Add solver authentication to the settlement

bench-report.json

@@ -33,23 +33,23 @@
     "create_buffers/max_buffers_in_one_instruction": 177040,
     "create_order/happy_path_creates_order_pda_with_expected_body": 4978,
     "initialize/happy_path_initializes_state_pda_with_expected_data": 4529,
-    "reclaim_buffer/funded_buffer_is_skipped": 6333,
-    "reclaim_buffer/happy_path_reclaims_empty_buffer_to_the_authority_itself": 7481,
-    "reclaim_buffer/max_buffers_in_one_instruction": 136650,
-    "reclaim_buffer/reclaims_multiple_buffers_skipping_funded": 18080,
+    "reclaim_buffer/funded_buffer_is_skipped": 6335,
+    "reclaim_buffer/happy_path_reclaims_empty_buffer_to_the_authority_itself": 7483,
+    "reclaim_buffer/max_buffers_in_one_instruction": 136652,
+    "reclaim_buffer/reclaims_multiple_buffers_skipping_funded": 18082,
     "reclaim_order/happy_path_returns_lamports_and_closes_pda": 2183,
-    "settle/finalizes_with_no_pushes": 7070,
-    "settle/pulls_from_multiple_orders": 19949,
-    "settle/pulls_funds_to_destination": 13542,
-    "settle/pulls_to_multiple_destinations": 14694,
-    "settle/pushes_a_single_order": 12380,
-    "settle/pushes_several_orders_from_different_buffers": 17632,
-    "settle/pushes_several_orders_from_one_buffer": 17631,
-    "settle/settles_a_single_order": 12398,
-    "settle/settles_multiple_orders": 22926,
-    "transfer_authority/manager_can_transfer_manager": 3175,
-    "transfer_authority/manager_can_transfer_reclaim_authority": 3177,
-    "transfer_authority/reclaim_authority_can_transfer_itself": 3181
+    "settle/finalizes_with_no_pushes": 7152,
+    "settle/pulls_from_multiple_orders": 20041,
+    "settle/pulls_funds_to_destination": 13630,
+    "settle/pulls_to_multiple_destinations": 14771,
+    "settle/pushes_a_single_order": 12485,
+    "settle/pushes_several_orders_from_different_buffers": 17749,
+    "settle/pushes_several_orders_from_one_buffer": 17748,
+    "settle/settles_a_single_order": 12503,
+    "settle/settles_multiple_orders": 23060,
+    "transfer_authority/manager_can_transfer_manager": 3174,
+    "transfer_authority/manager_can_transfer_reclaim_authority": 3176,
+    "transfer_authority/reclaim_authority_can_transfer_itself": 3180
   },
   "transaction_bytes": {
     "add_solver/add_with_many_existing_solvers": 366,
@@ -64,15 +64,15 @@
     "reclaim_buffer/max_buffers_in_one_instruction": 332,
     "reclaim_buffer/reclaims_multiple_buffers_skipping_funded": 466,
     "reclaim_order/happy_path_returns_lamports_and_closes_pda": 236,
-    "settle/finalizes_with_no_pushes": 289,
-    "settle/pulls_from_multiple_orders": 655,
-    "settle/pulls_funds_to_destination": 472,
-    "settle/pulls_to_multiple_destinations": 513,
-    "settle/pushes_a_single_order": 431,
-    "settle/pushes_several_orders_from_different_buffers": 573,
-    "settle/pushes_several_orders_from_one_buffer": 541,
-    "settle/settles_a_single_order": 431,
-    "settle/settles_multiple_orders": 715,
+    "settle/finalizes_with_no_pushes": 290,
+    "settle/pulls_from_multiple_orders": 656,
+    "settle/pulls_funds_to_destination": 473,
+    "settle/pulls_to_multiple_destinations": 514,
+    "settle/pushes_a_single_order": 432,
+    "settle/pushes_several_orders_from_different_buffers": 574,
+    "settle/pushes_several_orders_from_one_buffer": 542,
+    "settle/settles_a_single_order": 432,
+    "settle/settles_multiple_orders": 716,
     "transfer_authority/manager_can_transfer_manager": 333,
     "transfer_authority/manager_can_transfer_reclaim_authority": 333,
     "transfer_authority/reclaim_authority_can_transfer_itself": 333

