#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?
#include?

static?int?ec_field_inverse_mod_ord（const?EC_GROUP?*group?BIGNUM?*r
????????????????????????????????????const?BIGNUM?*x?BN_CTX?*ctx）
{
????BIGNUM?*e?=?NULL;
????BN_CTX?*new_ctx?=?NULL;
????int?ret?=?0;

????if?（group->mont_data?==?NULL）
????????return?0;

????if?（ctx?==?NULL?&&?（ctx?=?new_ctx?=?BN_CTX_secure_new（））?==?NULL）
????????return?0;

????BN_CTX_start（ctx）;
????if?（（e?=?BN_CTX_get（ctx））?==?NULL）
????????goto?err;

????/*-
?????*?We?want?inverse?in?constant?time?therefore?we?utilize?the?fact
?????*?order?must?be?prime?and?use?Fermats?Little?Theorem?instead.
?????*/
????if?（!BN_set_word（e?2））
????????goto?err;
????if?（!BN_sub（e?group->order?e））
????????goto?err;
????/*-
?????*?Exponent?e?is?public.
?????*?No?need?for?scatter-gather?or?BN_FLG_CONSTTIME.
?????*/
????if?（!BN_mod_exp_mont（r?x?e?group->order?ctx?group->mont_data））
????????goto?err;

????ret?=?1;

?err:
????BN_CTX_end（ctx）;
????BN_CTX_free（new_ctx）;
????return?ret;
}

static?int?ec_group_do_inverse_ord（const?EC_GROUP?*group?BIGNUM?*res
							const?BIGNUM?*x?BN_CTX?*ctx）
{
	if?（group->meth->field_inverse_mod_ord?!=?NULL）
		return?group->meth->field_inverse_mod_ord（group?res?x?ctx）;
	else
		return?ec_field_inverse_mod_ord（group?res?x?ctx）;
}

static?int?sm2_compute_z_digest（uint8_t?*out
?????????????????????????const?EVP_MD?*digest
?????????????????????????const?uint8_t?*id
?????????????????????????const?size_t?id_len
?????????????????????????const?EC_KEY?*key）
{
????int?rc?=?0;
????const?EC_GROUP?*group?=?EC_KEY_get0_group（key）;
????BN_CTX?*ctx?=?NULL;
????EVP_MD_CTX?*hash?=?NULL;
????BIGNUM?*p?=?NULL;
????BIGNUM?*a?=?NULL;
????BIGNUM?*b?=?NULL;
????BIGNUM?*xG?=?NULL;
????BIGNUM?*yG?=?NULL;
????BIGNUM?*xA?=?NULL;
????BIGNUM?*yA?=?NULL;
????int?p_bytes?=?0;
????uint8_t?*buf?=?NULL;
????uint16_t?entl?=?0;
????uint8_t?e_byte?=?0;

????hash?=?EVP_MD_CTX_new（）;
????ctx?=?BN_CTX_new（）;
????if?（hash?==?NULL?||?ctx?==?NULL）?{
????????goto?done;
????}

????p?=?BN_CTX_get（ctx）;
????a?=?BN_CTX_get（ctx）;
????b?=?BN_CTX_get（ctx）;
????xG?=?BN_CTX_get（ctx）;
????yG?=?BN_CTX_get（ctx）;
????xA?=?BN_CTX_get（ctx）;
????yA?=?BN_CTX_get（ctx）;

????if?（yA?==?NULL）?{
????????goto?done;
????}

????if?（!EVP_DigestInit（hash?digest））?{
????????goto?done;
????}

????/*?Z?=?h（ENTL?||?ID?||?a?||?b?||?xG?||?yG?||?xA?||?yA）?*/

????if?（id_len?>=?（UINT16_MAX?/?8））?{
????????/*?too?large?*/
????????goto?done;
????}

????entl?=?（uint16_t）（8?*?id_len）;

????e_byte?=?entl?>>?8;
????if?（!EVP_DigestUpdate（hash?&e_byte?1））?{
????????goto?done;
????}
????e_byte?=?entl?&?0xFF;
????if?（!EVP_DigestUpdate（hash?