From e729dbabbe885be3f36441cbd7279c5815715aa1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Drwi=C4=99ga?= <tomusdrw@users.noreply.github.com>
Date: Tue, 9 Jul 2019 17:09:14 +0200
Subject: [PATCH] [offchain] Support for sign & verify for crypto keys (#3023)

* Implement sign & verify.

* Use phrases and password.

* Sign & verify with authority keys.

* Fix tests.

* WiP

* WiP

* Allow the caller to decide on 'CryptoKind'.

* Remove TODO.

* Make seed private back.

* Fix non-std build and bump version.

* Use Into<u32> instead of asses.

* Add missing typedef.
---
 substrate/Cargo.lock                         |   1 +
 substrate/core/cli/src/lib.rs                |   2 +-
 substrate/core/client/db/src/offchain.rs     |  23 ++-
 substrate/core/client/src/backend.rs         |   2 +-
 substrate/core/client/src/in_mem.rs          |  30 ++-
 substrate/core/executor/src/wasm_executor.rs |  49 ++++-
 substrate/core/keystore/src/lib.rs           |  16 +-
 substrate/core/offchain/src/api.rs           | 201 +++++++++++++++++--
 substrate/core/offchain/src/lib.rs           |  81 ++++++--
 substrate/core/offchain/src/testing.rs       |  31 ++-
 substrate/core/primitives/Cargo.toml         |   2 +
 substrate/core/primitives/src/crypto.rs      |  59 +++++-
 substrate/core/primitives/src/offchain.rs    |  85 +++++---
 substrate/core/primitives/src/sr25519.rs     |   1 +
 substrate/core/service/src/components.rs     |   6 +-
 substrate/core/service/src/config.rs         |  12 +-
 substrate/core/service/src/lib.rs            |  73 +++++--
 substrate/core/service/test/src/lib.rs       |   2 +-
 substrate/core/sr-io/src/lib.rs              |  13 +-
 substrate/core/sr-io/with_std.rs             |  33 ++-
 substrate/core/sr-io/without_std.rs          |  93 ++++++---
 substrate/core/state-machine/src/lib.rs      |  10 +-
 22 files changed, 647 insertions(+), 178 deletions(-)

diff --git a/substrate/Cargo.lock b/substrate/Cargo.lock
index 08cfbc63ae..2c38d96c12 100644
--- a/substrate/Cargo.lock
+++ b/substrate/Cargo.lock
@@ -4544,6 +4544,7 @@ dependencies = [
  "tiny-bip39 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "twox-hash 1.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "wasmi 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "zeroize 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
diff --git a/substrate/core/cli/src/lib.rs b/substrate/core/cli/src/lib.rs
index 39b98c092b..a22278b830 100644
--- a/substrate/core/cli/src/lib.rs
+++ b/substrate/core/cli/src/lib.rs
@@ -376,7 +376,7 @@ where
 	let spec = load_spec(&cli.shared_params, spec_factory)?;
 	let mut config = service::Configuration::default_with_spec(spec.clone());
 	if cli.interactive_password {
-		config.password = input_keystore_password()?
+		config.password = input_keystore_password()?.into()
 	}
 
 	config.impl_name = impl_name;
diff --git a/substrate/core/client/db/src/offchain.rs b/substrate/core/client/db/src/offchain.rs
index 1ec6e357e6..3cefdbf47a 100644
--- a/substrate/core/client/db/src/offchain.rs
+++ b/substrate/core/client/db/src/offchain.rs
@@ -79,7 +79,7 @@ impl client::backend::OffchainStorage for LocalStorage {
 		&mut self,
 		prefix: &[u8],
 		item_key: &[u8],
-		old_value: &[u8],
+		old_value: Option<&[u8]>,
 		new_value: &[u8],
 	) -> bool {
 		let key: Vec<u8> = prefix.iter().chain(item_key).cloned().collect();
@@ -91,11 +91,10 @@ impl client::backend::OffchainStorage for LocalStorage {
 		let is_set;
 		{
 			let _key_guard = key_lock.lock();
-			is_set = self.db.get(columns::OFFCHAIN, &key)
+			let val = self.db.get(columns::OFFCHAIN, &key)
 				.ok()
-				.and_then(|x| x)
-				.map(|v| &*v == old_value)
-				.unwrap_or(true);
+				.and_then(|x| x);
+			is_set = val.as_ref().map(|x| &**x) == old_value;
 
 			if is_set {
 				self.set(prefix, item_key, new_value)
@@ -130,8 +129,20 @@ mod tests {
 		storage.set(prefix, key, value);
 		assert_eq!(storage.get(prefix, key), Some(value.to_vec()));
 
-		assert_eq!(storage.compare_and_set(prefix, key, value, b"asd"), true);
+		assert_eq!(storage.compare_and_set(prefix, key, Some(value), b"asd"), true);
 		assert_eq!(storage.get(prefix, key), Some(b"asd".to_vec()));
 		assert!(storage.locks.lock().is_empty(), "Locks map should be empty!");
 	}
+
+	#[test]
+	fn should_compare_and_set_on_empty_field() {
+		let mut storage = LocalStorage::new_test();
+		let prefix = b"prefix";
+		let key = b"key";
+
+		assert_eq!(storage.compare_and_set(prefix, key, None, b"asd"), true);
+		assert_eq!(storage.get(prefix, key), Some(b"asd".to_vec()));
+		assert!(storage.locks.lock().is_empty(), "Locks map should be empty!");
+	}
+
 }
diff --git a/substrate/core/client/src/backend.rs b/substrate/core/client/src/backend.rs
index 110b7b4d44..79bc1b475b 100644
--- a/substrate/core/client/src/backend.rs
+++ b/substrate/core/client/src/backend.rs
@@ -213,7 +213,7 @@ pub trait OffchainStorage: Clone + Send + Sync {
 		&mut self,
 		prefix: &[u8],
 		key: &[u8],
-		old_value: &[u8],
+		old_value: Option<&[u8]>,
 		new_value: &[u8],
 	) -> bool;
 }
diff --git a/substrate/core/client/src/in_mem.rs b/substrate/core/client/src/in_mem.rs
index b6546a67bb..8a229470be 100644
--- a/substrate/core/client/src/in_mem.rs
+++ b/substrate/core/client/src/in_mem.rs
@@ -794,19 +794,23 @@ impl backend::OffchainStorage for OffchainStorage {
 		&mut self,
 		prefix: &[u8],
 		key: &[u8],
-		old_value: &[u8],
+		old_value: Option<&[u8]>,
 		new_value: &[u8],
 	) -> bool {
+		use std::collections::hash_map::Entry;
 		let key = prefix.iter().chain(key).cloned().collect();
 
-		let mut set = false;
-		self.storage.entry(key).and_modify(|val| {
-			if val.as_slice() == old_value {
-				*val = new_value.to_vec();
-				set = true;
-			}
-		});
-		set
+		match self.storage.entry(key) {
+			Entry::Vacant(entry) => if old_value.is_none() {
+				entry.insert(new_value.to_vec());
+				true
+			} else { false },
+			Entry::Occupied(ref mut entry) if Some(entry.get().as_slice()) == old_value => {
+				entry.insert(new_value.to_vec());
+				true
+			},
+			_ => false,
+		}
 	}
 }
 
@@ -845,9 +849,13 @@ mod tests {
 		assert_eq!(storage.get(b"A", b"B"), Some(b"C".to_vec()));
 		assert_eq!(storage.get(b"B", b"A"), None);
 
-		storage.compare_and_set(b"A", b"B", b"X", b"D");
+		storage.compare_and_set(b"A", b"B", Some(b"X"), b"D");
 		assert_eq!(storage.get(b"A", b"B"), Some(b"C".to_vec()));
-		storage.compare_and_set(b"A", b"B", b"C", b"D");
+		storage.compare_and_set(b"A", b"B", Some(b"C"), b"D");
 		assert_eq!(storage.get(b"A", b"B"), Some(b"D".to_vec()));
+
+		assert!(!storage.compare_and_set(b"B", b"A", Some(b""), b"Y"));
+		assert!(storage.compare_and_set(b"B", b"A", None, b"X"));
+		assert_eq!(storage.get(b"B", b"A"), Some(b"X".to_vec()));
 	}
 }
diff --git a/substrate/core/executor/src/wasm_executor.rs b/substrate/core/executor/src/wasm_executor.rs
index f7f60f0d5d..83f1cf5a4b 100644
--- a/substrate/core/executor/src/wasm_executor.rs
+++ b/substrate/core/executor/src/wasm_executor.rs
@@ -729,18 +729,26 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 			.ok_or_else(|| "Calling unavailable API ext_new_crypto_key: wasm")?;
 
 		match res {
-			Ok(key_id) => Ok(key_id.0 as u32),
+			Ok(key_id) => Ok(key_id.into()),
 			Err(()) => Ok(u32::max_value()),
 		}
 	},
-	ext_encrypt(key: u32, data: *const u8, data_len: u32, msg_len: *mut u32) -> *mut u8 => {
+	ext_encrypt(
+		key: u32,
+		kind: u32,
+		data: *const u8,
+		data_len: u32,
+		msg_len: *mut u32
+	) -> *mut u8 => {
 		let key = u32_to_key(key)
 			.map_err(|_| "Key OOB while ext_encrypt: wasm")?;
+		let kind = offchain::CryptoKind::try_from(kind)
+			.map_err(|_| "crypto kind OOB while ext_encrypt: wasm")?;
 		let message = this.memory.get(data, data_len as usize)
 			.map_err(|_| "OOB while ext_encrypt: wasm")?;
 
