Daiki Ueno authored Jan 12, 2024 and Zoltán Fridrich committed Mar 18, 2024

This removes function calls that potentially leak bit-length of a
private key used to calculate a nonce in deterministic ECDSA.  Namely:

- _gnutls_dsa_compute_k has been rewritten to work on always
  zero-padded mp_limb_t arrays instead of mpz_t
- rnd_mpz_func has been replaced with rnd_datum_func, which is backed
  by a byte array instead of an mpz_t value

Signed-off-by: Daiki Ueno <ueno@gnu.org>