From 99e1ac36b85385d7c7fbd88ab39bc7698dd723f5 Mon Sep 17 00:00:00 2001
From: Simon Warta <simon@warta.it>
Date: Mon, 22 Mar 2021 13:02:29 +0100
Subject: [PATCH] Add support for multisig in encodeAminoPubkey

---
 packages/amino/src/encoding.spec.ts | 47 ++++++++++++++++++++++++++++-
 packages/amino/src/encoding.ts      | 23 +++++++++++++-
 packages/amino/src/pubkeys.ts       |  1 +
 3 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/packages/amino/src/encoding.spec.ts b/packages/amino/src/encoding.spec.ts
index 5fd43919..7fa4a203 100644
--- a/packages/amino/src/encoding.spec.ts
+++ b/packages/amino/src/encoding.spec.ts
@@ -7,7 +7,7 @@ import {
   encodeBech32Pubkey,
   encodeSecp256k1Pubkey,
 } from "./encoding";
-import { Pubkey } from "./pubkeys";
+import { MultisigThresholdPubkey, Pubkey } from "./pubkeys";
 
 describe("encoding", () => {
   describe("encodeSecp256k1Pubkey", () => {
@@ -135,5 +135,50 @@ describe("encoding", () => {
         "coralvalconspub1zcjduepqvxg72ccnl9r65fv0wn3amlk4sfzqfe2k36l073kjx2qyaf6sk23qw7j8wq",
       );
     });
+
+    it("works for multisig", () => {
+      // ./build/wasmd keys add test1
+      // ./build/wasmd keys add test2
+      // ./build/wasmd keys add test3
+      // ./build/wasmd keys add testgroup1 --multisig=test1,test2,test3 --multisig-threshold 2
+      // ./build/wasmd keys add testgroup2 --multisig=test1,test2,test3 --multisig-threshold 1
+      // ./build/wasmd keys add testgroup3 --multisig=test3,test1 --multisig-threshold 2
+
+      const test1 = decodeBech32Pubkey(
+        "wasmpub1addwnpepqwxttx8w2sfs6d8cuzqcuau84grp8xsw95qzdjkmvc44tnckskdxw3zw2km",
+      );
+      const test2 = decodeBech32Pubkey(
+        "wasmpub1addwnpepq2gx7x7e29kge5a4ycunytyqr0u8ynql5h583s8r9wdads9m3v8ks6y0nhc",
+      );
+      const test3 = decodeBech32Pubkey(
+        "wasmpub1addwnpepq0xfx5vavxmgdkn0p6x0l9p3udttghu3qcldd7ql08wa3xy93qq0xuzvtxc",
+      );
+
+      // 2/3 multisig
+      const testgroup1: MultisigThresholdPubkey = {
+        type: "tendermint/PubKeyMultisigThreshold",
+        value: {
+          threshold: "2",
+          pubkeys: [test1, test2, test3],
+        },
+      };
+      const expected1 = Bech32.decode(
+        "wasmpub1ytql0csgqgfzd666axrjzquvkkvwu4qnp5603cyp3emc02sxzwdqutgqym9dke3t2h83dpv6vufzd666axrjzq5sdudaj5tv3nfm2f3exgkgqxlcwfxplf0g0rqwx2um6mqthzc0dqfzd666axrjzq7vjdge6cdksmdx7r5vl72rrc6kk30ezp376mup77wamzvgtzqq7v7aysdd",
+      ).data;
+      expect(encodeAminoPubkey(testgroup1)).toEqual(expected1);
+
+      // 1/3 multisig
+      const testgroup2: MultisigThresholdPubkey = {
+        type: "tendermint/PubKeyMultisigThreshold",
+        value: {
+          threshold: "1",
+          pubkeys: [test1, test2, test3],
+        },
+      };
+      const expected2 = Bech32.decode(
+        "wasmpub1ytql0csgqyfzd666axrjzquvkkvwu4qnp5603cyp3emc02sxzwdqutgqym9dke3t2h83dpv6vufzd666axrjzq5sdudaj5tv3nfm2f3exgkgqxlcwfxplf0g0rqwx2um6mqthzc0dqfzd666axrjzq7vjdge6cdksmdx7r5vl72rrc6kk30ezp376mup77wamzvgtzqq7vc4ejke",
+      ).data;
+      expect(encodeAminoPubkey(testgroup2)).toEqual(expected2);
+    });
   });
 });
diff --git a/packages/amino/src/encoding.ts b/packages/amino/src/encoding.ts
index 5acbc8f9..689a67cd 100644
--- a/packages/amino/src/encoding.ts
+++ b/packages/amino/src/encoding.ts
@@ -1,7 +1,8 @@
 import { Bech32, fromBase64, fromHex, toBase64, toHex } from "@cosmjs/encoding";
+import { Uint53 } from "@cosmjs/math";
 import { arrayContentStartsWith } from "@cosmjs/utils";
 
