ey length for the given
   public or private KEY.  */
unsigned int gcry_pk_get_nbits (gcry_sexp_t key) _GCRY_GCC_ATTR_PURE;

/* Return the so called KEYGRIP which is the SHA-1 hash of the public
   key parameters expressed in a way depending on the algorithm.  */
unsigned char *gcry_pk_get_keygrip (gcry_sexp_t key, unsigned char *array);

/* Return the name of the curve matching KEY.  */
const char *gcry_pk_get_curve (gcry_sexp_t key, int iterator,
                               unsigned int *r_nbits);

/* Return an S-expression with the parameters of the named ECC curve
   NAME.  ALGO must be set to an ECC algorithm.  */
gcry_sexp_t gcry_pk_get_param (int algo, const char *name);

/* Return 0 if the public key algorithm A is available for use. */
#define gcry_pk_test_algo(a) \
            gcry_pk_algo_info( (a), GCRYCTL_TEST_ALGO, NULL, NULL )

/* Return an S-expression representing the context CTX.  */
gcry_error_t gcry_pubkey_get_sexp (gcry_sexp_t *r_sexp,
                                   int mode, gcry_ctx_t ctx);