Flutter & Firebase Auth(Google, Apple, Email Login) 사용하기

Setting

Firebase에서 안드로이드 앱을 등록할때 반드시 SHA 인증서 지문을 입력해줘야한다.

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keytool -list -v \
-alias androiddebugkey -keystore ~/.android/debug.keystore

비밀번호는 반드시 android로 한다

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// flutter pub add google_sign_in.dart

import 'package:google_sign_in/google_sign_in.dart';

Future<UserCredential> signInWithGoogle() async {
	try {
	  // Trigger the authentication flow
	  final GoogleSignInAccount? googleUser = await GoogleSignIn().signIn();

	  // Obtain the auth details from the request
	  final GoogleSignInAuthentication googleAuth =
	      await googleUser!.authentication;

	  // Create a new credential
	  final credential = GoogleAuthProvider.credential(
	    accessToken: googleAuth.accessToken,
	    idToken: googleAuth.idToken,
	  );

	  // Once signed in, return the UserCredential
	  return await FirebaseAuth.instance.signInWithCredential(credential);
	} catch (e) {
		print(e);
	}
}

구글 로그인의 경우 예외처리를 해줘도 PlatformExption이 발생하는데, reales 버전에서는 문제 없다고 한다…

사전준비
1. Firebase에서 앱을 추가할때 Apple Developer에서 발급받은 앱 ID가 필요
  - Apple Developer → Certificates → identifiers → 생성
  - App IDs → App → Sign In with Apple 체크 후 등록
2. Xcode Runner → Signing & Capabilities → + Capability → Sign in with Apple
3. GoogleService-Info.plist에서 REVERSED_CLIENT_ID 값을 Runner → Info → URL Types 추가 후 URL Schemes에 입력

필요조건

iOS 13 이상 : Signing with Apple

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// flutter pub add sign_in_with_apple

import 'package:sign_in_with_apple/sign_in_with_apple.dart';
import 'dart:math';
import 'dart:convert';

String generateNonce([int length = 32]) {
  final charset =
      '0123456789ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz-._';
  final random = Random.secure();
  return List.generate(length, (_) => charset[random.nextInt(charset.length)])
      .join();
}

/// Returns the sha256 hash of [input] in hex notation.
String sha256ofString(String input) {
  final bytes = utf8.encode(input);
  final digest = sha256.convert(bytes);
  return digest.toString();
}

Future<UserCredential> signInWithApple() async {
	try {
	  // Request credential for the currently signed in Apple account.
	  final appleCredential = await SignInWithApple.getAppleIDCredential(
	    scopes: [
	      AppleIDAuthorizationScopes.email,
	      AppleIDAuthorizationScopes.fullName,
	    ],
	  );

	  // Create an `OAuthCredential` from the credential returned by Apple.
	  final oauthCredential = OAuthProvider("apple.com").credential(
	    idToken: appleCredential.identityToken,
	    accessToken: appleCredential.authorizationCode,
	  );

	  // Sign in the user with Firebase. If the nonce we generated earlier does
	  // not match the nonce in `appleCredential.identityToken`, sign in will fail.
	  return await FirebaseAuth.instance.signInWithCredential(oauthCredential);
	} catch (e) {
		// 로그인을 취소했을 경우
		print(e);
	}
}

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void _emailSignUp() async {
    try {
      UserCredential userCredential = await FirebaseAuth.instance
          .createUserWithEmailAndPassword(
              email: "myemail@google.com", password: "SuperSecretPassword!");
    } on FirebaseAuthException catch (e) {
      if (e.code == 'weak-password') {
        print('The password provided is too weak.');
      } else if (e.code == 'email-already-in-use') {
        print('The account already exists for that email.');
      }
    } catch (e) {
      print(e);
    }
  }

  void _emailSignIn() async {
    try {
      // UserCredential userCredential =
      await FirebaseAuth.instance.signInWithEmailAndPassword(
          email: "myemail@google.com", password: "SuperSecretPassword!");
    } on FirebaseAuthException catch (e) {
      if (e.code == 'user-not-found') {
        print('No user found for that email.');
      } else if (e.code == 'wrong-password') {
        print('Wrong password provided for that user.');
      }
    }
  }

Use

StreamBuilder로 상태 가져오기

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class Home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return StreamBuilder<User?>(
      stream: FirebaseAuth.instance.authStateChanges(),
      builder: (BuildContext context, AsyncSnapshot<User?> user) {
        if (!user.hasData) {
          // 로그인한적이 없는 경우
          return SignIn();
        }

        // 로그인한 경우
        return MyPage();
      },
    );
  }
}

정보가져오기

FirebaseAuth.instance.currentUser!.
- photoURL
- displayName : google에서 따로 지정하지 않으면 null
- email
- emailVerified
- metadata
  - creationTime
  - lastSignInTime
- uid

동작하기

이메일 인증 메일 보내기 FirebaseAuth.instance.currentUser!.sendEmailVerification();
로그아웃 FirebaseAuth.instance.signOut();
유저 삭제 FirebaseAuth.instance.currentUser!.delete();
비밀번호 재설정 FirebaseAuth.instance.sendPasswordResetEmail(email: "email@example.com")

Setting

Google Login

Apple Login

Email Login

Use

StreamBuilder로 상태 가져오기

정보가져오기

동작하기