Introduces author_hasKey and author_hasSessionKeys rpc endpoints (#4720)

* Introduces `author_hasKey` and `author_hasSessionKeys` rpc endpoints

Both endpoints can be used to check if a key is present in the keystore.

- `hasKey` works on with an individual public key and key type. It
checks if a private key for the given combination exists in the
keystore.
- `hasSessionKeys` works with the full encoded session key blob stored
on-chain in `nextKeys`. This requires that the given blob can be decoded
by the runtime. It will return `true`, iff all public keys of the
session key exist in the storage.

Fixes: https://github.com/paritytech/substrate/issues/4696

* Update client/rpc-api/src/author/error.rs

Co-Authored-By: Nikolay Volf <nikvolf@gmail.com>

* Indentation

Co-authored-by: Nikolay Volf <nikvolf@gmail.com>

substrate/primitives/application-crypto/src/ed25519.rs

@@ -53,4 +53,8 @@ impl RuntimePublic for Public {
 	fn verify<M: AsRef<[u8]>>(&self, msg: &M, signature: &Self::Signature) -> bool {
 		sp_io::crypto::ed25519_verify(&signature, msg.as_ref(), self)
 	}
+
+	fn to_raw_vec(&self) -> Vec<u8> {
+		sp_core::crypto::Public::to_raw_vec(self)
+	}
 }

substrate/primitives/application-crypto/src/lib.rs

@@ -301,6 +301,10 @@ macro_rules! app_crypto_public_common {
 			fn verify<M: AsRef<[u8]>>(&self, msg: &M, signature: &Self::Signature) -> bool {
 				<$public as $crate::RuntimePublic>::verify(self.as_ref(), msg, &signature.as_ref())
 			}
+
+			fn to_raw_vec(&self) -> $crate::Vec<u8> {
+				<$public as $crate::RuntimePublic>::to_raw_vec(&self.0)
+			}
 		}
 	}
 }

substrate/primitives/application-crypto/src/sr25519.rs

@@ -53,4 +53,8 @@ impl RuntimePublic for Public {
 	fn verify<M: AsRef<[u8]>>(&self, msg: &M, signature: &Self::Signature) -> bool {
 		sp_io::crypto::sr25519_verify(&signature, msg.as_ref(), self)
 	}
+
+	fn to_raw_vec(&self) -> Vec<u8> {
+		sp_core::crypto::Public::to_raw_vec(self)
+	}
 }

substrate/primitives/application-crypto/src/traits.rs

@@ -106,10 +106,13 @@ pub trait RuntimePublic: Sized {
 
 	/// Verify that the given signature matches the given message using this public key.
 	fn verify<M: AsRef<[u8]>>(&self, msg: &M, signature: &Self::Signature) -> bool;
+
+	/// Returns `Self` as raw vec.
+	fn to_raw_vec(&self) -> Vec<u8>;
 }
 
 /// A runtime interface for an application's public key.
-pub trait RuntimeAppPublic: Sized  {
+pub trait RuntimeAppPublic: Sized {
 	/// An identifier for this application-specific key type.
 	const ID: KeyTypeId;
 
@@ -136,6 +139,9 @@ pub trait RuntimeAppPublic: Sized  {
 
 	/// Verify that the given signature matches the given message using this public key.
 	fn verify<M: AsRef<[u8]>>(&self, msg: &M, signature: &Self::Signature) -> bool;
+
+	/// Returns `Self` as raw vec.
+	fn to_raw_vec(&self) -> Vec<u8>;
 }
 
 /// Something that bound to a fixed `RuntimeAppPublic`.

substrate/primitives/core/src/crypto.rs

@@ -19,7 +19,6 @@
 // end::description[]
 
 use sp_std::hash::Hash;
-#[cfg(feature = "full_crypto")]
 use sp_std::vec::Vec;
 #[cfg(feature = "std")]
 use sp_std::convert::TryInto;
@@ -520,8 +519,7 @@ pub trait Public: AsRef<[u8]> + AsMut<[u8]> + Default + Derive + CryptoType + Pa
 	fn from_slice(data: &[u8]) -> Self;
 
 	/// Return a `Vec<u8>` filled with raw data.
-	#[cfg(feature = "std")]
-	fn to_raw_vec(&self) -> Vec<u8> { self.as_slice().to_owned() }
+	fn to_raw_vec(&self) -> Vec<u8> { self.as_slice().to_vec() }
 
 	/// Return a slice filled with raw data.
 	fn as_slice(&self) -> &[u8] { self.as_ref() }

substrate/primitives/core/src/testing.rs

@@ -127,6 +127,10 @@ impl crate::traits::BareCryptoStore for KeyStore {
 	fn password(&self) -> Option<&str> {
 		None
 	}
+
+	fn has_keys(&self, public_keys: &[(Vec<u8>, KeyTypeId)]) -> bool {
+		public_keys.iter().all(|(k, t)| self.keys.get(&t).and_then(|s| s.get(k)).is_some())
+	}
 }
 
