Extract Relayed Signatures (#94)

[This transaction](https://testnet.nearblocks.io/txns/G1f1HVUxDBWXAEimgNWobQ9yCx1EgA2tzYHJBFUfo3dj) was relayed by mintbase.testnet on behalf of neareth-dev.testnet. The signature is nested deep inside the transaction instead of on the outer successValue. We introduce a method for digging out the signature from the receipt that is compatible with both scenarios. Still need to verify that signatures are indeed valid.
Mintbase · Aug 9, 2024 · 774abe2 · 774abe2
1 parent 55a4dba
commit 774abe2
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Showing 2 changed files with 88 additions and 10 deletions.
diff --git a/src/utils/signature.ts b/src/utils/signature.ts
@@ -71,16 +71,54 @@ export function signatureFromOutcome(
   // The Partial object is intended to make up for the
   // difference between all the different near-api versions and wallet-selector bullshit
   // the field `final_execution_status` is in one, but not the other and we don't use it anyway.
-  outcome: FinalExecutionOutcome | Partial<FinalExecutionOutcome>
+  outcome:
+    | FinalExecutionOutcome
+    | Omit<FinalExecutionOutcome, "final_execution_status">
 ): Signature {
-  // TODO: Find example outcome when status is not of this casted type.
-  const b64Sig = (outcome.status as FinalExecutionStatus).SuccessValue;
-  if (b64Sig) {
-    const decodedValue = Buffer.from(b64Sig, "base64").toString("utf-8");
-    const signature = JSON.parse(decodedValue);
+  const txHash = outcome.transaction_outcome?.id;
+  // TODO - find a scenario when outcome.status is `FinalExecutionStatusBasic`!
+  let b64Sig = (outcome.status as FinalExecutionStatus).SuccessValue;
+  if (!b64Sig) {
+    // This scenario occurs when sign call is relayed (i.e. executed by someone else).
+    // E.g. https://testnet.nearblocks.io/txns/G1f1HVUxDBWXAEimgNWobQ9yCx1EgA2tzYHJBFUfo3dj
+    // We have to dig into `receipts_outcome` and extract the signature from within.
+    // We want the second occurence of the signature because
+    // the first is nested inside `{ Ok: MPCSignature }`)
+    b64Sig = outcome.receipts_outcome
+      // Map to get SuccessValues: The Signature will appear twice.
+      .map(
+        (receipt) =>
+          (receipt.outcome.status as FinalExecutionStatus).SuccessValue
+      )
+      // Reverse the to "find" the last non-empty value!
+      .reverse()
+      .find((value) => value && value.trim().length > 0);
+  }
+  if (!b64Sig) {
+    throw new Error(`No detectable signature found in transaction ${txHash}`);
+  }
+  if (b64Sig === "eyJFcnIiOiJGYWlsZWQifQ==") {
+    // {"Err": "Failed"}
+    throw new Error(`Signature Request Failed in ${txHash}`);
+  }
+  const decodedValue = Buffer.from(b64Sig, "base64").toString("utf-8");
+  const signature = JSON.parse(decodedValue);
+  if (isMPCSignature(signature)) {
     return transformSignature(signature);
+  } else {
+    throw new Error(`No detectable signature found in transaction ${txHash}`);
   }
-  throw new Error(
-    `No detectable signature found in transaction ${outcome.transaction_outcome?.id}`
+}
+
+// type guard for MPCSignature object.
+function isMPCSignature(obj: unknown): obj is MPCSignature {
+  return (
+    typeof obj === "object" &&
+    obj !== null &&
+    typeof (obj as MPCSignature).big_r === "object" &&
+    typeof (obj as MPCSignature).big_r.affine_point === "string" &&
+    typeof (obj as MPCSignature).s === "object" &&
+    typeof (obj as MPCSignature).s.scalar === "string" &&
+    typeof (obj as MPCSignature).recovery_id === "number"
   );
 }
diff --git a/tests/unit/utils.signature.test.ts b/tests/unit/utils.signature.test.ts
@@ -8,7 +8,11 @@ describe("utility: get Signature", () => {
   const url: string = "https://archival-rpc.testnet.near.org";
   // const accountId = "neareth-dev.testnet";
   const successHash = "GeqmwWmWxddzh2yCEhugbJkhzsJMhCuFyQZa61w5dk7N";
+  const relayedSuccessHash = "G1f1HVUxDBWXAEimgNWobQ9yCx1EgA2tzYHJBFUfo3dj";
   const failedHash = "6yRm5FjHn9raRYPoHH6wimizhT53PnPnuvkpecyQDqLY";
+  const nonExistantTxHash = "7yRm5FjHn9raRYPoHH6wimizhT53PnPnuvkpecyQDqLY";
+  const nonSignatureRequestHash =
+    "4pNDN238dgEjj5eNaAF4qzoztF4TmrN82hwJs2zTwuqe";
 
