새 앱을 빌드하거나 기존 앱에 로그인을 추가하는 경우 Firebase의 라이브러리와 서비스를 사용하면 인증 백엔드를 직접 빌드하지 않고도 보안 인증을 구현할 수 있습니다. Firebase Authentication은 비밀번호, 제휴 ID 공급업체, 이메일, SMS를 통한 로그인을 지원하는 완전한 백엔드 솔루션입니다.
사용하기 쉬운 삽입형 솔루션이 필요합니다
앱에 인증을 추가하는 가장 빠르고 쉬운 방법은 삽입형 UI 라이브러리인 FirebaseUI 인증을 사용하는 것입니다. FirebaseUI는 Firebase Authentication에서 지원하는 모든 로그인 방법에 대해 완전한 사용자 과정을 구현합니다.
FirebaseUI 인증은 삽입형 솔루션이므로 특정한 UX가 있으며 이 UX가 개발자의 니즈에 맞지 않을 수도 있습니다. UX를 변경하려면 오픈소스인 라이브러리를 가져와 자체 버전을 사용하면 됩니다. 하지만 로그인 과정이 상당히 다른 경우에는 다음 섹션에서 설명하는 것처럼 Firebase SDK로 자체 과정을 구현하는 것이 좋습니다.
앱의 로그인 환경을 더 세밀하게 제어하기 위해 자체 인증 과정을 구현하고 Firebase SDK를 사용하여 Firebase의 인증 서비스와 연동할 수 있습니다. 예를 들어 자체 이메일 주소와 비밀번호 과정 또는 Google 로그인 과정을 만들고 사용자의 이메일 주소와 비밀번호 또는 Google ID 토큰을 Firebase에 전달하여 사용자를 인증합니다.
익명 인증을 사용하여 사용자가 실제로 로그인하기 전에 로그인 상태에서 제공되는 앱 기능을 사용하도록 설정할 수 있습니다. 익명 '로그인'을 사용하면 실제 계정처럼 사용할 수 있는 임시 단일 세션 계정이 생성됩니다. 그런 다음 사용자가 로그인하거나 가입한 후에 이어서 앱을 계속 사용할 수 있도록 임시 계정을 실제 계정에 연결합니다.
서버에서 Firebase 서비스에 액세스하기 위해 Firebase Authentication을 사용할 필요가 없습니다. 대신 Admin SDK를 사용하세요. Admin SDK를 초기화할 때 서비스 계정 사용자 인증 정보로 인증합니다. 이 사용자 인증 정보는 특정 사용자가 아닌 Firebase 프로젝트를 나타내며 프로젝트 리소스에 대한 전체 액세스 권한을 부여합니다.
[[["이해하기 쉬움","easyToUnderstand","thumb-up"],["문제가 해결됨","solvedMyProblem","thumb-up"],["기타","otherUp","thumb-up"]],[["필요한 정보가 없음","missingTheInformationINeed","thumb-down"],["너무 복잡함/단계 수가 너무 많음","tooComplicatedTooManySteps","thumb-down"],["오래됨","outOfDate","thumb-down"],["번역 문제","translationIssue","thumb-down"],["샘플/코드 문제","samplesCodeIssue","thumb-down"],["기타","otherDown","thumb-down"]],["최종 업데이트: 2025-09-04(UTC)"],[],[],null,["I already have an authentication system\n\nIf your app already has a sign-in implementation and you want to use it to\nauthenticate with Firebase backend services, use **Custom Authentication**. This\nincludes apps that use any of the following:\n\n- Custom-built solutions, such as custom password-based systems.\n- Third-party identity management services, such as Auth0 or Okta.\n- Existing integrations with federated identity providers, such as Google, Facebook, or Apple. (And if you don't yet support federated identity, but you want to, see the next section.)\n\nWith custom authentication, you sign users in with the system of your choice,\ncreate a Firebase token for the user on your backend, and then use the token\nfrom the client to authenticate with Firebase.\n\nSee the docs for\n[iOS+](/docs/auth/ios/custom-auth),\n[Android](/docs/auth/android/custom-auth),\n[Web](/docs/auth/web/custom-auth),\n[Flutter](/docs/auth/flutter/custom-auth),\n[Unity](/docs/auth/unity/custom-auth), or\n[C++](/docs/auth/cpp/custom-auth).\n\nI want to build my authentication system with Firebase\n\nIf you're building a new app or adding sign-in to an existing app, Firebase has\nlibraries and services that can help you implement secure authentication without\nhaving to build the authentication backend yourself. Firebase Authentication is a\ncomplete backend solution for signing in with passwords, federated identity\nproviders, email links, and text messages.\n\nI want a drop-in solution that's easy to use\n\nThe fastest and easiest way to add authentication to an app is to use\n**FirebaseUI Auth** , a drop-in UI library. FirebaseUI implements complete user\nflows for all of Firebase Authentication's supported sign-in methods.\n\nBecause FirebaseUI Auth is a drop-in solution, it has a specific UX that might\nnot meet your needs. If you want to change the UX, you can fork the library,\nwhich is open source, and use your own version. However, for substantially\ndifferent sign-in flows, you might prefer to implement your own flows with the\nFirebase SDK as discussed in the next section.\n\nSee the FirebaseUI Auth docs for\n[iOS](/docs/auth/ios/firebaseui),\n[Android](/docs/auth/android/firebaseui), or\n[Web](/docs/auth/web/firebaseui).\n\nI want full control over the sign-in experience\n\nFor more control over your app's sign-in experience, you can implement your own\nauthentication flows and use the Firebase SDK to work with Firebase's\nauthentication services. For example, build your own email address and password\nflow or Google Sign-in flow, and pass the user's email address and password or\nGoogle ID token to Firebase to authenticate the user.