From 653775462cec3bac91a8c419262934346a54dcc7 Mon Sep 17 00:00:00 2001
From: Kai Hirota <34954529+kaihirota@users.noreply.github.com>
Date: Mon, 19 Feb 2024 16:04:21 +1100
Subject: [PATCH] add registration workflow

---
 src/ImmutableX.ts              | 12 +++++++
 src/types/signers.ts           | 11 +++++++
 src/utils/stark/starkSigner.ts | 26 +++++++++++++++
 src/workflows/registration.ts  | 58 ++++++++++++++++++++++++++++++++--
 src/workflows/workflows.ts     |  7 ++++
 5 files changed, 111 insertions(+), 3 deletions(-)

diff --git a/src/ImmutableX.ts b/src/ImmutableX.ts
index 560c68ba..14e7368b 100644
--- a/src/ImmutableX.ts
+++ b/src/ImmutableX.ts
@@ -169,6 +169,18 @@ export class ImmutableX {
     });
   }
 
+  /**
+   * Register a User to StarkEx contract if they are not already
+   * @param walletConnection - the pair of L1/L2 signers
+   * @returns a promise that resolves with void if successful
+   * @throws {@link index.IMXError}
+   */
+  public registerOnchain(walletConnection: WalletConnection) {
+    return this.workflows.registerOnchain(walletConnection).catch(err => {
+      throw formatError(err);
+    });
+  }
+
   /**
    * Checks if a User is registered on on-chain
    * @param walletConnection - the pair of L1/L2 signers
diff --git a/src/types/signers.ts b/src/types/signers.ts
index 706364a3..44ccccdd 100644
--- a/src/types/signers.ts
+++ b/src/types/signers.ts
@@ -1,4 +1,5 @@
 import { Signer as EthSigner } from '@ethersproject/abstract-signer';
+import { ec } from 'elliptic';
 
 export { EthSigner };
 
@@ -13,6 +14,16 @@ export interface StarkSigner {
    * @returns the signed prefixed-message
    */
   signMessage(message: string): Promise<string>;
+
+  /**
+   * Signs the prefixed-message
+   * @params message - this must be a UTF8-message
+   * @returns the signed prefixed-message
+   */
+  sign(message: string): Promise<ec.Signature>;
+
+  getYCoordinate(): string;
+
   /**
    * Get the Signer address
    * @returns the Signer's checksum address
diff --git a/src/utils/stark/starkSigner.ts b/src/utils/stark/starkSigner.ts
index 79f5afef..68fde42b 100644
--- a/src/utils/stark/starkSigner.ts
+++ b/src/utils/stark/starkSigner.ts
@@ -28,6 +28,17 @@ export class StandardStarkSigner implements StarkSigner {
     );
   }
 
+  public async sign(msg: string): Promise<ec.Signature> {
+    return this.keyPair.sign(this.fixMsgHashLen(msg));
+  }
+
+  public getYCoordinate(): string {
+    return encUtils.sanitizeBytes(
+      this.keyPair.getPublic().getY().toString(16),
+      2,
+    );
+  }
+
   /*
  The function _truncateToN in lib/elliptic/ec/index.js does a shift-right of delta bits,
  if delta is positive, where
@@ -60,3 +71,18 @@ export class StandardStarkSigner implements StarkSigner {
 export function createStarkSigner(starkPrivateKey: string): StarkSigner {
   return new StandardStarkSigner(starkPrivateKey);
 }
+
+export function serializePackedSignature(
+  sig: ec.Signature,
+  pubY: string,
+): string {
+  return encUtils.sanitizeHex(
+    encUtils.padLeft(sig.r.toString(16), 64) +
+      encUtils.padLeft(sig.s.toString(16), 64, '0') +
+      encUtils.padLeft(
+        new BN(encUtils.removeHexPrefix(pubY), 'hex').toString(16),
+        64,
+        '0',
+      ),
+  );
+}
diff --git a/src/workflows/registration.ts b/src/workflows/registration.ts
index 30dc41a8..e888e1d4 100644
--- a/src/workflows/registration.ts
+++ b/src/workflows/registration.ts
@@ -1,11 +1,17 @@
+import { ImmutableXConfiguration } from '..';
 import {
   UsersApi,
   GetSignableRegistrationResponse,
   RegisterUserResponse,
 } from '../api';
-import { WalletConnection } from '../types';
-import { signRaw } from '../utils';
-import { Registration } from '../contracts';
+import { StarkSigner, WalletConnection } from '../types';
+import { serializePackedSignature, signRaw, starkEcOrder } from '../utils';
+import { Registration, StarkV4__factory } from '../contracts';
+import { solidityKeccak256 } from 'ethers/lib/utils';
+import BN from 'bn.js';
+import * as encUtils from 'enc-utils';
+import { ec } from 'elliptic';
+import { TransactionResponse } from '@ethersproject/providers';
 
