Add encodeEd25519Pubkey

CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to
 
 ### Added
 
+- @cosmjs/amino: Add `encodeEd25519Pubkey` analogue to the existing
+  `encodeSecp256k1Pubkey`.
 - @cosmjs/utils: Add `isDefined` which checks for `undefined` in a
   TypeScript-friendly way.
 

packages/amino/src/encoding.spec.ts

@@ -1,3 +1,4 @@
+import { Random } from "@cosmjs/crypto";
 import { fromBase64, fromBech32, fromHex } from "@cosmjs/encoding";
 
 import {
@@ -5,6 +6,7 @@ import {
   decodeBech32Pubkey,
   encodeAminoPubkey,
   encodeBech32Pubkey,
+  encodeEd25519Pubkey,
   encodeSecp256k1Pubkey,
 } from "./encoding";
 import { Pubkey } from "./pubkeys";
@@ -37,6 +39,25 @@ describe("encoding", () => {
     });
   });
 
+  describe("encodeEd25519Pubkey", () => {
+    it("encodes a compressed pubkey", () => {
+      const pubkey = fromBase64("ICKLJPyWYIF35GpOclg0gu957WYJe4PHzyn2scCZoek=");
+      expect(encodeEd25519Pubkey(pubkey)).toEqual({
+        type: "tendermint/PubKeyEd25519",
+        value: "ICKLJPyWYIF35GpOclg0gu957WYJe4PHzyn2scCZoek=",
+      });
+    });
+
+    it("throws for wrong pubkey lengths", () => {
+      expect(() => encodeEd25519Pubkey(Random.getBytes(31))).toThrowError(
+        /ed25519 public key must be 32 bytes long/i,
+      );
+      expect(() => encodeEd25519Pubkey(Random.getBytes(64))).toThrowError(
+        /ed25519 public key must be 32 bytes long/i,
+      );
+    });
+  });
+
   describe("decodeAminoPubkey", () => {
     it("works for secp256k1", () => {
       const amino = fromBech32(

packages/amino/src/encoding.ts

@@ -3,6 +3,7 @@ import { Uint53 } from "@cosmjs/math";
 import { arrayContentStartsWith } from "@cosmjs/utils";
 
 import {
+  Ed25519Pubkey,
   isEd25519Pubkey,
   isMultisigThresholdPubkey,
   isSecp256k1Pubkey,
@@ -12,6 +13,10 @@ import {
   Secp256k1Pubkey,
 } from "./pubkeys";
 
+/**
+ * Takes a Secp256k1 public key as raw bytes and returns the Amino JSON
+ * representation of it (the type/value wrapper object).
+ */
 export function encodeSecp256k1Pubkey(pubkey: Uint8Array): Secp256k1Pubkey {
   if (pubkey.length !== 33 || (pubkey[0] !== 0x02 && pubkey[0] !== 0x03)) {
     throw new Error("Public key must be compressed secp256k1, i.e. 33 bytes starting with 0x02 or 0x03");
@@ -22,6 +27,20 @@ export function encodeSecp256k1Pubkey(pubkey: Uint8Array): Secp256k1Pubkey {
   };
 }
 
+/**
+ * Takes an Edd25519 public key as raw bytes and returns the Amino JSON
+ * representation of it (the type/value wrapper object).
+ */
+export function encodeEd25519Pubkey(pubkey: Uint8Array): Ed25519Pubkey {
+  if (pubkey.length !== 32) {
+    throw new Error("Ed25519 public key must be 32 bytes long");
+  }
+  return {
+    type: pubkeyType.ed25519,
+    value: toBase64(pubkey),
+  };
+}
+
 // As discussed in https://github.com/binance-chain/javascript-sdk/issues/163
 // Prefixes listed here: https://github.com/tendermint/tendermint/blob/d419fffe18531317c28c29a292ad7d253f6cafdf/docs/spec/blockchain/encoding.md#public-key-cryptography
 // Last bytes is varint-encoded length prefix

packages/amino/src/index.ts

@@ -10,6 +10,7 @@ export {
   decodeBech32Pubkey,
   encodeAminoPubkey,
   encodeBech32Pubkey,
+  encodeEd25519Pubkey,
   encodeSecp256k1Pubkey,
 } from "./encoding";
 export { createMultisigThresholdPubkey } from "./multisig";