feat: multisig support

proto/tm2/multisig.proto

@@ -0,0 +1,23 @@
+syntax = "proto3";
+package tm;
+
+option go_package = "github.com/gnolang/gno/tm2/pkg/crypto/multisig/pb";
+
+// imports
+import "google/protobuf/any.proto";
+
+// messages
+message PubKeyMultisig {
+	uint64 k = 1 [json_name = "threshold"];
+	repeated google.protobuf.Any pub_keys = 2 [json_name = "pubkeys"];
+}
+
+message Multisignature {
+	CompactBitArray bit_array = 1;
+	repeated bytes sigs = 2;
+}
+
+message CompactBitArray {
+	uint32 extra_bits_stored = 1 [json_name = "extra_bits"]; // The number of extra bits in elems.
+	bytes elems = 2 [json_name = "bits"];
+}

src/proto/tm2/multisig.test.ts

@@ -0,0 +1,27 @@
+import { bytesToHex } from '@noble/hashes/utils';
+import { CompactBitArray } from './multisig';
+
+describe('TestMarshalCompactBitArrayAmino', () => {
+  const testCases = [
+    { marshalledBA: `null`, hexOutput: '' },
+    { marshalledBA: `null`, hexOutput: '' },
+    { marshalledBA: `"_"`, hexOutput: '0801120100' },
+    { marshalledBA: `"x"`, hexOutput: '0801120180' },
+    { marshalledBA: `"xx___"`, hexOutput: '08051201c0' },
+    { marshalledBA: `"xx______x"`, hexOutput: '08011202c080' },
+    { marshalledBA: `"xx_____________x"`, hexOutput: '1202c001' },
+  ];
+
+  test.each(testCases)('$marshalledBA', async ({ marshalledBA, hexOutput }) => {
+    // Parse JSON into CompactBitArray
+    const jsonData = JSON.parse(marshalledBA);
+    const bA = CompactBitArray.fromJSON(jsonData);
+
+    // Marshal using Amino
+    const bz = CompactBitArray.encode(bA).finish();
+
+    // Convert bytes to hex and compare
+    const actualHex = bytesToHex(bz);
+    expect(actualHex).toBe(hexOutput);
+  });
+});