69 lines
2.1 KiB
Swift
69 lines
2.1 KiB
Swift
//
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// Copyright (c) 2021 Open Whisper Systems. All rights reserved.
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//
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import Foundation
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import SignalCoreKit
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@objc
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public class ContentProxy: NSObject {
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@available(*, unavailable, message: "do not instantiate this class.")
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private override init() {
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}
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@objc
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public class func sessionConfiguration() -> URLSessionConfiguration {
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let configuration = URLSessionConfiguration.ephemeral
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let proxyHost = "contentproxy.signal.org"
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let proxyPort = 443
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configuration.connectionProxyDictionary = [
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"HTTPEnable": 1,
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"HTTPProxy": proxyHost,
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"HTTPPort": proxyPort,
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"HTTPSEnable": 1,
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"HTTPSProxy": proxyHost,
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"HTTPSPort": proxyPort
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]
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return configuration
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}
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static let userAgent = "Signal iOS (+https://signal.org/download)"
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public class func configureProxiedRequest(request: inout URLRequest) -> Bool {
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request.addValue(userAgent, forHTTPHeaderField: "User-Agent")
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padRequestSize(request: &request)
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guard let url = request.url,
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let scheme = url.scheme,
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scheme.lowercased() == "https" else {
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return false
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}
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return true
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}
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public class func padRequestSize(request: inout URLRequest) {
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// Generate 1-64 chars of padding.
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let paddingLength: Int = 1 + Int(arc4random_uniform(64))
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let padding = self.padding(withLength: paddingLength)
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assert(padding.count == paddingLength)
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request.addValue(padding, forHTTPHeaderField: "X-SignalPadding")
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}
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private class func padding(withLength length: Int) -> String {
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// Pick a random ASCII char in the range 48-122
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var result = ""
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// Min and max values, inclusive.
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let minValue: UInt32 = 48
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let maxValue: UInt32 = 122
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for _ in 1...length {
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let value = minValue + arc4random_uniform(maxValue - minValue + 1)
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assert(value >= minValue)
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assert(value <= maxValue)
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result += String(UnicodeScalar(UInt8(value)))
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}
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return result
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}
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}
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