synhttp/synamisc.pas

{==============================================================================|
| Project : Ararat Synapse                                       | 001.004.000 |
|==============================================================================|
| Content: misc. procedures and functions                                      |
|==============================================================================|
| Copyright (c)1999-2022, Lukas Gebauer                                        |
| All rights reserved.                                                         |
|                                                                              |
| Redistribution and use in source and binary forms, with or without           |
| modification, are permitted provided that the following conditions are met:  |
|                                                                              |
| Redistributions of source code must retain the above copyright notice, this  |
| list of conditions and the following disclaimer.                             |
|                                                                              |
| Redistributions in binary form must reproduce the above copyright notice,    |
| this list of conditions and the following disclaimer in the documentation    |
| and/or other materials provided with the distribution.                       |
|                                                                              |
| Neither the name of Lukas Gebauer nor the names of its contributors may      |
| be used to endorse or promote products derived from this software without    |
| specific prior written permission.                                           |
|                                                                              |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"  |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE    |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE   |
| ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR  |
| ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL       |
| DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR   |
| SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER   |
| CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT           |
| LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY    |
| OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH  |
| DAMAGE.                                                                      |
|==============================================================================|
| The Initial Developer of the Original Code is Lukas Gebauer (Czech Republic).|
| Portions created by Lukas Gebauer are Copyright (c) 2002-2022.               |
| All Rights Reserved.                                                         |
|==============================================================================|
| Contributor(s):                                                              |
|==============================================================================|
| History: see HISTORY.HTM from distribution package                           |
|          (Found at URL: http://www.ararat.cz/synapse/)                       |
|==============================================================================}

{:@abstract(Miscellaneous network based utilities)}

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$Q-}
{$H+}

//Kylix does not known UNIX define
{$IFDEF LINUX}
  {$IFNDEF UNIX}
    {$DEFINE UNIX}
  {$ENDIF}
{$ENDIF}

{$IFDEF POSIX}
  {$IFNDEF UNIX}
    {$DEFINE UNIX}
  {$ENDIF}
{$ENDIF}

{$TYPEDADDRESS OFF}

{$IFDEF UNICODE}
  {$WARN IMPLICIT_STRING_CAST OFF}
  {$WARN IMPLICIT_STRING_CAST_LOSS OFF}
{$ENDIF}

unit synamisc;

interface

{$IFDEF VER125}
  {$DEFINE BCB}
{$ENDIF}
{$IFDEF BCB}
  {$ObjExportAll On}
  {$HPPEMIT '#pragma comment( lib , "wininet.lib" )'}
{$ENDIF}

uses
  synautil, blcksock, SysUtils, Classes
{$IFDEF POSIX}
  ,Types,Posix.Stdlib
{$ELSE}
  {$IFDEF UNIX}
  {$IFNDEF FPC}
  , Libc
  {$ENDIF}
{$ELSE}
  {$IFDEF ULTIBO}
    , GlobalConst, Iphlpapi
  {$ELSE}
    , Windows
  {$ENDIF}
{$ENDIF}
;


const
  lIPV4 = 1;
  lIPV6 = 2;

Type
  {:@abstract(This record contains information about proxy settings.)}
  TProxySetting = record
    Host: string;
    Port: string;
    Bypass: string;
    ResultCode: integer;
    Autodetected: boolean;
  end;

{:With this function you can turn on a computer on the network, if this computer
 supports Wake-on-LAN feature. You need the MAC address
 (network card identifier) of the computer. You can also assign a target IP
 addres. If you do not specify it, then broadcast is used to deliver magic
 wake-on-LAN packet.
 However broadcasts work only on your local network. When you need to wake-up a
 computer on another network, you must specify any existing IP addres on same
 network segment as targeting computer.}
procedure WakeOnLan(MAC, IP: string);

{:Autodetect current DNS servers used by the system. If more than one DNS server
 is defined, then the result is comma-delimited.}
function GetDNS: string;

