/*

 * Copyright 1995-2023 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 <stdlib.h>

#include "crypto/cryptlib.h"

#include "internal/thread_once.h"

int ossl_do_ex_data_init(OSSL_LIB_CTX *ctx)

{

    OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);

    if (global == NULL)

        return 0;

    global->ex_data_lock = CRYPTO_THREAD_lock_new();

    return global->ex_data_lock != NULL;

}

/*

 * Return the EX_CALLBACKS from the |ex_data| array that corresponds to

 * a given class.  On success, *holds the lock.*

 * The |global| parameter is assumed to be non null (checked by the caller).

 * If |read| is 1 then a read lock is obtained. Otherwise it is a write lock.

 */

static EX_CALLBACKS *get_and_lock(OSSL_EX_DATA_GLOBAL *global, int class_index,

                                  int read)

{

    EX_CALLBACKS *ip;

    if (class_index < 0 || class_index >= CRYPTO_EX_INDEX__COUNT) {

        ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_INVALID_ARGUMENT);

        return NULL;

    }

    if (global->ex_data_lock == NULL) {

        /*

         * If we get here, someone (who?) cleaned up the lock, so just

         * treat it as an error.

         */

         return NULL;

    }

    if (read) {

        if (!CRYPTO_THREAD_read_lock(global->ex_data_lock))

            return NULL;

    } else {

        if (!CRYPTO_THREAD_write_lock(global->ex_data_lock))

            return NULL;

    }

    ip = &global->ex_data[class_index];

    return ip;

}

static void cleanup_cb(EX_CALLBACK *funcs)

{

    OPENSSL_free(funcs);

}

/*

 * Release all "ex_data" state to prevent memory leaks. This can't be made

 * thread-safe without overhauling a lot of stuff, and shouldn't really be

 * called under potential race-conditions anyway (it's for program shutdown

 * after all).

 */

void ossl_crypto_cleanup_all_ex_data_int(OSSL_LIB_CTX *ctx)

{

    int i;

    OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);

    if (global == NULL)

        return;

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

        EX_CALLBACKS *ip = &global->ex_data[i];

        sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);

        ip->meth = NULL;

    }

    CRYPTO_THREAD_lock_free(global->ex_data_lock);

    global->ex_data_lock = NULL;

}

/*

 * Unregister a new index by replacing the callbacks with no-ops.

 * Any in-use instances are leaked.

 */

static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,

                     long argl, void *argp)

{

}

static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,

                       long argl, void *argp)

{

}

static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from,

                     void **from_d, int idx,

                     long argl, void *argp)

{

    return 1;

}

int ossl_crypto_free_ex_index_ex(OSSL_LIB_CTX *ctx, int class_index, int idx)

{

    EX_CALLBACKS *ip;

    EX_CALLBACK *a;

    int toret = 0;

    OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);

    if (global == NULL)

        return 0;

    ip = get_and_lock(global, class_index, 0);

    if (ip == NULL)

        return 0;

    if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth))

        goto err;

    a = sk_EX_CALLBACK_value(ip->meth, idx);

    if (a == NULL)

        goto err;

    a->new_func = dummy_new;

    a->dup_func = dummy_dup;

    a->free_func = dummy_free;

    toret = 1;

err:

    CRYPTO_THREAD_unlock(global->ex_data_lock);

    return toret;

}

int CRYPTO_free_ex_index(int class_index, int idx)

{

    return ossl_crypto_free_ex_index_ex(NULL, class_index, idx);

}

/*

 * Register a new index.

 */

int ossl_crypto_get_ex_new_index_ex(OSSL_LIB_CTX *ctx, int class_index,

                                    long argl, void *argp,

                                    CRYPTO_EX_new *new_func,

                                    CRYPTO_EX_dup *dup_func,

                                    CRYPTO_EX_free *free_func,

                                    int priority)

{

    int toret = -1;

    EX_CALLBACK *a;

    EX_CALLBACKS *ip;

    OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);

    if (global == NULL)

        return -1;

    ip = get_and_lock(global, class_index, 0);

    if (ip == NULL)

        return -1;

    if (ip->meth == NULL) {

        ip->meth = sk_EX_CALLBACK_new_null();

        /* We push an initial value on the stack because the SSL

         * "app_data" routines use ex_data index zero.  See RT 3710. */

        if (ip->meth == NULL

            || !sk_EX_CALLBACK_push(ip->meth, NULL)) {

            sk_EX_CALLBACK_free(ip->meth);

            ip->meth = NULL;

            ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);

            goto err;

        }

    }

    a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a));

    if (a == NULL)

        goto err;

    a->argl = argl;

    a->argp = argp;

    a->new_func = new_func;

    a->dup_func = dup_func;

    a->free_func = free_func;

    a->priority = priority;

    if (!sk_EX_CALLBACK_push(ip->meth, NULL)) {

        ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);

