feat: validator info deserialization (#403)

web3.js/module.flow.js

@@ -142,6 +142,22 @@ declare module '@solana/web3.js' {
     static assign(from: PublicKey, programId: PublicKey): Transaction;
   }
 
+  // === src/validator-info.js ===
+  declare export type Info = {|
+    name: string,
+    website?: string,
+    details?: string,
+    keybaseId?: string,
+  |};
+
+  declare export class ValidatorInfo {
+    key: PublicKey;
+    info: Info;
+
+    constructor(key: PublicKey, info: Info): ValidatorInfo;
+    static fromConfigData(buffer: Buffer): ?ValidatorInfo;
+  }
+
   // === src/transaction.js ===
   declare export type TransactionSignature = string;
 

web3.js/src/index.js

@@ -9,6 +9,7 @@ export {PublicKey} from './publickey';
 export {SystemProgram} from './system-program';
 export {Token, TokenAmount} from './token-program';
 export {Transaction, TransactionInstruction} from './transaction';
+export {ValidatorInfo} from './validator-info';
 export {sendAndConfirmTransaction} from './util/send-and-confirm-transaction';
 export {
   sendAndConfirmRawTransaction,

web3.js/src/validator-info.js

@@ -0,0 +1,101 @@
+// @flow
+
+import {struct} from 'superstruct';
+
+import * as Layout from './layout';
+import * as shortvec from './util/shortvec-encoding';
+import {PublicKey} from './publickey';
+
+const VALIDATOR_INFO_KEY = new PublicKey(
+  'Va1idator1nfo111111111111111111111111111111',
+);
+
+/**
+ * @private
+ */
+type ConfigKey = {|
+  publicKey: PublicKey,
+  isSigner: boolean,
+|};
+
+/**
+ * Info used to identity validators.
+ *
+ * @typedef {Object} Info
+ * @property {string} name validator name
+ * @property {?string} website optional, validator website
+ * @property {?string} details optional, extra information the validator chose to share
+ * @property {?string} keybaseId optional, used to identify validators on keybase.io
+ */
+export type Info = {|
+  name: string,
+  website?: string,
+  details?: string,
+  keybaseId?: string,
+|};
+
+const InfoString = struct({
+  name: 'string',
+  website: 'string?',
+  details: 'string?',
+  keybaseId: 'string?',
+});
+
+/**
+ * ValidatorInfo class
+ */
+export class ValidatorInfo {
+  /**
+   * validator public key
+   */
+  key: PublicKey;
+  /**
+   * validator information
+   */
+  info: Info;
+
+  /**
+   * Construct a valid ValidatorInfo
+   *
+   * @param key validator public key
+   * @param info validator information
+   */
+  constructor(key: PublicKey, info: Info) {
+    this.key = key;
+    this.info = info;
+  }
+
+  /**
+   * Deserialize ValidatorInfo from the config account data. Exactly two config
+   * keys are required in the data.
+   *
+   * @param buffer config account data
+   * @return null if info was not found
+   */
+  static fromConfigData(buffer: Buffer): ?ValidatorInfo {
+    const PUBKEY_LENGTH = 32;
+
+    let byteArray = [...buffer];
+    const configKeyCount = shortvec.decodeLength(byteArray);
+    if (configKeyCount !== 2) return null;
+
+    const configKeys: Array<ConfigKey> = [];
+    for (let i = 0; i < 2; i++) {
+      const publicKey = new PublicKey(byteArray.slice(0, PUBKEY_LENGTH));
+      byteArray = byteArray.slice(PUBKEY_LENGTH);
+      const isSigner = byteArray.slice(0, 1)[0] === 1;
+      byteArray = byteArray.slice(1);
+      configKeys.push({publicKey, isSigner});
+    }
+
+    if (configKeys[0].publicKey.equals(VALIDATOR_INFO_KEY)) {
+      if (configKeys[1].isSigner) {
+        const rawInfo = Layout.rustString().decode(Buffer.from(byteArray));
+        const info = InfoString(JSON.parse(rawInfo));
+        return new ValidatorInfo(configKeys[1].publicKey, info);
+      }
+    }
+
+    return null;
+  }
+}

web3.js/test/validator-info.test.js

@@ -0,0 +1,36 @@
+// @flow
+import nacl from 'tweetnacl';
+
+import {PublicKey} from '../src/publickey';
+import {ValidatorInfo} from '../src/validator-info';
+
+test('from config account data', () => {
+  const keypair = nacl.sign.keyPair.fromSeed(
+    Uint8Array.from(Array(32).fill(8)),
+  );
+
+  const expectedValidatorInfo = new ValidatorInfo(
+    new PublicKey(keypair.publicKey),
+    {
+      name: 'Validator',
+      keybaseId: 'validator_id',
+    },
+  );
+
+  // Config data string steps:
+  // 1) Generate a keypair
+  // 2) Airdrop lamports to the account
+  // 3) Modify the `solana-validator-info` tool
+  //   a) Remove the keybase id verification step
+  //   b) Print base64 account data in the `get --all` codepath
+  //   c) Add `println!("Account data: {:?}", base64::encode(&account.data));`
+  // 4) Use modified `solana-validator-info` tool to publish validator info
+  // 5) And then use it again to fetch the data! (feel free to trim some A's)
+  const configData = Buffer.from(
+    'AgdRlwF0SPKsXcI8nrx6x4wKJyV6xhRFjeCk8W+AAAAAABOY9ixtGkV8UbpqS189vS9p/KkyFiGNyJl+QWvRfZPKAS8AAAAAAAAAeyJrZXliYXNlSWQiOiJ2YWxpZGF0b3JfaWQiLCJuYW1lIjoiVmFsaWRhdG9yIn0',
+    'base64',
+  );
+  const info = ValidatorInfo.fromConfigData(configData);
+
+  expect(info).toEqual(expectedValidatorInfo);
+});