Generates private AccountIds from MultiLocations, in a stable & s…

…afe way (#484)

Co-authored-by: Chris Li <[email protected]>

primitives/Cargo.toml

@@ -9,6 +9,7 @@ repository = 'https://github.com/OAK-Foundation/OAK-blockchain'
 edition = "2021"
 
 [dependencies]
+impl-trait-for-tuples = "0.2.2"
 codec = { package = "parity-scale-codec", version = "3.0.0", features = [
   "derive",
 ], default-features = false }
@@ -22,12 +23,14 @@ sp-std = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v
 sp-consensus-aura = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "polkadot-v0.9.43" }
 sp-core = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "polkadot-v0.9.43" }
 sp-runtime = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "polkadot-v0.9.43" }
+sp-io = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "polkadot-v0.9.43" }
 
 ## Substrate FRAME Dependencies
 frame-support = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "polkadot-v0.9.43" }
 
 ## Polkdadot deps
 xcm = { git = "https://github.com/paritytech/polkadot", branch = "release-v0.9.43", default-features = false }
+xcm-executor = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "release-v0.9.43" }
 
 ## ORML deps
 orml-traits = { git = "https://github.com/open-web3-stack/open-runtime-module-library", default-features = false, branch = "polkadot-v0.9.43" }

primitives/src/lib.rs

@@ -94,3 +94,118 @@ impl<AbsoluteLocation: Get<MultiLocation>> Reserve
 		})
 	}
 }
+
+// https://github.com/AstarNetwork/Astar/blob/2a8df8d098f6abc3fdf5aaf6514e94f615f9bdab/primitives/src/xcm/mod.rs#L276-L418
+// TODO: remove this after uplift to `polkadot-v0.9.44` or beyond, and replace it with code in XCM builder.
+
+use codec::{Compact, Encode};
+use sp_io::hashing::blake2_256;
+use sp_std::prelude::*;
+use xcm_executor::traits::Convert as XcmConvert;
+
+/// Means of converting a location into a stable and unique descriptive identifier.
+pub trait DescribeLocation {
+	/// Create a description of the given `location` if possible. No two locations should have the
+	/// same descriptor.
+	fn describe_location(location: &MultiLocation) -> Option<Vec<u8>>;
+}
+
+#[impl_trait_for_tuples::impl_for_tuples(30)]
+impl DescribeLocation for Tuple {
+	fn describe_location(l: &MultiLocation) -> Option<Vec<u8>> {
+		for_tuples!( #(
+			match Tuple::describe_location(l) {
+				Some(result) => return Some(result),
+				None => {},
+			}
+		)* );
+		None
+	}
+}
+
+pub struct DescribeTerminus;
+impl DescribeLocation for DescribeTerminus {
+	fn describe_location(l: &MultiLocation) -> Option<Vec<u8>> {
+		match (l.parents, &l.interior) {
+			(0, Here) => Some(Vec::new()),
+			_ => return None,
+		}
+	}
+}
+
+pub struct DescribePalletTerminal;
+impl DescribeLocation for DescribePalletTerminal {
+	fn describe_location(l: &MultiLocation) -> Option<Vec<u8>> {
+		match (l.parents, &l.interior) {
+			(0, X1(PalletInstance(i))) =>
+				Some((b"Pallet", Compact::<u32>::from(*i as u32)).encode()),
+			_ => return None,
+		}
+	}
+}
+
+pub struct DescribeAccountId32Terminal;
+impl DescribeLocation for DescribeAccountId32Terminal {
+	fn describe_location(l: &MultiLocation) -> Option<Vec<u8>> {
+		match (l.parents, &l.interior) {
+			(0, X1(AccountId32 { id, .. })) => Some((b"AccountId32", id).encode()),
+			_ => return None,
+		}
+	}
+}
+
+pub struct DescribeAccountKey20Terminal;
+impl DescribeLocation for DescribeAccountKey20Terminal {
+	fn describe_location(l: &MultiLocation) -> Option<Vec<u8>> {
+		match (l.parents, &l.interior) {
+			(0, X1(AccountKey20 { key, .. })) => Some((b"AccountKey20", key).encode()),
+			_ => return None,
+		}
+	}
+}
+
+pub type DescribeAccountIdTerminal = (DescribeAccountId32Terminal, DescribeAccountKey20Terminal);
+
+pub type DescribeAllTerminal = (
+	DescribeTerminus,
+	DescribePalletTerminal,
+	DescribeAccountId32Terminal,
+	DescribeAccountKey20Terminal,
+);
+
+pub struct DescribeFamily<DescribeInterior>(PhantomData<DescribeInterior>);
+impl<Suffix: DescribeLocation> DescribeLocation for DescribeFamily<Suffix> {
+	fn describe_location(l: &MultiLocation) -> Option<Vec<u8>> {
+		match (l.parents, l.interior.first()) {
+			(0, Some(Parachain(index))) => {
+				let tail = l.interior.split_first().0;
+				let interior = Suffix::describe_location(&tail.into())?;
+				Some((b"ChildChain", Compact::<u32>::from(*index), interior).encode())
+			},
+			(1, Some(Parachain(index))) => {
+				let tail = l.interior.split_first().0;
+				let interior = Suffix::describe_location(&tail.into())?;
+				Some((b"SiblingChain", Compact::<u32>::from(*index), interior).encode())
+			},
+			(1, _) => {
+				let tail = l.interior.into();
+				let interior = Suffix::describe_location(&tail)?;
+				Some((b"ParentChain", interior).encode())
+			},
+			_ => return None,
+		}
+	}
+}
+
+pub struct HashedDescription<AccountId, Describe>(PhantomData<(AccountId, Describe)>);
+impl<AccountId: From<[u8; 32]> + Clone, Describe: DescribeLocation>
+	XcmConvert<MultiLocation, AccountId> for HashedDescription<AccountId, Describe>
+{
+	fn convert(value: MultiLocation) -> Result<AccountId, MultiLocation> {
+		if let Some(description) = Describe::describe_location(&value) {
+			Ok(blake2_256(&description).into())
+		} else {
+			Err(value)
+		}
+	}
+}

