Refactor key management (#3296)

* Add Call type to extensible transactions.

Cleanup some naming

* Merge Resource and BlockExhausted into just Exhausted

* Fix

* Another fix

* Call

* Some fixes

* Fix srml tests.

* Fix all tests.

* Refactor crypto so each application of it has its own type.

* Introduce new AuthorityProvider API into Aura

This will eventually allow for dynamic determination of authority
keys and avoid having to set them directly on CLI.

* Introduce authority determinator for Babe.

Experiment with modular consensus API.

* Work in progress to introduce KeyTypeId and avoid polluting API
with validator IDs

* Finish up drafting imonline

* Rework offchain workers API.

* Rework API implementation.

* Make it compile for wasm, simplify app_crypto.

* Fix compilation of im-online.

* Fix compilation of im-online.

* Fix more compilation errors.

* Make it compile.

* Fixing tests.

* Rewrite `keystore`

* Fix session tests

* Bring back `TryFrom`'s'

* Fix `srml-grandpa`

* Fix `srml-aura`

* Fix consensus babe

* More fixes

* Make service generate keys from dev_seed

* Build fixes

* Remove offchain tests

* More fixes and cleanups

* Fixes finality grandpa

* Fix `consensus-aura`

* Fix cli

* Fix `node-cli`

* Fix chain_spec builder

* Fix doc tests

* Add authority getter for grandpa.

* Test fix

* Fixes

* Make keystore accessible from the runtime

* Move app crypto to its own crate

* Update `Cargo.lock`

* Make the crypto stuff usable from the runtime

* Adds some runtime crypto tests

* Use last finalized block for grandpa authority

* Fix warning

* Adds `SessionKeys` runtime api

* Remove `FinalityPair` and `ConsensusPair`

* Minor governance tweaks to get it inline with docs.

* Make the governance be up to date with the docs.

* Build fixes.

* Generate the inital session keys

* Failing keystore is a hard error

* Make babe work again

* Fix grandpa

* Fix tests

* Disable `keystore` in consensus critical stuff

* Build fix.

* ImOnline supports multiple authorities at once.

* Update core/application-crypto/src/ed25519.rs

* Merge branch 'master' into gav-in-progress

* Remove unneeded code for now.

* Some `session` testing

* Support querying the public keys

* Cleanup offchain

* Remove warnings

* More cleanup

* Apply suggestions from code review

Co-Authored-By: Benjamin Kampmann <ben.kampmann@googlemail.com>

* More cleanups

* JSONRPC API for setting keys.

Also, rename traits::KeyStore* -> traits::BareCryptoStore*

* Bad merge

* Fix integration tests

* Fix test build

* Test fix

* Fixes

* Warnings

* Another warning

* Bump version.

substrate/core/session/src/lib.rs

@@ -0,0 +1,64 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Substrate.
+
+// Substrate is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Substrate is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Substrate core types around sessions.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use rstd::vec::Vec;
+
+#[cfg(feature = "std")]
+use sr_primitives::traits::{ProvideRuntimeApi, Block as BlockT};
+#[cfg(feature = "std")]
+use primitives::{H256, Blake2Hasher};
+
+client::decl_runtime_apis! {
+	/// Session keys runtime api.
+	pub trait SessionKeys {
+		/// Generate a set of session keys with optionally using the given seed.
+		///
+		/// The seed needs to be a valid `utf8` string.
+		///
+		/// Returns the concatenated SCALE encoded public keys.
+		fn generate_session_keys(seed: Option<Vec<u8>>) -> Vec<u8>;
+	}
+}
+
+/// Generate the initial session keys with the given seeds.
+#[cfg(feature = "std")]
+pub fn generate_initial_session_keys<B, E, Block, RA>(
+	client: std::sync::Arc<client::Client<B, E, Block, RA>>,
+	seeds: Vec<String>,
+) -> Result<(), client::error::Error>
+where
+	B: client::backend::Backend<Block, Blake2Hasher>,
+	E: client::CallExecutor<Block, Blake2Hasher>,
+	Block: BlockT<Hash=H256>,
+	client::Client<B, E, Block, RA>: ProvideRuntimeApi,
+	<client::Client<B, E, Block, RA> as ProvideRuntimeApi>::Api: SessionKeys<Block>,
+{
+	let info = client.info().chain;
+	let runtime_api = client.runtime_api();
+
+	for seed in seeds {
+		runtime_api.generate_session_keys(
+			&sr_primitives::generic::BlockId::Number(info.best_number),
+			Some(seed.as_bytes().to_vec()),
+		)?;
+	}
+
+	Ok(())
+}