add reCAPTCHA enterprise support on phone auth and phone MFA (#14114)

Co-authored-by: Srushti Vaidya <[email protected]>
Co-authored-by: Nick Cooke <[email protected]>

FirebaseAuth/Sources/Swift/Auth/Auth.swift

@@ -2307,7 +2307,7 @@ extension Auth: AuthInterop {
                                             action: AuthRecaptchaAction) async throws -> T
       .Response {
       let recaptchaVerifier = AuthRecaptchaVerifier.shared(auth: self)
-      if recaptchaVerifier.enablementStatus(forProvider: AuthRecaptchaProvider.password) {
+      if recaptchaVerifier.enablementStatus(forProvider: AuthRecaptchaProvider.password) != .off {
         try await recaptchaVerifier.injectRecaptchaFields(request: request,
                                                           provider: AuthRecaptchaProvider.password,
                                                           action: action)

FirebaseAuth/Sources/Swift/Backend/AuthBackend.swift

@@ -177,6 +177,7 @@ final class AuthBackend: AuthBackendProtocol {
         withJSONObject: postBody,
         options: JSONWritingOptions
       )
+
       if bodyData == nil {
         // This is an untested case. This happens exclusively when there is an error in the
         // framework implementation of dataWithJSONObject:options:error:. This shouldn't normally

FirebaseAuth/Sources/Swift/Backend/RPC/MultiFactor/Enroll/StartMFAEnrollmentRequest.swift

@@ -16,6 +16,18 @@ import Foundation
 
 private let kStartMFAEnrollmentEndPoint = "accounts/mfaEnrollment:start"
 
+/// The key for the "clientType" value in the request.
+private let kClientType = "clientType"
+
+/// The key for the reCAPTCHAToken parameter in the request.
+private let kreCAPTCHATokenKey = "recaptchaToken"
+
+/// The key for the "captchaResponse" value in the request.
+private let kCaptchaResponseKey = "captchaResponse"
+
+/// The key for the "recaptchaVersion" value in the request.
+private let kRecaptchaVersion = "recaptchaVersion"
+
 /// The key for the tenant id value in the request.
 private let kTenantIDKey = "tenantId"
 
@@ -79,4 +91,15 @@ class StartMFAEnrollmentRequest: IdentityToolkitRequest, AuthRPCRequest {
     }
     return body
   }
+
+  func injectRecaptchaFields(recaptchaResponse: String?, recaptchaVersion: String) {
+    // reCAPTCHA check is only available for phone based MFA
+    if let phoneEnrollmentInfo {
+      phoneEnrollmentInfo.injectRecaptchaFields(
+        recaptchaResponse: recaptchaResponse,
+        recaptchaVersion: recaptchaVersion,
+        clientType: clientType
+      )
+    }
+  }
 }

FirebaseAuth/Sources/Swift/Backend/RPC/MultiFactor/SignIn/StartMFASignInRequest.swift

@@ -57,4 +57,15 @@ class StartMFASignInRequest: IdentityToolkitRequest, AuthRPCRequest {
     }
     return body
   }
+
+  func injectRecaptchaFields(recaptchaResponse: String?, recaptchaVersion: String) {
+    // reCAPTCHA check is only available for phone based MFA
+    if let signInInfo {
+      signInInfo.injectRecaptchaFields(
+        recaptchaResponse: recaptchaResponse,
+        recaptchaVersion: recaptchaVersion,
+        clientType: clientType
+      )
+    }
+  }
 }

FirebaseAuth/Sources/Swift/Backend/RPC/Proto/Phone/AuthProtoStartMFAPhoneRequestInfo.swift

@@ -26,13 +26,25 @@ private let kSecretKey = "iosSecret"
 /// The key for the reCAPTCHAToken parameter in the request.
 private let kreCAPTCHATokenKey = "recaptchaToken"
 
