Currently we have a mishmash of attribution lines accompanying the SPDX
identifier. These lines are basically meaningless because:
- The date is often wrong
- The original author attributed is not the only contributor to a file
- The term "rust bitcoin developers" is basically just noise
Just remove all the attribution lines and be done with it. While we are
at it add an SPDX line to the few files missing it, whether this license
nonsense is even needed is left as an argument for another day.
We created the `crypto` crate as a container for cryptography modules
with the idea that it may be split out into a separate crate. There is
no reason for users of the lib to know about this module. Also, we have
two `taproot` modules, one in `crypto` and one at the crate root, this
makes for un-ergonomic usage of the lib.
Improve the public API by doing:
- Make the `crypto` module private (`pub(crate)`).
- Re-export `crypto::taproot::Signature` (and `Error`) from
`crate::taproot`
"schnorr" is a dirty word; the current `schnorr` module defines a
`Signature` that includes a sighash type, this sighash type is a bitcoin
specific construct related to taproot. Therefore the `Signature` is
better named `taproot::Signature`. Note also that the usage of `schnorr`
in `secp256k1` is probably justified because the
`secp256::schnorr::Signature` is just doing the crypto.
While we are at it, update docs and error messages to use "taproot"
instead of "schnorr". Also change function names and identifiers that
use "schnorr".
There is never any use for the `sighash` module unless one is signing,
which requires the `crypto` module. The `sighash` module should
therefore live in the `crypto` module. This is not an API breaking
change because we reexport it at the crate root.
Done as part of flattening util.
Currently in `util` module we have a bunch of modules that provide
cryptography related functionality.
Create a `crypto` module and move into it the following:
- ecdsa
- schnorr
- key
To improve uniformity and ergonomics, do the following re-names while we
are at it:
- EcdsaSig -> ecdsa::Signature
- SchnorrSig -> schnorr::Signature
- EcdsaSigError -> ecdsa::Error
- SchnorrSigError -> schnorr::Error
- InvalidSchnorrSigSize -> InvalidSignatureSize (this is an error enum variant)