Sign In With Ethereum

final _siweConfig = SIWEConfig(  getNonce: () async {    // The getNonce method functions as a safeguard    // against spoofing, akin to a CSRF token.    return await yourApi.getNonce();  },  getMessageParams: () async {    // Parameters to create the SIWE message internally.    // More info in https://github.com/ChainAgnostic/CAIPs/blob/main/CAIPs/caip-222.method    return SIWEMessageArgs(      domain: 'yourdomain.com',      uri: 'https://yourdomain.com/login',      statement: 'Please sign with your account',      methods: ['personal_sign', 'eth_sendTransaction'],    );  },  createMessage: (SIWECreateMessageArgs args) {    // Method for generating an EIP-4361-compatible message.    // You can use our provided formatMessage() method or implement your own    return SIWEUtils.formatMessage(args);  },  verifyMessage: (SIWEVerifyMessageArgs args) async {    // This function ensures the message is valid,    // has not been tampered with, and has been appropriately    // signed by the wallet address.    try {      final isValidMessage = await yourApi.verifyMessage(args.toJson());      return isValidMessage;    } catch (error) {      // error validating message      return false;    }  },  getSession: () async {    // Called after verifyMessage() succeeds    // The backend session should store the associated address and chainId    // and return it via the `getSession` method.    try {      final session = await yourApi.getSession();      return SIWESession(address: session.address, chains: [session.chainId]);    } catch (error) {      // error getting session      rethrow;    }  },  onSignIn: (SIWESession session) {    // Called after getSession() succeeds  },  signOut: () async {    // Called when wallet disconnects if `signOutOnDisconnect == true` and/or when    // `signOutOnAccountChange == true` and/or    // `signOutOnNetworkChange == true`    try {      final success = await yourApi.signOut();      return success;    } catch (error) {      // error signing out      return false;    }  },  onSignOut: () {    // Called after signOut() succeeds  },  // enabled: true, // OPTIONAL. Enables One-Click Auth + SIWE logic, if `false`, regular session proposal will be used. (default `true`)  // signOutOnDisconnect: true, // OPTIONAL (default `true`)  // signOutOnAccountChange: true, // OPTIONAL (default `true`)  // signOutOnNetworkChange: true, // OPTIONAL (default `true`));

final _appKitModal = ReownAppKitModal(  context: context,  projectId: '{YOUR_PROJECT_ID}',  metadata: const PairingMetadata(    name: 'Example App',    description: 'Example app description',    url: 'https://example.com/',    icons: ['https://example.com/logo.png'],    redirect: Redirect(      native: 'exampleapp://',      universal: 'https://reown.com/exampleapp',    ),  ),  siweConfig: SIWEConfig(...),);

class SIWEConfig {  final Future<String> Function() getNonce;  final Future<SIWEMessageArgs> Function() getMessageParams;  final String Function(SIWECreateMessageArgs args) createMessage;  final Future<bool> Function(SIWEVerifyMessageArgs args) verifyMessage;  final Future<SIWESession?> Function() getSession;  final Future<bool> Function() signOut;  // Callback when user signs in  final Function(SIWESession session)? onSignIn;  // Callback when user signs out  final VoidCallback? onSignOut;  // Defaults to true  final bool enabled;  // In milliseconds, defaults to 5 minutes  final int nonceRefetchIntervalMs;  // In milliseconds, defaults to 5 minutes  final int sessionRefetchIntervalMs;  // Defaults to true  final bool signOutOnDisconnect;  // Defaults to true  final bool signOutOnAccountChange;  // Defaults to true  final bool signOutOnNetworkChange;  //  SIWEConfig({    required this.getNonce,    required this.getMessageParams,    required this.createMessage,    required this.verifyMessage,    required this.getSession,    required this.signOut,    this.onSignIn,    this.onSignOut,    this.enabled = true,    this.signOutOnDisconnect = true,    this.signOutOnAccountChange = true,    this.signOutOnNetworkChange = true,    this.nonceRefetchIntervalMs = 300000,    this.sessionRefetchIntervalMs = 300000,  });}

SIWEUtils.generateNonce();

SIWEUtils.formatMessage(args);

await SIWEUtils.verifySignature(  address,  message,  signature,  chainId,  projectId);

SIWEUtils.getChainIdFromMessage(message);

SIWEUtils.getAddressFromMessage(message);

final _appKitModal = ReownAppKitModal(  context: context,  projectId: '{YOUR_PROJECT_ID}',  metadata: const PairingMetadata(    name: 'Example App',    description: 'Example app description',    url: 'https://example.com/',    icons: ['https://example.com/logo.png'],    redirect: Redirect(      native: 'exampleapp://',      universal: 'https://reown.com/exampleapp',    ),  ),  siweConfig: SIWEConfig(    getNonce: () async {      return SIWEUtils.generateNonce();    },    getMessageParams: () async {      return SIWEMessageArgs(        domain: Uri.parse(_appKitModal.appKit!.metadata.url).authority,        uri: _appKitModal.appKit!.metadata.url,        statement: '{Your custom message here}',        methods: MethodsConstants.allMethods,      );    },    createMessage: (SIWECreateMessageArgs args) {      return SIWEUtils.formatMessage(args);    },    verifyMessage: (SIWEVerifyMessageArgs args) async {      final chainId = SIWEUtils.getChainIdFromMessage(args.message);      final address = SIWEUtils.getAddressFromMessage(args.message);      final cacaoSignature = args.cacao != null          ? args.cacao!.s          : CacaoSignature(              t: CacaoSignature.EIP191,              s: args.signature,            );      return await SIWEUtils.verifySignature(        address,        args.message,        cacaoSignature,        chainId,        DartDefines.projectId,      );    },    getSession: () async {      final chainId = _appKitModal.selectedChain?.chainId ?? '1';      final namespace = ReownAppKitModalNetworks.getNamespaceForChainId(        chainId,      );      final address = _appKitModal.session!.getAddress(namespace)!;      return SIWESession(address: address, chains: [chainId]);    },    signOut: () async {      return true;    },  ),);