[stable2509] Backport #7456 (#10070)

Backport #7456 into `stable2509` from gui1117.

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[documentation](https://github.com/paritytech/polkadot-sdk/blob/master/docs/BACKPORT.md)
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  # To be used by other automation, do not modify:
  original-pr-number: #${pull_number}
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Co-authored-by: Guillaume Thiolliere <[email protected]>
Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Adrian Catangiu <[email protected]>

Author: 4 people

prdoc/pr_7456.prdoc

@@ -0,0 +1,8 @@
+title: 'pallet-assets: make touch other permissionless'
+doc:
+- audience: Runtime User
+  description: |-
+    In pallet assets, make `touch_other` call permissionless. Before this PR only `Admin` and `Freezer` of an asset could touch an account, now every account can.
+crates:
+- name: pallet-assets
+  bump: minor

substrate/frame/assets/src/functions.rs

@@ -338,23 +338,15 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 	}
 
 	/// Creates an account for `who` to hold asset `id` with a zero balance and takes a deposit.
-	///
-	/// When `check_depositor` is set to true, the depositor must be either the asset's Admin or
-	/// Freezer, otherwise the depositor can be any account.
 	pub(super) fn do_touch(
 		id: T::AssetId,
 		who: T::AccountId,
 		depositor: T::AccountId,
-		check_depositor: bool,
 	) -> DispatchResult {
 		ensure!(!Account::<T, I>::contains_key(&id, &who), Error::<T, I>::AlreadyExists);
 		let deposit = T::AssetAccountDeposit::get();
 		let mut details = Asset::<T, I>::get(&id).ok_or(Error::<T, I>::Unknown)?;
 		ensure!(details.status == AssetStatus::Live, Error::<T, I>::AssetNotLive);
-		ensure!(
-			!check_depositor || &depositor == &details.admin || &depositor == &details.freezer,
-			Error::<T, I>::NoPermission
-		);
 		let reason = Self::new_account(&who, &mut details, Some((&depositor, deposit)))?;
 		T::Currency::reserve(&depositor, deposit)?;
 		Asset::<T, I>::insert(&id, details);

substrate/frame/assets/src/lib.rs

@@ -94,6 +94,7 @@
 //! * `refund`: Return the deposit (if any) of the caller's asset account or a consumer reference
 //!   (if any) of the caller's account.
 //! * `refund_other`: Return the deposit (if any) of a specified asset account.
+//! * `touch_other`: Create an asset account for specified account. Caller must place a deposit.
 //!
 //! ### Permissioned Functions
 //!
@@ -116,8 +117,6 @@
 //!   Owner.
 //! * `set_metadata`: Set the metadata of an asset class; called by the asset class's Owner.
 //! * `clear_metadata`: Remove the metadata of an asset class; called by the asset class's Owner.
-//! * `touch_other`: Create an asset account for specified account. Caller must place a deposit;
-//!   called by the asset class's Freezer or Admin.
 //! * `block`: Disallows further `transfer`s to and from an account; called by the asset class's
 //!   Freezer.
 //!
@@ -1618,7 +1617,7 @@ pub mod pallet {
 		pub fn touch(origin: OriginFor<T>, id: T::AssetIdParameter) -> DispatchResult {
 			let who = ensure_signed(origin)?;
 			let id: T::AssetId = id.into();
-			Self::do_touch(id, who.clone(), who, false)
+			Self::do_touch(id, who.clone(), who)
 		}
 
 		/// Return the deposit (if any) of an asset account or a consumer reference (if any) of an
@@ -1695,9 +1694,10 @@ pub mod pallet {
 		///
 		/// A deposit will be taken from the signer account.
 		///
-		/// - `origin`: Must be Signed by `Freezer` or `Admin` of the asset `id`; the signer account
-		///   must have sufficient funds for a deposit to be taken.
-		/// - `id`: The identifier of the asset for the account to be created.
+		/// - `origin`: Must be Signed; the signer account must have sufficient funds for a deposit
+		///   to be taken.
+		/// - `id`: The identifier of the asset for the account to be created, the asset status must
+		///   be live.
 		/// - `who`: The account to be created.
 		///
 		/// Emits `Touched` event when successful.
@@ -1711,7 +1711,7 @@ pub mod pallet {
 			let origin = ensure_signed(origin)?;
 			let who = T::Lookup::lookup(who)?;
 			let id: T::AssetId = id.into();
-			Self::do_touch(id, who, origin, true)
+			Self::do_touch(id, who, origin)
 		}
 
