aws-appsync-realtime-client.../AppSyncRealTimeClient/Interceptor/APIKeyAuthInterceptor.swift

104 lines
3.6 KiB
Swift

//
// Copyright 2018-2021 Amazon.com,
// Inc. or its affiliates. All Rights Reserved.
//
// SPDX-License-Identifier: Apache-2.0
//
import Foundation
/// Auth interceptor for API Key based authentication
public class APIKeyAuthInterceptor: AuthInterceptor {
let apiKey: String
public init(_ apiKey: String) {
self.apiKey = apiKey
}
/// Intercept the connection and adds header, payload query to the request url.
///
/// The value of header should be the base64 string of the following:
/// * "host": <string> : this is the host for the AppSync endpoint
/// * "x-amz-date": <string> : UTC timestamp in the following ISO 8601 format: YYYYMMDD'T'HHMMSS'Z'
/// * "x-api-key": <string> : Api key configured for AppSync API
/// The value of payload is {}
/// - Parameter request: Signed request
public func interceptConnection(
_ request: AppSyncConnectionRequest,
for endpoint: URL
) -> AppSyncConnectionRequest {
let host = endpoint.host!
let authHeader = APIKeyAuthenticationHeader(apiKey: apiKey, host: host)
let base64Auth = AppSyncJSONHelper.base64AuthenticationBlob(authHeader)
let payloadData = SubscriptionConstants.emptyPayload.data(using: .utf8)
let payloadBase64 = payloadData?.base64EncodedString()
guard var urlComponents = URLComponents(url: request.url, resolvingAgainstBaseURL: false) else {
return request
}
let headerQuery = URLQueryItem(name: RealtimeProviderConstants.header, value: base64Auth)
let payloadQuery = URLQueryItem(name: RealtimeProviderConstants.payload, value: payloadBase64)
urlComponents.queryItems = [headerQuery, payloadQuery]
guard let url = urlComponents.url else {
return request
}
let signedRequest = AppSyncConnectionRequest(url: url)
return signedRequest
}
public func interceptMessage(_ message: AppSyncMessage, for endpoint: URL) -> AppSyncMessage {
let host = endpoint.host!
switch message.messageType {
case .subscribe:
let authHeader = APIKeyAuthenticationHeader(apiKey: apiKey, host: host)
var payload = message.payload ?? AppSyncMessage.Payload()
payload.authHeader = authHeader
let signedMessage = AppSyncMessage(
id: message.id,
payload: payload,
type: message.messageType
)
return signedMessage
default:
break
}
return message
}
}
/// Authentication header for API key based auth
private class APIKeyAuthenticationHeader: AuthenticationHeader {
static let ISO8601DateFormat: String = "yyyyMMdd'T'HHmmss'Z'"
let date: String?
let apiKey: String
var formatter: DateFormatter = {
var formatter = DateFormatter()
formatter.timeZone = TimeZone(secondsFromGMT: 0)
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = ISO8601DateFormat
return formatter
}()
init(apiKey: String, host: String) {
self.date = formatter.string(from: Date())
self.apiKey = apiKey
super.init(host: host)
}
private enum CodingKeys: String, CodingKey {
case date = "x-amz-date"
case apiKey = "x-api-key"
}
override func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(date, forKey: .date)
try container.encode(apiKey, forKey: .apiKey)
try super.encode(to: encoder)
}
}