session-ios/SessionMessagingKit/Utilities/MessageWrapper.swift
2020-11-09 10:58:47 +11:00

74 lines
3.4 KiB
Swift

import SessionSnodeKit
import SessionUtilitiesKit
public enum MessageWrapper {
public enum Error : LocalizedError {
case failedToWrapData
case failedToWrapMessageInEnvelope
case failedToWrapEnvelopeInWebSocketMessage
case failedToUnwrapData
public var errorDescription: String? {
switch self {
case .failedToWrapData: return "Failed to wrap data."
case .failedToWrapMessageInEnvelope: return "Failed to wrap message in envelope."
case .failedToWrapEnvelopeInWebSocketMessage: return "Failed to wrap envelope in web socket message."
case .failedToUnwrapData: return "Failed to unwrap data."
}
}
}
/// Wraps the given parameters in an `SNProtoEnvelope` and then a `WebSocketProtoWebSocketMessage` to match the desktop application.
public static func wrap(type: SNProtoEnvelope.SNProtoEnvelopeType, timestamp: UInt64, senderPublicKey: String, base64EncodedContent: String) throws -> Data {
do {
let envelope = try createEnvelope(type: type, timestamp: timestamp, senderPublicKey: senderPublicKey, base64EncodedContent: base64EncodedContent)
let webSocketMessage = try createWebSocketMessage(around: envelope)
return try webSocketMessage.serializedData()
} catch let error {
throw error as? Error ?? Error.failedToWrapData
}
}
private static func createEnvelope(type: SNProtoEnvelope.SNProtoEnvelopeType, timestamp: UInt64, senderPublicKey: String, base64EncodedContent: String) throws -> SNProtoEnvelope {
do {
let builder = SNProtoEnvelope.builder(type: type, timestamp: timestamp)
builder.setSource(senderPublicKey)
builder.setSourceDevice(1)
if let content = Data(base64Encoded: base64EncodedContent, options: .ignoreUnknownCharacters) {
builder.setContent(content)
} else {
throw Error.failedToWrapMessageInEnvelope
}
return try builder.build()
} catch let error {
SNLog("Failed to wrap message in envelope: \(error).")
throw Error.failedToWrapMessageInEnvelope
}
}
private static func createWebSocketMessage(around envelope: SNProtoEnvelope) throws -> WebSocketProtoWebSocketMessage {
do {
let requestBuilder = WebSocketProtoWebSocketRequestMessage.builder(verb: "PUT", path: "/api/v1/message", requestID: UInt64.random(in: 1..<UInt64.max))
requestBuilder.setBody(try envelope.serializedData())
let messageBuilder = WebSocketProtoWebSocketMessage.builder(type: .request)
messageBuilder.setRequest(try requestBuilder.build())
return try messageBuilder.build()
} catch let error {
SNLog("Failed to wrap envelope in web socket message: \(error).")
throw Error.failedToWrapEnvelopeInWebSocketMessage
}
}
/// - Note: `data` shouldn't be base 64 encoded.
public static func unwrap(data: Data) throws -> SNProtoEnvelope {
do {
let webSocketMessage = try WebSocketProtoWebSocketMessage.parseData(data)
let envelope = webSocketMessage.request!.body!
return try SNProtoEnvelope.parseData(envelope)
} catch let error {
SNLog("Failed to unwrap data: \(error).")
throw Error.failedToUnwrapData
}
}
}