# include <gcrypt.h>
# include <stdio.h>
# include <string.h>
# include <stdlib.h> 
# include <gpg-error.h>

# define AM_PATH_LIBGCRYPT
/* # define AM_CPPFLAGS = $(LIBGCRYPT_CFLAGS)
# define LDADD = $(LIBGCRYPT_LIBS) */



int main ()

{

/* Version check */

if (gcry_check_version(GCRYPT_VERSION))

puts ("\nIntialization Succeed\n");

    else

    {   
        puts ("libgcrypt version mismatch\n");
        exit(2);
    }


/* Disable secure memory */

gcry_control(GCRYCTL_DISABLE_SECMEM,0);

/* inform the libgcrypt that the intialization has completed */

gcry_control(GCRYCTL_INITIALIZATION_FINISHED,0);

if (!gcry_control(GCRYCTL_INITIALIZATION_FINISHED_P))

    {
        puts ("libgcrypt has not been intialized\n");
        abort ();
    }

/* Allocating new context for EC operations */

gcry_ctx_t my_ctx;
const char *curve = "NIST P-521" ;
gcry_error_t err = 1 ;
err = gcry_mpi_ec_new ( &my_ctx, NULL, curve);

// Displaying the error  
puts("Allocating a context for EC operations is");
fputs (gcry_strerror(err), stderr);
puts ("\n");

// get the private key
const char *d = "d";
int copy1 = 1;
gcry_mpi_t x = gcry_mpi_ec_get_mpi(d, my_ctx, copy1);

//displaying the private key

gcry_buffer_t x_buffer;
x_buffer.size = 0;
x_buffer.len = 1024;
unsigned char *x_buffer_name = x_buffer.data;
size_t x_buffer_len = 1024 ;
size_t *x_size;
const gcry_mpi_t x_copy = x;
gcry_mpi_release (x_copy);
gcry_error_t err2 = 0;
err2 = gcry_mpi_print(GCRYMPI_FMT_USG, x_buffer_name, x_buffer_len, x_size, x_copy);

fputs (gcry_strerror(err2), stderr);
puts ("\n"); 
        



gcry_mpi_release (x_copy);
gcry_ctx_release (my_ctx);
gcry_mpi_release (x);

return 0;

}