\n\nSee the Firebase Authentication SDK docs:\n\n| Firebase services ||\n|----------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| **Email address and password sign-in** | [iOS+](/docs/auth/ios/password-auth) \\| [Android](/docs/auth/android/password-auth) \\| [Web](/docs/auth/web/password-auth) \\| [Flutter](/docs/auth/flutter/password-auth) \\| [Unity](/docs/auth/unity/password-auth) \\| [C++](/docs/auth/cpp/password-auth) |\n| **Phone number sign-in** | [iOS+](/docs/auth/ios/phone-auth) \\| [Android](/docs/auth/android/phone-auth) \\| [Web](/docs/auth/web/phone-auth) \\| [Flutter](/docs/auth/flutter/phone-auth) \\| [Unity](/docs/auth/unity/phone-auth) \\| [C++](/docs/auth/cpp/phone-auth) |\n| **Email link sign-in** | [iOS+](/docs/auth/ios/email-link-auth) \\| [Android](/docs/auth/android/email-link-auth) \\| [Web](/docs/auth/web/email-link-auth) \\| [Flutter](/docs/auth/flutter/email-link-auth) \\| [Unity](/docs/auth/unity/email-link-auth) \\| [C++](/docs/auth/cpp/email-link-auth) |\n| **Google** | [iOS+](/docs/auth/ios/google-signin) \\| [Android](/docs/auth/android/google-signin) \\| [Web](/docs/auth/web/google-signin) \\| [Flutter](/docs/auth/flutter/federated-auth#google) \\| [Unity](/docs/auth/unity/google-signin) \\| [C++](/docs/auth/cpp/google-signin) |\n| **Facebook** | [iOS+](/docs/auth/ios/facebook-login) \\| [Android](/docs/auth/android/facebook-login) \\| [Web](/docs/auth/web/facebook-login) \\| [Flutter](/docs/auth/flutter/federated-auth#facebook) \\| [Unity](/docs/auth/unity/facebook-login) \\| [C++](/docs/auth/cpp/facebook-login) |\n| **Apple** | [iOS+](/docs/auth/ios/apple) \\| [Android](/docs/auth/android/apple) \\| [Web](/docs/auth/web/apple) \\| [Flutter](/docs/auth/flutter/federated-auth#apple) \\| [Unity](/docs/auth/unity/apple) \\| [C++](/docs/auth/cpp/apple) |\n| **Play Games** | [Android](/docs/auth/android/play-games) \\| [Unity](/docs/auth/unity/play-games) \\| [C++](/docs/auth/cpp/play-games) |\n| **Game Center** | [iOS+](/docs/auth/ios/game-center) |\n| **GitHub** | [iOS+](/docs/auth/ios/github-auth) \\| [Android](/docs/auth/android/github-auth) \\| [Web](/docs/auth/web/github-auth) \\| [Flutter](/docs/auth/flutter/federated-auth#github) \\| [Unity](/docs/auth/unity/github-auth) \\| [C++](/docs/auth/cpp/github-auth) |\n| **Microsoft** | [iOS+](/docs/auth/ios/microsoft-oauth) \\| [Android](/docs/auth/android/microsoft-oauth) \\| [Web](/docs/auth/web/microsoft-oauth) \\| [Unity](/docs/auth/unity/microsoft-oauth) \\| [C++](/docs/auth/cpp/microsoft-oauth) |\n| **Twitter** | [iOS+](/docs/auth/ios/twitter-login) \\| [Android](/docs/auth/android/twitter-login) \\| [Web](/docs/auth/web/twitter-login) \\| [Flutter](/docs/auth/flutter/federated-auth#twitter) \\| [Unity](/docs/auth/unity/twitter-login) \\| [C++](/docs/auth/cpp/twitter-login) |\n| **Yahoo** | [iOS+](/docs/auth/ios/yahoo-oauth) \\| [Android](/docs/auth/android/yahoo-oauth) \\| [Web](/docs/auth/web/yahoo-oauth) \\| [Unity](/docs/auth/unity/yahoo-oauth) \\| [C++](/docs/auth/cpp/yahoo-oauth) |\n\nI want to build rich pre-sign-in experiences\n\nYou can enable users to use the signed-in features of your app before they\nactually sign in using **Anonymous Auth**. With anonymous \"sign-in\", you create\ntemporary single-session accounts, which you can use like a real account. Then,\nafter the user signs in or signs up, link the temporary account to the real\naccount to let them continue where they left off.\n\nAnonymous Auth works well alongside either Custom Auth or any of Firebase's\nauthentication services.\n\nSee the docs for\n[iOS+](/docs/auth/ios/anonymous-auth),\n[Android](/docs/auth/android/anonymous-auth),\n[Web](/docs/auth/web/anonymous-auth),\n[Flutter](/docs/auth/flutter/anonymous-auth),\n[Unity](/docs/auth/unity/anonymous-auth), or\n[C++](/docs/auth/cpp/anonymous-auth).\n\nI want to access Firebase services from my backend\n\nTo access Firebase services from a server, you don't need to use\nFirebase Authentication. Instead, use the [Admin SDK](/docs/admin/setup). When you\ninitialize the Admin SDK, you authenticate with service account credentials,\nwhich represent your Firebase project rather than a particular user, and which\ngrant full access to your project's resources."]]
