We switch from EcDSA to Edx25519 for the underlying signature scheme.
Edx25519 is implemented in gnunet, starting with (gnunet-)commit
ce38d1f6c9bd7857a1c3bc2094a0ee9752b86c32.
- Unit-tests for commit, derive, attest and verify added, with multiple
combinations of minimum age and commited age.
- Fixed crypto implementation (eddsa -> ecdsa)
- Using now standard functionality from GNUNET:
GNUNET_CRYPTO_ecdsa_{private,public}_key_derive
All tests pass (unit tests in util/ and 'make check' in testing).
- functions TALER_age_commitment_attest and TALER_age_commitment_verify
implemented.
- age restriction implementation moved into util/age_restriction.c