{:Read InternetExplorer 5.0+ proxy setting for given protocol. This function
works only on windows!}
function GetIEProxy(protocol: string): TProxySetting;

{:Return all known IP addresses of required type on the local system. Addresses are divided by
comma/comma-delimited.}
function GetLocalIPsFamily(value: TSocketFamily): string;

{:Return all known IP addresses on the local system. Addresses are divided by
comma/comma-delimited.}
function GetLocalIPs: string;

{$IFDEF MSWINDOWS}
{:Autodetect system proxy setting for specified URL. This function
works only on windows!}
function GetProxyForURL(const AURL: WideString): TProxySetting;
{$ENDIF}

implementation

{==============================================================================}
procedure WakeOnLan(MAC, IP: string);
var
  sock: TUDPBlockSocket;
  HexMac: string;
  data: string;
  n: integer;
  b: Byte;
begin
  if MAC <> '' then
  begin
    MAC := ReplaceString(MAC, '-', '');
    MAC := ReplaceString(MAC, ':', '');
    if Length(MAC) < 12 then
      Exit;
    HexMac := '';
    for n := 0 to 5 do
    begin
      b := StrToIntDef('$' + MAC[n * 2 + 1] + MAC[n * 2 + 2], 0);
      HexMac := HexMac + char(b);
    end;
    if IP = '' then
      IP := cBroadcast;
    sock := TUDPBlockSocket.Create;
    try
      sock.CreateSocket;
      sock.EnableBroadcast(true);
      sock.Connect(IP, '9');
      data := #$FF + #$FF + #$FF + #$FF + #$FF + #$FF;
      for n := 1 to 16 do
        data := data + HexMac;
      sock.SendString(data);
    finally
      sock.Free;
    end;
  end;
end;

{==============================================================================}

{$IFNDEF UNIX}
function GetDNSbyIpHlp: string;
{$IFDEF ULTIBO}
var
  InfoSize: DWORD;
  FixedInfo: TFixedInfo;
  PDnsServer: PIP_ADDR_STRING;
  ResultCode: DWORD;
begin
  Result:='';
  
  InfoSize:=SizeOf(TFixedInfo);
  ResultCode:=GetNetworkParams(@FixedInfo,InfoSize);
  if ResultCode <> ERROR_SUCCESS then Exit;
  
  Result:=FixedInfo.DnsServerList.IpAddress.S;
  PDnsServer:=FixedInfo.DnsServerList.Next;
  while PDnsServer <> nil do
   begin
    if Result <> '' then Result:=Result + ',';
    Result:=Result + PDnsServer^.IPAddress.S;
    PDnsServer:=PDnsServer.Next;
   end;
end;
{$ELSE}
type
  PTIP_ADDRESS_STRING = ^TIP_ADDRESS_STRING;
  TIP_ADDRESS_STRING = array[0..15] of Ansichar;
  PTIP_ADDR_STRING = ^TIP_ADDR_STRING;
  TIP_ADDR_STRING = packed record
    Next: PTIP_ADDR_STRING;
    IpAddress: TIP_ADDRESS_STRING;
    IpMask: TIP_ADDRESS_STRING;
    Context: DWORD;
  end;
  PTFixedInfo = ^TFixedInfo;
  TFixedInfo = packed record
    HostName: array[1..128 + 4] of Ansichar;
    DomainName: array[1..128 + 4] of Ansichar;
    CurrentDNSServer: PTIP_ADDR_STRING;
    DNSServerList: TIP_ADDR_STRING;
    NodeType: UINT;
    ScopeID: array[1..256 + 4] of Ansichar;
    EnableRouting: UINT;
    EnableProxy: UINT;
    EnableDNS: UINT;
  end;
const
  IpHlpDLL = 'IPHLPAPI.DLL';
var
  IpHlpModule: THandle;
  FixedInfo: PTFixedInfo;
  InfoSize: Longint;
  PDnsServer: PTIP_ADDR_STRING;
  err: integer;
  GetNetworkParams: function(FixedInfo: PTFixedInfo; pOutPutLen: PULONG): DWORD; stdcall;
begin
  InfoSize := 0;
  Result := '...';
  IpHlpModule := LoadLibrary(IpHlpDLL);
  if IpHlpModule = 0 then
    exit;
  try
    GetNetworkParams := GetProcAddress(IpHlpModule,PAnsiChar(AnsiString('GetNetworkParams')));
    if @GetNetworkParams = nil then
      Exit;
    err := GetNetworkParams(Nil, @InfoSize);
    if err <> ERROR_BUFFER_OVERFLOW then
      Exit;
    Result := '';
    GetMem (FixedInfo, InfoSize);
    try
      err := GetNetworkParams(FixedInfo, @InfoSize);
      if err <> ERROR_SUCCESS then
        exit;
      with FixedInfo^ do
      begin
        Result := DnsServerList.IpAddress;
        PDnsServer := DnsServerList.Next;
        while PDnsServer <> Nil do
        begin
          if Result <> '' then
            Result := Result + ',';
          Result := Result + PDnsServer^.IPAddress;
          PDnsServer := PDnsServer.Next;
        end;
    end;
    finally
      FreeMem(FixedInfo);
    end;
  finally
    FreeLibrary(IpHlpModule);
  end;
end;