 		let res = this.ext.offchain()
-			.map(|api| api.encrypt(key, &*message))
+			.map(|api| api.encrypt(key, kind, &*message))
 			.ok_or_else(|| "Calling unavailable API ext_encrypt: wasm")?;
 
 		let (offset,len) = match res {
@@ -759,14 +767,22 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 
 		Ok(offset)
 	},
-	ext_decrypt(key: u32, data: *const u8, data_len: u32, msg_len: *mut u32) -> *mut u8 => {
+	ext_decrypt(
+		key: u32,
+		kind: u32,
+		data: *const u8,
+		data_len: u32,
+		msg_len: *mut u32
+	) -> *mut u8 => {
 		let key = u32_to_key(key)
 			.map_err(|_| "Key OOB while ext_decrypt: wasm")?;
+		let kind = offchain::CryptoKind::try_from(kind)
+			.map_err(|_| "crypto kind OOB while ext_decrypt: wasm")?;
 		let message = this.memory.get(data, data_len as usize)
 			.map_err(|_| "OOB while ext_decrypt: wasm")?;
 
 		let res = this.ext.offchain()
-			.map(|api| api.decrypt(key, &*message))
+			.map(|api| api.decrypt(key, kind, &*message))
 			.ok_or_else(|| "Calling unavailable API ext_decrypt: wasm")?;
 
 		let (offset,len) = match res {
@@ -785,14 +801,22 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 
 		Ok(offset)
 	},
-	ext_sign(key: u32, data: *const u8, data_len: u32, sig_data_len: *mut u32) -> *mut u8  => {
+	ext_sign(
+		key: u32,
+		kind: u32,
+		data: *const u8,
+		data_len: u32,
+		sig_data_len: *mut u32
+	) -> *mut u8  => {
 		let key = u32_to_key(key)
 			.map_err(|_| "Key OOB while ext_sign: wasm")?;
+		let kind = offchain::CryptoKind::try_from(kind)
+			.map_err(|_| "crypto kind OOB while ext_sign: wasm")?;
 		let message = this.memory.get(data, data_len as usize)
 			.map_err(|_| "OOB while ext_sign: wasm")?;
 
 		let res = this.ext.offchain()
-			.map(|api| api.sign(key, &*message))
+			.map(|api| api.sign(key, kind, &*message))
 			.ok_or_else(|| "Calling unavailable API ext_sign: wasm")?;
 
 		let (offset,len) = match res {
@@ -813,6 +837,7 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 	},
 	ext_verify(
 		key: u32,
+		kind: u32,
 		msg: *const u8,
 		msg_len: u32,
 		signature: *const u8,
@@ -820,13 +845,15 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 	) -> u32 => {
 		let key = u32_to_key(key)
 			.map_err(|_| "Key OOB while ext_verify: wasm")?;
+		let kind = offchain::CryptoKind::try_from(kind)
+			.map_err(|_| "crypto kind OOB while ext_verify: wasm")?;
 		let message = this.memory.get(msg, msg_len as usize)
 			.map_err(|_| "OOB while ext_verify: wasm")?;
 		let signature = this.memory.get(signature, signature_len as usize)
 			.map_err(|_| "OOB while ext_verify: wasm")?;
 
 		let res = this.ext.offchain()
-			.map(|api| api.verify(key, &*message, &*signature))
+			.map(|api| api.verify(key, kind, &*message, &*signature))
 			.ok_or_else(|| "Calling unavailable API ext_verify: wasm")?;
 
 		match res {
@@ -945,7 +972,7 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 			.ok_or_else(|| "Calling unavailable API ext_http_request_start: wasm")?;
 
 		if let Ok(id) = id {
-			Ok(id.0 as u32)
+			Ok(id.into())
 		} else {
 			Ok(u32::max_value())
 		}
@@ -996,7 +1023,7 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 
 		Ok(match res {
 			Ok(()) => 0,
-			Err(e) => e as u8 as u32,
+			Err(e) => e.into(),
 		})
 	},
 	ext_http_response_wait(
@@ -1074,7 +1101,7 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 				read as u32
 			},
 			Err(err) => {
-				u32::max_value() - err as u8 as u32 + 1
+				u32::max_value() - u32::from(err) + 1
 			}
 		})
 	},
diff --git a/substrate/core/keystore/src/lib.rs b/substrate/core/keystore/src/lib.rs
index 882807e36e..77106059f8 100644
--- a/substrate/core/keystore/src/lib.rs
+++ b/substrate/core/keystore/src/lib.rs
@@ -23,7 +23,7 @@ use std::path::PathBuf;
 use std::fs::{self, File};
 use std::io::{self, Write};
 
-use substrate_primitives::crypto::{KeyTypeId, Pair, Public, TypedKey};
+use substrate_primitives::crypto::{KeyTypeId, Pair, Public};
 
 /// Keystore error.
 #[derive(Debug, derive_more::Display, derive_more::From)]
@@ -69,7 +69,7 @@ impl Store {
 		Ok(Store { path, additional: HashMap::new() })
 	}
 
-	fn get_pair<TPair: Pair + TypedKey>(&self, public: &TPair::Public) -> Result<Option<TPair>> {
+	fn get_pair<TPair: Pair>(&self, public: &TPair::Public) -> Result<Option<TPair>> {
 		let key = (TPair::KEY_TYPE, public.to_raw_vec());
 		if let Some(bytes) = self.additional.get(&key) {
 			let pair = TPair::from_seed_slice(bytes)
@@ -79,13 +79,13 @@ impl Store {
 		Ok(None)
 	}
 
-	fn insert_pair<TPair: Pair + TypedKey>(&mut self, pair: &TPair) {
+	fn insert_pair<TPair: Pair>(&mut self, pair: &TPair) {
 		let key = (TPair::KEY_TYPE, pair.public().to_raw_vec());
 		self.additional.insert(key, pair.to_raw_vec());
 	}
 
 	/// Generate a new key, placing it into the store.
-	pub fn generate<TPair: Pair + TypedKey>(&self, password: &str) -> Result<TPair> {
+	pub fn generate<TPair: Pair>(&self, password: &str) -> Result<TPair> {
 		let (pair, phrase, _) = TPair::generate_with_phrase(Some(password));
 		let mut file = File::create(self.key_file_path::<TPair>(&pair.public()))?;
 		::serde_json::to_writer(&file, &phrase)?;
@@ -94,7 +94,7 @@ impl Store {
 	}
 
 	/// Create a new key from seed. Do not place it into the store.
-	pub fn generate_from_seed<TPair: Pair + TypedKey>(&mut self, seed: &str) -> Result<TPair> {
+	pub fn generate_from_seed<TPair: Pair>(&mut self, seed: &str) -> Result<TPair> {
 		let pair = TPair::from_string(seed, None)
 			.ok().ok_or(Error::InvalidSeed)?;
 		self.insert_pair(&pair);
@@ -102,7 +102,7 @@ impl Store {
 	}
 
 	/// Load a key file with given public key.
-	pub fn load<TPair: Pair + TypedKey>(&self, public: &TPair::Public, password: &str) -> Result<TPair> {
+	pub fn load<TPair: Pair>(&self, public: &TPair::Public, password: &str) -> Result<TPair> {
 		if let Some(pair) = self.get_pair(public)? {
 			return Ok(pair)
 		}
@@ -120,7 +120,7 @@ impl Store {
 	}
 
 	/// Get public keys of all stored keys.
-	pub fn contents<TPublic: Public + TypedKey>(&self) -> Result<Vec<TPublic>> {
+	pub fn contents<TPublic: Public>(&self) -> Result<Vec<TPublic>> {
 		let mut public_keys: Vec<TPublic> = self.additional.keys()
 			.filter_map(|(ty, public)| {
 				if *ty != TPublic::KEY_TYPE {
@@ -151,7 +151,7 @@ impl Store {
 		Ok(public_keys)
 	}
 
-	fn key_file_path<TPair: Pair + TypedKey>(&self, public: &TPair::Public) -> PathBuf {
+	fn key_file_path<TPair: Pair>(&self, public: &TPair::Public) -> PathBuf {
 		let mut buf = self.path.clone();
 		let bytes: [u8; 4] = TPair::KEY_TYPE.to_le_bytes();
 		let key_type = hex::encode(bytes);
diff --git a/substrate/core/offchain/src/api.rs b/substrate/core/offchain/src/api.rs
index bb5db3daff..b6aba784b3 100644
--- a/substrate/core/offchain/src/api.rs
+++ b/substrate/core/offchain/src/api.rs
@@ -16,15 +16,18 @@
 
 use std::sync::Arc;
 use client::backend::OffchainStorage;
+use crate::AuthorityKeyProvider;
 use futures::{Stream, Future, sync::mpsc};
 use log::{info, debug, warn, error};
-use parity_codec::Decode;
+use parity_codec::{Encode, Decode};
 use primitives::offchain::{
 	Timestamp, HttpRequestId, HttpRequestStatus, HttpError,
 	Externalities as OffchainExt,
 	CryptoKind, CryptoKeyId,
 	StorageKind,
 };
+use primitives::crypto::{Pair, Protected};
+use primitives::{ed25519, sr25519};
 use runtime_primitives::{
 	generic::BlockId,
 	traits::{self, Extrinsic},
@@ -36,12 +39,26 @@ enum ExtMessage {
 	SubmitExtrinsic(Vec<u8>),
 }
 
