

     * The "origin" is determined by the |keymgmt| pointers being identical

     * or when the provider and the name ID match.  The latter case handles the

     * situation where the fetch cache is flushed and a "new" key manager is

     * created.

     */

    if (pk->keymgmt == keymgmt

        || (pk->keymgmt->name_id == keymgmt->name_id

            && pk->keymgmt->prov == keymgmt->prov))

        return pk->keydata;

    if (!CRYPTO_THREAD_read_lock(pk->lock))

        return NULL;

    /*

     * If the provider native "origin" hasn't changed since last time, we

     * try to find our keymgmt in the operation cache.  If it has changed

     * and our keymgmt isn't found, we will clear the cache further down.

     */

    if (pk->dirty_cnt == pk->dirty_cnt_copy) {

        /* If this key is already exported to |keymgmt|, no more to do */

        op = evp_keymgmt_util_find_operation_cache(pk, keymgmt, selection);

        if (op != NULL && op->keymgmt != NULL) {

            void *ret = op->keydata;

            CRYPTO_THREAD_unlock(pk->lock);

            return ret;

        }

    }

    CRYPTO_THREAD_unlock(pk->lock);

    /* If the "origin" |keymgmt| doesn't support exporting, give up */

    if (pk->keymgmt->export == NULL)

        return NULL;

    /*

     * Make sure that the type of the keymgmt to export to matches the type

     * of the "origin"

     */

    if (!ossl_assert(match_type(pk->keymgmt, keymgmt)))

        return NULL;

    /*

     * We look at the already cached provider keys, and import from the

     * first that supports it (i.e. use its export function), and export

     * the imported data to the new provider.

     */

    /* Setup for the export callback */

    import_data.keydata = NULL;  /* evp_keymgmt_util_try_import will create it */

    import_data.keymgmt = keymgmt;

    import_data.selection = selection;

    /*

     * The export function calls the callback (evp_keymgmt_util_try_import),

     * which does the import for us.  If successful, we're done.

     */

    if (!evp_keymgmt_util_export(pk, selection,

                                 &evp_keymgmt_util_try_import, &import_data))

        /* If there was an error, bail out */

        return NULL;

    if (!CRYPTO_THREAD_write_lock(pk->lock)) {

        evp_keymgmt_freedata(keymgmt, import_data.keydata);

        return NULL;

    }

    /* Check to make sure some other thread didn't get there first */

    op = evp_keymgmt_util_find_operation_cache(pk, keymgmt, selection);

    if (op != NULL && op->keydata != NULL) {

        void *ret = op->keydata;

        CRYPTO_THREAD_unlock(pk->lock);

        /*

         * Another thread seemms to have already exported this so we abandon

         * all the work we just did.

         */

        evp_keymgmt_freedata(keymgmt, import_data.keydata);

        return ret;

    }

    /*

     * If the dirty counter changed since last time, then clear the

     * operation cache.  In that case, we know that |i| is zero.

     */

    if (pk->dirty_cnt != pk->dirty_cnt_copy)

        evp_keymgmt_util_clear_operation_cache(pk, 0);

    /* Add the new export to the operation cache */

    if (!evp_keymgmt_util_cache_keydata(pk, keymgmt, import_data.keydata,

                                        selection)) {

        CRYPTO_THREAD_unlock(pk->lock);

        evp_keymgmt_freedata(keymgmt, import_data.keydata);

        return NULL;

    }

    /* Synchronize the dirty count */

    pk->dirty_cnt_copy = pk->dirty_cnt;

    CRYPTO_THREAD_unlock(pk->lock);

    return import_data.keydata;

}

static void op_cache_free(OP_CACHE_ELEM *e)

{

    evp_keymgmt_freedata(e->keymgmt, e->keydata);

    EVP_KEYMGMT_free(e->keymgmt);

    OPENSSL_free(e);

}

int evp_keymgmt_util_clear_operation_cache(EVP_PKEY *pk, int locking)

