/*

 * Copyright 2020-2025 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.h>

#include <openssl/core_dispatch.h>

#include <openssl/decoder.h>

#include <openssl/ui.h>

#include "internal/core.h"

#include "internal/namemap.h"

#include "internal/property.h"

#include "internal/provider.h"

#include "crypto/decoder.h"

#include "encoder_local.h"

#include "crypto/context.h"

/*

 * Decoder can have multiple names, separated with colons in a name string

 */

#define NAME_SEPARATOR ':'

static void ossl_decoder_free(void *data)

{

    OSSL_DECODER_free(data);

}

static int ossl_decoder_up_ref(void *data)

{

    return OSSL_DECODER_up_ref(data);

}

/* Simple method structure constructor and destructor */

static OSSL_DECODER *ossl_decoder_new(void)

{

    OSSL_DECODER *decoder = NULL;

    if ((decoder = OPENSSL_zalloc(sizeof(*decoder))) == NULL)

        return NULL;

    if (!CRYPTO_NEW_REF(&decoder->base.refcnt, 1)) {

        OSSL_DECODER_free(decoder);

        return NULL;

    }

    return decoder;

}

int OSSL_DECODER_up_ref(OSSL_DECODER *decoder)

{

    int ref = 0;

    CRYPTO_UP_REF(&decoder->base.refcnt, &ref);

    return 1;

}

void OSSL_DECODER_free(OSSL_DECODER *decoder)

{

    int ref = 0;

    if (decoder == NULL)

        return;

    CRYPTO_DOWN_REF(&decoder->base.refcnt, &ref);

    if (ref > 0)

        return;

    OPENSSL_free(decoder->base.name);

    ossl_property_free(decoder->base.parsed_propdef);

    ossl_provider_free(decoder->base.prov);

    CRYPTO_FREE_REF(&decoder->base.refcnt);

    OPENSSL_free(decoder);

}

/* Data to be passed through ossl_method_construct() */

struct decoder_data_st {

    OSSL_LIB_CTX *libctx;

    int id;                      /* For get_decoder_from_store() */

    const char *names;           /* For get_decoder_from_store() */

    const char *propquery;       /* For get_decoder_from_store() */

    OSSL_METHOD_STORE *tmp_store; /* For get_tmp_decoder_store() */

    unsigned int flag_construct_error_occurred : 1;

};

/*

 * Generic routines to fetch / create DECODER methods with

 * ossl_method_construct()

 */

/* Temporary decoder method store, constructor and destructor */

static void *get_tmp_decoder_store(void *data)

{

    struct decoder_data_st *methdata = data;

    if (methdata->tmp_store == NULL)

        methdata->tmp_store = ossl_method_store_new(methdata->libctx);

    return methdata->tmp_store;

}

static void dealloc_tmp_decoder_store(void *store)

{

    if (store != NULL)

        ossl_method_store_free(store);

}

/* Get the permanent decoder store */

static OSSL_METHOD_STORE *get_decoder_store(OSSL_LIB_CTX *libctx)

{

    return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_DECODER_STORE_INDEX);

}

static int reserve_decoder_store(void *store, void *data)

{

    struct decoder_data_st *methdata = data;

    if (store == NULL

        && (store = get_decoder_store(methdata->libctx)) == NULL)

        return 0;

    return ossl_method_lock_store(store);

}

static int unreserve_decoder_store(void *store, void *data)

{

    struct decoder_data_st *methdata = data;

    if (store == NULL

        && (store = get_decoder_store(methdata->libctx)) == NULL)

        return 0;

    return ossl_method_unlock_store(store);

}

/* Get decoder methods from a store, or put one in */

static void *get_decoder_from_store(void *store, const OSSL_PROVIDER **prov,

                                    void *data)

{

    struct decoder_data_st *methdata = data;

    void *method = NULL;

    int id;

    /*

     * get_decoder_from_store() is only called to try and get the method

     * that OSSL_DECODER_fetch() is asking for, and the name or name id are

     * passed via methdata.