function ReadReg(SubKey, Vn: PChar): string;
var
 OpenKey: HKEY;
 DataType, DataSize: integer;
 Temp: array [0..2048] of char;
begin
  Result := '';
  if RegOpenKeyEx(HKEY_LOCAL_MACHINE, SubKey, REG_OPTION_NON_VOLATILE,
    KEY_READ, OpenKey) = ERROR_SUCCESS then
  begin
    DataType := REG_SZ;
    DataSize := SizeOf(Temp);
    if RegQueryValueEx(OpenKey, Vn, nil, @DataType, @Temp, @DataSize) = ERROR_SUCCESS then
      SetString(Result, Temp, DataSize div SizeOf(Char) - 1);
    RegCloseKey(OpenKey);
   end;
end ;
{$ENDIF}
{$ENDIF}

function GetDNS: string;
{$IFDEF ULTIBO}
begin
  Result := GetDNSbyIpHlp;
end;
{$ELSE}
{$IFDEF UNIX}
var
  l: TStringList;
  n: integer;
begin
  Result := '';
  l := TStringList.Create;
  try
    l.LoadFromFile('/etc/resolv.conf');
    for n := 0 to l.Count - 1 do
      if Pos('NAMESERVER', uppercase(l[n])) = 1 then
      begin
        if Result <> '' then
          Result := Result + ',';
        Result := Result + SeparateRight(l[n], ' ');
      end;
  finally
    l.Free;
  end;
end;
{$ELSE}
const
  NTdyn = 'System\CurrentControlSet\Services\Tcpip\Parameters\Temporary';
  NTfix = 'System\CurrentControlSet\Services\Tcpip\Parameters';
  W9xfix = 'System\CurrentControlSet\Services\MSTCP';
begin
  Result := GetDNSbyIpHlp;
  if Result = '...' then
  begin
    if Win32Platform = VER_PLATFORM_WIN32_NT then
    begin
      Result := ReadReg(NTdyn, 'NameServer');
      if result = '' then
        Result := ReadReg(NTfix, 'NameServer');
      if result = '' then
        Result := ReadReg(NTfix, 'DhcpNameServer');
    end
    else
      Result := ReadReg(W9xfix, 'NameServer');
    Result := ReplaceString(trim(Result), ' ', ',');
  end;
end;
{$ENDIF}
{$ENDIF}

