Menambahkan autentikasi multi-faktor ke aplikasi Android

Jika telah mengupgrade ke Firebase Authentication dengan Identity Platform, Anda dapat menambahkan autentikasi multi-faktor SMS ke aplikasi Android.

Autentikasi multi-faktor meningkatkan keamanan aplikasi Anda. Meskipun penyerang sering membobol sandi dan akun media sosial, menyadap pesan teks lebih sulit dilakukan.

Sebelum memulai

  1. Aktifkan minimal satu penyedia yang mendukung autentikasi multi-faktor. Setiap penyedia mendukung MFA, kecuali autentikasi dengan ponsel, autentikasi anonim, dan Apple Game Center.

  2. Pastikan aplikasi Anda memverifikasi email pengguna. MFA memerlukan verifikasi email. Tindakan ini mencegah pelaku kejahatan mendaftar ke layanan dengan email yang bukan miliknya, lalu mengunci pemilik sebenarnya dari akunnya dengan menambahkan faktor kedua.

  3. Daftarkan hash SHA-1 aplikasi Anda di Firebase Console (perubahan Anda akan otomatis diterapkan ke Google Cloud Firebase).

    1. Ikuti langkah-langkah di bagian Mengautentikasi klien untuk mendapatkan hash SHA-1 aplikasi Anda.

    2. Buka Firebase Console.

    3. Buka Project Settings.

    4. Di bagian Your apps, klik ikon Android.

    5. Ikuti panduan untuk menambahkan hash SHA-1 Anda.

Mengaktifkan autentikasi multi-faktor

  1. Buka halaman Authentication > Sign-in method di Firebase console.

  2. Di bagian Advanced, aktifkan SMS Multi-factor Authentication.

    Anda juga harus memasukkan nomor telepon yang akan digunakan untuk menguji aplikasi. Meskipun opsional, mendaftarkan nomor telepon pengujian sangat direkomendasikan untuk menghindari throttling selama tahap pengembangan.

  3. Jika Anda belum memberikan otorisasi pada domain aplikasi, tambahkan domain tersebut ke daftar yang diizinkan di halaman Authentication > Settings di Firebase console.

Memilih pola pendaftaran

Anda dapat memilih apakah aplikasi memerlukan autentikasi multi-faktor atau tidak, serta cara dan waktu untuk mendaftarkan pengguna. Beberapa pola yang umum antara lain:

  • Mendaftarkan faktor kedua pengguna sebagai bagian dari pendaftaran. Gunakan metode ini jika aplikasi Anda memerlukan autentikasi multi-faktor untuk semua pengguna.

  • Menawarkan opsi yang dapat dilewati untuk mendaftarkan faktor kedua selama pendaftaran. Aplikasi yang ingin mendukung, tetapi tidak memerlukan, autentikasi multi-faktor dapat memilih pendekatan ini.

  • Memungkinkan untuk menambahkan faktor kedua dari halaman pengelolaan akun atau profil pengguna, bukan dari layar pendaftaran. Hal ini akan meminimalkan hambatan selama proses pendaftaran, sekaligus tetap menyediakan autentikasi multi-faktor untuk pengguna yang rentan terhadap ancaman keamanan.

  • Memerlukan penambahan faktor kedua secara inkremental saat pengguna ingin mengakses fitur dengan persyaratan keamanan yang ditingkatkan.

Mendaftarkan faktor kedua

Untuk mendaftarkan faktor sekunder baru untuk pengguna:

  1. Autentikasi ulang pengguna.

  2. Minta pengguna untuk memasukkan nomor teleponnya.

  3. Dapatkan sesi multi-faktor untuk pengguna:

    Kotlin+KTX 

    user.multiFactor.session.addOnCompleteListener { task ->
    if (task.isSuccessful) {
        val multiFactorSession: MultiFactorSession? = task.result
    }
}

    Java 

    user.getMultiFactor().getSession()
  .addOnCompleteListener(
      new OnCompleteListener<MultiFactorSession>() {
      @Override
      public void onComplete(@NonNull Task<MultiFactorSession> task) {
        if (task.isSuccessful()) {
          MultiFactorSession multiFactorSession = task.getResult();
        }
      }
      });

