From 5fe0f5582e69f48fa37f1afbe2605c3beb87d723 Mon Sep 17 00:00:00 2001
From: Simon Warta <simon@warta.it>
Date: Mon, 22 Mar 2021 18:45:31 +0100
Subject: [PATCH] Check threashold against number of pubkeys

---
 packages/amino/src/multisig.spec.ts | 6 ++++++
 packages/amino/src/multisig.ts      | 7 ++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/amino/src/multisig.spec.ts b/packages/amino/src/multisig.spec.ts
index ce239345..758e1f64 100644
--- a/packages/amino/src/multisig.spec.ts
+++ b/packages/amino/src/multisig.spec.ts
@@ -59,5 +59,11 @@ describe("multisig", () => {
     it("works with nosort", () => {
       expect(createMultisigThresholdPubkey([test3, test1], 2, true)).toEqual(testgroup4);
     });
+
+    it("throws for threshold lager than number of keys", () => {
+      expect(() => createMultisigThresholdPubkey([test1, test2, test3], 5)).toThrowError(
+        /threshold k = 5 exceeds number of keys n = 3/i,
+      );
+    });
   });
 });
diff --git a/packages/amino/src/multisig.ts b/packages/amino/src/multisig.ts
index 51203f87..795b5caf 100644
--- a/packages/amino/src/multisig.ts
+++ b/packages/amino/src/multisig.ts
@@ -20,6 +20,11 @@ export function createMultisigThresholdPubkey(
   threshold: number,
   nosort = false,
 ): MultisigThresholdPubkey {
+  const uintThreshold = new Uint53(threshold);
+  if (uintThreshold.toNumber() > pubkeys.length) {
+    throw new Error(`Threshold k = ${uintThreshold.toNumber()} exceeds number of keys n = ${pubkeys.length}`);
+  }
+
   const outPubkeys = nosort
     ? pubkeys
     : Array.from(pubkeys).sort((lhs, rhs) => {
@@ -31,7 +36,7 @@ export function createMultisigThresholdPubkey(
   return {
     type: "tendermint/PubKeyMultisigThreshold",
     value: {
-      threshold: new Uint53(threshold).toString(),
+      threshold: uintThreshold.toString(),
       pubkeys: outPubkeys,
     },
   };