{==============================================================================}

function GetIEProxy(protocol: string): TProxySetting;
{$IFDEF ULTIBO}
begin
  Result.Host := '';
  Result.Port := '';
  Result.Bypass := '';
end;
{$ELSE}
{$IFDEF UNIX}
begin
  Result.Host := '';
  Result.Port := '';
  Result.Bypass := '';
  Result.ResultCode := -1;
  Result.Autodetected := false;
end;
{$ELSE}
type
  PInternetPerConnOption = ^INTERNET_PER_CONN_OPTION;
  INTERNET_PER_CONN_OPTION = record
    dwOption: DWORD;
    case Integer of
      0: (dwValue: DWORD);
//      1: (pszValue:LPTSTR);
      1: (pszValue:PAnsiChar);
      2: (ftValue: FILETIME);
    end;

  PInternetPerConnOptionList = ^INTERNET_PER_CONN_OPTION_LIST;
  INTERNET_PER_CONN_OPTION_LIST = record
    dwSize        :DWORD;
//    pszConnection :LPTSTR;
    pszConnection :PAnsiChar;
    dwOptionCount :DWORD;
    dwOptionError :DWORD;
    pOptions      :PInternetPerConnOption;
  end;
const
  INTERNET_PER_CONN_FLAGS               = 1;
  INTERNET_PER_CONN_PROXY_SERVER        = 2;
  INTERNET_PER_CONN_PROXY_BYPASS        = 3;
  INTERNET_PER_CONN_AUTOCONFIG_URL      = 4;
  INTERNET_PER_CONN_AUTODISCOVERY_FLAGS = 5;
  PROXY_TYPE_DIRECT         = $00000001;   // direct to net
  PROXY_TYPE_PROXY          = $00000002;   // via named proxy
  PROXY_TYPE_AUTO_PROXY_URL = $00000004;   // autoproxy URL
  PROXY_TYPE_AUTO_DETECT    = $00000008;   // use autoproxy detection
  AUTO_PROXY_FLAG_USER_SET                  =      $00000001;   // user changed this setting
  AUTO_PROXY_FLAG_ALWAYS_DETECT             =      $00000002;   // force detection even when its not needed
  AUTO_PROXY_FLAG_DETECTION_RUN             =      $00000004;   // detection has been run
  AUTO_PROXY_FLAG_MIGRATED                  =      $00000008;   // migration has just been done
  AUTO_PROXY_FLAG_DONT_CACHE_PROXY_RESULT   =      $00000010;   // don't cache result of host=proxy name
  AUTO_PROXY_FLAG_CACHE_INIT_RUN            =      $00000020;   // don't initalize and run unless URL expired
  AUTO_PROXY_FLAG_DETECTION_SUSPECT         =      $00000040;   // if we're on a LAN & Modem, with only one IP, bad?!?
  INTERNET_OPTION_PER_CONNECTION_OPTION   = 75;
  WininetDLL = 'WININET.DLL';
var
  WininetModule: THandle;
  Option : array[0..4] of INTERNET_PER_CONN_OPTION;
  List   : INTERNET_PER_CONN_OPTION_LIST;
  Err: Boolean;
  Len: DWORD;
  Proxy: string;
  DefProxy: string;
  ProxyList: TStringList;
  n: integer;
  InternetQueryOption: function (hInet: Pointer; dwOption: DWORD;
    lpBuffer: Pointer; var lpdwBufferLength: DWORD): BOOL; stdcall;
begin
  Result.Host := '';
  Result.Port := '';
  Result.Bypass := '';
  Result.ResultCode := 0;
  Result.Autodetected := false;
  WininetModule := LoadLibrary(WininetDLL);
  if WininetModule = 0 then
    exit;
  try
    InternetQueryOption := GetProcAddress(WininetModule,PAnsiChar(AnsiString('InternetQueryOptionA')));
    if @InternetQueryOption = nil then
      Exit;

    if protocol = '' then
      protocol := 'http';
    ProxyList := TStringList.Create;
    try
      Option[0].dwOption := INTERNET_PER_CONN_AUTOCONFIG_URL;
      Option[1].dwOption := INTERNET_PER_CONN_AUTODISCOVERY_FLAGS;
      Option[2].dwOption := INTERNET_PER_CONN_FLAGS;
      Option[3].dwOption := INTERNET_PER_CONN_PROXY_BYPASS;
      Option[4].dwOption := INTERNET_PER_CONN_PROXY_SERVER;