        OPENSSL_free(a);

        goto err;

    }

    toret = sk_EX_CALLBACK_num(ip->meth) - 1;

    (void)sk_EX_CALLBACK_set(ip->meth, toret, a);

 err:

    CRYPTO_THREAD_unlock(global->ex_data_lock);

    return toret;

}

int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,

                            CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,

                            CRYPTO_EX_free *free_func)

{

    return ossl_crypto_get_ex_new_index_ex(NULL, class_index, argl, argp,

                                           new_func, dup_func, free_func, 0);

}

/*

 * Initialise a new CRYPTO_EX_DATA for use in a particular class - including

 * calling new() callbacks for each index in the class used by this variable

 * Thread-safe by copying a class's array of "EX_CALLBACK" entries

 * in the lock, then using them outside the lock. Note this only applies

 * to the global "ex_data" state (ie. class definitions), not 'ad' itself.

 */

int ossl_crypto_new_ex_data_ex(OSSL_LIB_CTX *ctx, int class_index, void *obj,

                               CRYPTO_EX_DATA *ad)

{

    int mx, i;

    void *ptr;

    EX_CALLBACK **storage = NULL;

    EX_CALLBACK *stack[10];

    EX_CALLBACKS *ip;

    OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ctx);

    if (global == NULL)

        return 0;

    ip = get_and_lock(global, class_index, 1);

    if (ip == NULL)

        return 0;

    ad->ctx = ctx;

    ad->sk = NULL;

    mx = sk_EX_CALLBACK_num(ip->meth);

    if (mx > 0) {

        if (mx < (int)OSSL_NELEM(stack))

            storage = stack;

        else

            storage = OPENSSL_malloc(sizeof(*storage) * mx);

        if (storage != NULL)

            for (i = 0; i < mx; i++)

                storage[i] = sk_EX_CALLBACK_value(ip->meth, i);

    }

    CRYPTO_THREAD_unlock(global->ex_data_lock);

    if (mx > 0 && storage == NULL)

        return 0;

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

        if (storage[i] != NULL && storage[i]->new_func != NULL) {

            ptr = CRYPTO_get_ex_data(ad, i);

            storage[i]->new_func(obj, ptr, ad, i,

                                 storage[i]->argl, storage[i]->argp);

        }

    }

    if (storage != stack)

        OPENSSL_free(storage);

    return 1;

}

int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)

{

    return ossl_crypto_new_ex_data_ex(NULL, class_index, obj, ad);

}

/*

 * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks

 * for each index in the class used by this variable

 */

int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,

                       const CRYPTO_EX_DATA *from)

{

    int mx, j, i;

    void *ptr;

    EX_CALLBACK *stack[10];

    EX_CALLBACK **storage = NULL;

    EX_CALLBACKS *ip;

    int toret = 0;

    OSSL_EX_DATA_GLOBAL *global;

    to->ctx = from->ctx;

    if (from->sk == NULL)

        /* Nothing to copy over */

        return 1;

    global = ossl_lib_ctx_get_ex_data_global(from->ctx);

    if (global == NULL)

        return 0;

    ip = get_and_lock(global, class_index, 1);

    if (ip == NULL)

        return 0;

    mx = sk_EX_CALLBACK_num(ip->meth);

    j = sk_void_num(from->sk);

    if (j < mx)

        mx = j;

    if (mx > 0) {

        if (mx < (int)OSSL_NELEM(stack))

            storage = stack;

        else

            storage = OPENSSL_malloc(sizeof(*storage) * mx);

        if (storage != NULL)

            for (i = 0; i < mx; i++)

                storage[i] = sk_EX_CALLBACK_value(ip->meth, i);

    }

    CRYPTO_THREAD_unlock(global->ex_data_lock);

    if (mx == 0)

        return 1;

    if (storage == NULL)

        return 0;

    /*

     * Make sure the ex_data stack is at least |mx| elements long to avoid

     * issues in the for loop that follows; so go get the |mx|'th element

     * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign

     * to itself. This is normally a no-op; but ensures the stack is the

     * proper size

     */

    if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1)))

        goto err;

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

        ptr = CRYPTO_get_ex_data(from, i);

        if (storage[i] != NULL && storage[i]->dup_func != NULL)

            if (!storage[i]->dup_func(to, from, &ptr, i,

                                      storage[i]->argl, storage[i]->argp))

                goto err;

        CRYPTO_set_ex_data(to, i, ptr);

    }

    toret = 1;

 err:

    if (storage != stack)

        OPENSSL_free(storage);

    return toret;

