feat: add createProgramAddress

web3.js/src/publickey.js

@@ -78,7 +78,7 @@ export class PublicKey {
   }
 
   /**
-   * Derive a public key from another key, a seed, and a programId.
+   * Derive a public key from another key, a seed, and a program ID.
    */
   static async createWithSeed(
     fromPublicKey: PublicKey,
@@ -93,4 +93,25 @@ export class PublicKey {
     const hash = await sha256(new Uint8Array(buffer));
     return new PublicKey('0x' + hash);
   }
+
+  /**
+   * Derive a program address from seeds and a program ID.
+   */
+  static async createProgramAddress(
+    seeds: Array<string>,
+    programId: PublicKey,
+  ): Promise<PublicKey> {
+    let buffer = Buffer.alloc(0);
+    seeds.forEach(function (seed) {
+      buffer = Buffer.concat([buffer, Buffer.from(seed)]);
+    });
+    buffer = Buffer.concat([
+      buffer,
+      programId.toBuffer(),
+      Buffer.from('ProgramDerivedAddress'),
+    ]);
+    let hash = await sha256(new Uint8Array(buffer));
+    hash = await sha256(new Uint8Array(new BN(hash, 16).toBuffer()));
+    return new PublicKey('0x' + hash);
+  }
 }

web3.js/test/publickey.test.js

@@ -238,3 +238,40 @@ test('createWithSeed', async () => {
     ),
   ).toBe(true);
 });
+
+test('createProgramAddress', async () => {
+  const programId = new PublicKey(
+    'BPFLoader1111111111111111111111111111111111',
+  );
+
+  let programAddress = await PublicKey.createProgramAddress([''], programId);
+  expect(
+    programAddress.equals(
+      new PublicKey('CsdSsqp6Upkh2qajhZMBM8xT4GAyDNSmcV37g4pN8rsc'),
+    ),
+  ).toBe(true);
+  programAddress = await PublicKey.createProgramAddress(['☉'], programId);
+  expect(
+    programAddress.equals(
+      new PublicKey('A8mYnN8Pfx7Nn6f8RoQgsPNtAGAWmmKSBCDfyDvE6sXF'),
+    ),
+  ).toBe(true);
+  programAddress = await PublicKey.createProgramAddress(
+    ['Talking', 'Squirrels'],
+    programId,
+  );
+  expect(
+    programAddress.equals(
+      new PublicKey('CawYq8Rmj4JRR992wVnGEFUjMEkmtmcFgEL4iS1qPczu'),
+    ),
+  ).toBe(true);
+  programAddress = await PublicKey.createProgramAddress(
+    ['Talking', 'Squirrels'],
+    programId,
+  );
+  const programAddress2 = await PublicKey.createProgramAddress(
+    ['Talking'],
+    programId,
+  );
+  expect(programAddress.equals(programAddress2)).toBe(false);
+});