+/// The key for the "captchaResponse" value in the request.
+private let kCaptchaResponseKey = "captchaResponse"
+
+/// The key for the "recaptchaVersion" value in the request.
+private let kRecaptchaVersion = "recaptchaVersion"
+
+/// The key for the "clientType" value in the request.
+private let kClientType = "clientType"
+
 class AuthProtoStartMFAPhoneRequestInfo: NSObject, AuthProto {
   required init(dictionary: [String: AnyHashable]) {
     fatalError()
   }
 
   var phoneNumber: String?
   var codeIdentity: CodeIdentity
+  var captchaResponse: String?
+  var recaptchaVersion: String?
+  var clientType: String?
   init(phoneNumber: String?, codeIdentity: CodeIdentity) {
     self.phoneNumber = phoneNumber
     self.codeIdentity = codeIdentity
@@ -43,6 +55,15 @@ class AuthProtoStartMFAPhoneRequestInfo: NSObject, AuthProto {
     if let phoneNumber = phoneNumber {
       dict[kPhoneNumberKey] = phoneNumber
     }
+    if let captchaResponse = captchaResponse {
+      dict[kCaptchaResponseKey] = captchaResponse
+    }
+    if let recaptchaVersion = recaptchaVersion {
+      dict[kRecaptchaVersion] = recaptchaVersion
+    }
+    if let clientType = clientType {
+      dict[kClientType] = clientType
+    }
     switch codeIdentity {
     case let .credential(appCredential):
       dict[kReceiptKey] = appCredential.receipt
@@ -54,4 +75,11 @@ class AuthProtoStartMFAPhoneRequestInfo: NSObject, AuthProto {
     }
     return dict
   }
+
+  func injectRecaptchaFields(recaptchaResponse: String?, recaptchaVersion: String,
+                             clientType: String?) {
+    captchaResponse = recaptchaResponse
+    self.recaptchaVersion = recaptchaVersion
+    self.clientType = clientType
+  }
 }

FirebaseAuth/Sources/Swift/Backend/RPC/SendVerificationTokenRequest.swift

@@ -29,11 +29,20 @@ private let kSecretKey = "iosSecret"
 /// The key for the reCAPTCHAToken parameter in the request.
 private let kreCAPTCHATokenKey = "recaptchaToken"
 
+/// The key for the "clientType" value in the request.
+private let kClientType = "clientType"
+
+/// The key for the "captchaResponse" value in the request.
+private let kCaptchaResponseKey = "captchaResponse"
+
+/// The key for the "recaptchaVersion" value in the request.
+private let kRecaptchaVersion = "recaptchaVersion"
+
 /// The key for the tenant id value in the request.
 private let kTenantIDKey = "tenantId"
 
 ///  A verification code can be an appCredential or a reCaptcha Token
-enum CodeIdentity {
+enum CodeIdentity: Equatable {
   case credential(AuthAppCredential)
   case recaptcha(String)
   case empty
@@ -50,6 +59,12 @@ class SendVerificationCodeRequest: IdentityToolkitRequest, AuthRPCRequest {
   /// verification code.
   let codeIdentity: CodeIdentity
 
+  /// Response to the captcha.
+  var captchaResponse: String?
+
+  /// The reCAPTCHA version.
+  var recaptchaVersion: String?
+
   init(phoneNumber: String, codeIdentity: CodeIdentity,
        requestConfiguration: AuthRequestConfiguration) {
     self.phoneNumber = phoneNumber
@@ -71,10 +86,21 @@ class SendVerificationCodeRequest: IdentityToolkitRequest, AuthRPCRequest {
       postBody[kreCAPTCHATokenKey] = reCAPTCHAToken
     case .empty: break
     }
-
+    if let captchaResponse {
+      postBody[kCaptchaResponseKey] = captchaResponse
+    }
+    if let recaptchaVersion {
+      postBody[kRecaptchaVersion] = recaptchaVersion
+    }
     if let tenantID {
       postBody[kTenantIDKey] = tenantID
     }
+    postBody[kClientType] = clientType
     return postBody
   }
+
+  func injectRecaptchaFields(recaptchaResponse: String?, recaptchaVersion: String) {
+    captchaResponse = recaptchaResponse
+    self.recaptchaVersion = recaptchaVersion
+  }
 }

FirebaseAuth/Sources/Swift/Utilities/AuthErrorUtils.swift

@@ -203,6 +203,10 @@ class AuthErrorUtils {
     error(code: .missingAndroidPackageName, message: message)
   }
 
+  static func invalidRecaptchaTokenError() -> Error {
+    error(code: .invalidRecaptchaToken)
+  }
+
   static func unauthorizedDomainError(message: String?) -> Error {
     error(code: .unauthorizedDomain, message: message)
   }

