feat: use seedutil to generate mnemonic

This changes adds the functionality to seedutil to generate a random
24 word mnemonic, which then replaces lnd for the purposes of generating
the seed and mnemonic for a new xud node. This removes a dependency and
allows xud to create a node without the help of lnd.

Closes ExchangeUnion#1253.

lib/service/InitService.ts

@@ -3,7 +3,7 @@ import { promises as fs } from 'fs';
 import NodeKey from '../nodekey/NodeKey';
 import swapErrors from '../swaps/errors';
 import SwapClientManager from '../swaps/SwapClientManager';
-import { decipher } from '../utils/seedutil';
+import { decipher, generate } from '../utils/seedutil';
 import errors from './errors';
 
 interface InitService {
@@ -32,7 +32,7 @@ class InitService extends EventEmitter {
     await this.prepareCall();
 
     try {
-      const seedMnemonic = await this.swapClientManager.genSeed();
+      const seedMnemonic = await generate();
 
       // we use the deciphered seed (without the salt and extra fields that make up the enciphered seed)
       // to generate an xud nodekey from the same seed used for wallets

lib/swaps/SwapClientManager.ts

@@ -1,5 +1,5 @@
-import { promises as fs } from 'fs';
 import { EventEmitter } from 'events';
+import { promises as fs } from 'fs';
 import Config from '../Config';
 import { SwapClientType } from '../constants/enums';
 import { Models } from '../db/DB';
@@ -151,28 +151,6 @@ class SwapClientManager extends EventEmitter {
     }
   }
 
-  /**
-   * Generates a cryptographically random 24 word seed mnemonic from an lnd client.
-   */
-  public genSeed = async () => {
-    const lndClients = this.getLndClientsMap().values();
-    // loop through swap clients until we find an lnd client awaiting unlock
-    for (const lndClient of lndClients) {
-      if (lndClient.isWaitingUnlock()) {
-        try {
-          const seed = await lndClient.genSeed();
-          return seed;
-        } catch (err) {
-          lndClient.logger.error('could not generate seed', err);
-        }
-      }
-    }
-
-    // TODO: use seedutil tool to generate a seed instead of throwing error
-    // when we can't generate one with lnd
-    throw errors.SWAP_CLIENT_WALLET_NOT_CREATED('could not generate aezeed');
-  }
-
   /**
    * Initializes wallets with seed and password.
    */

lib/utils/seedutil.ts

@@ -1,3 +1,4 @@
+import assert from 'assert';
 import { exec as childProcessExec } from 'child_process';
 import { promisify } from 'util';
 
@@ -49,4 +50,16 @@ async function decipher(mnemonic: string[]) {
   return Buffer.from(decipheredSeed, 'hex');
 }
 
-export { keystore, encipher, decipher };
+async function generate() {
+  const { stdout, stderr } = await exec('./seedutil/seedutil generate');
+
+  if (stderr) {
+    throw new Error(stderr);
+  }
+
+  const mnemonic = stdout.trim().split(' ');
+  assert.equal(mnemonic.length, 24, 'seedutil did not generate mnemonic of exactly 24 words');
+  return mnemonic;
+}
+
+export { keystore, encipher, decipher, generate };

seedutil/SeedUtil.spec.ts

@@ -132,6 +132,17 @@ describe('SeedUtil decipher', () => {
   });
 });
 
+describe('SeedUtil generate', () => {
+  test('it prints a 24 word mnemonic which can be deciphered', async () => {
+    const cmd = './seedutil/seedutil generate';
+    const mnemonic = await executeCommand(cmd);
+    expect(mnemonic.split(' ')).toHaveLength(24);
+
+    const cmd2 = `./seedutil/seedutil decipher ${mnemonic}`;
+    await executeCommand(cmd2);
+  });
+});
+
 describe('SeedUtil keystore', () => {
   beforeEach(async () => {
     await deleteDir(DEFAULT_KEYSTORE_PATH);

seedutil/main.go

@@ -8,6 +8,8 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
+	"time"
 
 	"github.com/ethereum/go-ethereum/accounts/keystore"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -26,7 +28,7 @@ var (
 	defaultKeyStorePath = filepath.Join(filepath.Dir(os.Args[0]))
 )
 
-func parseMnemonic(words []string) aezeed.Mnemonic{
+func parseMnemonic(words []string) aezeed.Mnemonic {
 	if len(words) < aezeed.NummnemonicWords {
 		fmt.Fprintf(os.Stderr, "\nerror: expecting %v-word mnemonic seed separated by spaces\n", aezeed.NummnemonicWords)
 		os.Exit(1)
@@ -54,7 +56,8 @@ func mnemonicToCipherSeed(mnemonic aezeed.Mnemonic, aezeedPassphrase *string) *a
 func main() {
 	keystoreCommand := flag.NewFlagSet("keystore", flag.ExitOnError)
 	encipherCommand := flag.NewFlagSet("encipher", flag.ExitOnError)
-	mnemonicCommand := flag.NewFlagSet("mnemonic", flag.ExitOnError)
+	decipherCommand := flag.NewFlagSet("decipher", flag.ExitOnError)
+	generateCommand := flag.NewFlagSet("generate", flag.ExitOnError)
 
 	if len(os.Args) < 2 {
 		fmt.Println("subcommand is required")
@@ -117,9 +120,9 @@ func main() {
 		encipheredSeed, _ := cipherSeed.Encipher([]byte(*aezeedPassphrase))
 		fmt.Println(hex.EncodeToString(encipheredSeed[:]))
 	case "decipher":
-		aezeedPassphrase := mnemonicCommand.String("aezeedpass", defaultAezeedPassphrase, "aezeed passphrase")
-		mnemonicCommand.Parse(os.Args[2:])
-		args = mnemonicCommand.Args()
+		aezeedPassphrase := decipherCommand.String("aezeedpass", defaultAezeedPassphrase, "aezeed passphrase")
+		decipherCommand.Parse(os.Args[2:])
+		args = decipherCommand.Args()
 
 		mnemonic := parseMnemonic(args)
 		decipheredSeed, err := mnemonic.Decipher([]byte(*aezeedPassphrase))
@@ -129,6 +132,23 @@ func main() {
 		}
 
 		fmt.Println(hex.EncodeToString(decipheredSeed[:]))
+	case "generate":
+		aezeedPassphrase := generateCommand.String("aezeedpass", defaultAezeedPassphrase, "aezeed passphrase")
+		generateCommand.Parse(os.Args[2:])
+
+		cipherSeed, err := aezeed.New(0, nil, time.Now())
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+
+		mnemonic, err := cipherSeed.ToMnemonic([]byte(*aezeedPassphrase))
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+
+		fmt.Println(strings.Join([]string(mnemonic[:]), " "))
 	default:
 		flag.PrintDefaults()
 		os.Exit(1)