Pieter moved some stuff I need into the contrib/ directory which does
not expose anything through the shared lib, so I need to statically
link.
I might also use this to do evil things to expose the SHA256 code
in libsecp, but not for now ;).
This should be a major version number since I changed public constants
in the ffi module. I'm not doing so as the invariant "will the constants
be meaningful to the underlying library" has not changed.
In general this library's version numbers do not map well to the
underlying library, which is as-yet not versioned at all, so users
need to always be running "the lastest" rust-secp256k1 anyway, and
semantic versioning can't really be used meaninfully. So this is a
bit of a judgement call.
I didn't mean for both of these to go into the same commit, but given how
small the ECDH code was, and the fact that no commit prior to this one will
compile (as both libsecp256k1 and rustc have changed so much), I'm letting
it slide.
Rather than have global initialization functions, which required
expensive synchronization on the part of the Rust library,
libsecp256k1 now carries its context in thread-local data which
must be passed to every function.
What this means for the rust-secp256k1 API is:
- Most functions on `PublicKey` and `SecretKey` now require a
`Secp256k1` to be given to them.
- `Secp256k1::verify` and `::verify_raw` now take a `&self`
- `SecretKey::new` now takes a `Secp256k1` rather than a Rng; a
future commit will allow specifying the Rng in the `Secp256k1`
so that functionality is not lost.
- The FFI functions have all changed to take a context argument
- `secp256k1::init()` is gone, as is the dependency on std::sync
- There is a `ffi::Context` type which must be handled carefully
by anyone using it directly (hopefully nobody :))
rust-secp256k1 was based off of https://github.com/sipa/secp256k1,
which has been inactive nearly as long as this repository (prior to
a couple days ago anyway). The correct repository is
https://github.com/bitcoin/secp256k1
This is a major breaking change to the library for one reason: there
are no longer any Nonce types in the safe interface. The signing functions
do not take a nonce; this is generated internally.
This also means that I was able to drop all my RFC6979 code, since
libsecp256k1 has its own implementation.
If you need to generate your own nonces, you need to create an unsafe
function of type `ffi::NonceFn`, then pass it to the appropriate
functions in the `ffi` module. There is no safe interface for doing
this, deliberately: there is basically no need to directly fiddle
with nonces ever.
Andrew Poelstra