  4. Buat objek OnVerificationStateChangedCallbacks untuk menangani berbagai peristiwa pada proses verifikasi:

    Kotlin+KTX 

    val callbacks = object : OnVerificationStateChangedCallbacks() {
    override fun onVerificationCompleted(credential: PhoneAuthCredential) {
        // This callback will be invoked in two situations:
        // 1) Instant verification. In some cases, the phone number can be
        //    instantly verified without needing to send or enter a verification
        //    code. You can disable this feature by calling
        //    PhoneAuthOptions.builder#requireSmsValidation(true) when building
        //    the options to pass to PhoneAuthProvider#verifyPhoneNumber().
        // 2) Auto-retrieval. On some devices, Google Play services can
        //    automatically detect the incoming verification SMS and perform
        //    verification without user action.
        this@MainActivity.credential = credential
    }

    override fun onVerificationFailed(e: FirebaseException) {
        // This callback is invoked in response to invalid requests for
        // verification, like an incorrect phone number.
        if (e is FirebaseAuthInvalidCredentialsException) {
            // Invalid request
            // ...
        } else if (e is FirebaseTooManyRequestsException) {
            // The SMS quota for the project has been exceeded
            // ...
        }
        // Show a message and update the UI
        // ...
    }

    override fun onCodeSent(
        verificationId: String, forceResendingToken: ForceResendingToken
    ) {
        // The SMS verification code has been sent to the provided phone number.
        // We now need to ask the user to enter the code and then construct a
        // credential by combining the code with a verification ID.
        // Save the verification ID and resending token for later use.
        this@MainActivity.verificationId = verificationId
        this@MainActivity.forceResendingToken = forceResendingToken
        // ...
    }
}

    Java 

    OnVerificationStateChangedCallbacks callbacks =
new OnVerificationStateChangedCallbacks() {
  @Override
  public void onVerificationCompleted(PhoneAuthCredential credential) {
    // This callback will be invoked in two situations:
    // 1) Instant verification. In some cases, the phone number can be
    //    instantly verified without needing to send or enter a verification
    //    code. You can disable this feature by calling
    //    PhoneAuthOptions.builder#requireSmsValidation(true) when building
    //    the options to pass to PhoneAuthProvider#verifyPhoneNumber().
    // 2) Auto-retrieval. On some devices, Google Play services can
    //    automatically detect the incoming verification SMS and perform
    //    verification without user action.
    this.credential = credential;
  }
  @Override
  public void onVerificationFailed(FirebaseException e) {
    // This callback is invoked in response to invalid requests for
    // verification, like an incorrect phone number.
    if (e instanceof FirebaseAuthInvalidCredentialsException) {
    // Invalid request
    // ...
    } else if (e instanceof FirebaseTooManyRequestsException) {
    // The SMS quota for the project has been exceeded
    // ...
    }
    // Show a message and update the UI
    // ...
  }
  @Override
  public void onCodeSent(
    String verificationId, PhoneAuthProvider.ForceResendingToken token) {
    // The SMS verification code has been sent to the provided phone number.
    // We now need to ask the user to enter the code and then construct a
    // credential by combining the code with a verification ID.
    // Save the verification ID and resending token for later use.
    this.verificationId = verificationId;
    this.forceResendingToken = token;
    // ...
  }
};

  5. Lakukan inisialisasi objek PhoneInfoOptions dengan nomor telepon pengguna, sesi multi-faktor, dan callback Anda:

    Kotlin+KTX 

    val phoneAuthOptions = PhoneAuthOptions.newBuilder()
    .setPhoneNumber(phoneNumber)
    .setTimeout(30L, TimeUnit.SECONDS)
    .setMultiFactorSession(MultiFactorSession)
    .setCallbacks(callbacks)
    .build()

    Java 

    PhoneAuthOptions phoneAuthOptions =
  PhoneAuthOptions.newBuilder()
      .setPhoneNumber(phoneNumber)
      .setTimeout(30L, TimeUnit.SECONDS)
      .setMultiFactorSession(multiFactorSession)
      .setCallbacks(callbacks)
      .build();

    Secara default, verifikasi instan diaktifkan. Untuk menonaktifkannya, tambahkan panggilan ke requireSmsValidation(true).