client/src/instructions.rs

@@ -26,6 +26,7 @@ pub struct InitializedIntent<'a> {
 /// Builder for a `BeginSettle` instruction settling the given orders.
 pub struct BeginSettle<'a> {
     pub program_id: Pubkey,
+    pub solver: Pubkey,
     pub finalize_ix_index: u16,
     /// The off-chain auction this settlement executes, carried so it can be tied
     /// back to its auction off-chain.
@@ -48,6 +49,7 @@ impl From<BeginSettle<'_>> for Instruction {
         cow_settlement_interface::instruction::settle::BeginSettle {
             program_id: builder.program_id,
             state_pda,
+            solver: builder.solver,
             finalize_ix_index: builder.finalize_ix_index,
             auction_id: builder.auction_id,
             order_pdas: &order_pdas,
@@ -275,6 +277,7 @@ mod tests {
     use ::proptest::{prelude::*, test_runner::TestCaseError};
     use cow_settlement_interface::{
         data::intent::fixtures::arb_order_intent,
+        fixtures::pubkey_from_seed,
         instruction::{
             fixtures::fake_account_from_array,
             settle::{
@@ -294,7 +297,7 @@ mod tests {
             finalize_ix_index in any::<u16>(),
             intents in prop::collection::vec(arb_order_intent(), 1..=5),
         ) {
-            let program_id = Pubkey::new_unique();
+            let program_id = pubkey_from_seed("program id");
             // No pulls here: this test only checks that orders are derived and
             // laid out correctly.
             let orders: Vec<InitializedIntent> = intents
@@ -303,6 +306,7 @@ mod tests {
                 .collect();
             let ix = Instruction::from(BeginSettle {
                 program_id,
+                solver: pubkey_from_seed("solver"),
                 finalize_ix_index,
                 auction_id: 0,
                 orders: &orders,
@@ -358,7 +362,7 @@ mod tests {
                 1..=5,
             ),
         ) {
-            let program_id = Pubkey::new_unique();
+            let program_id = pubkey_from_seed("program id");
             let orders: Vec<FinalizedIntent> = cases
                 .iter()
                 .map(|(intent, amount)| FinalizedIntent {

client/src/parse.rs

@@ -115,6 +115,7 @@ mod tests {
             .into(),
             SettlementInstruction::BeginSettle => BeginSettle {
                 program_id,
+                solver: payer,
                 finalize_ix_index: 1,
                 auction_id: 42,
                 orders: &[InitializedIntent {

interface/src/data/state.rs

@@ -146,6 +146,11 @@ impl<T: Deref<Target = [u8]>> StateAccount<T> {
         self.solver_region().binary_search(&seek)
     }
 
+    /// Whether `solver` is in the solver list.
+    pub fn is_solver(&self, solver: &Pubkey) -> bool {
+        self.solver_search(solver).is_ok()
+    }
+
     /// The stored solvers, in order (sorted ascending by address).
     pub fn solvers(&self) -> impl Iterator<Item = Pubkey> + '_ {
         self.solver_region()
@@ -481,6 +486,29 @@ mod tests {
         use super::*;
 
         proptest! {
+            /// `is_solver` is true for every stored solver and false for one that
+            /// isn't stored.
+            #[test]
+            fn is_solver_reflects_membership(
+                header in fixtures::arb_init_params(),
+                // Unique and already sorted, being a `BTreeSet`.
+                raw_solvers in prop::collection::btree_set(any::<[u8; 32]>(), 0..50),
+                raw_absent in any::<[u8; 32]>(),
+            ) {
+                prop_assume!(!raw_solvers.contains(&raw_absent));
+                let stored: Vec<Pubkey> =
+                    raw_solvers.into_iter().map(Pubkey::new_from_array).collect();
+                let absent = Pubkey::new_from_array(raw_absent);
+
+                let bytes = fixtures::state_account_bytes(&header, &stored);
+                let state = StateAccount::attach(&bytes[..]).expect("valid header");
+
+                for solver in &stored {
+                    prop_assert!(state.is_solver(solver));
+                }
+                prop_assert!(!state.is_solver(&absent));
+            }
+
             /// The encode roundtrip: any two role holders written with
             /// `initialize` read back unchanged.
             #[test]