ecc: Fix EdDSA encoding for Ed448.
* cipher/ecc-curves.c (mpi_ec_setup_elliptic_curve): Fix point/scalar length condition. * cipher/ecc-eddsa.c (eddsa_encodempi): The second argument is NBITS. (eddsa_encode_x_y): Likewise. (_gcry_ecc_eddsa_encodepoint): Follow the change. (_gcry_ecc_eddsa_ensure_compact): Likewise. (_gcry_ecc_eddsa_decodepoint): Likewise. (_gcry_ecc_eddsa_sign): Likewise. Remove restriction of 256 bits.
In EdDSA with Ed448, point size / scalar size is 57-byte with last
octet which represents sign.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>