+/// A persisted key seed.
+#[derive(Encode, Decode)]
+struct CryptoKey {
+	kind: CryptoKind,
+	phrase: String,
+}
+
+enum Key {
+	Sr25519(sr25519::Pair),
+	Ed25519(ed25519::Pair),
+}
+
 /// Asynchronous offchain API.
 ///
 /// NOTE this is done to prevent recursive calls into the runtime (which are not supported currently).
-pub(crate) struct Api<S> {
+pub(crate) struct Api<Storage, KeyProvider> {
 	sender: mpsc::UnboundedSender<ExtMessage>,
-	db: S,
+	db: Storage,
+	keys_password: Protected<String>,
+	key_provider: KeyProvider,
 }
 
 fn unavailable_yet<R: Default>(name: &str) -> R {
@@ -52,8 +69,60 @@ fn unavailable_yet<R: Default>(name: &str) -> R {
 
 const LOCAL_DB: &str = "LOCAL (fork-aware) DB";
 const STORAGE_PREFIX: &[u8] = b"storage";
+const KEYS_PREFIX: &[u8] = b"keys";
 
-impl<S: OffchainStorage> OffchainExt for Api<S> {
+const NEXT_ID: &[u8] = b"crypto_key_id";
+
+impl<Storage, KeyProvider> Api<Storage, KeyProvider> where
+	Storage: OffchainStorage,
+	KeyProvider: AuthorityKeyProvider,
+{
+	fn keypair<P: Pair>(&self, phrase: &str) -> Result<P, ()> {
+		P::from_phrase(phrase, Some(self.keys_password.as_ref()))
+			.map_err(|e| {
+				warn!("Error recovering Offchain Worker key. Password invalid? {:?}", e);
+				()
+			})
+			.map(|x| x.0)
+	}
+
+	fn read_key(&self, id: Option<CryptoKeyId>, kind: CryptoKind) -> Result<Key, ()> {
+		if let Some(id) = id {
+			let key = self.db.get(KEYS_PREFIX, &id.0.encode())
+				.and_then(|key| CryptoKey::decode(&mut &*key))
+				.ok_or(())?;
+			if key.kind != kind {
+				warn!(
+					"Invalid crypto kind (got: {:?}, expected: {:?}), when requesting key {:?}",
+					key.kind,
+					kind,
+					id
+				);
+				return Err(())
+			}
+
+			Ok(match key.kind {
+				CryptoKind::Sr25519 => Key::Sr25519(self.keypair(&key.phrase)?),
+				CryptoKind::Ed25519 => Key::Ed25519(self.keypair(&key.phrase)?),
+			})
+		} else {
+			let key = match kind {
+				CryptoKind::Sr25519 => self.key_provider.authority_key().map(Key::Sr25519),
+				CryptoKind::Ed25519 => self.key_provider.authority_key().map(Key::Ed25519),
+			};
+
+			key.ok_or_else(|| {
+				warn!("AuthorityKey is not configured, yet offchain worker tried to access it.");
+				()
+			})
+		}
+	}
+}
+
+impl<Storage, KeyProvider> OffchainExt for Api<Storage, KeyProvider> where
+	Storage: OffchainStorage,
+	KeyProvider: AuthorityKeyProvider,
+{
 	fn submit_transaction(&mut self, ext: Vec<u8>) -> Result<(), ()> {
 		self.sender
 			.unbounded_send(ExtMessage::SubmitExtrinsic(ext))
@@ -61,29 +130,61 @@ impl<S: OffchainStorage> OffchainExt for Api<S> {
 			.map_err(|_| ())
 	}
 
-	fn new_crypto_key(&mut self, _crypto: CryptoKind) -> Result<CryptoKeyId, ()> {
-		unavailable_yet::<()>("new_crypto_key");
-		Err(())
+	fn new_crypto_key(&mut self, kind: CryptoKind) -> Result<CryptoKeyId, ()> {
+		let phrase = match kind {
+			CryptoKind::Ed25519 => {
+				ed25519::Pair::generate_with_phrase(Some(self.keys_password.as_ref())).1
+			},
+			CryptoKind::Sr25519 => {
+				sr25519::Pair::generate_with_phrase(Some(self.keys_password.as_ref())).1
+			},
+		};
+
+		let (id, id_encoded) = loop {
+			let encoded = self.db.get(KEYS_PREFIX, NEXT_ID);
+			let encoded_slice = encoded.as_ref().map(|x| x.as_slice());
+			let new_id = encoded_slice.and_then(|mut x| u16::decode(&mut x)).unwrap_or_default()
+				.checked_add(1)
+				.ok_or(())?;
+			let new_id_encoded = new_id.encode();
+
+			if self.db.compare_and_set(KEYS_PREFIX, NEXT_ID, encoded_slice, &new_id_encoded) {
+				break (new_id, new_id_encoded);
+			}
+		};
+
+		self.db.set(KEYS_PREFIX, &id_encoded, &CryptoKey { phrase, kind } .encode());
+
+		Ok(CryptoKeyId(id))
 	}
 
-	fn encrypt(&mut self, _key: Option<CryptoKeyId>, _data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn encrypt(&mut self, _key: Option<CryptoKeyId>, _kind: CryptoKind, _data: &[u8]) -> Result<Vec<u8>, ()> {
 		unavailable_yet::<()>("encrypt");
 		Err(())
 	}
 
-	fn decrypt(&mut self, _key: Option<CryptoKeyId>, _data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn decrypt(&mut self, _key: Option<CryptoKeyId>, _kind: CryptoKind, _data: &[u8]) -> Result<Vec<u8>, ()> {
 		unavailable_yet::<()>("decrypt");
 		Err(())
+
 	}
 
-	fn sign(&mut self, _key: Option<CryptoKeyId>, _data: &[u8]) -> Result<Vec<u8>, ()> {
-		unavailable_yet::<()>("sign");
-		Err(())
+	fn sign(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()> {
+		let key = self.read_key(key, kind)?;
+
+		Ok(match key {
+			Key::Sr25519(pair) => pair.sign(data).0.to_vec(),
+			Key::Ed25519(pair) => pair.sign(data).0.to_vec(),
+		})
 	}
 
-	fn verify(&mut self, _key: Option<CryptoKeyId>, _msg: &[u8], _signature: &[u8]) -> Result<bool, ()> {
-		unavailable_yet::<()>("verify");
-		Err(())
+	fn verify(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, msg: &[u8], signature: &[u8]) -> Result<bool, ()> {
+		let key = self.read_key(key, kind)?;
+
+		Ok(match key {
+			Key::Sr25519(pair) => sr25519::Pair::verify_weak(signature, msg, pair.public()),
+			Key::Ed25519(pair) => ed25519::Pair::verify_weak(signature, msg, pair.public()),
+		})
 	}
 
 	fn timestamp(&mut self) -> Timestamp {
@@ -114,7 +215,7 @@ impl<S: OffchainStorage> OffchainExt for Api<S> {
 	) -> bool {
 		match kind {
 			StorageKind::PERSISTENT => {
-				self.db.compare_and_set(STORAGE_PREFIX, key, old_value, new_value)
+				self.db.compare_and_set(STORAGE_PREFIX, key, Some(old_value), new_value)
 			},
 			StorageKind::LOCAL => unavailable_yet(LOCAL_DB),
 		}
@@ -195,16 +296,20 @@ pub(crate) struct AsyncApi<A: ChainApi> {
 
 impl<A: ChainApi> AsyncApi<A> {
 	/// Creates new Offchain extensions API implementation  an the asynchronous processing part.
-	pub fn new<S: OffchainStorage>(
+	pub fn new<S: OffchainStorage, P: AuthorityKeyProvider>(
 		transaction_pool: Arc<Pool<A>>,
 		db: S,
+		keys_password: Protected<String>,
+		key_provider: P,
 		at: BlockId<A::Block>,
-	) -> (Api<S>, AsyncApi<A>) {
+	) -> (Api<S, P>, AsyncApi<A>) {
 		let (sender, rx) = mpsc::unbounded();
 
 		let api = Api {
 			sender,
 			db,
+			keys_password,
+			key_provider,
 		};
 
 		let async_api = AsyncApi {
@@ -251,8 +356,9 @@ impl<A: ChainApi> AsyncApi<A> {
 mod tests {
 	use super::*;
 	use client_db::offchain::LocalStorage;
+	use crate::tests::TestProvider;
 
-	fn offchain_api() -> (Api<LocalStorage>, AsyncApi<impl ChainApi>) {
+	fn offchain_api() -> (Api<LocalStorage, TestProvider>, AsyncApi<impl ChainApi>) {
 		let _ = env_logger::try_init();
 		let db = LocalStorage::new_test();
 		let client = Arc::new(test_client::new());
@@ -260,7 +366,7 @@ mod tests {
 			Pool::new(Default::default(), transaction_pool::ChainApi::new(client.clone()))
 		);
 
-		AsyncApi::new(pool, db, BlockId::Number(0))
+		AsyncApi::new(pool, db, "pass".to_owned().into(), TestProvider::default(), BlockId::Number(0))
 	}
 