   it("successful: signatureFromTxHash", async () => {
     const sig = await signatureFromTxHash(url, successHash);
@@ -17,11 +21,33 @@ describe("utility: get Signature", () => {
       s: "0x5194CCE1D9F239C28C7765453873A07F35850A485DFE285551FB62C899B61170",
       yParity: 1,
     });
+
+    const relayedSig = await signatureFromTxHash(url, relayedSuccessHash);
+    expect(relayedSig).toEqual({
+      r: "0x593873A56AB98F91C60C23DCA370835CA05254A0305F2753A1CFC3CEB4C46F86",
+      s: "0x783D9887FB4AA9B07E672D7FA88587FB45E7FDC066F7ECA0774E6FE36806404F",
+      yParity: 1,
+    });
   });
 
-  it("signatureFromTxHash fails with no signature", async () => {
+  it("signatureFromTxHash fails Error", async () => {
     await expect(signatureFromTxHash(url, failedHash)).rejects.toThrow(
-      `No detectable signature found in transaction ${failedHash}`
+      `Signature Request Failed in ${failedHash}`
+    );
+  });
+
+  it("signatureFromTxHash fails with no signature", async () => {
+    await expect(
+      signatureFromTxHash(url, nonSignatureRequestHash)
+    ).rejects.toThrow(
+      `No detectable signature found in transaction ${nonSignatureRequestHash}`
+    );
+  });
+
+  // This one takes too long.
+  it.skip("signatureFromTxHash fails with server error", async () => {
+    await expect(signatureFromTxHash(url, nonExistantTxHash)).rejects.toThrow(
+      "JSON-RPC error: Server error"
     );
   });
 
@@ -57,6 +83,20 @@ describe("utility: get Signature", () => {
         SuccessValue:
           "eyJiaWdfciI6eyJhZmZpbmVfcG9pbnQiOiIwMkVBRDJCMUYwN0NDNDk4REIyNTU2MzE0QTZGNzdERkUzRUUzRDE0NTNCNkQ3OTJBNzcwOTE5MjRFNTFENEMyNDcifSwicyI6eyJzY2FsYXIiOiIxQTlGNjBDMkNDMjM5OEE1MDk3N0Q0Q0E5M0M0MDE2OEU4RjJDRTdBOUM5MEUzNzQ1MjJERjNDNzZDRjU0RjJFIn0sInJlY292ZXJ5X2lkIjoxfQ==",
       },
+      // irrelevant fields
+      receipts_outcome: [],
+      transaction: null,
+      transaction_outcome: {
+        id: "",
+        outcome: {
+          logs: [],
+          receipt_ids: [],
+          gas_burnt: 0,
+          tokens_burnt: "",
+          executor_id: "string",
+          status: {},
+        },
+      },
     };
     expect(signatureFromOutcome(outcome)).toEqual({
       r: "0xEAD2B1F07CC498DB2556314A6F77DFE3EE3D1453B6D792A77091924E51D4C247",