     */

    if ((id = methdata->id) == 0 && methdata->names != NULL) {

        OSSL_NAMEMAP *namemap = ossl_namemap_stored(methdata->libctx);

        const char *names = methdata->names;

        const char *q = strchr(names, NAME_SEPARATOR);

        size_t l = (q == NULL ? strlen(names) : (size_t)(q - names));

        if (namemap == 0)

            return NULL;

        id = ossl_namemap_name2num_n(namemap, names, l);

    }

    if (id == 0)

        return NULL;

    if (store == NULL

        && (store = get_decoder_store(methdata->libctx)) == NULL)

        return NULL;

    if (!ossl_method_store_fetch(store, id, methdata->propquery, prov, &method))

        return NULL;

    return method;

}

static int put_decoder_in_store(void *store, void *method,

                                const OSSL_PROVIDER *prov,

                                const char *names, const char *propdef,

                                void *data)

{

    struct decoder_data_st *methdata = data;

    OSSL_NAMEMAP *namemap;

    int id;

    size_t l = 0;

    /*

     * put_decoder_in_store() is only called with an OSSL_DECODER method that

     * was successfully created by construct_decoder() below, which means that

     * all the names should already be stored in the namemap with the same

     * numeric identity, so just use the first to get that identity.

     */

    if (names != NULL) {

        const char *q = strchr(names, NAME_SEPARATOR);

        l = (q == NULL ? strlen(names) : (size_t)(q - names));

    }

    if ((namemap = ossl_namemap_stored(methdata->libctx)) == NULL

        || (id = ossl_namemap_name2num_n(namemap, names, l)) == 0)

        return 0;

    if (store == NULL && (store = get_decoder_store(methdata->libctx)) == NULL)

        return 0;

    return ossl_method_store_add(store, prov, id, propdef, method,

                                 ossl_decoder_up_ref,

                                 ossl_decoder_free);

}

/* Create and populate a decoder method */

void *ossl_decoder_from_algorithm(int id, const OSSL_ALGORITHM *algodef,

                                  OSSL_PROVIDER *prov)

{

    OSSL_DECODER *decoder = NULL;

    const OSSL_DISPATCH *fns = algodef->implementation;

    OSSL_LIB_CTX *libctx = ossl_provider_libctx(prov);

    if ((decoder = ossl_decoder_new()) == NULL)

        return NULL;

    decoder->base.id = id;

    if ((decoder->base.name = ossl_algorithm_get1_first_name(algodef)) == NULL) {

        OSSL_DECODER_free(decoder);

        return NULL;

    }

    decoder->base.algodef = algodef;

    if ((decoder->base.parsed_propdef

         = ossl_parse_property(libctx, algodef->property_definition)) == NULL) {

        OSSL_DECODER_free(decoder);

        return NULL;

    }

    for (; fns->function_id != 0; fns++) {

        switch (fns->function_id) {

        case OSSL_FUNC_DECODER_NEWCTX:

            if (decoder->newctx == NULL)

                decoder->newctx = OSSL_FUNC_decoder_newctx(fns);

            break;

        case OSSL_FUNC_DECODER_FREECTX:

            if (decoder->freectx == NULL)

                decoder->freectx = OSSL_FUNC_decoder_freectx(fns);

            break;

        case OSSL_FUNC_DECODER_GET_PARAMS:

            if (decoder->get_params == NULL)

                decoder->get_params =

                    OSSL_FUNC_decoder_get_params(fns);

            break;

        case OSSL_FUNC_DECODER_GETTABLE_PARAMS:

            if (decoder->gettable_params == NULL)

                decoder->gettable_params =

                    OSSL_FUNC_decoder_gettable_params(fns);

            break;

        case OSSL_FUNC_DECODER_SET_CTX_PARAMS:

            if (decoder->set_ctx_params == NULL)

                decoder->set_ctx_params =

                    OSSL_FUNC_decoder_set_ctx_params(fns);

            break;

        case OSSL_FUNC_DECODER_SETTABLE_CTX_PARAMS:

            if (decoder->settable_ctx_params == NULL)

                decoder->settable_ctx_params =

                    OSSL_FUNC_decoder_settable_ctx_params(fns);

            break;

        case OSSL_FUNC_DECODER_DOES_SELECTION:

            if (decoder->does_selection == NULL)

                decoder->does_selection =

                    OSSL_FUNC_decoder_does_selection(fns);

            break;

        case OSSL_FUNC_DECODER_DECODE:

            if (decoder->decode == NULL)

                decoder->decode = OSSL_FUNC_decoder_decode(fns);

            break;

        case OSSL_FUNC_DECODER_EXPORT_OBJECT:

            if (decoder->export_object == NULL)

                decoder->export_object = OSSL_FUNC_decoder_export_object(fns);

            break;

        }

    }

    /*

     * Try to check that the method is sensible.