  6. Kirim pesan verifikasi ke ponsel pengguna:

    Kotlin+KTX 

    PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions)

    Java 

    PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions);

    Meskipun tidak diwajibkan, sebaiknya beri tahu pengguna terlebih dahulu bahwa mereka akan menerima pesan SMS, dan dikenakan tarif standar.

  7. Setelah kode SMS dikirim, minta pengguna untuk memverifikasi kode tersebut:

    Kotlin+KTX 

    // Ask user for the verification code.
val credential = PhoneAuthProvider.getCredential(verificationId, verificationCode)

    Java 

    // Ask user for the verification code.
PhoneAuthCredential credential
  = PhoneAuthProvider.getCredential(verificationId, verificationCode);

  8. Lakukan inisialisasi objek MultiFactorAssertion dengan PhoneAuthCredential:

    Kotlin+KTX 

    val multiFactorAssertion
  = PhoneMultiFactorGenerator.getAssertion(credential)

    Java 

    MultiFactorAssertion multiFactorAssertion
  = PhoneMultiFactorGenerator.getAssertion(credential);

  9. Selesaikan pendaftaran. Secara opsional, Anda dapat menentukan nama tampilan untuk faktor kedua. Hal ini berguna bagi pengguna dengan beberapa faktor kedua, karena nomor telepon disamarkan selama alur autentikasi (misalnya, +1******1234).

    Kotlin+KTX 

    // Complete enrollment. This will update the underlying tokens
// and trigger ID token change listener.
FirebaseAuth.getInstance()
    .currentUser
    ?.multiFactor
    ?.enroll(multiFactorAssertion, "My personal phone number")
    ?.addOnCompleteListener {
        // ...
    }

    Java 

    // Complete enrollment. This will update the underlying tokens
// and trigger ID token change listener.
FirebaseAuth.getInstance()
  .getCurrentUser()
  .getMultiFactor()
  .enroll(multiFactorAssertion, "My personal phone number")
  .addOnCompleteListener(
      new OnCompleteListener<Void>() {
      @Override
      public void onComplete(@NonNull Task<Void> task) {
        // ...
      }
      });

Kode di bawah menunjukkan contoh lengkap proses pendaftaran faktor kedua:

Kotlin+KTX 

val multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential)
user.multiFactor.session
    .addOnCompleteListener { task ->
        if (task.isSuccessful) {
            val multiFactorSession = task.result
            val phoneAuthOptions = PhoneAuthOptions.newBuilder()
                .setPhoneNumber(phoneNumber)
                .setTimeout(30L, TimeUnit.SECONDS)
                .setMultiFactorSession(multiFactorSession)
                .setCallbacks(callbacks)
                .build()
            // Send SMS verification code.
            PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions)
        }
    }

// Ask user for the verification code.
val credential = PhoneAuthProvider.getCredential(verificationId, verificationCode)

val multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential)

// Complete enrollment.
FirebaseAuth.getInstance()
    .currentUser
    ?.multiFactor
    ?.enroll(multiFactorAssertion, "My personal phone number")
    ?.addOnCompleteListener {
        // ...
    }

Java 

MultiFactorAssertion multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential);
user.getMultiFactor().getSession()
  .addOnCompleteListener(
      new OnCompleteListener<MultiFactorSession>() {
      @Override
      public void onComplete(@NonNull Task<MultiFactorSession> task) {
        if (task.isSuccessful()) {
          MultiFactorSession multiFactorSession = task.getResult();
          PhoneAuthOptions phoneAuthOptions =
            PhoneAuthOptions.newBuilder()
                .setPhoneNumber(phoneNumber)
                .setTimeout(30L, TimeUnit.SECONDS)
                .setMultiFactorSession(multiFactorSession)
                .setCallbacks(callbacks)
                .build();
          // Send SMS verification code.
          PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions);
        }
      }
      });