FirebaseAuth/Sources/Swift/Utilities/AuthRecaptchaVerifier.swift

@@ -23,24 +23,47 @@
 
   @available(iOS 13, tvOS 13, macOS 10.15, macCatalyst 13, watchOS 7, *)
   class AuthRecaptchaConfig {
-    let siteKey: String
-    let enablementStatus: [String: Bool]
+    var siteKey: String?
+    let enablementStatus: [AuthRecaptchaProvider: AuthRecaptchaEnablementStatus]
 
-    init(siteKey: String, enablementStatus: [String: Bool]) {
+    init(siteKey: String? = nil,
+         enablementStatus: [AuthRecaptchaProvider: AuthRecaptchaEnablementStatus]) {
       self.siteKey = siteKey
       self.enablementStatus = enablementStatus
     }
   }
 
-  enum AuthRecaptchaProvider {
-    case password
+  @available(iOS 13, tvOS 13, macOS 10.15, macCatalyst 13, watchOS 7, *)
+  enum AuthRecaptchaEnablementStatus: String, CaseIterable {
+    case enforce = "ENFORCE"
+    case audit = "AUDIT"
+    case off = "OFF"
+
+    // Convenience property for mapping values
+    var stringValue: String { rawValue }
   }
 
-  enum AuthRecaptchaAction {
+  @available(iOS 13, tvOS 13, macOS 10.15, macCatalyst 13, watchOS 7, *)
+  enum AuthRecaptchaProvider: String, CaseIterable {
+    case password = "EMAIL_PASSWORD_PROVIDER"
+    case phone = "PHONE_PROVIDER"
+
+    // Convenience property for mapping values
+    var stringValue: String { rawValue }
+  }
+
+  @available(iOS 13, tvOS 13, macOS 10.15, macCatalyst 13, watchOS 7, *)
+  enum AuthRecaptchaAction: String {
     case defaultAction
     case signInWithPassword
     case getOobCode
     case signUpPassword
+    case sendVerificationCode
+    case mfaSmsSignIn
+    case mfaSmsEnrollment
+
+    // Convenience property for mapping values
+    var stringValue: String { rawValue }
   }
 
   @available(iOS 13, tvOS 13, macOS 10.15, macCatalyst 13, watchOS 7, *)
@@ -49,14 +72,9 @@
     private(set) var agentConfig: AuthRecaptchaConfig?
     private(set) var tenantConfigs: [String: AuthRecaptchaConfig] = [:]
     private(set) var recaptchaClient: RCARecaptchaClientProtocol?
-
-    private static let _shared = AuthRecaptchaVerifier()
-    private let providerToStringMap = [AuthRecaptchaProvider.password: "EMAIL_PASSWORD_PROVIDER"]
-    private let actionToStringMap = [AuthRecaptchaAction.signInWithPassword: "signInWithPassword",
-                                     AuthRecaptchaAction.getOobCode: "getOobCode",
-                                     AuthRecaptchaAction.signUpPassword: "signUpPassword"]
+    private static var _shared = AuthRecaptchaVerifier()
     private let kRecaptchaVersion = "RECAPTCHA_ENTERPRISE"
-    private init() {}
+    init() {}
 
     class func shared(auth: Auth?) -> AuthRecaptchaVerifier {
       if _shared.auth != auth {
@@ -67,6 +85,12 @@
       return _shared
     }
 
+    /// This function is only for testing.
+    class func setShared(_ instance: AuthRecaptchaVerifier, auth: Auth?) {
+      _shared = instance
+      _ = shared(auth: auth)
+    }
+
     func siteKey() -> String? {
       if let tenantID = auth?.tenantID {
         if let config = tenantConfigs[tenantID] {
@@ -77,22 +101,17 @@
       return agentConfig?.siteKey
     }
 