 	#[test]
@@ -294,4 +400,59 @@ mod tests {
 		assert_eq!(api.local_storage_compare_and_set(kind, key, b"value", b"xxx"), true);
 		assert_eq!(api.local_storage_get(kind, key), Some(b"xxx".to_vec()));
 	}
+
+	#[test]
+	fn should_create_a_new_key_and_sign_and_verify_stuff() {
+		let test = |kind: CryptoKind| {
+			// given
+			let mut api = offchain_api().0;
+			let msg = b"Hello world!";
+
+			// when
+			let key_id = api.new_crypto_key(kind).unwrap();
+			let signature = api.sign(Some(key_id), kind, msg).unwrap();
+
+			// then
+			let res = api.verify(Some(key_id), kind, msg, &signature).unwrap();
+			assert_eq!(res, true);
+			let res = api.verify(Some(key_id), kind, msg, &[]).unwrap();
+			assert_eq!(res, false);
+			let res = api.verify(Some(key_id), kind, b"Different msg", &signature).unwrap();
+			assert_eq!(res, false);
+
+			assert_eq!(
+				api.verify(Some(key_id), CryptoKind::Sr25519, msg, &signature).is_err(),
+				kind != CryptoKind::Sr25519
+			);
+
+		};
+
+		test(CryptoKind::Ed25519);
+		test(CryptoKind::Sr25519);
+	}
+
+	#[test]
+	fn should_sign_and_verify_with_authority_key() {
+		// given
+		let mut api = offchain_api().0;
+		api.key_provider.ed_key = Some(ed25519::Pair::generate().0);
+		let msg = b"Hello world!";
+		let kind = CryptoKind::Ed25519;
+
+		// when
+		let signature = api.sign(None, kind, msg).unwrap();
+
+		// then
+		let res = api.verify(None, kind, msg, &signature).unwrap();
+		assert_eq!(res, true);
+		let res = api.verify(None, kind, msg, &[]).unwrap();
+		assert_eq!(res, false);
+		let res = api.verify(None, kind, b"Different msg", &signature).unwrap();
+		assert_eq!(res, false);
+
+		assert!(
+			api.verify(None, CryptoKind::Sr25519, msg, &signature).is_err(),
+			"Invalid kind should trigger a missing key error."
+		);
+	}
 }
diff --git a/substrate/core/offchain/src/lib.rs b/substrate/core/offchain/src/lib.rs
index 88676e6ec8..de3a5da084 100644
--- a/substrate/core/offchain/src/lib.rs
+++ b/substrate/core/offchain/src/lib.rs
@@ -41,7 +41,10 @@ use std::{
 
 use client::runtime_api::ApiExt;
 use log::{debug, warn};
-use primitives::ExecutionContext;
+use primitives::{
+	ExecutionContext,
+	crypto,
+};
 use runtime_primitives::{
 	generic::BlockId,
 	traits::{self, ProvideRuntimeApi},
@@ -55,38 +58,71 @@ pub mod testing;
 
 pub use offchain_primitives::OffchainWorkerApi;
 
+/// Provides currently configured authority key.
+pub trait AuthorityKeyProvider: Clone + 'static {
+	/// Returns currently configured authority key.
+	fn authority_key<TPair: crypto::Pair>(&self) -> Option<TPair>;
+}
+
 /// An offchain workers manager.
-pub struct OffchainWorkers<C, S, Block: traits::Block> {
-	client: Arc<C>,
-	db: S,
+pub struct OffchainWorkers<
+	Client,
+	Storage,
+	KeyProvider,
+	Block: traits::Block,
+> {
+	client: Arc<Client>,
+	db: Storage,
+	authority_key: KeyProvider,
+	keys_password: crypto::Protected<String>,
 	_block: PhantomData<Block>,
 }
 
-impl<C, S, Block: traits::Block> OffchainWorkers<C, S, Block> {
+impl<Client, Storage, KeyProvider, Block: traits::Block> OffchainWorkers<
+	Client,
+	Storage,
+	KeyProvider,
+	Block,
+> {
 	/// Creates new `OffchainWorkers`.
 	pub fn new(
-		client: Arc<C>,
-		db: S,
+		client: Arc<Client>,
+		db: Storage,
+		authority_key: KeyProvider,
+		keys_password: crypto::Protected<String>,
 	) -> Self {
 		Self {
 			client,
 			db,
+			authority_key,
+			keys_password,
 			_block: PhantomData,
 		}
 	}
 }
 
-impl<C, S, Block: traits::Block> fmt::Debug for OffchainWorkers<C, S, Block> {
+impl<Client, Storage, KeyProvider, Block: traits::Block> fmt::Debug for OffchainWorkers<
+	Client,
+	Storage,
+	KeyProvider,
+	Block,
+> {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		f.debug_tuple("OffchainWorkers").finish()
 	}
 }
 
-impl<C, S, Block> OffchainWorkers<C, S, Block> where
+impl<Client, Storage, KeyProvider, Block> OffchainWorkers<
+	Client,
+	Storage,
+	KeyProvider,
+	Block,
+> where
 	Block: traits::Block,
-	S: client::backend::OffchainStorage + 'static,
-	C: ProvideRuntimeApi,
-	C::Api: OffchainWorkerApi<Block>,
+	Client: ProvideRuntimeApi,
+	Client::Api: OffchainWorkerApi<Block>,
+	KeyProvider: AuthorityKeyProvider,
+	Storage: client::backend::OffchainStorage + 'static,
 {
 	/// Start the offchain workers after given block.
 	#[must_use]
@@ -106,6 +142,8 @@ impl<C, S, Block> OffchainWorkers<C, S, Block> where
 			let (api, runner) = api::AsyncApi::new(
 				pool.clone(),
 				self.db.clone(),
+				self.keys_password.clone(),
+				self.authority_key.clone(),
 				at.clone(),
 			);
 			debug!("Running offchain workers at {:?}", at);
@@ -122,6 +160,23 @@ impl<C, S, Block> OffchainWorkers<C, S, Block> where
 mod tests {
 	use super::*;
 	use futures::Future;
+	use primitives::{ed25519, sr25519, crypto::{TypedKey, Pair}};
+
+	#[derive(Clone, Default)]
+	pub(crate) struct TestProvider {
+		pub(crate) sr_key: Option<sr25519::Pair>,
+		pub(crate) ed_key: Option<ed25519::Pair>,
+	}
+
+	impl AuthorityKeyProvider for TestProvider {
+		fn authority_key<TPair: crypto::Pair>(&self) -> Option<TPair> {
+			TPair::from_seed_slice(&match TPair::KEY_TYPE {
+				sr25519::Pair::KEY_TYPE => self.sr_key.as_ref().map(|key| key.to_raw_vec()),
+				ed25519::Pair::KEY_TYPE => self.ed_key.as_ref().map(|key| key.to_raw_vec()),
+				_ => None,
+			}?).ok()
+		}
+	}
 
 	#[test]
 	fn should_call_into_runtime_and_produce_extrinsic() {
@@ -133,7 +188,7 @@ mod tests {
 		let db = client_db::offchain::LocalStorage::new_test();
 
 		// when
-		let offchain = OffchainWorkers::new(client, db);
+		let offchain = OffchainWorkers::new(client, db, TestProvider::default(), "".to_owned().into());
 		runtime.executor().spawn(offchain.on_block_imported(&0u64, &pool));
 
 		// then
diff --git a/substrate/core/offchain/src/testing.rs b/substrate/core/offchain/src/testing.rs
index 15e1a01ecb..2d8c690e9a 100644
--- a/substrate/core/offchain/src/testing.rs
+++ b/substrate/core/offchain/src/testing.rs
@@ -143,19 +143,40 @@ impl offchain::Externalities for TestOffchainExt {
 		unimplemented!("not needed in tests so far")
 	}
 
-	fn encrypt(&mut self, _key: Option<CryptoKeyId>, _data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn encrypt(
+		&mut self,
+		_key: Option<CryptoKeyId>,
+		_kind: CryptoKind,
+		_data: &[u8],
+	) -> Result<Vec<u8>, ()> {
 		unimplemented!("not needed in tests so far")
 	}
 
-	fn decrypt(&mut self, _key: Option<CryptoKeyId>, _data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn decrypt(
+		&mut self,
+		_key: Option<CryptoKeyId>,
+		_kind: CryptoKind,
+		_data: &[u8],
+	) -> Result<Vec<u8>, ()> {
 		unimplemented!("not needed in tests so far")
 	}
 
-	fn sign(&mut self, _key: Option<CryptoKeyId>, _data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn sign(
+		&mut self,
+		_key: Option<CryptoKeyId>,
+		_kind: CryptoKind,
+		_data: &[u8],
+	) -> Result<Vec<u8>, ()> {
 		unimplemented!("not needed in tests so far")
 	}
 
-	fn verify(&mut self, _key: Option<CryptoKeyId>, _msg: &[u8], _signature: &[u8]) -> Result<bool, ()> {
+	fn verify(
+		&mut self,
+		_key: Option<CryptoKeyId>,
+		_kind: CryptoKind,
+		_msg: &[u8],
+		_signature: &[u8],
+	) -> Result<bool, ()> {
 		unimplemented!("not needed in tests so far")
 	}
 
@@ -190,7 +211,7 @@ impl offchain::Externalities for TestOffchainExt {
 		match kind {
 			StorageKind::LOCAL => &mut state.local_storage,
 			StorageKind::PERSISTENT => &mut state.persistent_storage,
-		}.compare_and_set(b"", key, old_value, new_value)
+		}.compare_and_set(b"", key, Some(old_value), new_value)
 	}
 
 	fn local_storage_get(&mut self, kind: StorageKind, key: &[u8]) -> Option<Vec<u8>> {
diff --git a/substrate/core/primitives/Cargo.toml b/substrate/core/primitives/Cargo.toml
index 106349906b..94dac26bec 100644
--- a/substrate/core/primitives/Cargo.toml
+++ b/substrate/core/primitives/Cargo.toml
@@ -27,6 +27,7 @@ tiny-bip39 = { version = "0.6.1", optional = true }
 hex = { version = "0.3", optional = true }
 regex = { version = "1.1", optional = true }
 num-traits = { version = "0.2", default-features = false }
+zeroize = { version = "0.9.2", default-features = false }
 