 		/// Return the deposit (if any) of a target asset account. Useful if you are the depositor.
@@ -1823,7 +1823,6 @@ pub mod pallet {
 
 	/// Implements [`AccountTouch`] trait.
 	/// Note that a depositor can be any account, without any specific privilege.
-	/// This implementation is supposed to be used only for creation of system accounts.
 	impl<T: Config<I>, I: 'static> AccountTouch<T::AssetId, T::AccountId> for Pallet<T, I> {
 		type Balance = DepositBalanceOf<T, I>;
 
@@ -1846,7 +1845,7 @@ pub mod pallet {
 			who: &T::AccountId,
 			depositor: &T::AccountId,
 		) -> DispatchResult {
-			Self::do_touch(asset, who.clone(), depositor.clone(), false)
+			Self::do_touch(asset, who.clone(), depositor.clone())
 		}
 	}
 

substrate/frame/assets/src/tests.rs

@@ -1004,12 +1004,14 @@ fn touching_and_freezing_account_with_zero_asset_balance_should_work() {
 	});
 }
 
+// In the past only admin and freezer could call `touch_other`.
+// Test that this behavior is still supported.
 #[test]
-fn touch_other_works() {
+fn touch_other_works_legacy() {
 	new_test_ext().execute_with(|| {
 		// 1 will be admin
 		// 2 will be freezer
-		// 4 will be an account attempting to execute `touch_other`
+		// 4 will be an account successfully attempting to execute `touch_other`
 		Balances::make_free_balance_be(&1, 100);
 		Balances::make_free_balance_be(&2, 100);
 		Balances::make_free_balance_be(&4, 100);
@@ -1019,19 +1021,42 @@ fn touch_other_works() {
 		assert_eq!(Assets::balance(0, 1), 100);
 		// account `3` does not exist
 		assert!(!Account::<Test>::contains_key(0, &3));
-		// creation of asset account `3` by account `4` fails
-		assert_noop!(
-			Assets::touch_other(RuntimeOrigin::signed(4), 0, 3),
-			Error::<Test>::NoPermission
-		);
+		// creation of asset account `30` by account `4` works
+		assert_ok!(Assets::touch_other(RuntimeOrigin::signed(4), 0, 30));
 		// creation of asset account `3` by admin `1` works
 		assert!(!Account::<Test>::contains_key(0, &3));
 		assert_ok!(Assets::touch_other(RuntimeOrigin::signed(1), 0, 3));
 		assert!(Account::<Test>::contains_key(0, &3));
 		// creation of asset account `4` by freezer `2` works
 		assert!(!Account::<Test>::contains_key(0, &4));
 		assert_ok!(Assets::touch_other(RuntimeOrigin::signed(2), 0, 4));
+	});
+}
+
+#[test]
+fn touch_other_works() {
+	new_test_ext().execute_with(|| {
+		Balances::make_free_balance_be(&3, 100);
+		assert_ok!(Assets::force_create(RuntimeOrigin::root(), 0, 1, false, 1));
+		assert_ok!(Assets::mint(RuntimeOrigin::signed(1), 0, 3, 100));
+		assert_eq!(Assets::balance(0, 3), 100);
+
+		// account `4` does not exist
+		assert!(!Account::<Test>::contains_key(0, &4));
+
+		// creation of asset account `4` by funded account `3` works
+		assert_ok!(Assets::touch_other(RuntimeOrigin::signed(3), 0, 4));
 		assert!(Account::<Test>::contains_key(0, &4));
+
+		// account `6` does not exist
+		assert!(!Account::<Test>::contains_key(0, &6));
+
+		// creation of asset account `6` by not funded account `5` fails
+		assert_noop!(
+			Assets::touch_other(RuntimeOrigin::signed(5), 0, 6),
+			BalancesError::<Test>::InsufficientBalance,
+		);
+		assert!(!Account::<Test>::contains_key(0, &6));
 	});
 }