/* Return an MPI (or opaque MPI) described by NAME and the context EC.
If COPY is true a copy is returned, if not a const MPI may be
returned. In any case mpi_free must be used. */
gcry_mpi_t
_gcry_ecc_get_mpi (const char *name, mpi_ec_t ec, int copy)
{
if (!*name)
return NULL;
if (!strcmp (name, "p") && ec->p)
return mpi_is_const (ec->p) && !copy? ec->p : mpi_copy (ec->p);
if (!strcmp (name, "a") && ec->a)
return mpi_is_const (ec->a) && !copy? ec->a : mpi_copy (ec->a);
if (!strcmp (name, "b") && ec->b)
return mpi_is_const (ec->b) && !copy? ec->b : mpi_copy (ec->b);
if (!strcmp (name, "n") && ec->n)
return mpi_is_const (ec->n) && !copy? ec->n : mpi_copy (ec->n);
if (!strcmp (name, "d") && ec->d)
return mpi_is_const (ec->d) && !copy? ec->d : mpi_copy (ec->d);
/* Return a requested point coordinate. */
if (!strcmp (name, "g.x") && ec->G && ec->G->x)
return mpi_is_const (ec->G->x) && !copy? ec->G->x : mpi_copy (ec->G->x);
if (!strcmp (name, "g.y") && ec->G && ec->G->y)
return mpi_is_const (ec->G->y) && !copy? ec->G->y : mpi_copy (ec->G->y);
if (!strcmp (name, "q.x") && ec->Q && ec->Q->x)
return mpi_is_const (ec->Q->x) && !copy? ec->Q->x : mpi_copy (ec->Q->x);
if (!strcmp (name, "q.y") && ec->Q && ec->Q->y)
return mpi_is_const (ec->G->y) && !copy? ec->Q->y : mpi_copy (ec->Q->y);
/* If the base point has been requested, return it in standard
encoding. */
if (!strcmp (name, "g") && ec->G)
return _gcry_mpi_ec_ec2os (ec->G, ec);
/* If the public key has been requested, return it by default in
standard uncompressed encoding or if requested in other
encodings. */
if (*name == 'q' && (!name[1] || name[1] == '@'))
{
/* If only the private key is given, compute the public key. */
if (!ec->Q)
ec->Q = _gcry_ecc_compute_public (NULL, ec, NULL, NULL);
if (!ec->Q)
return NULL;
if (name[1] != '@')
return _gcry_mpi_ec_ec2os (ec->Q, ec);
if (!strcmp (name+2, "eddsa") && ec->model == MPI_EC_TWISTEDEDWARDS)
{
unsigned char *encpk;
unsigned int encpklen;
if (!_gcry_ecc_eddsa_encodepoint (ec->Q, ec, NULL, NULL,
&encpk, &encpklen))
return mpi_set_opaque (NULL, encpk, encpklen*8);
}
}
return NULL;
}
gcry_mpi_t
_gcry_mpi_ec_get_mpi (const char *name, gcry_ctx_t ctx, int copy)
{
mpi_ec_t ec = _gcry_ctx_get_pointer (ctx, CONTEXT_TYPE_EC);
if (!strcmp (name, "p") && ec->p)
return mpi_is_const (ec->p) && !copy? ec->p : mpi_copy (ec->p);
if (!strcmp (name, "a") && ec->a)
return mpi_is_const (ec->a) && !copy? ec->a : mpi_copy (ec->a);
if (!strcmp (name, "b") && ec->b)
return mpi_is_const (ec->b) && !copy? ec->b : mpi_copy (ec->b);
if (!strcmp (name, "n") && ec->n)
return mpi_is_const (ec->n) && !copy? ec->n : mpi_copy (ec->n);
if (!strcmp (name, "d") && ec->d)
return mpi_is_const (ec->d) && !copy? ec->d : mpi_copy (ec->d);
/* Return a requested point coordinate. */
if (!strcmp (name, "g.x") && ec->G && ec->G->x)
return mpi_is_const (ec->G->x) && !copy? ec->G->x : mpi_copy (ec->G->x);
if (!strcmp (name, "g.y") && ec->G && ec->G->y)
return mpi_is_const (ec->G->y) && !copy? ec->G->y : mpi_copy (ec->G->y);
if (!strcmp (name, "q.x") && ec->Q && ec->Q->x)
return mpi_is_const (ec->Q->x) && !copy? ec->Q->x : mpi_copy (ec->Q->x);
if (!strcmp (name, "q.y") && ec->Q && ec->Q->y)
return mpi_is_const (ec->G->y) && !copy? ec->Q->y : mpi_copy (ec->Q->y);
/* If a point has been requested, return it in standard encoding. */
if (!strcmp (name, "g") && ec->G)
return _gcry_mpi_ec_ec2os (ec->G, ec);
if (!strcmp (name, "q"))
{
/* If only the private key is given, compute the public key. */
if (!ec->Q && ec->d && ec->G && ec->p && ec->a)
{
ec->Q = gcry_mpi_point_new (0);
_gcry_mpi_ec_mul_point (ec->Q, ec->d, ec->G, ec);
}
if (ec->Q)
return _gcry_mpi_ec_ec2os (ec->Q, ec);
}
return NULL;
}