 [dev-dependencies]
 substrate-serializer = { path = "../serializer" }
@@ -72,4 +73,5 @@ std = [
 	"schnorrkel",
 	"regex",
 	"num-traits/std",
+	"zeroize/std"
 ]
diff --git a/substrate/core/primitives/src/crypto.rs b/substrate/core/primitives/src/crypto.rs
index 0d01da1b48..6aac4e08bc 100644
--- a/substrate/core/primitives/src/crypto.rs
+++ b/substrate/core/primitives/src/crypto.rs
@@ -28,6 +28,7 @@ use regex::Regex;
 use base58::{FromBase58, ToBase58};
 #[cfg(feature = "std")]
 use std::hash::Hash;
+use zeroize::Zeroize;
 
 /// The root phrase for our publicly known keys.
 pub const DEV_PHRASE: &str = "bottom drive obey lake curtain smoke basket hold race lonely fit walk";
@@ -66,6 +67,43 @@ impl<S, T: UncheckedFrom<S>> UncheckedInto<T> for S {
 	}
 }
 
+/// A store for sensitive data.
+///
+/// Calls `Zeroize::zeroize` upon `Drop`.
+#[derive(Clone)]
+pub struct Protected<T: Zeroize>(T);
+
+impl<T: Zeroize> AsRef<T> for Protected<T> {
+	fn as_ref(&self) -> &T {
+		&self.0
+	}
+}
+
+#[cfg(feature = "std")]
+impl<T: Zeroize> std::fmt::Debug for Protected<T> {
+	fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
+		write!(fmt, "<protected>")
+	}
+}
+
+impl<T: Zeroize> From<T> for Protected<T> {
+	fn from(t: T) -> Self {
+		Protected(t)
+	}
+}
+
+impl<T: Zeroize> Zeroize for Protected<T> {
+	fn zeroize(&mut self) {
+		self.0.zeroize()
+	}
+}
+
+impl<T: Zeroize> Drop for Protected<T> {
+	fn drop(&mut self) {
+		self.zeroize()
+	}
+}
+
 /// An error with the interpretation of a secret.
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[cfg(feature = "std")]
@@ -289,7 +327,7 @@ impl<T: AsMut<[u8]> + AsRef<[u8]> + Default + Derive> Ss58Codec for T {
 }
 
 /// Trait suitable for typical cryptographic PKI key public type.
-pub trait Public: PartialEq + Eq {
+pub trait Public: TypedKey + PartialEq + Eq {
 	/// A new instance from the given slice that should be 32 bytes long.
 	///
 	/// NOTE: No checking goes on to ensure this is a real public key. Only use it if
@@ -308,9 +346,8 @@ pub trait Public: PartialEq + Eq {
 ///
 /// For now it just specifies how to create a key from a phrase and derivation path.
 #[cfg(feature = "std")]
-pub trait Pair: Sized + 'static
-{
-	/// TThe type which is used to encode a public key.
+pub trait Pair: TypedKey + Sized + 'static {
+	/// The type which is used to encode a public key.
 	type Public: Public + Hash;
 
 	/// The type used to (minimally) encode the data required to securely create
@@ -319,7 +356,7 @@ pub trait Pair: Sized + 'static
 
 	/// The type used to represent a signature. Can be created from a key pair and a message
 	/// and verified with the message and a public key.
-	type Signature;
+	type Signature: AsRef<[u8]>;
 
 	/// Error returned from the `derive` function.
 	type DeriveError;
@@ -476,7 +513,7 @@ mod tests {
 	#[derive(PartialEq, Eq, Hash)]
 	struct TestPublic;
 	impl Public for TestPublic {
-		fn from_slice(bytes: &[u8]) -> Self {
+		fn from_slice(_bytes: &[u8]) -> Self {
 			Self
 		}
 		fn as_slice(&self) -> &[u8] {
@@ -486,10 +523,13 @@ mod tests {
 			vec![]
 		}
 	}
+	impl TypedKey for TestPublic {
+		const KEY_TYPE: u32 = 4242;
+	}
 	impl Pair for TestPair {
 		type Public = TestPublic;
 		type Seed = [u8; 0];
-		type Signature = ();
+		type Signature = [u8; 0];
 		type DeriveError = ();
 
 		fn generate() -> (Self, <Self as Pair>::Seed) { (TestPair::Generated, []) }
@@ -510,7 +550,7 @@ mod tests {
 			Err(())
 		}
 		fn from_seed(_seed: &<TestPair as Pair>::Seed) -> Self { TestPair::Seed(vec![]) }
-		fn sign(&self, _message: &[u8]) -> Self::Signature { () }
+		fn sign(&self, _message: &[u8]) -> Self::Signature { [] }
 		fn verify<P: AsRef<Self::Public>, M: AsRef<[u8]>>(
 			_sig: &Self::Signature,
 			_message: M,
@@ -542,6 +582,9 @@ mod tests {
 			vec![]
 		}
 	}
+	impl TypedKey for TestPair {
+		const KEY_TYPE: u32 = 4242;
+	}
 
 	#[test]
 	fn interpret_std_seed_should_work() {
diff --git a/substrate/core/primitives/src/offchain.rs b/substrate/core/primitives/src/offchain.rs
index 7c068ca886..2ea93423d9 100644
--- a/substrate/core/primitives/src/offchain.rs
+++ b/substrate/core/primitives/src/offchain.rs
@@ -16,11 +16,13 @@
 
 //! Offchain workers types
 
+use crate::crypto;
+use parity_codec::{Encode, Decode};
 use rstd::prelude::{Vec, Box};
 use rstd::convert::TryFrom;
 
 /// A type of supported crypto.
-#[derive(Clone, Copy, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq, Encode, Decode)]
 #[cfg_attr(feature = "std", derive(Debug))]
 #[repr(C)]
 pub enum StorageKind {
@@ -50,15 +52,21 @@ impl TryFrom<u32> for StorageKind {
 	}
 }
 
+impl From<StorageKind> for u32 {
+	fn from(c: StorageKind) -> Self {
+		c as u8 as u32
+	}
+}
+
 /// A type of supported crypto.
-#[derive(Clone, Copy, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq, Encode, Decode)]
 #[cfg_attr(feature = "std", derive(Debug))]
 #[repr(C)]
 pub enum CryptoKind {
 	/// SR25519 crypto (Schnorrkel)
-	Sr25519 = 1,
+	Sr25519 = crypto::key_types::SR25519 as isize,
 	/// ED25519 crypto (Edwards)
-	Ed25519 = 2,
+	Ed25519 = crypto::key_types::ED25519 as isize,
 }
 
 impl TryFrom<u32> for CryptoKind {
@@ -66,23 +74,41 @@ impl TryFrom<u32> for CryptoKind {
 
 	fn try_from(kind: u32) -> Result<Self, Self::Error> {
 		match kind {
-			e if e == u32::from(CryptoKind::Sr25519 as u8) => Ok(CryptoKind::Sr25519),
-			e if e == u32::from(CryptoKind::Ed25519 as u8) => Ok(CryptoKind::Ed25519),
+			e if e == CryptoKind::Sr25519 as isize as u32 => Ok(CryptoKind::Sr25519),
+			e if e == CryptoKind::Ed25519 as isize as u32 => Ok(CryptoKind::Ed25519),
 			_ => Err(()),
 		}
 	}
 }
 
+impl From<CryptoKind> for u32 {
+	fn from(c: CryptoKind) -> Self {
+		c as isize as u32
+	}
+}
+
 /// Opaque type for created crypto keys.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 #[cfg_attr(feature = "std", derive(Debug))]
 pub struct CryptoKeyId(pub u16);
 
+impl From<CryptoKeyId> for u32 {
+	fn from(c: CryptoKeyId) -> Self {
+		c.0 as u32
+	}
+}
+
 /// Opaque type for offchain http requests.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 #[cfg_attr(feature = "std", derive(Debug))]
 pub struct HttpRequestId(pub u16);
 
+impl From<HttpRequestId> for u32 {
+	fn from(c: HttpRequestId) -> Self {
+		c.0 as u32
+	}
+}
+
 /// An error enum returned by some http methods.
 #[derive(Clone, Copy, PartialEq, Eq)]
 #[cfg_attr(feature = "std", derive(Debug))]
@@ -106,6 +132,12 @@ impl TryFrom<u32> for HttpError {
 	}
 }
 
+impl From<HttpError> for u32 {
+	fn from(c: HttpError) -> Self {
+		c as u8 as u32
+	}
+}
+
 /// Status of the HTTP request
 #[derive(Clone, Copy, PartialEq, Eq)]
 #[cfg_attr(feature = "std", derive(Debug))]
@@ -216,31 +248,34 @@ pub trait Externalities {
 
 	/// Encrypt a piece of data using given crypto key.
 	///
-	/// If `key` is `None`, it will attempt to use current authority key.
+	/// If `key` is `None`, it will attempt to use current authority key of `CryptoKind`.
 	///
-	/// Returns an error if `key` is not available or does not exist.
-	fn encrypt(&mut self, key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()>;
+	/// Returns an error if `key` is not available or does not exist,
+	/// or the expected `CryptoKind` does not match.
+	fn encrypt(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()>;
 
 	/// Decrypt a piece of data using given crypto key.
 	///
-	/// If `key` is `None`, it will attempt to use current authority key.
+	/// If `key` is `None`, it will attempt to use current authority key of `CryptoKind`.
 	///
-	/// Returns an error if data cannot be decrypted or the `key` is not available or does not exist.
-	fn decrypt(&mut self, key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()>;
+	/// Returns an error if data cannot be decrypted or the `key` is not available or does not exist,
+	/// or the expected `CryptoKind` does not match.
+	fn decrypt(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()>;
 