      List.dwSize        := SizeOf(INTERNET_PER_CONN_OPTION_LIST);
      List.pszConnection := nil;      // LAN
      List.dwOptionCount := 5;
      List.dwOptionError := 0;
      List.pOptions      := @Option;


      Err := InternetQueryOption(nil, INTERNET_OPTION_PER_CONNECTION_OPTION, @List, List.dwSize);
      if Err then
        begin
          ProxyList.CommaText := ReplaceString(Option[4].pszValue, ' ', ',');
          Proxy := '';
          DefProxy := '';
          for n := 0 to ProxyList.Count -1 do
          begin
            if Pos(lowercase(protocol) + '=', lowercase(ProxyList[n])) = 1 then
            begin
              Proxy := SeparateRight(ProxyList[n], '=');
              break;
            end;
            if Pos('=', ProxyList[n]) < 1 then
              DefProxy := ProxyList[n];
          end;
          if Proxy = '' then
            Proxy := DefProxy;
          if Proxy <> '' then
          begin
            Result.Host := Trim(SeparateLeft(Proxy, ':'));
            Result.Port := Trim(SeparateRight(Proxy, ':'));
          end;
          Result.Bypass := ReplaceString(Option[3].pszValue, ' ', ',');
        end;
    finally
      ProxyList.Free;
    end;
  finally
    FreeLibrary(WininetModule);
  end;
end;
{$ENDIF}
{$ENDIF}

{==============================================================================}

function GetLocalIPsFamily(value: TSocketFamily): string;
var
  TcpSock: TTCPBlockSocket;
  ipList: TStringList;
begin
  Result := '';
  ipList := TStringList.Create;
  try
    TcpSock := TTCPBlockSocket.create;
    try
      if value <> SF_Any then
        TcpSock.family := value;
      TcpSock.ResolveNameToIP(TcpSock.LocalName, ipList);
      Result := ipList.CommaText;
    finally
      TcpSock.Free;
    end;
  finally
    ipList.Free;
  end;
end;

function GetLocalIPs: string;
begin
  Result := GetLocalIPsFamily(SF_Any);
end;