// Ask user for the verification code.
PhoneAuthCredential credential =
  PhoneAuthProvider.getCredential(verificationId, verificationCode);

MultiFactorAssertion multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential);
// Complete enrollment.
FirebaseAuth.getInstance()
  .getCurrentUser()
  .getMultiFactor()
  .enroll(multiFactorAssertion, "My personal phone number")
  .addOnCompleteListener(
      new OnCompleteListener<Void>() {
      @Override
      public void onComplete(@NonNull Task<Void> task) {
        // ...
      }
      });

Selamat! Anda berhasil mendaftarkan faktor autentikasi kedua untuk pengguna.

Memproses login pengguna dengan faktor kedua

Untuk memproses login pengguna dengan verifikasi SMS dua faktor:

  1. Proses login pengguna dengan faktor pertamanya, lalu tangkap pengecualian FirebaseAuthMultiFactorException. Error ini berisi resolver, yang dapat Anda gunakan untuk mendapatkan faktor kedua yang didaftarkan pengguna. Error ini juga berisi sesi yang mendasarinya yang membuktikan bahwa pengguna berhasil diautentikasi dengan faktor pertamanya.

    Misalnya, jika faktor pertama pengguna adalah email dan sandi:

    Kotlin+KTX 

    FirebaseAuth.getInstance()
    .signInWithEmailAndPassword(email, password)
    .addOnCompleteListener(
        OnCompleteListener { task ->
            if (task.isSuccessful) {
                // User is not enrolled with a second factor and is successfully
                // signed in.
                // ...
                return@OnCompleteListener
            }
            if (task.exception is FirebaseAuthMultiFactorException) {
                // The user is a multi-factor user. Second factor challenge is
                // required.
                val multiFactorResolver =
                    (task.exception as FirebaseAuthMultiFactorException).resolver
                // ...
            } else {
                // Handle other errors, such as wrong password.
            }
        })

    Java 

    FirebaseAuth.getInstance()
  .signInWithEmailAndPassword(email, password)
  .addOnCompleteListener(
      new OnCompleteListener<AuthResult>() {
      @Override
      public void onComplete(@NonNull Task<AuthResult> task) {
        if (task.isSuccessful()) {
          // User is not enrolled with a second factor and is successfully
          // signed in.
          // ...
          return;
        }
        if (task.getException() instanceof FirebaseAuthMultiFactorException) {
          // The user is a multi-factor user. Second factor challenge is
          // required.
          MultiFactorResolver multiFactorResolver = task.getException().getResolver();
          // ...
        } else {
          // Handle other errors such as wrong password.
        }
      }
      });

    Jika faktor pertama pengguna adalah penyedia gabungan, seperti OAuth, tangkap error setelah memanggil startActivityForSignInWithProvider().

  2. Jika pengguna mendaftarkan beberapa faktor sekunder, tanyakan kepada mereka faktor mana yang ingin digunakan:

    Kotlin+KTX 

    // Ask user which second factor to use.
// You can get the list of enrolled second factors using
//   multiFactorResolver.hints

// Check the selected factor:
if (multiFactorResolver.hints[selectedIndex].factorId
    === PhoneMultiFactorGenerator.FACTOR_ID
) {
    // User selected a phone second factor.
    val selectedHint =
        multiFactorResolver.hints[selectedIndex] as PhoneMultiFactorInfo
} else if (multiFactorResolver.hints[selectedIndex].factorId
    === TotpMultiFactorGenerator.FACTOR_ID) {
    // User selected a TOTP second factor.
} else {
    // Unsupported second factor.
}

    Java 

    // Ask user which second factor to use.
// You can get the masked phone number using
// resolver.getHints().get(selectedIndex).getPhoneNumber()
// You can get the display name using
// resolver.getHints().get(selectedIndex).getDisplayName()
if ( resolver.getHints()
               .get(selectedIndex)
               .getFactorId()
               .equals( PhoneMultiFactorGenerator.FACTOR_ID ) ) {
// User selected a phone second factor.
MultiFactorInfo selectedHint =
  multiFactorResolver.getHints().get(selectedIndex);
} else if ( resolver
              .getHints()
              .get(selectedIndex)
              .getFactorId()
              .equals(TotpMultiFactorGenerator.FACTOR_ID ) ) {
  // User selected a TOTP second factor.
} else {
// Unsupported second factor.
}

  3. Lakukan inisialisasi objek PhoneAuthOptions dengan petunjuk (hint) dan sesi multi-faktor. Nilai ini terdapat dalam resolver yang disertakan pada FirebaseAuthMultiFactorException.