-import { Pubkey, pubkeyType, Secp256k1Pubkey } from "./pubkeys";
+import { isMultisigThresholdPubkey, Pubkey, pubkeyType, Secp256k1Pubkey } from "./pubkeys";
 
 export function encodeSecp256k1Pubkey(pubkey: Uint8Array): Secp256k1Pubkey {
   if (pubkey.length !== 33 || (pubkey[0] !== 0x02 && pubkey[0] !== 0x03)) {
@@ -19,6 +20,8 @@ export function encodeSecp256k1Pubkey(pubkey: Uint8Array): Secp256k1Pubkey {
 const pubkeyAminoPrefixSecp256k1 = fromHex("eb5ae987" + "21" /* fixed length */);
 const pubkeyAminoPrefixEd25519 = fromHex("1624de64" + "20" /* fixed length */);
 const pubkeyAminoPrefixSr25519 = fromHex("0dfb1005" + "20" /* fixed length */);
+/** See https://github.com/tendermint/tendermint/commit/38b401657e4ad7a7eeb3c30a3cbf512037df3740 */
+const pubkeyAminoPrefixMultisigThreshold = fromHex("22c1f7e2" /* variable length not included */);
 
 /**
  * Decodes a pubkey in the Amino binary format to a type/value object.
@@ -67,10 +70,28 @@ export function decodeBech32Pubkey(bechEncoded: string): Pubkey {
   return decodeAminoPubkey(data);
 }
 
+function encodeSmallUint(value: number | string): number[] {
+  const checked = Uint53.fromString(value.toString()).toNumber();
+  if (checked > 127) throw new Error("Encoding numbers > 127 is not supported here.");
+  return [checked];
+}
+
 /**
  * Encodes a public key to binary Amino.
  */
 export function encodeAminoPubkey(pubkey: Pubkey): Uint8Array {
+  if (isMultisigThresholdPubkey(pubkey)) {
+    const out = Array.from(pubkeyAminoPrefixMultisigThreshold);
+    out.push(8); // TODO: What is this?
+    out.push(...encodeSmallUint(pubkey.value.threshold));
+    for (const pubkeyData of pubkey.value.pubkeys.map((p) => encodeAminoPubkey(p))) {
+      out.push(18); // TODO: What is this?
+      out.push(...encodeSmallUint(pubkeyData.length));
+      out.push(...pubkeyData);
+    }
+    return new Uint8Array(out);
+  }
+
   let aminoPrefix: Uint8Array;
   switch (pubkey.type) {
     // Note: please don't add cases here without writing additional unit tests
diff --git a/packages/amino/src/pubkeys.ts b/packages/amino/src/pubkeys.ts
index 90da0a79..215d0016 100644
--- a/packages/amino/src/pubkeys.ts
+++ b/packages/amino/src/pubkeys.ts
@@ -18,6 +18,7 @@ export const pubkeyType = {
   ed25519: "tendermint/PubKeyEd25519" as const,
   /** @see https://github.com/tendermint/tendermint/blob/v0.33.0/crypto/sr25519/codec.go#L12 */
   sr25519: "tendermint/PubKeySr25519" as const,
+  multisigThreshold: "tendermint/PubKeyMultisigThreshold" as const,
 };
 
 /**