{==============================================================================}

{$IFDEF MSWINDOWS}
function GetProxyForURL(const AURL: WideString): TProxySetting;
type
  HINTERNET = Pointer;
  INTERNET_PORT = Word;
  PWinHTTPProxyInfo = ^TWinHTTPProxyInfo;
  WINHTTP_PROXY_INFO = record
    dwAccessType: DWORD;
    lpszProxy: LPWSTR;
    lpszProxyBypass: LPWSTR;
  end;
  TWinHTTPProxyInfo = WINHTTP_PROXY_INFO;
  LPWINHTTP_PROXY_INFO = PWinHTTPProxyInfo;
  PWinHTTPAutoProxyOptions = ^TWinHTTPAutoProxyOptions;
  WINHTTP_AUTOPROXY_OPTIONS = record
    dwFlags: DWORD;
    dwAutoDetectFlags: DWORD;
    lpszAutoConfigUrl: LPCWSTR;
    lpvReserved: Pointer;
    dwReserved: DWORD;
    fAutoLogonIfChallenged: BOOL;
  end;
  TWinHTTPAutoProxyOptions = WINHTTP_AUTOPROXY_OPTIONS;
  LPWINHTTP_AUTOPROXY_OPTIONS = PWinHTTPAutoProxyOptions;
  PWinHTTPCurrentUserIEProxyConfig = ^TWinHTTPCurrentUserIEProxyConfig;
  WINHTTP_CURRENT_USER_IE_PROXY_CONFIG = record
    fAutoDetect: BOOL;
    lpszAutoConfigUrl: LPWSTR;
    lpszProxy: LPWSTR;
    lpszProxyBypass: LPWSTR;
  end;
  TWinHTTPCurrentUserIEProxyConfig = WINHTTP_CURRENT_USER_IE_PROXY_CONFIG;
  LPWINHTTP_CURRENT_USER_IE_PROXY_CONFIG = PWinHTTPCurrentUserIEProxyConfig;
const
  WINHTTP_NO_REFERER = nil;
  WINHTTP_NO_PROXY_NAME = nil;
  WINHTTP_NO_PROXY_BYPASS = nil;
  WINHTTP_DEFAULT_ACCEPT_TYPES = nil;
  WINHTTP_ACCESS_TYPE_DEFAULT_PROXY = 0;
  WINHTTP_ACCESS_TYPE_NO_PROXY = 1;
  WINHTTP_OPTION_PROXY = 38;
  WINHTTP_OPTION_PROXY_USERNAME = $1002;
  WINHTTP_OPTION_PROXY_PASSWORD = $1003;
  WINHTTP_AUTOPROXY_AUTO_DETECT = $00000001;
  WINHTTP_AUTOPROXY_CONFIG_URL = $00000002;
  WINHTTP_AUTO_DETECT_TYPE_DHCP = $00000001;
  WINHTTP_AUTO_DETECT_TYPE_DNS_A = $00000002;
  WINHTTP_FLAG_BYPASS_PROXY_CACHE = $00000100;
  WINHTTP_FLAG_REFRESH = WINHTTP_FLAG_BYPASS_PROXY_CACHE;
var
  WinHttpModule: THandle;
  Session: HINTERNET;
  AutoDetectProxy: Boolean;
  WinHttpProxyInfo: TWinHTTPProxyInfo;
  AutoProxyOptions: TWinHTTPAutoProxyOptions;
  IEProxyConfig: TWinHTTPCurrentUserIEProxyConfig;
  WinHttpOpen: function (pwszUserAgent: LPCWSTR; dwAccessType: DWORD;
    pwszProxyName, pwszProxyBypass: LPCWSTR; dwFlags: DWORD): HINTERNET; stdcall;
  WinHttpConnect: function(hSession: HINTERNET; pswzServerName: LPCWSTR;
    nServerPort: INTERNET_PORT; dwReserved: DWORD): HINTERNET; stdcall;
  WinHttpOpenRequest: function(hConnect: HINTERNET; pwszVerb: LPCWSTR;
    pwszObjectName: LPCWSTR; pwszVersion: LPCWSTR; pwszReferer: LPCWSTR;
    ppwszAcceptTypes: PLPWSTR; dwFlags: DWORD): HINTERNET; stdcall;
  WinHttpQueryOption: function(hInet: HINTERNET; dwOption: DWORD;
    lpBuffer: Pointer; var lpdwBufferLength: DWORD): BOOL; stdcall;
  WinHttpGetProxyForUrl: function(hSession: HINTERNET; lpcwszUrl: LPCWSTR;
    pAutoProxyOptions: LPWINHTTP_AUTOPROXY_OPTIONS;
    var pProxyInfo: WINHTTP_PROXY_INFO): BOOL; stdcall;
  WinHttpGetIEProxyConfigForCurrentUser: function(
    var pProxyInfo: WINHTTP_CURRENT_USER_IE_PROXY_CONFIG): BOOL; stdcall;
  WinHttpCloseHandle: function(hInternet: HINTERNET): BOOL; stdcall;
begin
  Result.Host := '';
  Result.Port := '';
  Result.Bypass := '';
  Result.ResultCode := 0;
  Result.Autodetected := false;
  WinHttpModule := LoadLibrary('winhttp.dll');
  if WinHttpModule = 0 then
    exit;
  try
    WinHttpOpen := GetProcAddress(WinHttpModule,PAnsiChar(AnsiString('WinHttpOpen')));
    if @WinHttpOpen = nil then
      Exit;
    WinHttpConnect := GetProcAddress(WinHttpModule,PAnsiChar(AnsiString('WinHttpConnect')));
    if @WinHttpConnect = nil then
      Exit;
    WinHttpOpenRequest := GetProcAddress(WinHttpModule,PAnsiChar(AnsiString('WinHttpOpenRequest')));
    if @WinHttpOpenRequest = nil then
      Exit;
    WinHttpQueryOption := GetProcAddress(WinHttpModule,PAnsiChar(AnsiString('WinHttpQueryOption')));
    if @WinHttpQueryOption = nil then
      Exit;
    WinHttpGetProxyForUrl := GetProcAddress(WinHttpModule,PAnsiChar(AnsiString('WinHttpGetProxyForUrl')));
    if @WinHttpGetProxyForUrl = nil then
      Exit;
    WinHttpGetIEProxyConfigForCurrentUser := GetProcAddress(WinHttpModule,PAnsiChar(AnsiString('WinHttpGetIEProxyConfigForCurrentUser')));
    if @WinHttpGetIEProxyConfigForCurrentUser = nil then
      Exit;
    WinHttpCloseHandle := GetProcAddress(WinHttpModule,PAnsiChar(AnsiString('WinHttpCloseHandle')));
    if @WinHttpCloseHandle = nil then
      Exit;