    Kotlin+KTX 

    val phoneAuthOptions = PhoneAuthOptions.newBuilder()
    .setMultiFactorHint(selectedHint)
    .setTimeout(30L, TimeUnit.SECONDS)
    .setMultiFactorSession(multiFactorResolver.session)
    .setCallbacks(callbacks) // Optionally disable instant verification.
    // .requireSmsValidation(true)
    .build()

    Java 

    PhoneAuthOptions phoneAuthOptions =
  PhoneAuthOptions.newBuilder()
      .setMultiFactorHint(selectedHint)
      .setTimeout(30L, TimeUnit.SECONDS)
      .setMultiFactorSession(multiFactorResolver.getSession())
      .setCallbacks(callbacks)
      // Optionally disable instant verification.
      // .requireSmsValidation(true)
      .build();

  4. Kirim pesan verifikasi ke ponsel pengguna:

    Kotlin+KTX 

    // Send SMS verification code
PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions)

    Java 

    // Send SMS verification code
PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions);

  5. Setelah kode SMS dikirim, minta pengguna untuk memverifikasi kode tersebut:

    Kotlin+KTX 

    // Ask user for the verification code. Then, pass it to getCredential:
val credential =
    PhoneAuthProvider.getCredential(verificationId, verificationCode)

    Java 

    // Ask user for the verification code. Then, pass it to getCredential:
PhoneAuthCredential credential
    = PhoneAuthProvider.getCredential(verificationId, verificationCode);

  6. Lakukan inisialisasi objek MultiFactorAssertion dengan PhoneAuthCredential:

    Kotlin+KTX 

    val multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential)

    Java 

    MultiFactorAssertion multiFactorAssertion
    = PhoneMultiFactorGenerator.getAssertion(credential);

  7. Panggil resolver.resolveSignIn() untuk menyelesaikan autentikasi sekunder. Selanjutnya, Anda dapat mengakses hasil login asli, yang mencakup kredensial autentikasi dan data khusus penyedia standar:

    Kotlin+KTX 

    multiFactorResolver
    .resolveSignIn(multiFactorAssertion)
    .addOnCompleteListener { task ->
        if (task.isSuccessful) {
            val authResult = task.result
            // AuthResult will also contain the user, additionalUserInfo,
            // and an optional credential (null for email/password)
            // associated with the first factor sign-in.

            // For example, if the user signed in with Google as a first
            // factor, authResult.getAdditionalUserInfo() will contain data
            // related to Google provider that the user signed in with;
            // authResult.getCredential() will contain the Google OAuth
            //   credential;
            // authResult.getCredential().getAccessToken() will contain the
            //   Google OAuth access token;
            // authResult.getCredential().getIdToken() contains the Google
            //   OAuth ID token.
        }
    }

    Java 

    multiFactorResolver
  .resolveSignIn(multiFactorAssertion)
  .addOnCompleteListener(
      new OnCompleteListener<AuthResult>() {
      @Override
      public void onComplete(@NonNull Task<AuthResult> task) {
        if (task.isSuccessful()) {
          AuthResult authResult = task.getResult();
          // AuthResult will also contain the user, additionalUserInfo,
          // and an optional credential (null for email/password)
          // associated with the first factor sign-in.
          // For example, if the user signed in with Google as a first
          // factor, authResult.getAdditionalUserInfo() will contain data
          // related to Google provider that the user signed in with.
          // authResult.getCredential() will contain the Google OAuth
          // credential.
          // authResult.getCredential().getAccessToken() will contain the
          // Google OAuth access token.
          // authResult.getCredential().getIdToken() contains the Google
          // OAuth ID token.
        }
      }
      });

