// Licensed to the .NET Foundation under one or more agreements.

// The .NET Foundation licenses this file to you under the MIT license.

// See the LICENSE file in the project root for more information.

using System.Collections;

using System.Globalization;

using System.Net.NetworkInformation;

using System.Runtime.Serialization;

using System.Text.RegularExpressions;

namespace System.Net

{

public class WebProxy : IWebProxy, ISerializable

{

private ArrayList _bypassList;

private Regex[] _regExBypassList;

public WebProxy() : this((Uri)null, false, null, null) { }

public WebProxy(Uri Address) : this(Address, false, null, null) { }

public WebProxy(Uri Address, bool BypassOnLocal) : this(Address, BypassOnLocal, null, null) { }

public WebProxy(Uri Address, bool BypassOnLocal, string[] BypassList) : this(Address, BypassOnLocal, BypassList, null) { }

public WebProxy(Uri Address, bool BypassOnLocal, string[] BypassList, ICredentials Credentials)

{

this.Address = Address;

this.Credentials = Credentials;

this.BypassProxyOnLocal = BypassOnLocal;

if (BypassList != null)

{

_bypassList = new ArrayList(BypassList);

UpdateRegExList(true);

}

}

public WebProxy(string Host, int Port)

: this(new Uri("http://" + Host + ":" + Port.ToString(CultureInfo.InvariantCulture)), false, null, null)

{

}

public WebProxy(string Address)

: this(CreateProxyUri(Address), false, null, null)

{

}

public WebProxy(string Address, bool BypassOnLocal)

: this(CreateProxyUri(Address), BypassOnLocal, null, null)

{

}

public WebProxy(string Address, bool BypassOnLocal, string[] BypassList)

: this(CreateProxyUri(Address), BypassOnLocal, BypassList, null)

{

}

public WebProxy(string Address, bool BypassOnLocal, string[] BypassList, ICredentials Credentials)

: this(CreateProxyUri(Address), BypassOnLocal, BypassList, Credentials)

{

}

public Uri Address { get; set; }

public bool BypassProxyOnLocal { get; set; }

public string[] BypassList

{

get { return _bypassList != null ? (string[])_bypassList.ToArray(typeof(string)) : Array.Empty<string>(); }

set

{

_bypassList = new ArrayList(value);

UpdateRegExList(true);

}

}

public ArrayList BypassArrayList => _bypassList ?? (_bypassList = new ArrayList());

public ICredentials Credentials { get; set; }

public bool UseDefaultCredentials

{

get { return Credentials == CredentialCache.DefaultCredentials; }

set { Credentials = value ? CredentialCache.DefaultCredentials : null; }

}

public Uri GetProxy(Uri destination)

{

if (destination == null)

{

throw new ArgumentNullException(nameof(destination));

}

return IsBypassed(destination) ? destination : Address;

}

private static Uri CreateProxyUri(string address) =>

address == null ? null :

address.IndexOf("://") == -1 ? new Uri("http://" + address) :

new Uri(address);

private void UpdateRegExList(bool canThrow)

{

Regex[] regExBypassList = null;

ArrayList bypassList = _bypassList;

try

{

if (bypassList != null && bypassList.Count > 0)

{

regExBypassList = new Regex[bypassList.Count];

for (int i = 0; i < bypassList.Count; i++)

{

regExBypassList[i] = new Regex((string)bypassList[i], RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);

}

}

}

catch

{

if (!canThrow)

{

_regExBypassList = null;

return;

}

throw;

}

// Update field here, as it could throw earlier in the loop

_regExBypassList = regExBypassList;

}

private bool IsMatchInBypassList(Uri input)

{

UpdateRegExList(false);

if (_regExBypassList != null)

{

string matchUriString = input.IsDefaultPort ?

input.Scheme + "://" + input.Host :

input.Scheme + "://" + input.Host + ":" + input.Port.ToString();

foreach (Regex r in _regExBypassList)

{

if (r.IsMatch(matchUriString))

{

return true;

}

}

}

return false;

}

private bool IsLocal(Uri host)

{

string hostString = host.Host;

IPAddress hostAddress;

if (IPAddress.TryParse(hostString, out hostAddress))

{

return IPAddress.IsLoopback(hostAddress) || IsAddressLocal(hostAddress);

}

// No dot? Local.

int dot = hostString.IndexOf('.');

if (dot == -1)

{

return true;

}

// If it matches the primary domain, it's local. (Whether or not the hostname matches.)

string local = "." + IPGlobalProperties.GetIPGlobalProperties().DomainName;

return

local.Length == (hostString.Length - dot) &&

string.Compare(local, 0, hostString, dot, local.Length, StringComparison.OrdinalIgnoreCase) == 0;

}

private static bool IsAddressLocal(IPAddress ipAddress)

{

// Perf note: The .NET Framework caches this and then uses network change notifications to track

// whether the set should be recomputed. We could consider doing the same if this is observed as

// a bottleneck, but that tracking has its own costs.

IPAddress[] localAddresses = Dns.GetHostEntryAsync(Dns.GetHostName()).GetAwaiter().GetResult().AddressList; // TODO: Use synchronous GetHostEntry when available

for (int i = 0; i < localAddresses.Length; i++)

{

if (ipAddress.Equals(localAddresses[i]))

{

return true;

}

}

return false;

}

public bool IsBypassed(Uri host)

{

if (host == null)

{

throw new ArgumentNullException(nameof(host));

}

return

Address == null ||

host.IsLoopback ||

(BypassProxyOnLocal && IsLocal(host)) ||

IsMatchInBypassList(host);

}

protected WebProxy(SerializationInfo serializationInfo, StreamingContext streamingContext)

{

throw new PlatformNotSupportedException();

}

void ISerializable.GetObjectData(SerializationInfo serializationInfo, StreamingContext streamingContext)

{

throw new PlatformNotSupportedException();

}

protected virtual void GetObjectData(SerializationInfo serializationInfo, StreamingContext streamingContext)

{

throw new PlatformNotSupportedException();

}

[Obsolete("This method has been deprecated. Please use the proxy selected for you by default. http://go.microsoft.com/fwlink/?linkid=14202")]

public static WebProxy GetDefaultProxy()

{

// The .NET Framework here returns a proxy that fetches IE settings and

// executes JavaScript to determine the correct proxy.

throw new PlatformNotSupportedException();

}

}

}