- Update to 0.17.0
* Keys that use explicit curve parameters can now be read and written.
Reading of explicit curves can be disabled by using the
`valid_curve_encodings` keyword argument in `VerifyingKey.from_pem()`,
`VerifyingKey.from_der()`, `SigningKey.from_pem()`, and
`SigningKey.from_der()`.
* Keys can now be written with use of explicit curve parameters,
use `curve_parameters_encoding` keyword argument of `VerifyingKey.to_pem()`,
`VerifyingKey.to_der()`, `SigningKey.to_pem(), or `SigningKey.to_der()` to
specify the format. By default `named_curve` will be used, unless the
curve doesn't have an associated OID (as will be the case for an unsupported
curve), then `explicit` encoding will be used.
* Allow specifying acceptable point formats when loading public keys
(this also fixes a minor bug where python-ecdsa would accept raw
encoding for points in PKCS#8 files). Set of accepted encodings is controlled
by `valid_encodings` keyword argument in
`ECDH.load_received_public_key_bytes()`, `VerifyingKey.from_string()`,
`VerifyingKey.from_pem()`, VerifyingKey.from_der()`.
* `PointJacobi` and `Point` now inherit from `AbstractPoint` that implements
the methods for parsing points. That added `from_bytes()` and
`to_bytes()` methods to both of them.
* Curve parameters can now be read and written to PEM and DER files. The
`Curve` class supports new `to_der()`, `from_der()`, `to_pem()`, and
`from_pem()` methods.
* Describe in detail which methods can raise `RSZeroError`, and that
`SigningKey.sign_deterministic()` won't raise it.
* Correctly truncate hash values larger than the curve order (only impacted
custom curves and the curves added in this release).
* Correctly handle curves for which the order is larger than the prime
(only impacted custom curves and the secp160r1 curve added in this release).