    AutoDetectProxy := False;
    FillChar(AutoProxyOptions, SizeOf(AutoProxyOptions), 0);
    if WinHttpGetIEProxyConfigForCurrentUser(IEProxyConfig) then
    begin
      if IEProxyConfig.fAutoDetect then
      begin
        AutoProxyOptions.dwFlags := WINHTTP_AUTOPROXY_AUTO_DETECT;
        AutoProxyOptions.dwAutoDetectFlags := WINHTTP_AUTO_DETECT_TYPE_DHCP or
          WINHTTP_AUTO_DETECT_TYPE_DNS_A;
        AutoDetectProxy := True;
      end;
      if IEProxyConfig.lpszAutoConfigURL <> '' then
      begin
        AutoProxyOptions.dwFlags := AutoProxyOptions.dwFlags or
          WINHTTP_AUTOPROXY_CONFIG_URL;
        AutoProxyOptions.lpszAutoConfigUrl := IEProxyConfig.lpszAutoConfigUrl;
        AutoDetectProxy := True;
      end;
      if not AutoDetectProxy then
      begin
        Result.Host := IEProxyConfig.lpszProxy;
        Result.Bypass := IEProxyConfig.lpszProxyBypass;
        Result.Autodetected := false;
      end;
    end
    else
    begin
      AutoProxyOptions.dwFlags := WINHTTP_AUTOPROXY_AUTO_DETECT;
      AutoProxyOptions.dwAutoDetectFlags := WINHTTP_AUTO_DETECT_TYPE_DHCP or
        WINHTTP_AUTO_DETECT_TYPE_DNS_A;
      AutoDetectProxy := True;
    end;
    if AutoDetectProxy then
    begin
      Session := WinHttpOpen(nil, WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,
        WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
      if Assigned(Session) then
      try
        if WinHttpGetProxyForUrl(Session, LPCWSTR(AURL),
          @AutoProxyOptions, WinHttpProxyInfo) then
        begin
          Result.Host := WinHttpProxyInfo.lpszProxy;
          Result.Bypass := WinHttpProxyInfo.lpszProxyBypass;
          Result.Autodetected := True;
        end
        else
          Result.ResultCode := GetLastError;
      finally
        WinHttpCloseHandle(Session);
      end
      else
        Result.ResultCode := GetLastError;
    end;
    if Result.Host <> '' then
    begin
      Result.Port := Trim(SeparateRight(Result.Host, ':'));
      Result.Host := Trim(SeparateLeft(Result.Host, ':'));
    end;
  finally
    FreeLibrary(WinHttpModule);
  end;
end;
{$ENDIF}


end.