NIOApns

A non-blocking Swift module for sending remote Apple Push Notificaiton requests to APNS built on http/2, SwiftNIO for use on server side swift platforms.

• Pitch discussion: Swift Server Forums
• Proposal: SSWG-0005

Installation

To install NIOApns, just add the package as a dependency in your Package.swift

dependencies: [
    .package(url: "https://github.com/kylebrowning/swift-nio-http2-apns.git", .upToNextMinor(from: "0.1.0")
]

Getting Started

let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
let apnsConfig = try APNSConfiguration(keyIdentifier: "9UC9ZLQ8YW",
                                   teamIdentifier: "ABBM6U9RM5",
                                   signingMode: .file(path: "/Users/kylebrowning/Downloads/AuthKey_9UC9ZLQ8YW.p8"),
                                   topic: "com.grasscove.Fern",
                                   environment: .sandbox)

let apns = try APNSConnection.connect(configuration: apnsConfig, on: group.next()).wait()
let alert = Alert(title: "Hey There", subtitle: "Full moon sighting", body: "There was a full moon last night did you see it")
let aps = APSPayload(alert: alert, badge: 1, sound: "cow.wav")
let notification = APNSNotification(aps: aps)
let res = try apns.send(notification, to: "de1d666223de85db0186f654852cc960551125ee841ca044fdf5ef6a4756a77e").wait()
try apns.close().wait()
try group.syncShutdownGracefully()

APNSConfiguration

APNSConfiguration is a structure that provides the system with common configuration.

public struct APNSConfiguration {
    public let keyIdentifier: String
    public let teamIdentifier: String
    public let signingMode: SigningMode
    public let topic: String
    public let environment: APNSEnvironment
    public let tlsConfiguration: TLSConfiguration

    public var url: URL {
        switch environment {
        case .production:
            return URL(string: "https://api.push.apple.com")!
        case .sandbox:
            return URL(string: "https://api.development.push.apple.com")!
        }
    }

Example APNSConfiguration

let apnsConfig = try APNSConfiguration(keyIdentifier: "9UC9ZLQ8YW",
                                   teamIdentifier: "ABBM6U9RM5",
                                   signingMode: .file(path: "/Users/kylebrowning/Downloads/AuthKey_9UC9ZLQ8YW.p8"),
                                   topic: "com.grasscove.Fern",
                                   environment: .sandbox)

SigningMode

SigningMode provides a method by which engineers can choose how their certificates are signed. Since security is important keeping we extracted this logic into three options. file, data, or custom.

public struct SigningMode {
    public let signer: APNSSigner
    init(signer: APNSSigner) {
        self.signer = signer
    }
}

extension SigningMode {
    public static func file(path: String) throws -> SigningMode {
        return .init(signer: try FileSigner(url: URL(fileURLWithPath: path)))
    }
    public static func data(data: Data) throws -> SigningMode {
        return .init(signer: try DataSigner(data: data))
    }
    public static func custom(signer: APNSSigner) -> SigningMode {
        return .init(signer: signer)
    }
}

Example Custom SigningMode that uses AWS for private keystorage

public class CustomSigner: APNSSigner {
   public func sign(digest: Data) throws -> Data {
     return try AWSKeyStore.sign(digest: digest)
   }
   public func verify(digest: Data, signature: Data) -> Bool {
      // verification
   }
}
let customSigner = CustomSigner()
let apnsConfig = APNSConfig(keyId: "9UC9ZLQ8YW",
                      teamId: "ABBM6U9RM5",
                      signingMode: .custom(signer: customSigner),
                      topic: "com.grasscove.Fern",
                      env: .sandbox)

APNSConnection

APNSConnection is a class with methods thats provides a wrapper to NIO's ClientBootstrap. The swift-nio-http2 dependency is utilized here. It also provides a function to send a notification to a specific device token string.

Example APNSConnection

let apnsConfig = ...
let apns = try APNSConnection.connect(configuration: apnsConfig, on: group.next()).wait()

Alert

Alert is the actual meta data of the push notification alert someone wishes to send. More details on the specifcs of each property are provided here. THey follow a 1-1 naming scheme listed in Apple's documentation

Example Alert

let alert = Alert(title: "Hey There", subtitle: "Full moon sighting", body: "There was a full moon last night did you see it")

APSPayload

APSPayload is the meta data of the push notification. Things like the alert, badge count. More details on the specifcs of each property are provided here. THey follow a 1-1 naming scheme listed in Apple's documentation

Example APSPayload

let alert = ...
let aps = APSPayload(alert: alert, badge: 1, sound: "cow.wav")

Custom Notification Data

Apple provides engineers with the ability to add custom payload data to each notification. In order to faciliate this we have the APNSNotificationProtocol.

Example

struct AcmeNotification: APNSNotificationProtocol {
    let acme2: [String]
    let aps: APSPayload
    
    init(acme2: [String], aps: APSPayload) {
        self.acme2 = acme2
        self.aps = aps
    }
}

let apns: APNSConnection: = ...
let aps: APSPayload = ...
let notification = AcmeNotification(acme2: ["bang", "whiz"], aps: aps)
let res = try apns.send(notification, to: "de1d666223de85db0186f654852cc960551125ee841ca044fdf5ef6a4756a77e").wait()