 type registerOffchainWorkflowParams = WalletConnection & {
   usersApi: UsersApi;
@@ -81,3 +87,49 @@ export async function getSignableRegistrationOnchain(
     verification_signature: response.data.verification_signature,
   };
 }
+
+export async function signRegisterEthAddress(
+  starkSigner: StarkSigner,
+  ethAddress: string,
+  starkPublicKey: string,
+): Promise<string> {
+  const hash: string = solidityKeccak256(
+    ['string', 'address', 'uint256'],
+    ['UserRegistration:', ethAddress, starkPublicKey],
+  );
+  const msgHash: BN = new BN(encUtils.removeHexPrefix(hash), 16);
+  const modMsgHash: BN = msgHash.mod(starkEcOrder);
+  const signature: ec.Signature = await starkSigner.sign(
+    modMsgHash.toString(16),
+  );
+  const pubY: string = encUtils.sanitizeHex(starkSigner.getYCoordinate());
+  return serializePackedSignature(signature, pubY);
+}
+
+export async function registerOnchainWorkflow(
+  walletConnection: WalletConnection,
+  config: ImmutableXConfiguration,
+): Promise<TransactionResponse> {
+  const ethAddress = await walletConnection.ethSigner.getAddress();
+  const starkPublicKey = await walletConnection.starkSigner.getAddress();
+
+  const signature = await signRegisterEthAddress(
+    walletConnection.starkSigner,
+    ethAddress,
+    starkPublicKey,
+  );
+
+  const contract = StarkV4__factory.connect(
+    config.ethConfiguration.coreContractAddress,
+    walletConnection.ethSigner,
+  );
+
+  const populatedTransaction =
+    await contract.populateTransaction.registerEthAddress(
+      ethAddress,
+      starkPublicKey,
+      signature,
+    );
+
+  return walletConnection.ethSigner.sendTransaction(populatedTransaction);
+}
diff --git a/src/workflows/workflows.ts b/src/workflows/workflows.ts
index 8b645c37..cc4021d4 100644
--- a/src/workflows/workflows.ts
+++ b/src/workflows/workflows.ts
@@ -42,6 +42,7 @@ import { Registration__factory } from '../contracts';
 import {
   isRegisteredOnChainWorkflow,
   registerOffchainWorkflow,
+  registerOnchainWorkflow,
 } from './registration';
 import { mintingWorkflow } from './minting';
 import { transfersWorkflow, batchTransfersWorkflow } from './transfers';
@@ -131,6 +132,12 @@ export class Workflows {
     });
   }
 
+  public async registerOnchain(walletConnection: WalletConnection) {
+    await this.validateChain(walletConnection.ethSigner);
+
+    return registerOnchainWorkflow(walletConnection, this.config);
+  }
+
   public async isRegisteredOnchain(walletConnection: WalletConnection) {
     await this.validateChain(walletConnection.ethSigner);