feat: Multi factor Authentication

FirebaseSwiftUI/FirebaseAuthSwiftUI/Sources/Auth/MultiFactor.swift

@@ -0,0 +1,114 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+@preconcurrency import FirebaseAuth
+import SwiftUI
+
+public enum SecondFactorType {
+  case sms
+  case totp
+}
+
+public struct TOTPEnrollmentInfo {
+  public let sharedSecretKey: String
+  public let qrCodeURL: URL?
+  public let accountName: String?
+  public let issuer: String?
+  public let verificationStatus: VerificationStatus
+
+  public enum VerificationStatus {
+    case pending
+    case verified
+    case failed
+  }
+
+  public init(sharedSecretKey: String,
+              qrCodeURL: URL? = nil,
+              accountName: String? = nil,
+              issuer: String? = nil,
+              verificationStatus: VerificationStatus = .pending) {
+    self.sharedSecretKey = sharedSecretKey
+    self.qrCodeURL = qrCodeURL
+    self.accountName = accountName
+    self.issuer = issuer
+    self.verificationStatus = verificationStatus
+  }
+}
+
+public struct EnrollmentSession {
+  public let id: String
+  public let type: SecondFactorType
+  public let session: MultiFactorSession
+  public let totpInfo: TOTPEnrollmentInfo?
+  public let phoneNumber: String?
+  public let verificationId: String?
+  public let status: EnrollmentStatus
+  public let createdAt: Date
+  public let expiresAt: Date
+
+  // Internal handle to finish TOTP
+  internal let _totpSecret: AnyObject?
+
+  public enum EnrollmentStatus {
+    case initiated
+    case verificationSent
+    case verificationPending
+    case completed
+    case failed
+    case expired
+  }
+
+  public init(id: String = UUID().uuidString,
+              type: SecondFactorType,
+              session: MultiFactorSession,
+              totpInfo: TOTPEnrollmentInfo? = nil,
+              phoneNumber: String? = nil,
+              verificationId: String? = nil,
+              status: EnrollmentStatus = .initiated,
+              createdAt: Date = Date(),
+              expiresAt: Date = Date().addingTimeInterval(600), // 10 minutes default
+              _totpSecret: AnyObject? = nil) {
+    self.id = id
+    self.type = type
+    self.session = session
+    self.totpInfo = totpInfo
+    self.phoneNumber = phoneNumber
+    self.verificationId = verificationId
+    self.status = status
+    self.createdAt = createdAt
+    self.expiresAt = expiresAt
+    self._totpSecret = _totpSecret
+  }
+
+  public var isExpired: Bool {
+    return Date() > expiresAt
+  }
+
+  public var canProceed: Bool {
+    return !isExpired &&
+      (status == .initiated || status == .verificationSent || status == .verificationPending)
+  }
+}
+
+public enum MFAHint {
+  case phone(displayName: String?, uid: String, phoneNumber: String?)
+  case totp(displayName: String?, uid: String)
+}
+
+public struct MFARequired {
+  public let hints: [MFAHint]
+
+  public init(hints: [MFAHint]) {
+    self.hints = hints
+  }
+}

FirebaseSwiftUI/FirebaseAuthSwiftUI/Sources/AuthServiceError.swift

@@ -38,6 +38,8 @@ public enum AuthServiceError: LocalizedError {
   case accountMergeConflict(context: AccountMergeConflictContext)
   case invalidPhoneAuthenticationArguments(String)
   case providerNotFound(String)
+  case multiFactorAuth(String)
+
 
   public var errorDescription: String? {
     switch self {
@@ -61,6 +63,8 @@ public enum AuthServiceError: LocalizedError {
       return description
     case let .invalidPhoneAuthenticationArguments(description):
         return description
+    case let .multiFactorAuth(description):
+      return description
     }
   }
 }

FirebaseSwiftUI/FirebaseAuthSwiftUI/Sources/Services/AuthConfiguration.swift

@@ -25,14 +25,23 @@ public struct AuthConfiguration {
   public let emailLinkSignInActionCodeSettings: ActionCodeSettings?
   public let verifyEmailActionCodeSettings: ActionCodeSettings?
 
+    // MARK: - MFA Configuration
+
+  public let mfaEnabled: Bool
+  public let allowedSecondFactors: Set<SecondFactorType>
+  public let mfaIssuer: String
+
   public init(shouldHideCancelButton: Bool = false,
               interactiveDismissEnabled: Bool = true,
               shouldAutoUpgradeAnonymousUsers: Bool = false,
               customStringsBundle: Bundle? = nil,
               tosUrl: URL? = nil,
               privacyPolicyUrl: URL? = nil,
               emailLinkSignInActionCodeSettings: ActionCodeSettings? = nil,
-              verifyEmailActionCodeSettings: ActionCodeSettings? = nil) {
+              verifyEmailActionCodeSettings: ActionCodeSettings? = nil,
+              mfaEnabled: Bool = false,
+              allowedSecondFactors: Set<SecondFactorType> = [.sms, .totp],
+              mfaIssuer: String = "Firebase Auth") {
     self.shouldHideCancelButton = shouldHideCancelButton
     self.interactiveDismissEnabled = interactiveDismissEnabled
     self.shouldAutoUpgradeAnonymousUsers = shouldAutoUpgradeAnonymousUsers
@@ -41,5 +50,8 @@ public struct AuthConfiguration {
     self.privacyPolicyUrl = privacyPolicyUrl
     self.emailLinkSignInActionCodeSettings = emailLinkSignInActionCodeSettings
     self.verifyEmailActionCodeSettings = verifyEmailActionCodeSettings
+    self.mfaEnabled = mfaEnabled
+    self.allowedSecondFactors = allowedSecondFactors
+    self.mfaIssuer = mfaIssuer
   }
 }