 /// Macro for exporting functions from wasm in with the expected signature for using it with the

substrate/primitives/core/src/traits.rs

@@ -69,6 +69,11 @@ pub trait BareCryptoStore: Send + Sync {
 
 	/// Get the password for this store.
 	fn password(&self) -> Option<&str>;
+
+	/// Checks if the private keys for the given public key and key type combinations exist.
+	///
+	/// Returns `true` iff all private keys could be found.
+	fn has_keys(&self, public_keys: &[(Vec<u8>, KeyTypeId)]) -> bool;
 }
 
 /// A pointer to the key store.

substrate/primitives/offchain/src/lib.rs

@@ -19,8 +19,6 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 #![warn(missing_docs)]
 
-use sp_runtime::traits::NumberFor;
-
 /// Local Storage Prefix used by the Offchain Worker API to
 pub const STORAGE_PREFIX: &[u8] = b"storage";
 
@@ -31,7 +29,7 @@ sp_api::decl_runtime_apis! {
 		/// Starts the off-chain task for given block number.
 		#[skip_initialize_block]
 		#[changed_in(2)]
-		fn offchain_worker(number: NumberFor<Block>);
+		fn offchain_worker(number: sp_runtime::traits::NumberFor<Block>);
 
 		/// Starts the off-chain task for given block header.
 		#[skip_initialize_block]

substrate/primitives/runtime/src/testing.rs

@@ -115,6 +115,10 @@ impl sp_application_crypto::RuntimeAppPublic for UintAuthorityId {
 
 		u64::from_le_bytes(msg_signature) == *signature
 	}
+
+	fn to_raw_vec(&self) -> Vec<u8> {
+		AsRef::<[u8]>::as_ref(self).to_vec()
+	}
 }
 
 impl OpaqueKeys for UintAuthorityId {

substrate/primitives/runtime/src/traits.rs

@@ -1106,12 +1106,14 @@ macro_rules! count {
 #[macro_export]
 macro_rules! impl_opaque_keys {
 	(
+		$( #[ $attr:meta ] )*
 		pub struct $name:ident {
 			$(
 				pub $field:ident: $type:ty,
 			)*
 		}
 	) => {
+		$( #[ $attr ] )*
 		#[derive(
 			Default, Clone, PartialEq, Eq,
 			$crate::codec::Encode,
@@ -1143,6 +1145,37 @@ macro_rules! impl_opaque_keys {
 				};
 				$crate::codec::Encode::encode(&keys)
 			}
+
+			/// Converts `Self` into a `Vec` of `(raw public key, KeyTypeId)`.
+			pub fn into_raw_public_keys(
+				self,
+			) -> $crate::sp_std::vec::Vec<($crate::sp_std::vec::Vec<u8>, $crate::KeyTypeId)> {
+				let mut keys = Vec::new();
+				$(
+					keys.push((
+						$crate::RuntimeAppPublic::to_raw_vec(&self.$field),
+						<
+							<
+								$type as $crate::BoundToRuntimeAppPublic
+							>::Public as $crate::RuntimeAppPublic
+						>::ID,
+					));
+				)*
+
+				keys
+			}
+
+			/// Decode `Self` from the given `encoded` slice and convert `Self` into the raw public
+			/// keys (see [`Self::into_raw_public_keys`]).
+			///
+			/// Returns `None` when the decoding failed, otherwise `Some(_)`.
+			pub fn decode_into_raw_public_keys(
+				encoded: &[u8],
+			) -> Option<$crate::sp_std::vec::Vec<($crate::sp_std::vec::Vec<u8>, $crate::KeyTypeId)>> {
+				<Self as $crate::codec::Decode>::decode(&mut &encoded[..])
+					.ok()
+					.map(|s| s.into_raw_public_keys())
+			}
 		}
 
 		impl $crate::traits::OpaqueKeys for $name {

substrate/primitives/session/Cargo.toml

@@ -7,8 +7,9 @@ edition = "2018"
 [dependencies]
 sp-api = { version = "2.0.0", default-features = false, path = "../api" }
 sp-std = { version = "2.0.0", default-features = false, path = "../std" }
+sp-core = { version = "2.0.0", default-features = false, path = "../core" }
 sp-runtime = { version = "2.0.0", optional = true, path = "../runtime" }
 
 [features]
 default = [ "std" ]
-std = [ "sp-api/std", "sp-std/std", "sp-runtime" ]
+std = [ "sp-api/std", "sp-std/std", "sp-runtime", "sp-core/std" ]

substrate/primitives/session/src/lib.rs

@@ -25,6 +25,8 @@ use sp_runtime::{generic::BlockId, traits::Block as BlockT};
 #[cfg(feature = "std")]
 use sp_api::ProvideRuntimeApi;
 
+use sp_core::crypto::KeyTypeId;
+
 sp_api::decl_runtime_apis! {
 	/// Session keys runtime api.
 	pub trait SessionKeys {
@@ -36,6 +38,11 @@ sp_api::decl_runtime_apis! {
 		///
 		/// Returns the concatenated SCALE encoded public keys.
 		fn generate_session_keys(seed: Option<Vec<u8>>) -> Vec<u8>;
+
+		/// Decode the given public session keys.
+		///
+		/// Returns the list of public raw public keys + key type.
+		fn decode_session_keys(encoded: Vec<u8>) -> Option<Vec<(Vec<u8>, KeyTypeId)>>;
 	}
 }