-    func enablementStatus(forProvider provider: AuthRecaptchaProvider) -> Bool {
-      guard let providerString = providerToStringMap[provider] else {
-        return false
-      }
-      if let tenantID = auth?.tenantID {
-        guard let tenantConfig = tenantConfigs[tenantID],
-              let status = tenantConfig.enablementStatus[providerString] else {
-          return false
-        }
+    func enablementStatus(forProvider provider: AuthRecaptchaProvider)
+      -> AuthRecaptchaEnablementStatus {
+      if let tenantID = auth?.tenantID,
+         let tenantConfig = tenantConfigs[tenantID],
+         let status = tenantConfig.enablementStatus[provider] {
         return status
-      } else {
-        guard let agentConfig,
-              let status = agentConfig.enablementStatus[providerString] else {
-          return false
-        }
+      } else if let agentConfig = agentConfig,
+                let status = agentConfig.enablementStatus[provider] {
         return status
+      } else {
+        return AuthRecaptchaEnablementStatus.off
       }
     }
 
@@ -101,7 +120,7 @@
       guard let siteKey = siteKey() else {
         throw AuthErrorUtils.recaptchaSiteKeyMissing()
       }
-      let actionString = actionToStringMap[action] ?? ""
+      let actionString = action.stringValue
       #if !(COCOAPODS || SWIFT_PACKAGE)
         // No recaptcha on internal build system.
         return actionString
@@ -156,30 +175,40 @@
       let request = GetRecaptchaConfigRequest(requestConfiguration: auth.requestConfiguration)
       let response = try await auth.backend.call(with: request)
       AuthLog.logInfo(code: "I-AUT000029", message: "reCAPTCHA config retrieval succeeded.")
-      // Response's site key is of the format projects/<project-id>/keys/<site-key>'
-      guard let keys = response.recaptchaKey?.components(separatedBy: "/"),
-            keys.count == 4 else {
-        throw AuthErrorUtils.error(code: .recaptchaNotEnabled, message: "Invalid siteKey")
-      }
-      let siteKey = keys[3]
-      var enablementStatus: [String: Bool] = [:]
+      try await parseRecaptchaConfigFromResponse(response: response)
+    }
+
+    func parseRecaptchaConfigFromResponse(response: GetRecaptchaConfigResponse) async throws {
+      var enablementStatus: [AuthRecaptchaProvider: AuthRecaptchaEnablementStatus] = [:]
+      var isRecaptchaEnabled = false
       if let enforcementState = response.enforcementState {
         for state in enforcementState {
-          if let provider = state["provider"],
-             provider == providerToStringMap[AuthRecaptchaProvider.password] {
-            if let enforcement = state["enforcementState"] {
-              if enforcement == "ENFORCE" || enforcement == "AUDIT" {
-                enablementStatus[provider] = true
-              } else if enforcement == "OFF" {
-                enablementStatus[provider] = false
-              }
-            }
+          guard let providerString = state["provider"],
+                let enforcementString = state["enforcementState"],
+                let provider = AuthRecaptchaProvider(rawValue: providerString),
+                let enforcement = AuthRecaptchaEnablementStatus(rawValue: enforcementString) else {
+            continue // Skip to the next state in the loop
+          }
+          enablementStatus[provider] = enforcement
+          if enforcement != .off {
+            isRecaptchaEnabled = true
           }
         }
       }
+      var siteKey = ""
+      // Response's site key is of the format projects/<project-id>/keys/<site-key>'
+      if isRecaptchaEnabled {
+        if let recaptchaKey = response.recaptchaKey {
+          let keys = recaptchaKey.components(separatedBy: "/")
+          if keys.count != 4 {
+            throw AuthErrorUtils.error(code: .recaptchaNotEnabled, message: "Invalid siteKey")
+          }
+          siteKey = keys[3]
+        }
+      }
       let config = AuthRecaptchaConfig(siteKey: siteKey, enablementStatus: enablementStatus)
 
-      if let tenantID = auth.tenantID {
+      if let tenantID = auth?.tenantID {
         tenantConfigs[tenantID] = config
       } else {
         agentConfig = config
@@ -190,7 +219,7 @@
                                provider: AuthRecaptchaProvider,
                                action: AuthRecaptchaAction) async throws {
       try await retrieveRecaptchaConfig(forceRefresh: false)
-      if enablementStatus(forProvider: provider) {
+      if enablementStatus(forProvider: provider) != .off {
         let token = try await verify(forceRefresh: false, action: action)
         request.injectRecaptchaFields(recaptchaResponse: token, recaptchaVersion: kRecaptchaVersion)
       } else {