 	/// Sign a piece of data using given crypto key.
 	///
-	/// If `key` is `None`, it will attempt to use current authority key.
+	/// If `key` is `None`, it will attempt to use current authority key of `CryptoKind`.
 	///
-	/// Returns an error if `key` is not available or does not exist.
-	fn sign(&mut self, key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()>;
+	/// Returns an error if `key` is not available or does not exist,
+	/// or the expected `CryptoKind` does not match.
+	fn sign(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()>;
 
 	/// Verifies that `signature` for `msg` matches given `key`.
 	///
 	/// Returns an `Ok` with `true` in case it does, `false` in case it doesn't.
 	/// Returns an error in case the key is not available or does not exist or the parameters
-	/// lengths are incorrect.
-	fn verify(&mut self, key: Option<CryptoKeyId>, msg: &[u8], signature: &[u8]) -> Result<bool, ()>;
+	/// lengths are incorrect or `CryptoKind` does not match.
+	fn verify(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, msg: &[u8], signature: &[u8]) -> Result<bool, ()>;
 
 	/// Returns current UNIX timestamp (in millis)
 	fn timestamp(&mut self) -> Timestamp;
@@ -359,20 +394,20 @@ impl<T: Externalities + ?Sized> Externalities for Box<T> {
 		(&mut **self).new_crypto_key(crypto)
 	}
 
-	fn encrypt(&mut self, key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
-		(&mut **self).encrypt(key, data)
+	fn encrypt(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()> {
+		(&mut **self).encrypt(key, kind, data)
 	}
 
-	fn decrypt(&mut self, key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
-		(&mut **self).decrypt(key, data)
+	fn decrypt(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()> {
+		(&mut **self).decrypt(key, kind, data)
 	}
 
-	fn sign(&mut self, key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
-		(&mut **self).sign(key, data)
+	fn sign(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()> {
+		(&mut **self).sign(key, kind, data)
 	}
 
-	fn verify(&mut self, key: Option<CryptoKeyId>, msg: &[u8], signature: &[u8]) -> Result<bool, ()> {
-		(&mut **self).verify(key, msg, signature)
+	fn verify(&mut self, key: Option<CryptoKeyId>, kind: CryptoKind, msg: &[u8], signature: &[u8]) -> Result<bool, ()> {
+		(&mut **self).verify(key, kind, msg, signature)
 	}
 
 	fn timestamp(&mut self) -> Timestamp {
diff --git a/substrate/core/primitives/src/sr25519.rs b/substrate/core/primitives/src/sr25519.rs
index e92b9f0003..e01d989143 100644
--- a/substrate/core/primitives/src/sr25519.rs
+++ b/substrate/core/primitives/src/sr25519.rs
@@ -379,6 +379,7 @@ fn derive_hard_junction(secret: &SecretKey, cc: &[u8; CHAIN_CODE_LENGTH]) -> Sec
 	secret.hard_derive_mini_secret_key(Some(ChainCode(cc.clone())), b"").0.expand()
 }
 
+/// The raw secret seed, which can be used to recreate the `Pair`.
 #[cfg(feature = "std")]
 type Seed = [u8; MINI_SECRET_KEY_LENGTH];
 
diff --git a/substrate/core/service/src/components.rs b/substrate/core/service/src/components.rs
index fe72e2c280..228bfcc0e6 100644
--- a/substrate/core/service/src/components.rs
+++ b/substrate/core/service/src/components.rs
@@ -21,7 +21,7 @@ use serde::{Serialize, de::DeserializeOwned};
 use crate::chain_spec::ChainSpec;
 use client_db;
 use client::{self, Client, runtime_api};
-use crate::{error, Service};
+use crate::{error, Service, AuthorityKeyProvider};
 use consensus_common::{import_queue::ImportQueue, SelectChain};
 use network::{self, OnDemand, FinalityProofProvider};
 use substrate_executor::{NativeExecutor, NativeExecutionDispatch};
@@ -191,7 +191,7 @@ fn maintain_transaction_pool<Api, Backend, Block, Executor, PoolApi>(
 	client: &Client<Backend, Executor, Block, Api>,
 	transaction_pool: &TransactionPool<PoolApi>,
 ) -> error::Result<()> where
-	Block: BlockT<Hash = <Blake2Hasher as ::primitives::Hasher>::Out>,
+	Block: BlockT<Hash = <Blake2Hasher as primitives::Hasher>::Out>,
 	Backend: client::backend::Backend<Block, Blake2Hasher>,
 	Client<Backend, Executor, Block, Api>: ProvideRuntimeApi,
 	<Client<Backend, Executor, Block, Api> as ProvideRuntimeApi>::Api: runtime_api::TaggedTransactionQueue<Block>,
@@ -231,6 +231,7 @@ pub trait OffchainWorker<C: Components> {
 		offchain: &offchain::OffchainWorkers<
 			ComponentClient<C>,
 			ComponentOffchainStorage<C>,
+			AuthorityKeyProvider,
 			ComponentBlock<C>
 		>,
 		pool: &Arc<TransactionPool<C::TransactionPoolApi>>,
@@ -246,6 +247,7 @@ impl<C: Components> OffchainWorker<Self> for C where
 		offchain: &offchain::OffchainWorkers<
 			ComponentClient<C>,
 			ComponentOffchainStorage<C>,
+			AuthorityKeyProvider,
 			ComponentBlock<C>
 		>,
 		pool: &Arc<TransactionPool<C::TransactionPoolApi>>,
diff --git a/substrate/core/service/src/config.rs b/substrate/core/service/src/config.rs
index 8769f1dac9..5db9b756a1 100644
--- a/substrate/core/service/src/config.rs
+++ b/substrate/core/service/src/config.rs
@@ -16,12 +16,14 @@
 
 //! Service configuration.
 
-use std::{path::PathBuf, net::SocketAddr};
-use transaction_pool;
-use crate::chain_spec::ChainSpec;
 pub use client::ExecutionStrategies;
 pub use client_db::PruningMode;
 pub use network::config::{ExtTransport, NetworkConfiguration, Roles};
+
+use std::{path::PathBuf, net::SocketAddr};
+use transaction_pool;
+use crate::chain_spec::ChainSpec;
+use primitives::crypto::Protected;
 use runtime_primitives::BuildStorage;
 use serde::{Serialize, de::DeserializeOwned};
 use target_info::Target;
@@ -86,7 +88,7 @@ pub struct Configuration<C, G: Serialize + DeserializeOwned + BuildStorage> {
 	/// Disable GRANDPA when running in validator mode
 	pub disable_grandpa: bool,
 	/// Node keystore's password
-	pub password: String,
+	pub password: Protected<String>,
 }
 
 impl<C: Default, G: Serialize + DeserializeOwned + BuildStorage> Configuration<C, G> {
@@ -120,7 +122,7 @@ impl<C: Default, G: Serialize + DeserializeOwned + BuildStorage> Configuration<C
 			offchain_worker: Default::default(),
 			force_authoring: false,
 			disable_grandpa: false,
-			password: "".to_string(),
+			password: "".to_string().into(),
 		};
 		configuration.network.boot_nodes = configuration.chain_spec.boot_nodes().to_vec();
 
diff --git a/substrate/core/service/src/lib.rs b/substrate/core/service/src/lib.rs
index 83f0488a7e..3c2b6bf86e 100644
--- a/substrate/core/service/src/lib.rs
+++ b/substrate/core/service/src/lib.rs
@@ -39,7 +39,7 @@ use keystore::Store as Keystore;
 use network::NetworkState;
 use log::{info, warn, debug, error};
 use parity_codec::{Encode, Decode};
-use primitives::{Pair, Public, crypto::TypedKey, ed25519};
+use primitives::{Pair, ed25519, crypto};
 use runtime_primitives::generic::BlockId;
 use runtime_primitives::traits::{Header, NumberFor, SaturatedConversion};
 use substrate_executor::NativeExecutor;
@@ -74,14 +74,14 @@ const DEFAULT_PROTOCOL_ID: &str = "sup";
 /// Substrate service.
 pub struct Service<Components: components::Components> {
 	client: Arc<ComponentClient<Components>>,
-	select_chain: Option<<Components as components::Components>::SelectChain>,
+	select_chain: Option<Components::SelectChain>,
 	network: Arc<components::NetworkService<Components>>,
 	/// Sinks to propagate network status updates.
 	network_status_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<(
 		NetworkStatus<ComponentBlock<Components>>, NetworkState
 	)>>>>,
 	transaction_pool: Arc<TransactionPool<Components::TransactionPoolApi>>,
-	keystore: Option<Keystore>,
+	keystore: AuthorityKeyProvider,
 	exit: ::exit_future::Exit,
 	signal: Option<Signal>,
 	/// Sender for futures that must be spawned as background tasks.
@@ -101,6 +101,7 @@ pub struct Service<Components: components::Components> {
 	_offchain_workers: Option<Arc<offchain::OffchainWorkers<
 		ComponentClient<Components>,
 		ComponentOffchainStorage<Components>,
+		AuthorityKeyProvider,
 		ComponentBlock<Components>>
 	>>,
 }
@@ -192,7 +193,7 @@ impl<Components: components::Components> Service<Components> {
 			public_key = match keystore.contents::<ed25519::Public>()?.get(0) {
 				Some(public_key) => public_key.to_string(),
 				None => {
-					let key: ed25519::Pair = keystore.generate(&config.password)?;
+					let key: ed25519::Pair = keystore.generate(&config.password.as_ref())?;
 					let public_key = key.public();
 					info!("Generated a new keypair: {:?}", public_key);
 					public_key.to_string()
@@ -259,6 +260,12 @@ impl<Components: components::Components> Service<Components> {
 		let network = network_mut.service().clone();
 		let network_status_sinks = Arc::new(Mutex::new(Vec::new()));
 
