crypto/encode_decode/decoder_meth.c - third_party/openssl - Git at Google

 /*
  * Copyright 2020-2022 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.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 ':'

 /* Simple method structure constructor and destructor */
 static OSSL_DECODER *ossl_decoder_new(void)
 {
     OSSL_DECODER *decoder = NULL;

     if ((decoder = OPENSSL_zalloc(sizeof(*decoder))) == NULL
         || (decoder->base.lock = CRYPTO_THREAD_lock_new()) == NULL) {
         OSSL_DECODER_free(decoder);
         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
         return NULL;
     }

     decoder->base.refcnt = 1;

     return decoder;
 }

 int OSSL_DECODER_up_ref(OSSL_DECODER *decoder)
 {
     int ref = 0;

     CRYPTO_UP_REF(&decoder->base.refcnt, &ref, decoder->base.lock);
     return 1;
 }

 void OSSL_DECODER_free(OSSL_DECODER *decoder)
 {
     int ref = 0;

     if (decoder == NULL)
         return;

     CRYPTO_DOWN_REF(&decoder->base.refcnt, &ref, decoder->base.lock);
     if (ref > 0)
         return;
     OPENSSL_free(decoder->base.name);
     ossl_property_free(decoder->base.parsed_propdef);
     ossl_provider_free(decoder->base.prov);
     CRYPTO_THREAD_lock_free(decoder->base.lock);
     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);
 }

 /* 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,
                                  (int (*)(void *))OSSL_DECODER_up_ref,
                                  (void (*)(void *))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;
     decoder->base.parsed_propdef
         = ossl_parse_property(libctx, algodef->property_definition);

     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, int id,
                          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 = 0;

     if (store == NULL || namemap == NULL) {
         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_INVALID_ARGUMENT);
         return NULL;
     }

     /*
      * If we have been passed both an id and a name, we have an
      * internal programming error.
      */
     if (!ossl_assert(id == 0 || name == NULL)) {
         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR);
         return NULL;
     }

     if (id == 0 && name != NULL)
         id = ossl_namemap_name2num(namemap, name);

     /*
      * If we haven't found the name yet, chances are that the algorithm to
      * be fetched is unsupported.
      */
     if (id == 0)
         unsupported = 1;

     if (id == 0
         || !ossl_method_store_cache_get(store, NULL, id, propq, &method)) {
         OSSL_METHOD_CONSTRUCT_METHOD mcm = {
             get_tmp_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, 0, name, properties);
     dealloc_tmp_decoder_store(methdata.tmp_store);
     return method;
 }

 OSSL_DECODER *ossl_decoder_fetch_by_number(OSSL_LIB_CTX *libctx, int id,
                                            const char *properties)
 {
     struct decoder_data_st methdata;
     void *method;

     methdata.libctx = libctx;
     methdata.tmp_store = NULL;
     method = inner_ossl_decoder_fetch(&methdata, id, NULL, properties);
     dealloc_tmp_decoder_store(methdata.tmp_store);
     return method;
 }

 /*
  * 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, 0, 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;

     if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);

     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);
     }
 }
	/*
	* Copyright 2020-2022 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.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 ':'

	/* Simple method structure constructor and destructor */
	static OSSL_DECODER *ossl_decoder_new(void)
	{
	OSSL_DECODER *decoder = NULL;

	if ((decoder = OPENSSL_zalloc(sizeof(*decoder))) == NULL
	\|\| (decoder->base.lock = CRYPTO_THREAD_lock_new()) == NULL) {
	OSSL_DECODER_free(decoder);
	ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
	return NULL;
	}

	decoder->base.refcnt = 1;

	return decoder;
	}

	int OSSL_DECODER_up_ref(OSSL_DECODER *decoder)
	{
	int ref = 0;

	CRYPTO_UP_REF(&decoder->base.refcnt, &ref, decoder->base.lock);
	return 1;
	}

	void OSSL_DECODER_free(OSSL_DECODER *decoder)
	{
	int ref = 0;

	if (decoder == NULL)
	return;

	CRYPTO_DOWN_REF(&decoder->base.refcnt, &ref, decoder->base.lock);
	if (ref > 0)
	return;
	OPENSSL_free(decoder->base.name);
	ossl_property_free(decoder->base.parsed_propdef);
	ossl_provider_free(decoder->base.prov);
	CRYPTO_THREAD_lock_free(decoder->base.lock);
	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);
	}

	/* 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,
	(int ()(void ))OSSL_DECODER_up_ref,
	(void ()(void ))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;
	decoder->base.parsed_propdef
	= ossl_parse_property(libctx, algodef->property_definition);

	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, int id,
	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 = 0;

	if (store == NULL \|\| namemap == NULL) {
	ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_INVALID_ARGUMENT);
	return NULL;
	}

	/*
	* If we have been passed both an id and a name, we have an
	* internal programming error.
	*/
	if (!ossl_assert(id == 0 \|\| name == NULL)) {
	ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR);
	return NULL;
	}

	if (id == 0 && name != NULL)
	id = ossl_namemap_name2num(namemap, name);

	/*
	* If we haven't found the name yet, chances are that the algorithm to
	* be fetched is unsupported.
	*/
	if (id == 0)
	unsupported = 1;

	if (id == 0
	\|\| !ossl_method_store_cache_get(store, NULL, id, propq, &method)) {
	OSSL_METHOD_CONSTRUCT_METHOD mcm = {
	get_tmp_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, 0, name, properties);
	dealloc_tmp_decoder_store(methdata.tmp_store);
	return method;
	}

	OSSL_DECODER ossl_decoder_fetch_by_number(OSSL_LIB_CTX libctx, int id,
	const char *properties)
	{
	struct decoder_data_st methdata;
	void *method;

	methdata.libctx = libctx;
	methdata.tmp_store = NULL;
	method = inner_ossl_decoder_fetch(&methdata, id, NULL, properties);
	dealloc_tmp_decoder_store(methdata.tmp_store);
	return method;
	}

	/*
	* 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, 0, 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;

	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
	ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);

	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);
	}
	}