{

    if (pk != NULL) {

        if (locking && pk->lock != NULL && !CRYPTO_THREAD_write_lock(pk->lock))

            return 0;

        sk_OP_CACHE_ELEM_pop_free(pk->operation_cache, op_cache_free);

        pk->operation_cache = NULL;

        if (locking && pk->lock != NULL)

            CRYPTO_THREAD_unlock(pk->lock);

    }

    return 1;

}

OP_CACHE_ELEM *evp_keymgmt_util_find_operation_cache(EVP_PKEY *pk,

                                                     EVP_KEYMGMT *keymgmt,

                                                     int selection)

{

    int i, end = sk_OP_CACHE_ELEM_num(pk->operation_cache);

    OP_CACHE_ELEM *p;

    /*

     * A comparison and sk_P_CACHE_ELEM_find() are avoided to not cause

     * problems when we've only a read lock.

     */

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

        p = sk_OP_CACHE_ELEM_value(pk->operation_cache, i);

        if (keymgmt == p->keymgmt && (p->selection & selection) == selection)

            return p;

    }

    return NULL;

}

int evp_keymgmt_util_cache_keydata(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,

                                   void *keydata, int selection)

{

    OP_CACHE_ELEM *p = NULL;

    if (keydata != NULL) {

        if (pk->operation_cache == NULL) {

            pk->operation_cache = sk_OP_CACHE_ELEM_new_null();

            if (pk->operation_cache == NULL)

                return 0;

        }

        p = OPENSSL_malloc(sizeof(*p));

        if (p == NULL)

            return 0;

        p->keydata = keydata;

        p->keymgmt = keymgmt;

        p->selection = selection;

        if (!EVP_KEYMGMT_up_ref(keymgmt)) {

            OPENSSL_free(p);

            return 0;

        }

        if (!sk_OP_CACHE_ELEM_push(pk->operation_cache, p)) {

            EVP_KEYMGMT_free(keymgmt);

            OPENSSL_free(p);

            return 0;

        }

    }

    return 1;

}

void evp_keymgmt_util_cache_keyinfo(EVP_PKEY *pk)

{

    /*

     * Cache information about the provider "origin" key.

     *

     * This services functions like EVP_PKEY_get_size, EVP_PKEY_get_bits, etc

     */

    if (pk->keydata != NULL) {

        int bits = 0;

        int security_bits = 0;

        int size = 0;

        OSSL_PARAM params[4];

        params[0] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_BITS, &bits);

        params[1] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_SECURITY_BITS,

                                             &security_bits);

        params[2] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_MAX_SIZE, &size);

        params[3] = OSSL_PARAM_construct_end();

        if (evp_keymgmt_get_params(pk->keymgmt, pk->keydata, params)) {

            pk->cache.size = size;

            pk->cache.bits = bits;

            pk->cache.security_bits = security_bits;

        }

    }

}

void *evp_keymgmt_util_fromdata(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,

                                int selection, const OSSL_PARAM params[])

{

    void *keydata = NULL;

    if ((keydata = evp_keymgmt_newdata(keymgmt)) == NULL

        || !evp_keymgmt_import(keymgmt, keydata, selection, params)

        || !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {

        evp_keymgmt_freedata(keymgmt, keydata);

        keydata = NULL;

    }

    return keydata;

}

int evp_keymgmt_util_has(EVP_PKEY *pk, int selection)

{

    /* Check if key is even assigned */

    if (pk->keymgmt == NULL)

        return 0;

    return evp_keymgmt_has(pk->keymgmt, pk->keydata, selection);

}

/*

 * evp_keymgmt_util_match() doesn't just look at the provider side "origin",

 * but also in the operation cache to see if there's any common keymgmt that

 * supplies OP_keymgmt_match.