}

struct ex_callback_entry {

    const EX_CALLBACK *excb;

    int index;

};

static int ex_callback_compare(const void *a, const void *b)

{

    const struct ex_callback_entry *ap = (const struct ex_callback_entry *)a;

    const struct ex_callback_entry *bp = (const struct ex_callback_entry *)b;

    if (ap->excb == bp->excb)

        return 0;

    if (ap->excb == NULL)

        return 1;

    if (bp->excb == NULL)

        return -1;

    if (ap->excb->priority == bp->excb->priority)

        return 0;

    return ap->excb->priority > bp->excb->priority ? -1 : 1;

}

/*

 * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for

 * each index in the class used by this variable

 */

void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)

{

    int mx, i;

    EX_CALLBACKS *ip;

    void *ptr;

    const EX_CALLBACK *f;

    struct ex_callback_entry stack[10];

    struct ex_callback_entry *storage = NULL;

    OSSL_EX_DATA_GLOBAL *global = ossl_lib_ctx_get_ex_data_global(ad->ctx);

    if (global == NULL)

        goto err;

    ip = get_and_lock(global, class_index, 1);

    if (ip == NULL)

        goto err;

    mx = sk_EX_CALLBACK_num(ip->meth);

    if (mx > 0) {

        if (mx < (int)OSSL_NELEM(stack))

            storage = stack;

        else

            storage = OPENSSL_malloc(sizeof(*storage) * mx);

        if (storage != NULL)

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

                storage[i].excb = sk_EX_CALLBACK_value(ip->meth, i);

                storage[i].index = i;

            }

    }

    CRYPTO_THREAD_unlock(global->ex_data_lock);

    if (storage != NULL) {

        /* Sort according to priority. High priority first */

        qsort(storage, mx, sizeof(*storage), ex_callback_compare);

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

            f = storage[i].excb;

            if (f != NULL && f->free_func != NULL) {

                ptr = CRYPTO_get_ex_data(ad, storage[i].index);

                f->free_func(obj, ptr, ad, storage[i].index, f->argl, f->argp);

            }

        }

    }

    if (storage != stack)

        OPENSSL_free(storage);

 err:

    sk_void_free(ad->sk);

    ad->sk = NULL;

    ad->ctx = NULL;

}

/*

 * Allocate a given CRYPTO_EX_DATA item using the class specific allocation

 * function

 */

int CRYPTO_alloc_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad,

                         int idx)

{

    void *curval;

    curval = CRYPTO_get_ex_data(ad, idx);

    /* Already there, no need to allocate */

    if (curval != NULL)

        return 1;

    return ossl_crypto_alloc_ex_data_intern(class_index, obj, ad, idx);

}

int ossl_crypto_alloc_ex_data_intern(int class_index, void *obj,

                                     CRYPTO_EX_DATA *ad, int idx)

{

    EX_CALLBACK *f;

    EX_CALLBACKS *ip;

    OSSL_EX_DATA_GLOBAL *global;

    global = ossl_lib_ctx_get_ex_data_global(ad->ctx);

    if (global == NULL)

        return 0;

    ip = get_and_lock(global, class_index, 1);

    if (ip == NULL)

        return 0;

    f = sk_EX_CALLBACK_value(ip->meth, idx);

    CRYPTO_THREAD_unlock(global->ex_data_lock);

    /*

     * This should end up calling CRYPTO_set_ex_data(), which allocates

     * everything necessary to support placing the new data in the right spot.

     */

    if (f->new_func == NULL)

        return 0;

    f->new_func(obj, NULL, ad, idx, f->argl, f->argp);

    return 1;

}

/*

 * For a given CRYPTO_EX_DATA variable, set the value corresponding to a

 * particular index in the class used by this variable

 */

int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)

{

    int i;

    if (ad->sk == NULL) {

        if ((ad->sk = sk_void_new_null()) == NULL) {

            ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);

            return 0;

        }

    }

    for (i = sk_void_num(ad->sk); i <= idx; ++i) {

        if (!sk_void_push(ad->sk, NULL)) {

            ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);

            return 0;

        }

    }

    if (sk_void_set(ad->sk, idx, val) != val) {

        /* Probably the index is out of bounds */

        ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_INVALID_ARGUMENT);

        return 0;

    }

    return 1;

}

/*

 * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a

 * particular index in the class used by this variable

 */

void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)

{

    if (ad->sk == NULL || idx >= sk_void_num(ad->sk))

        return NULL;

    return sk_void_value(ad->sk, idx);

}

OSSL_LIB_CTX *ossl_crypto_ex_data_get_ossl_lib_ctx(const CRYPTO_EX_DATA *ad)

{

    return ad->ctx;

}