Introduce Tinkernet multisig XCM configs to Kusama/Rococo through xcm-builder (#7165)

* Introduce Tinkernet multisig XCM configs

* fmt fix

* overflow handling, comments, clippy fixes

* Adding Tinkernet XCM configs to xcm-builder

* switching spaces to tab

* remove derivation.rs in favor of location_conversion.rs

* replace hardcoded literals with constants

* autoformat

* Fix for the unit test

* replacing expect with an error and renaming constants

* Resolving clippy warning

---------

Co-authored-by: parity-processbot <>

polkadot/xcm/xcm-builder/src/origin_conversion.rs

@@ -16,8 +16,12 @@
 
 //! Various implementations for `ConvertOrigin`.
 
+use crate::location_conversion::{
+	derive_tinkernet_multisig, KUSAMA_TINKERNET_MULTISIG_PALLET, KUSAMA_TINKERNET_PARA_ID,
+};
 use frame_support::traits::{EnsureOrigin, Get, GetBacking, OriginTrait};
 use frame_system::RawOrigin as SystemRawOrigin;
+use parity_scale_codec::Decode;
 use polkadot_parachain::primitives::IsSystem;
 use sp_runtime::traits::TryConvert;
 use sp_std::marker::PhantomData;
@@ -241,6 +245,37 @@ where
 	}
 }
 
+/// Convert a Tinkernet Multisig `MultiLocation` value into a `Signed` origin.
+pub struct TinkernetMultisigAsNative<RuntimeOrigin>(PhantomData<RuntimeOrigin>);
+impl<RuntimeOrigin: OriginTrait> ConvertOrigin<RuntimeOrigin>
+	for TinkernetMultisigAsNative<RuntimeOrigin>
+where
+	RuntimeOrigin::AccountId: Decode,
+{
+	fn convert_origin(
+		origin: impl Into<MultiLocation>,
+		kind: OriginKind,
+	) -> Result<RuntimeOrigin, MultiLocation> {
+		let origin = origin.into();
+		match (kind, origin) {
+			(
+				OriginKind::Native,
+				MultiLocation {
+					parents: _,
+					interior:
+						X3(
+							Junction::Parachain(KUSAMA_TINKERNET_PARA_ID),
+							Junction::PalletInstance(KUSAMA_TINKERNET_MULTISIG_PALLET),
+							// Index from which the multisig account is derived.
+							Junction::GeneralIndex(id),
+						),
+				},
+			) => Ok(RuntimeOrigin::signed(derive_tinkernet_multisig(id).map_err(|_| origin)?)),
+			(_, origin) => Err(origin),
+		}
+	}
+}
+
 /// `EnsureOrigin` barrier to convert from dispatch origin to XCM origin, if one exists.
 pub struct EnsureXcmOrigin<RuntimeOrigin, Conversion>(PhantomData<(RuntimeOrigin, Conversion)>);
 impl<RuntimeOrigin: OriginTrait + Clone, Conversion: TryConvert<RuntimeOrigin, MultiLocation>>