     * If you have a constructor, you must have a destructor and vice versa.

     * You must have at least one of the encoding driver functions.

     */

    if (!((decoder->newctx == NULL && decoder->freectx == NULL)

          || (decoder->newctx != NULL && decoder->freectx != NULL))

        || decoder->decode == NULL) {

        OSSL_DECODER_free(decoder);

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INVALID_PROVIDER_FUNCTIONS);

        return NULL;

    }

    if (prov != NULL && !ossl_provider_up_ref(prov)) {

        OSSL_DECODER_free(decoder);

        return NULL;

    }

    decoder->base.prov = prov;

    return decoder;

}

/*

 * The core fetching functionality passes the names of the implementation.

 * This function is responsible to getting an identity number for them,

 * then call ossl_decoder_from_algorithm() with that identity number.

 */

static void *construct_decoder(const OSSL_ALGORITHM *algodef,

                               OSSL_PROVIDER *prov, void *data)

{

    /*

     * This function is only called if get_decoder_from_store() returned

     * NULL, so it's safe to say that of all the spots to create a new

     * namemap entry, this is it.  Should the name already exist there, we

     * know that ossl_namemap_add() will return its corresponding number.

     */

    struct decoder_data_st *methdata = data;

    OSSL_LIB_CTX *libctx = ossl_provider_libctx(prov);

    OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);

    const char *names = algodef->algorithm_names;

    int id = ossl_namemap_add_names(namemap, 0, names, NAME_SEPARATOR);

    void *method = NULL;

    if (id != 0)

        method = ossl_decoder_from_algorithm(id, algodef, prov);

    /*

     * Flag to indicate that there was actual construction errors.  This

     * helps inner_evp_generic_fetch() determine what error it should

     * record on inaccessible algorithms.

     */

    if (method == NULL)

        methdata->flag_construct_error_occurred = 1;

    return method;

}

/* Intermediary function to avoid ugly casts, used below */

static void destruct_decoder(void *method, void *data)

{

    OSSL_DECODER_free(method);

}

static int up_ref_decoder(void *method)

{

    return OSSL_DECODER_up_ref(method);

}

static void free_decoder(void *method)

{

    OSSL_DECODER_free(method);

}

/* Fetching support.  Can fetch by numeric identity or by name */

static OSSL_DECODER *

inner_ossl_decoder_fetch(struct decoder_data_st *methdata,

                         const char *name, const char *properties)

{

    OSSL_METHOD_STORE *store = get_decoder_store(methdata->libctx);

    OSSL_NAMEMAP *namemap = ossl_namemap_stored(methdata->libctx);

    const char *const propq = properties != NULL ? properties : "";

    void *method = NULL;

    int unsupported, id;

    if (store == NULL || namemap == NULL) {

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_INVALID_ARGUMENT);

        return NULL;

    }

    id = name != NULL ? ossl_namemap_name2num(namemap, name) : 0;

    /*

     * If we haven't found the name yet, chances are that the algorithm to

     * be fetched is unsupported.

     */

    unsupported = id == 0;

    if (id == 0

        || !ossl_method_store_cache_get(store, NULL, id, propq, &method)) {

        OSSL_METHOD_CONSTRUCT_METHOD mcm = {

            get_tmp_decoder_store,

            reserve_decoder_store,

            unreserve_decoder_store,

            get_decoder_from_store,

            put_decoder_in_store,

            construct_decoder,

            destruct_decoder

        };

        OSSL_PROVIDER *prov = NULL;

        methdata->id = id;

        methdata->names = name;

        methdata->propquery = propq;

        methdata->flag_construct_error_occurred = 0;

        if ((method = ossl_method_construct(methdata->libctx, OSSL_OP_DECODER,

                                            &prov, 0 /* !force_cache */,

                                            &mcm, methdata)) != NULL) {

            /*

             * If construction did create a method for us, we know that

             * there is a correct name_id and meth_id, since those have

             * already been calculated in get_decoder_from_store() and

             * put_decoder_in_store() above.