runtime/neumann/src/xcm_config.rs

@@ -36,7 +36,9 @@ use orml_xcm_support::{
 	DepositToAlternative, IsNativeConcrete, MultiCurrencyAdapter, MultiNativeAsset,
 };
 
-use primitives::AbsoluteAndRelativeReserveProvider;
+use primitives::{
+	AbsoluteAndRelativeReserveProvider, DescribeAllTerminal, DescribeFamily, HashedDescription,
+};
 
 parameter_types! {
 	pub const RelayLocation: MultiLocation = MultiLocation::parent();
@@ -55,7 +57,9 @@ pub type LocationToAccountId = (
 	SiblingParachainConvertsVia<Sibling, AccountId>,
 	// Straight up local `AccountId32` origins just alias directly to `AccountId`.
 	AccountId32Aliases<RelayNetwork, AccountId>,
-	Account32Hash<RelayNetwork, AccountId>,
+	// Generates private `AccountId`s from `MultiLocation`s, in a stable & safe way.
+	// Replaces the old `Account32Hash` approach.
+	HashedDescription<AccountId, DescribeFamily<DescribeAllTerminal>>,
 );
 
 pub type LocalAssetTransactor = MultiCurrencyAdapter<

runtime/oak/src/xcm_config.rs

@@ -38,7 +38,9 @@ use orml_xcm_support::{
 	DepositToAlternative, IsNativeConcrete, MultiCurrencyAdapter, MultiNativeAsset,
 };
 
-use primitives::AbsoluteAndRelativeReserveProvider;
+use primitives::{
+	AbsoluteAndRelativeReserveProvider, DescribeAllTerminal, DescribeFamily, HashedDescription,
+};
 
 parameter_types! {
 	pub const RelayLocation: MultiLocation = MultiLocation::parent();
@@ -57,7 +59,9 @@ pub type LocationToAccountId = (
 	SiblingParachainConvertsVia<Sibling, AccountId>,
 	// Straight up local `AccountId32` origins just alias directly to `AccountId`.
 	AccountId32Aliases<RelayNetwork, AccountId>,
-	Account32Hash<RelayNetwork, AccountId>,
+	// Generates private `AccountId`s from `MultiLocation`s, in a stable & safe way.
+	// Replaces the old `Account32Hash` approach.
+	HashedDescription<AccountId, DescribeFamily<DescribeAllTerminal>>,
 );
 
 pub type LocalAssetTransactor = MultiCurrencyAdapter<

runtime/turing/src/xcm_config.rs

@@ -37,7 +37,9 @@ use orml_xcm_support::{
 	DepositToAlternative, IsNativeConcrete, MultiCurrencyAdapter, MultiNativeAsset,
 };
 
-use primitives::AbsoluteAndRelativeReserveProvider;
+use primitives::{
+	AbsoluteAndRelativeReserveProvider, DescribeAllTerminal, DescribeFamily, HashedDescription,
+};
 
 parameter_types! {
 	pub const RelayLocation: MultiLocation = MultiLocation::parent();
@@ -57,7 +59,9 @@ pub type LocationToAccountId = (
 	SiblingParachainConvertsVia<Sibling, AccountId>,
 	// Straight up local `AccountId32` origins just alias directly to `AccountId`.
 	AccountId32Aliases<RelayNetwork, AccountId>,
-	Account32Hash<RelayNetwork, AccountId>,
+	// Generates private `AccountId`s from `MultiLocation`s, in a stable & safe way.
+	// Replaces the old `Account32Hash` approach.
+	HashedDescription<AccountId, DescribeFamily<DescribeAllTerminal>>,
 );
 
 pub type LocalAssetTransactor = MultiCurrencyAdapter<