fix(ibc-core): pack host consensus state into wasm consensus state for wasm clients (#1252)

* add custom consensus state packing

* change feature flag

* change doc comments

* add pack_host_consensus_state fn

* fix imports

* update changelog entry

Author: rnbguy

.changelog/unreleased/features/1237-unpack-wasm-client-state.md

@@ -1,2 +1,3 @@
-- Unpack Wasm client state at `ConnectionOpenTry` and `ConnectionOpenAck` for
-  host client state. ([#1237](https://github.com/cosmos/ibc-rs/issues/1237)).
+- Unpack/pack Wasm client/consensus state at `ConnectionOpenTry` and
+  `ConnectionOpenAck` for host client/consensus state.
+  ([#1237](https://github.com/cosmos/ibc-rs/issues/1237)).

ibc-core/ics03-connection/Cargo.toml

@@ -35,7 +35,7 @@ std = [
   "ibc-core-host/std",
   "ibc-core-handler-types/std",
   "ibc-primitives/std",
-  "wasm-wrapped-client-state",
+  "wasm-client",
 ]
 serde = [
   "ibc-core-client/serde",
@@ -67,7 +67,7 @@ parity-scale-codec = [
   "ibc-core-handler-types/parity-scale-codec",
   "ibc-primitives/parity-scale-codec",
 ]
-wasm-wrapped-client-state = [
+wasm-client = [
   "dep:ibc-client-wasm-types",
   "dep:prost",
 ]

ibc-core/ics03-connection/src/handler/conn_open_ack.rs

@@ -15,7 +15,7 @@ use ibc_primitives::prelude::*;
 use ibc_primitives::proto::{Any, Protobuf};
 use ibc_primitives::ToVec;
 
-use crate::handler::unpack_host_client_state;
+use crate::handler::{pack_host_consensus_state, unpack_host_client_state};
 
 pub fn validate<Ctx>(ctx_a: &Ctx, msg: MsgConnectionOpenAck) -> Result<(), ContextError>
 where
@@ -123,6 +123,9 @@ where
         let expected_consensus_state_of_a_on_b =
             ctx_a.host_consensus_state(&msg.consensus_height_of_a_on_b)?;
 
+        let stored_consensus_state_of_a_on_b =
+            pack_host_consensus_state(expected_consensus_state_of_a_on_b, vars.client_id_on_b());
+
         let client_cons_state_path_on_b = ClientConsensusStatePath::new(
             vars.client_id_on_b().clone(),
             msg.consensus_height_of_a_on_b.revision_number(),
@@ -135,7 +138,7 @@ where
                 &msg.proof_consensus_state_of_a_on_b,
                 consensus_state_of_b_on_a.root(),
                 Path::ClientConsensusState(client_cons_state_path_on_b),
-                expected_consensus_state_of_a_on_b.into().to_vec(),
+                stored_consensus_state_of_a_on_b.to_vec(),
             )
             .map_err(|e| ConnectionError::ConsensusStateVerificationFailure {
                 height: msg.proofs_height_on_b,

ibc-core/ics03-connection/src/handler/conn_open_try.rs

@@ -16,7 +16,7 @@ use ibc_primitives::prelude::*;
 use ibc_primitives::proto::{Any, Protobuf};
 use ibc_primitives::ToVec;
 
-use crate::handler::unpack_host_client_state;
+use crate::handler::{pack_host_consensus_state, unpack_host_client_state};
 
 pub fn validate<Ctx>(ctx_b: &Ctx, msg: MsgConnectionOpenTry) -> Result<(), ContextError>
 where
@@ -119,6 +119,9 @@ where
         let expected_consensus_state_of_b_on_a =
             ctx_b.host_consensus_state(&msg.consensus_height_of_b_on_a)?;
 
+        let stored_consensus_state_of_b_on_a =
+            pack_host_consensus_state(expected_consensus_state_of_b_on_a, &vars.client_id_on_a);
+
         let client_cons_state_path_on_a = ClientConsensusStatePath::new(
             client_id_on_a.clone(),
             msg.consensus_height_of_b_on_a.revision_number(),
@@ -131,7 +134,7 @@ where
                 &msg.proof_consensus_state_of_b_on_a,
                 consensus_state_of_a_on_b.root(),
                 Path::ClientConsensusState(client_cons_state_path_on_a),
-                expected_consensus_state_of_b_on_a.into().to_vec(),
+                stored_consensus_state_of_b_on_a.to_vec(),
             )
             .map_err(|e| ConnectionError::ConsensusStateVerificationFailure {
                 height: msg.proofs_height_on_a,

ibc-core/ics03-connection/src/handler/mod.rs

@@ -8,11 +8,11 @@ pub mod conn_open_confirm;
 pub mod conn_open_init;
 pub mod conn_open_try;
 
-/// Unpacks the client state from the provided [`Any`] type.
+/// Unpacks the client state from the format that is stored at the counterparty chain.
 ///
-/// Currently, the IBC-go enabled chains stores Wasm LightClient states in a
-/// WasmClientState wrapper. This function unpacks the client state from
-/// the WasmClientState wrapper if the client identifier is of Wasm client type.
+/// Currently, the IBC-go enabled chains stores Wasm LightClient states in a WasmClientState
+/// wrapper. This function unpacks the client state from the WasmClientState wrapper
+/// if the client identifier at counterparty is of Wasm client type.
 pub(crate) fn unpack_host_client_state<CS>(
     value: Any,
     host_client_id_at_counterparty: &ClientId,
@@ -21,7 +21,7 @@ where
     CS: TryFrom<Any>,
     <CS as TryFrom<Any>>::Error: Into<ClientError>,
 {
-    #[cfg(feature = "wasm-wrapped-client-state")]
+    #[cfg(feature = "wasm-client")]
     if host_client_id_at_counterparty.is_wasm_client_id() {
         use ibc_client_wasm_types::client_state::ClientState as WasmClientState;
         use ibc_core_connection_types::error::ConnectionError;
@@ -46,10 +46,44 @@ where
         Ok(CS::try_from(value).map_err(Into::<ClientError>::into)?)
     }
 
-    #[cfg(not(feature = "wasm-wrapped-client-state"))]
+    #[cfg(not(feature = "wasm-client"))]
     {
         // this avoids lint warning for unused variable.
         let _ = host_client_id_at_counterparty;
         Ok(CS::try_from(value).map_err(Into::<ClientError>::into)?)
     }
 }
+
+/// Pack the host consensus state in the expected format stored at the counterparty chain.
+///
+/// Currently, the IBC-go enabled chains stores Wasm LightClient states in a WasmConsensusState
+/// wrapper. This function packs the consensus state in the WasmConsensusState wrapper
+/// if the client identifier at counterparty is of Wasm client type.
+pub(crate) fn pack_host_consensus_state<CS>(
+    value: CS,
+    host_client_id_at_counterparty: &ClientId,
+) -> Any
+where
+    CS: Into<Any>,
+{
+    let any_value = value.into();
+
+    #[cfg(feature = "wasm-client")]
+    if host_client_id_at_counterparty.is_wasm_client_id() {
+        use ibc_client_wasm_types::consensus_state::ConsensusState as WasmConsensusState;
+        use prost::Message;
+
+        let wasm_consensus_state = WasmConsensusState::new(any_value.encode_to_vec());
+
+        wasm_consensus_state.into()
+    } else {
+        any_value
+    }
+
+    #[cfg(not(feature = "wasm-client"))]
+    {
+        // this avoids lint warning for unused variable.
+        let _ = host_client_id_at_counterparty;
+        any_value
+    }
+}