Kode di bawah menunjukkan contoh lengkap proses login pengguna multi-faktor:

Kotlin+KTX 

FirebaseAuth.getInstance()
    .signInWithEmailAndPassword(email, password)
    .addOnCompleteListener { task ->
        if (task.isSuccessful) {
            // User is not enrolled with a second factor and is successfully
            // signed in.
            // ...
            return@addOnCompleteListener
        }
        if (task.exception is FirebaseAuthMultiFactorException) {
            val multiFactorResolver =
                (task.exception as FirebaseAuthMultiFactorException).resolver

            // Ask user which second factor to use. Then, get
            // the selected hint:
            val selectedHint =
                multiFactorResolver.hints[selectedIndex] as PhoneMultiFactorInfo

            // Send the SMS verification code.
            PhoneAuthProvider.verifyPhoneNumber(
                PhoneAuthOptions.newBuilder()
                    .setActivity(this)
                    .setMultiFactorSession(multiFactorResolver.session)
                    .setMultiFactorHint(selectedHint)
                    .setCallbacks(generateCallbacks())
                    .setTimeout(30L, TimeUnit.SECONDS)
                    .build()
            )

            // Ask user for the SMS verification code, then use it to get
            // a PhoneAuthCredential:
            val credential =
                PhoneAuthProvider.getCredential(verificationId, verificationCode)

            // Initialize a MultiFactorAssertion object with the
            // PhoneAuthCredential.
            val multiFactorAssertion: MultiFactorAssertion =
                PhoneMultiFactorGenerator.getAssertion(credential)

            // Complete sign-in.
            multiFactorResolver
                .resolveSignIn(multiFactorAssertion)
                .addOnCompleteListener { task ->
                    if (task.isSuccessful) {
                        // User successfully signed in with the
                        // second factor phone number.
                    }
                    // ...
                }
        } else {
            // Handle other errors such as wrong password.
        }
    }

Java 

FirebaseAuth.getInstance()
  .signInWithEmailAndPassword(email, password)
  .addOnCompleteListener(
      new OnCompleteListener<AuthResult>() {
      @Override
      public void onComplete(@NonNull Task<AuthResult> task) {
        if (task.isSuccessful()) {
          // User is not enrolled with a second factor and is successfully
          // signed in.
          // ...
          return;
        }
        if (task.getException() instanceof FirebaseAuthMultiFactorException) {
          FirebaseAuthMultiFactorException e =
            (FirebaseAuthMultiFactorException) task.getException();

          MultiFactorResolver multiFactorResolver = e.getResolver();

          // Ask user which second factor to use.
          MultiFactorInfo selectedHint =
            multiFactorResolver.getHints().get(selectedIndex);

          // Send the SMS verification code.
          PhoneAuthProvider.verifyPhoneNumber(
            PhoneAuthOptions.newBuilder()
                .setActivity(this)
                .setMultiFactorSession(multiFactorResolver.getSession())
                .setMultiFactorHint(selectedHint)
                .setCallbacks(generateCallbacks())
                .setTimeout(30L, TimeUnit.SECONDS)
                .build());

          // Ask user for the SMS verification code.
          PhoneAuthCredential credential =
            PhoneAuthProvider.getCredential(verificationId, verificationCode);

          // Initialize a MultiFactorAssertion object with the
          // PhoneAuthCredential.
          MultiFactorAssertion multiFactorAssertion =
            PhoneMultiFactorGenerator.getAssertion(credential);

          // Complete sign-in.
          multiFactorResolver
            .resolveSignIn(multiFactorAssertion)
            .addOnCompleteListener(
                new OnCompleteListener<AuthResult>() {
                  @Override
                  public void onComplete(@NonNull Task<AuthResult> task) {
                  if (task.isSuccessful()) {
                    // User successfully signed in with the
                    // second factor phone number.
                  }
                  // ...
                  }
                });
        } else {
          // Handle other errors such as wrong password.
        }
      }
      });

Selamat! Anda berhasil memproses login pengguna menggunakan autentikasi multi-faktor.

Langkah berikutnya