             */

            if (id == 0 && name != NULL)

                id = ossl_namemap_name2num(namemap, name);

            if (id != 0)

                ossl_method_store_cache_set(store, prov, id, propq, method,

                                            up_ref_decoder, free_decoder);

        }

        /*

         * If we never were in the constructor, the algorithm to be fetched

         * is unsupported.

         */

        unsupported = !methdata->flag_construct_error_occurred;

    }

    if ((id != 0 || name != NULL) && method == NULL) {

        int code = unsupported ? ERR_R_UNSUPPORTED : ERR_R_FETCH_FAILED;

        if (name == NULL)

            name = ossl_namemap_num2name(namemap, id, 0);

        ERR_raise_data(ERR_LIB_OSSL_DECODER, code,

                       "%s, Name (%s : %d), Properties (%s)",

                       ossl_lib_ctx_get_descriptor(methdata->libctx),

                       name == NULL ? "<null>" : name, id,

                       properties == NULL ? "<null>" : properties);

    }

    return method;

}

OSSL_DECODER *OSSL_DECODER_fetch(OSSL_LIB_CTX *libctx, const char *name,

                                 const char *properties)

{

    struct decoder_data_st methdata;

    void *method;

    methdata.libctx = libctx;

    methdata.tmp_store = NULL;

    method = inner_ossl_decoder_fetch(&methdata, name, properties);

    dealloc_tmp_decoder_store(methdata.tmp_store);

    return method;

}

int ossl_decoder_store_cache_flush(OSSL_LIB_CTX *libctx)

{

    OSSL_METHOD_STORE *store = get_decoder_store(libctx);

    if (store != NULL)

        return ossl_method_store_cache_flush_all(store);

    return 1;

}

int ossl_decoder_store_remove_all_provided(const OSSL_PROVIDER *prov)

{

    OSSL_LIB_CTX *libctx = ossl_provider_libctx(prov);

    OSSL_METHOD_STORE *store = get_decoder_store(libctx);

    if (store != NULL)

        return ossl_method_store_remove_all_provided(store, prov);

    return 1;

}

/*

 * Library of basic method functions

 */

const OSSL_PROVIDER *OSSL_DECODER_get0_provider(const OSSL_DECODER *decoder)

{

    if (!ossl_assert(decoder != NULL)) {

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    return decoder->base.prov;

}

const char *OSSL_DECODER_get0_properties(const OSSL_DECODER *decoder)

{

    if (!ossl_assert(decoder != NULL)) {

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    return decoder->base.algodef->property_definition;

}

const OSSL_PROPERTY_LIST *

ossl_decoder_parsed_properties(const OSSL_DECODER *decoder)

{

    if (!ossl_assert(decoder != NULL)) {

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    return decoder->base.parsed_propdef;

}

int ossl_decoder_get_number(const OSSL_DECODER *decoder)

{

    if (!ossl_assert(decoder != NULL)) {

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    return decoder->base.id;

}

const char *OSSL_DECODER_get0_name(const OSSL_DECODER *decoder)

{

    return decoder->base.name;

}

const char *OSSL_DECODER_get0_description(const OSSL_DECODER *decoder)

{

    return decoder->base.algodef->algorithm_description;

}

int OSSL_DECODER_is_a(const OSSL_DECODER *decoder, const char *name)

{

    if (decoder->base.prov != NULL) {

        OSSL_LIB_CTX *libctx = ossl_provider_libctx(decoder->base.prov);

        OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);

        return ossl_namemap_name2num(namemap, name) == decoder->base.id;

    }

    return 0;

}

static int resolve_name(OSSL_DECODER *decoder, const char *name)

{

    OSSL_LIB_CTX *libctx = ossl_provider_libctx(decoder->base.prov);

    OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);

    return ossl_namemap_name2num(namemap, name);

}

int ossl_decoder_fast_is_a(OSSL_DECODER *decoder, const char *name, int *id_cache)

{

    int id = *id_cache;

    if (id <= 0)

        *id_cache = id = resolve_name(decoder, name);

    return id > 0 && ossl_decoder_get_number(decoder) == id;

}

struct do_one_data_st {

    void (*user_fn)(OSSL_DECODER *decoder, void *arg);

    void *user_arg;

};

static void do_one(ossl_unused int id, void *method, void *arg)

{

    struct do_one_data_st *data = arg;

    data->user_fn(method, data->user_arg);