+		let keystore_authority_key = AuthorityKeyProvider {
+			roles: config.roles,
+			password: config.password.clone(),
+			keystore: keystore.map(Arc::new),
+		};
+
 		#[allow(deprecated)]
 		let offchain_storage = client.backend().offchain_storage();
 		let offchain_workers = match (config.offchain_worker, offchain_storage) {
@@ -266,6 +273,8 @@ impl<Components: components::Components> Service<Components> {
 				Some(Arc::new(offchain::OffchainWorkers::new(
 					client.clone(),
 					db,
+					keystore_authority_key.clone(),
+					config.password.clone(),
 				)))
 			},
 			(true, None) => {
@@ -469,7 +478,7 @@ impl<Components: components::Components> Service<Components> {
 			to_spawn_tx,
 			to_spawn_rx,
 			to_poll: Vec::new(),
-			keystore,
+			keystore: keystore_authority_key,
 			config,
 			exit,
 			rpc_handlers,
@@ -481,23 +490,10 @@ impl<Components: components::Components> Service<Components> {
 	}
 
 	/// give the authority key, if we are an authority and have a key
-	pub fn authority_key<TPair>(&self) -> Option<TPair>
-	where
-		TPair: Pair + TypedKey,
-		<TPair as Pair>::Public: Public + TypedKey,
-	{
-		if self.config.roles != Roles::AUTHORITY { return None }
-		if let Some(keystore) = &self.keystore {
-			if let Ok(Some(Ok(key))) =  keystore.contents::<TPair::Public>().map(|keys| keys.get(0)
-					.map(|k| keystore.load::<TPair>(k, &self.config.password)))
-			{
-				Some(key)
-			} else {
-				None
-			}
-		} else {
-			None
-		}
+	pub fn authority_key<TPair: Pair>(&self) -> Option<TPair> {
+		use offchain::AuthorityKeyProvider;
+
+		self.keystore.authority_key()
 	}
 
 	/// return a shared instance of Telemetry (if enabled)
@@ -870,6 +866,39 @@ impl<C: Components> network::TransactionPool<ComponentExHash<C>, ComponentBlock<
 	}
 }
 
+/// A provider of current authority key.
+#[derive(Clone)]
+pub struct AuthorityKeyProvider {
+	roles: Roles,
+	keystore: Option<Arc<Keystore>>,
+	password: crypto::Protected<String>,
+}
+
+impl offchain::AuthorityKeyProvider for AuthorityKeyProvider {
+	fn authority_key<TPair: Pair>(&self) -> Option<TPair> {
+		if self.roles != Roles::AUTHORITY {
+			return None
+		}
+
+		let keystore = match self.keystore {
+			Some(ref keystore) => keystore,
+			None => return None
+		};
+
+		let loaded_key = keystore
+				.contents()
+				.map(|keys| keys.get(0)
+					.map(|k| keystore.load(k, self.password.as_ref()))
+				);
+
+		if let Ok(Some(Ok(key))) = loaded_key {
+			Some(key)
+		} else {
+			None
+		}
+	}
+}
+
 /// Constructs a service factory with the given name that implements the `ServiceFactory` trait.
 /// The required parameters are required to be given in the exact order. Some parameters are followed
 /// by `{}` blocks. These blocks are required and used to initialize the given parameter.
diff --git a/substrate/core/service/test/src/lib.rs b/substrate/core/service/test/src/lib.rs
index 48b310db5f..543f98d7ad 100644
--- a/substrate/core/service/test/src/lib.rs
+++ b/substrate/core/service/test/src/lib.rs
@@ -194,7 +194,7 @@ fn node_config<F: ServiceFactory> (
 		offchain_worker: false,
 		force_authoring: false,
 		disable_grandpa: false,
-		password: "".to_string(),
+		password: "".to_string().into(),
 	}
 }
 
diff --git a/substrate/core/sr-io/src/lib.rs b/substrate/core/sr-io/src/lib.rs
index 47df468d20..6721cc7ecd 100644
--- a/substrate/core/sr-io/src/lib.rs
+++ b/substrate/core/sr-io/src/lib.rs
@@ -249,28 +249,33 @@ export_api! {
 		/// If `key` is `None`, it will attempt to use current authority key.
 		///
 		/// Returns an error if `key` is not available or does not exist.
-		fn encrypt(key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()>;
+		fn encrypt(key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()>;
 
 		/// Decrypt a piece of data using given crypto key.
 		///
 		/// If `key` is `None`, it will attempt to use current authority key.
 		///
 		/// Returns an error if data cannot be decrypted or the `key` is not available or does not exist.
-		fn decrypt(key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()>;
+		fn decrypt(key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()>;
 
 		/// Sign a piece of data using given crypto key.
 		///
 		/// If `key` is `None`, it will attempt to use current authority key.
 		///
 		/// Returns an error if `key` is not available or does not exist.
-		fn sign(key: Option<CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()>;
+		fn sign(key: Option<CryptoKeyId>, kind: CryptoKind, data: &[u8]) -> Result<Vec<u8>, ()>;
 
 		/// Verifies that `signature` for `msg` matches given `key`.
 		///
 		/// Returns an `Ok` with `true` in case it does, `false` in case it doesn't.
 		/// Returns an error in case the key is not available or does not exist or the parameters
 		/// lengths are incorrect.
-		fn verify(key: Option<CryptoKeyId>, msg: &[u8], signature: &[u8]) -> Result<bool, ()>;
+		fn verify(
+			key: Option<CryptoKeyId>,
+			kind: CryptoKind,
+			msg: &[u8],
+			signature: &[u8]
+		) -> Result<bool, ()>;
 
 		/// Returns current UNIX timestamp (in millis)
 		fn timestamp() -> Timestamp;
diff --git a/substrate/core/sr-io/with_std.rs b/substrate/core/sr-io/with_std.rs
index aee2dc1bc8..25be27046a 100644
--- a/substrate/core/sr-io/with_std.rs
+++ b/substrate/core/sr-io/with_std.rs
@@ -275,27 +275,44 @@ impl OffchainApi for () {
 		}, "new_crypto_key can be called only in the offchain worker context")
 	}
 
-	fn encrypt(key: Option<offchain::CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn encrypt(
+		key: Option<offchain::CryptoKeyId>,
+		kind: offchain::CryptoKind,
+		data: &[u8],
+	) -> Result<Vec<u8>, ()> {
 		with_offchain(|ext| {
-			ext.encrypt(key, data)
+			ext.encrypt(key, kind, data)
 		}, "encrypt can be called only in the offchain worker context")
 	}
 
-	fn decrypt(key: Option<offchain::CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn decrypt(
+		key: Option<offchain::CryptoKeyId>,
+		kind: offchain::CryptoKind,
+		data: &[u8],
+	) -> Result<Vec<u8>, ()> {
 		with_offchain(|ext| {
-			ext.decrypt(key, data)
+			ext.decrypt(key, kind, data)
 		}, "decrypt can be called only in the offchain worker context")
 	}
 
-	fn sign(key: Option<offchain::CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn sign(
+		key: Option<offchain::CryptoKeyId>,
+		kind: offchain::CryptoKind,
+		data: &[u8],
+	) -> Result<Vec<u8>, ()> {
 		with_offchain(|ext| {
-			ext.sign(key, data)
+			ext.sign(key, kind, data)
 		}, "sign can be called only in the offchain worker context")
 	}
 
-	fn verify(key: Option<offchain::CryptoKeyId>, msg: &[u8], signature: &[u8]) -> Result<bool, ()> {
+	fn verify(
+		key: Option<offchain::CryptoKeyId>,
+		kind: offchain::CryptoKind,
+		msg: &[u8],
+		signature: &[u8],
+	) -> Result<bool, ()> {
 		with_offchain(|ext| {
-			ext.verify(key, msg, signature)
+			ext.verify(key, kind, msg, signature)
 		}, "verify can be called only in the offchain worker context")
 	}
 
diff --git a/substrate/core/sr-io/without_std.rs b/substrate/core/sr-io/without_std.rs
index ad1b26b8c1..5565f9ab38 100644
--- a/substrate/core/sr-io/without_std.rs
+++ b/substrate/core/sr-io/without_std.rs
@@ -395,18 +395,24 @@ pub mod ext {
 
 		/// Encrypt a piece of data using given crypto key.
 		///
-		/// If `key` is `0`, it will attempt to use current authority key.
+		/// If `key` is `0`, it will attempt to use current authority key of given `kind`.
 		///
 		/// # Returns
 		///
 		/// - `0` in case the key is invalid, `msg_len` is set to `u32::max_value`
 		/// - Otherwise, pointer to the encrypted message in memory,
 		///	`msg_len` contains the length of the message.
-		fn ext_encrypt(key: u32, data: *const u8, data_len: u32, msg_len: *mut u32) -> *mut u8;
+		fn ext_encrypt(
+			key: u32,
+			kind: u32,
+			data: *const u8,
+			data_len: u32,
+			msg_len: *mut u32
+		) -> *mut u8;
 