 *

 * evp_keymgmt_util_match() adheres to the return values that EVP_PKEY_eq()

 * and EVP_PKEY_parameters_eq() return, i.e.:

 *

 *  1   same key

 *  0   not same key

 * -1   not same key type

 * -2   unsupported operation

 */

int evp_keymgmt_util_match(EVP_PKEY *pk1, EVP_PKEY *pk2, int selection)

{

    EVP_KEYMGMT *keymgmt1 = NULL, *keymgmt2 = NULL;

    void *keydata1 = NULL, *keydata2 = NULL;

    if (pk1 == NULL || pk2 == NULL) {

        if (pk1 == NULL && pk2 == NULL)

            return 1;

        return 0;

    }

    keymgmt1 = pk1->keymgmt;

    keydata1 = pk1->keydata;

    keymgmt2 = pk2->keymgmt;

    keydata2 = pk2->keydata;

    if (keymgmt1 != keymgmt2) {

        /*

         * The condition for a successful cross export is that the

         * keydata to be exported is NULL (typed, but otherwise empty

         * EVP_PKEY), or that it was possible to export it with

         * evp_keymgmt_util_export_to_provider().

         *

         * We use |ok| to determine if it's ok to cross export one way,

         * but also to determine if we should attempt a cross export

         * the other way.  There's no point doing it both ways.

         */

        int ok = 0;

        /* Complex case, where the keymgmt differ */

        if (keymgmt1 != NULL

            && keymgmt2 != NULL

            && !match_type(keymgmt1, keymgmt2)) {

            ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);

            return -1;           /* Not the same type */

        }

        /*

         * The key types are determined to match, so we try cross export,

         * but only to keymgmt's that supply a matching function.

         */

        if (keymgmt2 != NULL

            && keymgmt2->match != NULL) {

            void *tmp_keydata = NULL;

            ok = 1;

            if (keydata1 != NULL) {

                tmp_keydata =

                    evp_keymgmt_util_export_to_provider(pk1, keymgmt2,

                                                        selection);

                ok = (tmp_keydata != NULL);

            }

            if (ok) {

                keymgmt1 = keymgmt2;

                keydata1 = tmp_keydata;

            }

        }

        /*

         * If we've successfully cross exported one way, there's no point

         * doing it the other way, hence the |!ok| check.

         */

        if (!ok

            && keymgmt1 != NULL

            && keymgmt1->match != NULL) {

            void *tmp_keydata = NULL;

            ok = 1;

            if (keydata2 != NULL) {

                tmp_keydata =

                    evp_keymgmt_util_export_to_provider(pk2, keymgmt1,

                                                        selection);

                ok = (tmp_keydata != NULL);

            }

            if (ok) {

                keymgmt2 = keymgmt1;

                keydata2 = tmp_keydata;

            }

        }

    }

    /* If we still don't have matching keymgmt implementations, we give up */

    if (keymgmt1 != keymgmt2)

        return -2;

    /* If both keydata are NULL, then they're the same key */

    if (keydata1 == NULL && keydata2 == NULL)

        return 1;

    /* If only one of the keydata is NULL, then they're different keys */

    if (keydata1 == NULL || keydata2 == NULL)

        return 0;

    /* If both keydata are non-NULL, we let the backend decide */

    return evp_keymgmt_match(keymgmt1, keydata1, keydata2, selection);

}

int evp_keymgmt_util_copy(EVP_PKEY *to, EVP_PKEY *from, int selection)

{

    /* Save copies of pointers we want to play with without affecting |to| */

    EVP_KEYMGMT *to_keymgmt = to->keymgmt;

    void *to_keydata = to->keydata, *alloc_keydata = NULL;

    /* An unassigned key can't be copied */

    if (from == NULL || from->keydata == NULL)

        return 0;

    /*

     * If |to| is unassigned, ensure it gets the same KEYMGMT as |from|,

     * Note that the final setting of KEYMGMT is done further down, with

     * EVP_PKEY_set_type_by_keymgmt(); we don't want to do that prematurely.