}

void OSSL_DECODER_do_all_provided(OSSL_LIB_CTX *libctx,

                                  void (*user_fn)(OSSL_DECODER *decoder,

                                                  void *arg),

                                  void *user_arg)

{

    struct decoder_data_st methdata;

    struct do_one_data_st data;

    methdata.libctx = libctx;

    methdata.tmp_store = NULL;

    (void)inner_ossl_decoder_fetch(&methdata, NULL, NULL /* properties */);

    data.user_fn = user_fn;

    data.user_arg = user_arg;

    if (methdata.tmp_store != NULL)

        ossl_method_store_do_all(methdata.tmp_store, &do_one, &data);

    ossl_method_store_do_all(get_decoder_store(libctx), &do_one, &data);

    dealloc_tmp_decoder_store(methdata.tmp_store);

}

int OSSL_DECODER_names_do_all(const OSSL_DECODER *decoder,

                              void (*fn)(const char *name, void *data),

                              void *data)

{

    if (decoder == NULL)

        return 0;

    if (decoder->base.prov != NULL) {

        OSSL_LIB_CTX *libctx = ossl_provider_libctx(decoder->base.prov);

        OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);

        return ossl_namemap_doall_names(namemap, decoder->base.id, fn, data);

    }

    return 1;

}

const OSSL_PARAM *

OSSL_DECODER_gettable_params(OSSL_DECODER *decoder)

{

    if (decoder != NULL && decoder->gettable_params != NULL) {

        void *provctx = ossl_provider_ctx(OSSL_DECODER_get0_provider(decoder));

        return decoder->gettable_params(provctx);

    }

    return NULL;

}

int OSSL_DECODER_get_params(OSSL_DECODER *decoder, OSSL_PARAM params[])

{

    if (decoder != NULL && decoder->get_params != NULL)

        return decoder->get_params(params);

    return 0;

}

const OSSL_PARAM *

OSSL_DECODER_settable_ctx_params(OSSL_DECODER *decoder)

{

    if (decoder != NULL && decoder->settable_ctx_params != NULL) {

        void *provctx = ossl_provider_ctx(OSSL_DECODER_get0_provider(decoder));

        return decoder->settable_ctx_params(provctx);

    }

    return NULL;

}

/*

 * Decoder context support

 */

/*

 * |encoder| value NULL is valid, and signifies that there is no decoder.

 * This is useful to provide fallback mechanisms.

 *  Functions that want to verify if there is a decoder can do so with

 * OSSL_DECODER_CTX_get_decoder()

 */

OSSL_DECODER_CTX *OSSL_DECODER_CTX_new(void)

{

    OSSL_DECODER_CTX *ctx;

    ctx = OPENSSL_zalloc(sizeof(*ctx));

    return ctx;

}

int OSSL_DECODER_CTX_set_params(OSSL_DECODER_CTX *ctx,

                                const OSSL_PARAM params[])

{

    int ok = 1;

    size_t i;

    size_t l;

    if (!ossl_assert(ctx != NULL)) {

        ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);

        return 0;

    }

    if (ctx->decoder_insts == NULL)

        return 1;

    l = OSSL_DECODER_CTX_get_num_decoders(ctx);

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

        OSSL_DECODER_INSTANCE *decoder_inst =

            sk_OSSL_DECODER_INSTANCE_value(ctx->decoder_insts, i);

        OSSL_DECODER *decoder =

            OSSL_DECODER_INSTANCE_get_decoder(decoder_inst);

        OSSL_DECODER *decoderctx =

            OSSL_DECODER_INSTANCE_get_decoder_ctx(decoder_inst);

        if (decoderctx == NULL || decoder->set_ctx_params == NULL)

            continue;

        if (!decoder->set_ctx_params(decoderctx, params))

            ok = 0;

    }

    return ok;

}

void OSSL_DECODER_CTX_free(OSSL_DECODER_CTX *ctx)

{

    if (ctx != NULL) {

        if (ctx->cleanup != NULL)

            ctx->cleanup(ctx->construct_data);

        sk_OSSL_DECODER_INSTANCE_pop_free(ctx->decoder_insts,

                                          ossl_decoder_instance_free);

        ossl_pw_clear_passphrase_data(&ctx->pwdata);

        OPENSSL_free(ctx);

    }

}