 		/// Decrypt a piece of data using given crypto key.
 		///
-		/// If `key `is `0`, it will attempt to use current authority key.
+		/// If `key` is `0`, it will attempt to use current authority key of given `kind`.
 		///
 		/// # Returns
 		///
@@ -414,11 +420,17 @@ pub mod ext {
 		/// `msg_len` is set to `u32::max_value`
 		/// - Otherwise, pointer to the decrypted message in memory,
 		///	`msg_len` contains the length of the message.
-		fn ext_decrypt(key: u32, data: *const u8, data_len: u32, msg_len: *mut u32) -> *mut u8;
+		fn ext_decrypt(
+			key: u32,
+			kind: u32,
+			data: *const u8,
+			data_len: u32,
+			msg_len: *mut u32
+		) -> *mut u8;
 
 		/// Sign a piece of data using given crypto key.
 		///
-		/// If `key` is `0`, it will attempt to use current authority key.
+		/// If `key` is `0`, it will attempt to use current authority key of given `kind`.
 		///
 		/// # Returns
 		///
@@ -426,11 +438,17 @@ pub mod ext {
 		/// `sig_data_len` is set to `u32::max_value`
 		/// - Otherwise, pointer to the signature in memory,
 		///	`sig_data_len` contains the length of the signature.
-		fn ext_sign(key: u32, data: *const u8, data_len: u32, sig_data_len: *mut u32) -> *mut u8;
+		fn ext_sign(
+			key: u32,
+			kind: u32,
+			data: *const u8,
+			data_len: u32,
+			sig_data_len: *mut u32
+		) -> *mut u8;
 
 		/// Verifies that `signature` for `msg` matches given `key`.
 		///
-		/// If `key` is `0`, it will attempt to use current authority key.
+		/// If `key` is `0`, it will attempt to use current authority key of given `kind`.
 		///
 		/// # Returns
 		/// - `0` in case the signature is correct
@@ -438,6 +456,7 @@ pub mod ext {
 		/// - `u32::max_value` if the key is invalid.
 		fn ext_verify(
 			key: u32,
+			kind: u32,
 			msg: *const u8,
 			msg_len: u32,
 			signature: *const u8,
@@ -870,7 +889,7 @@ impl OffchainApi for () {
 	}
 
 	fn new_crypto_key(crypto: offchain::CryptoKind) -> Result<offchain::CryptoKeyId, ()> {
-		let crypto = crypto as u8 as u32;
+		let crypto = crypto.into();
 		let ret = unsafe {
 			ext_new_crypto_key.get()(crypto)
 		};
@@ -882,41 +901,63 @@ impl OffchainApi for () {
 		}
 	}
 
-	fn encrypt(key: Option<offchain::CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
-		let key = key.map(|x| x.0 as u32).unwrap_or(0);
+	fn encrypt(
+		key: Option<offchain::CryptoKeyId>,
+		kind: offchain::CryptoKind,
+		data: &[u8],
+	) -> Result<Vec<u8>, ()> {
+		let key = key.map(Into::into).unwrap_or(0);
+		let kind = kind.into();
 		let mut len = 0_u32;
 		unsafe {
-			let ptr = ext_encrypt.get()(key, data.as_ptr(), data.len() as u32, &mut len);
+			let ptr = ext_encrypt.get()(key, kind, data.as_ptr(), data.len() as u32, &mut len);
 
 			from_raw_parts(ptr, len).ok_or(())
 		}
 	}
 
-	fn decrypt(key: Option<offchain::CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
-		let key = key.map(|x| x.0 as u32).unwrap_or(0);
+	fn decrypt(
+		key: Option<offchain::CryptoKeyId>,
+		kind: offchain::CryptoKind,
+		data: &[u8],
+	) -> Result<Vec<u8>, ()> {
+		let key = key.map(Into::into).unwrap_or(0);
+		let kind = kind.into();
 		let mut len = 0_u32;
 		unsafe {
-			let ptr = ext_decrypt.get()(key, data.as_ptr(), data.len() as u32, &mut len);
+			let ptr = ext_decrypt.get()(key, kind, data.as_ptr(), data.len() as u32, &mut len);
 
 			from_raw_parts(ptr, len).ok_or(())
 		}
 	}
 
-	fn sign(key: Option<offchain::CryptoKeyId>, data: &[u8]) -> Result<Vec<u8>, ()> {
-		let key = key.map(|x| x.0 as u32).unwrap_or(0);
+	fn sign(
+		key: Option<offchain::CryptoKeyId>,
+		kind: offchain::CryptoKind,
+		data: &[u8],
+	) -> Result<Vec<u8>, ()> {
+		let key = key.map(Into::into).unwrap_or(0);
+		let kind = kind.into();
 		let mut len = 0_u32;
 		unsafe {
-			let ptr = ext_sign.get()(key, data.as_ptr(), data.len() as u32, &mut len);
+			let ptr = ext_sign.get()(key, kind, data.as_ptr(), data.len() as u32, &mut len);
 
 			from_raw_parts(ptr, len).ok_or(())
 		}
 	}
 
-	fn verify(key: Option<offchain::CryptoKeyId>, msg: &[u8], signature: &[u8]) -> Result<bool, ()> {
-		let key = key.map(|x| x.0 as u32).unwrap_or(0);
+	fn verify(
+		key: Option<offchain::CryptoKeyId>,
+		kind: offchain::CryptoKind,
+		msg: &[u8],
+		signature: &[u8],
+	) -> Result<bool, ()> {
+		let key = key.map(Into::into).unwrap_or(0);
+		let kind = kind.into();
 		let val = unsafe {
 			ext_verify.get()(
 				key,
+				kind,
 				msg.as_ptr(),
 				msg.len() as u32,
 				signature.as_ptr(),
@@ -954,7 +995,7 @@ impl OffchainApi for () {
 	fn local_storage_set(kind: offchain::StorageKind, key: &[u8], value: &[u8]) {
 		unsafe {
 			ext_local_storage_set.get()(
-				kind as u8 as u32,
+				kind.into(),
 				key.as_ptr(),
 				key.len() as u32,
 				value.as_ptr(),
@@ -966,7 +1007,7 @@ impl OffchainApi for () {
 	fn local_storage_compare_and_set(kind: offchain::StorageKind, key: &[u8], old_value: &[u8], new_value: &[u8]) -> bool {
 		unsafe {
 			ext_local_storage_compare_and_set.get()(
-				kind as u8 as u32,
+				kind.into(),
 				key.as_ptr(),
 				key.len() as u32,
 				old_value.as_ptr(),
@@ -981,7 +1022,7 @@ impl OffchainApi for () {
 		let mut len = 0u32;
 		unsafe {
 			let ptr = ext_local_storage_get.get()(
-				kind as u8 as u32,
+				kind.into(),
 				key.as_ptr(),
 				key.len() as u32,
 				&mut len,
@@ -1019,7 +1060,7 @@ impl OffchainApi for () {
 
 		let result = unsafe {
 			ext_http_request_add_header.get()(
-				request_id.0 as u32,
+				request_id.into(),
 				name.as_ptr(),
 				name.len() as u32,
 				value.as_ptr(),
@@ -1041,7 +1082,7 @@ impl OffchainApi for () {
 	) -> Result<(), offchain::HttpError> {
 		let res = unsafe {
 			ext_http_request_write_body.get()(
-				request_id.0 as u32,
+				request_id.into(),
 				chunk.as_ptr(),
 				chunk.len() as u32,
 				deadline.map_or(0, |x| x.unix_millis()),
@@ -1084,7 +1125,7 @@ impl OffchainApi for () {
 		let mut len = 0u32;
 		let raw_result = unsafe {
 			let ptr = ext_http_response_headers.get()(
-				request_id.0 as u32,
+				request_id.into(),
 				&mut len,
 			);
 
@@ -1101,7 +1142,7 @@ impl OffchainApi for () {
 	) -> Result<usize, offchain::HttpError> {
 		let res = unsafe {
 			ext_http_response_read_body.get()(
-				request_id.0 as u32,
+				request_id.into(),
 				buffer.as_mut_ptr(),
 				buffer.len() as u32,
 				deadline.map_or(0, |x| x.unix_millis()),
diff --git a/substrate/core/state-machine/src/lib.rs b/substrate/core/state-machine/src/lib.rs
index 7cff304675..f151fedaf5 100644
--- a/substrate/core/state-machine/src/lib.rs
+++ b/substrate/core/state-machine/src/lib.rs
@@ -250,6 +250,7 @@ impl offchain::Externalities for NeverOffchainExt {
 	fn encrypt(
 		&mut self,
 		_key: Option<offchain::CryptoKeyId>,
+		_kind: offchain::CryptoKind,
 		_data: &[u8],
 	) -> Result<Vec<u8>, ()> {
 		unreachable!()
@@ -258,18 +259,25 @@ impl offchain::Externalities for NeverOffchainExt {
 	fn decrypt(
 		&mut self,
 		_key: Option<offchain::CryptoKeyId>,
+		_kind: offchain::CryptoKind,
 		_data: &[u8],
 	) -> Result<Vec<u8>, ()> {
 		unreachable!()
 	}
 
-	fn sign(&mut self, _key: Option<offchain::CryptoKeyId>, _data: &[u8]) -> Result<Vec<u8>, ()> {
+	fn sign(
+		&mut self,
+		_key: Option<offchain::CryptoKeyId>,
+		_kind: offchain::CryptoKind,
+		_data: &[u8],
+	) -> Result<Vec<u8>, ()> {
 		unreachable!()
 	}
 
 	fn verify(
 		&mut self,
 		_key: Option<offchain::CryptoKeyId>,
+		_kind: offchain::CryptoKind,
 		_msg: &[u8],
 		_signature: &[u8],
 	) -> Result<bool, ()> {