     */

    if (to_keymgmt == NULL)

        to_keymgmt = from->keymgmt;

    if (to_keymgmt == from->keymgmt && to_keymgmt->dup != NULL

        && to_keydata == NULL) {

        to_keydata = alloc_keydata = evp_keymgmt_dup(to_keymgmt,

                                                     from->keydata,

                                                     selection);

        if (to_keydata == NULL)

            return 0;

    } else if (match_type(to_keymgmt, from->keymgmt)) {

        struct evp_keymgmt_util_try_import_data_st import_data;

        import_data.keymgmt = to_keymgmt;

        import_data.keydata = to_keydata;

        import_data.selection = selection;

        if (!evp_keymgmt_util_export(from, selection,

                                     &evp_keymgmt_util_try_import,

                                     &import_data))

            return 0;

        /*

         * In case to_keydata was previously unallocated,

         * evp_keymgmt_util_try_import() may have created it for us.

         */

        if (to_keydata == NULL)

            to_keydata = alloc_keydata = import_data.keydata;

    } else {

        ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);

        return 0;

    }

    /*

     * We only need to set the |to| type when its |keymgmt| isn't set.

     * We can then just set its |keydata| to what we have, which might

     * be exactly what it had when entering this function.

     * This is a bit different from using evp_keymgmt_util_assign_pkey(),

     * which isn't as careful with |to|'s original |keymgmt|, since it's

     * meant to forcibly reassign an EVP_PKEY no matter what, which is

     * why we don't use that one here.

     */

    if (to->keymgmt == NULL

        && !EVP_PKEY_set_type_by_keymgmt(to, to_keymgmt)) {

        evp_keymgmt_freedata(to_keymgmt, alloc_keydata);

        return 0;

    }

    to->keydata = to_keydata;

    evp_keymgmt_util_cache_keyinfo(to);

    return 1;

}

void *evp_keymgmt_util_gen(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,

                           void *genctx, OSSL_CALLBACK *cb, void *cbarg)

{

    void *keydata = NULL;

    if ((keydata = evp_keymgmt_gen(keymgmt, genctx, cb, cbarg)) == NULL

        || !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {

        evp_keymgmt_freedata(keymgmt, keydata);

        keydata = NULL;

    }

    return keydata;

}

/*

 * Returns the same numbers as EVP_PKEY_get_default_digest_name()

 * When the string from the EVP_KEYMGMT implementation is "", we use

 * SN_undef, since that corresponds to what EVP_PKEY_get_default_nid()

 * returns for no digest.

 */

int evp_keymgmt_util_get_deflt_digest_name(EVP_KEYMGMT *keymgmt,

                                           void *keydata,

                                           char *mdname, size_t mdname_sz)

{

    OSSL_PARAM params[3];

    char mddefault[100] = "";

    char mdmandatory[100] = "";

    char *result = NULL;

    int rv = -2;

    params[0] =

        OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_DEFAULT_DIGEST,

                                         mddefault, sizeof(mddefault));

    params[1] =

        OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_MANDATORY_DIGEST,

                                         mdmandatory,

                                         sizeof(mdmandatory));

    params[2] = OSSL_PARAM_construct_end();

    if (!evp_keymgmt_get_params(keymgmt, keydata, params))

        return 0;

    if (OSSL_PARAM_modified(params + 1)) {

        if (params[1].return_size <= 1) /* Only a NUL byte */

            result = SN_undef;

        else

            result = mdmandatory;

        rv = 2;

    } else if (OSSL_PARAM_modified(params)) {

        if (params[0].return_size <= 1) /* Only a NUL byte */

            result = SN_undef;

        else

            result = mddefault;

        rv = 1;

    }

    if (rv > 0)

        OPENSSL_strlcpy(mdname, result, mdname_sz);

    return rv;

}

/*

 * If |keymgmt| has the method function |query_operation_name|, use it to get

 * the name of a supported operation identity.  Otherwise, return the keytype,

 * assuming that it works as a default operation name.

 */

const char *evp_keymgmt_util_query_operation_name(EVP_KEYMGMT *keymgmt,

                                                  int op_id)

{

    const char *name = NULL;

    if (keymgmt != NULL) {

        if (keymgmt->query_operation_name != NULL)

            name = keymgmt->query_operation_name(op_id);

        if (name == NULL)

            name = EVP_KEYMGMT_get0_name(keymgmt);

    }

    return name;

}