Hello,

I am very sorry about last email by mistakes. I have some questions about multiplication on ecp curves.

I add an ecp curve parameter in ecp_curve.c form SM2 algorithm standard, and the parameter is as follow:

Then I followed the loading method of secp256r1 to load, but I don’t know how to perform fast calculations, so I commented NIST_MODP( p256 ).

#if defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
        case MBEDTLS_ECP_DP_SECP256R1:
            NIST_MODP( p256 );
            return( LOAD_GROUP( secp256r1 ) );
#endif

#if defined(MBEDTLS_ECP_DP_SM256_ENABLED)
        case MBEDTLS_ECP_DP_SM256:
            //NIST_MODP( p256 ); 
            return( LOAD_GROUP_A( sm256 ) );
#endif

Then I call the functional interface mbedtls_ecp_mul to perform the multiplication operation, but the heap memory keeps increasing .

void test()
{
    int ret;
    mbedtls_mpi Ud;
    mbedtls_ecp_group grp;
    mbedtls_ecp_point T_Q;

    mbedtls_mpi_init(&Ud);
    mbedtls_ecp_group_init( &grp );
    mbedtls_ecp_point_init( &T_Q );

    ret = mbedtls_mpi_read_binary(&Ud, arrUd, sizeof(arr_U_d));
//    ret = mbedtls_ecp_group_load(&grp,MBEDTLS_ECP_DP_SECP256R1);
    ret = mbedtls_ecp_group_load(&grp,MBEDTLS_ECP_DP_SM256);
    ret = mbedtls_ecp_mul(&grp, &T_Q, &Ud, &(grp.G), NULL, NULL) ;
    printf("%x\n", -ret);

    mbedtls_mpi_free(&Ud);
    mbedtls_ecp_group_free( &grp );
    mbedtls_ecp_point_free( &T_Q );
}
int main()

{
    for(int i = 0; i < 10; i++)
        test();
    return 0;
}

The heap memory is mesaured by massif( valgring tools),

Can someone tell me what this is because of and how to fix this problem ?

Best Regards.

Shudong Zhang