Delphi/Rdp check username and password before connect - delphi

as the subject say am trying to connect to server using this code in delphi
procedure TmainF.Button1Click(Sender: TObject);
var
rdp1 : TMsRdpClient7NotSafeForScripting ;
begin
rdp1 := TMsRdpClient7NotSafeForScripting.Create(self);
rdp1.Parent := mainF;
rdp1.Server:=server_name;
rdp1.UserName := user.Text;
rdp1.AdvancedSettings7.ClearTextPassword := password.Text;
rdp1.ConnectingText := 'connecting';
rdp1.DisconnectedText := 'disconnected';
rdp1.AdvancedSettings7.AuthenticationLevel:=0;
rdp1.AdvancedSettings7.EnableCredSspSupport:=true;
rdp1.Connect;
end;
the code is working fine but if the user entered a wrong user name or password
the rdp object is showing the remote desktop login prompt box to reenter the user name or password like the image
I want to validate the username and password before connect
or prevent this box and show a custom message from my app
I tried to use OnLogonError() procedure but it's not fired any code
and I read this Question but the code is c# and I confused with .getocx() and I can't find (PromptForCredentials) in (MSTSCLib_TLB.pas)
any help :( ??
sorry for my bad English.

There is an interface IMsRdpClientNonScriptable5 that has the following methods:
Get_AllowPromptingForCredentials()
Set_AllowPromptingForCredentials()
If you call Set_AllowPromptingForCredentials() with the parameter set to false the dialog won't appear.
As for how to get an instance of this interface - easy, you just cast the ControlInterface of your RDP client object:
Ircns5 := rdp1.ControlInterface as IMsRdpClientNonScriptable5;
if Assigned(Ircns5) then
Ircns5.Set_AllowPromptingForCredentials(False);

You could pass the username and password to the Windows API function "LogonUser" before establishing the connection. For this to work the authenticating entity must be available on the user's network.
{$APPTYPE CONSOLE}
uses SysUtils, Windows;
var
hToken : THandle;
begin
if (ParamCount <> 3) then
begin
WriteLn ('LogonUserTest.exe [user name] [domain] [password]');
Halt ($FF);
end; { if }
try
Win32Check (LogonUser (PChar (ParamStr (1)), PChar (ParamStr (2)),
PChar (ParamStr (3)), Logon32_Logon_Interactive,
LOGON32_PROVIDER_DEFAULT, hToken));
WriteLn ('LogonUser success');
CloseHandle (hToken);
except
on E: Exception do
Writeln (E.ClassName, ': ', E.Message);
end; { try / except }
end.

Related

Check username/password in Active Directory from PC that is NOT part of domain

Edit: I modified the code according to Andrei Galatyn's comment and hints that I shall not rely on token being nil when invalid, but it's still not working for PC's that are not part of the domain.
I want to verify if a user entered a username/password combination that is valid in a LDAP server.
Currently I use this code:
function CheckWinUserAccount(Username, Password, Domain : string) : boolean;
var token: THandle;
begin
result:=False;
if LogonUser( PChar(Username), PChar(Domain), PChar(Password),
LOGON32_LOGON_NETWORK, LOGON32_PROVIDER_DEFAULT, token) then
begin
CloseHandle(token);
result:=True;
end;
end;
It works perfectly if executed on a PC that is part of the LDAP domain, but not on a PC that only uses the LDAP PC as DNS but is not part of the domain.
My data:
Domain: graz.local
Username: LDTest
I tried entering the username as LDTest, as graz\LDTest and as graz.local\LDTest.
I also tried specifying the domain as graz, graz.local, ldap://graz.local
None of that worked. Any idea?
Btw: I was not sure if this is possible at all (accessing the domain server from a non-domain-PC), but using the LDAP Administrator (by Softerra) this works.
As noted by Andrei Galatyn use LOGON32_LOGON_NETWORK instead of
LOGON32_LOGON_INTERACTIVE when calling "LogonUser". The username
should not include the domain name, the domain name can either be the
NetBIOS domain name ("graz") or the DNS domain name ("graz.local").
EDIT: Using "LogonUser" only works if the client has already established a connection to the domain.
Here is the code which performs the authentication using LDAP.
{$APPTYPE CONSOLE}
uses
SysUtils,
Windows,
JwaWinLDAP,
JwaRpcDce;
var
sUsername, sDomain, sPassword, sDC : String;
LDAP : PLDAP;
SWAI : SEC_WINNT_AUTH_IDENTITY;
begin
if (ParamCount <> 4) then
begin
WriteLn ('WinLdapTest [username] [domain] [password] [domain controller]');
Halt (1);
end; { if }
sUsername := ParamStr (1);
sDomain := ParamStr (2);
sPassword := ParamStr (3);
sDC := ParamStr (4);
LDAP := ldap_openW (PChar (sDC), LDAP_PORT);
if (Assigned (LDAP)) then
try
SWAI.User := PChar (sUserName);
SWAI.UserLength := Length (sUserName);
SWAI.Domain := PChar (sDomain);
SWAI.DomainLength := Length (sDomain);
SWAI.Password := PChar (sPassword);
SWAI.PasswordLength := Length (sPassword);
SWAI.Flags := SEC_WINNT_AUTH_IDENTITY_UNICODE;
if (ldap_bind_sW (LDAP, PChar (sDC), PChar (#SWAI),
LDAP_AUTH_NTLM) = LDAP_SUCCESS) then
WriteLN ('"ldap_bind" success')
else WriteLN ('"ldap_bind" failure');
finally
ldap_unbind (LDAP);
end { try / finally }
else WriteLn ('"ldap_open" failed');
end.
The code uses the JEDI API library and assumes that you're using Delphi 2009 or higher (Unicode strings). To automatically retrieve the DC name you could call DsGetDcName.

Check if user authentication in Active DIrectory

i would like to know whether a user inputs the correct combination of Domain, User and Password for his Active Directory user.
I tried to make a very simple program that is not able to connect but by reading the error message i can know if the user/password is correct.
This is trick based (the logic is on reading the Exception message), anyway i testd this prototype on 2 servers and i noticed that the excpetion messages change from server to server so this is not reliable.
uses adshlp, ActiveDs_TLB;
// 3 TEdit and a TButton
procedure TForm4.Button1Click(Sender: TObject);
Var
aUser : IAdsUser;
pDomain, pUser, pPassword : string;
myResult : HRESULT;
Counter: integer;
begin
pDomain := edtDomain.Text;
pUser:= edtUser.Text;
pPassword := edtPwd.Text;
Counter := GetTickCount;
Try
myResult := ADsOpenObject(Format('LDAP://%s',[pDomain]),Format('%s\%s',[pDomain,pUser]),pPassword,
ADS_READONLY_SERVER,
IAdsUser,aUser);
except
On E : EOleException do
begin
if (GetTickCount - Counter > 3000) then ShowMessage ('Problem with connection') else
if Pos('password',E.Message) > 0 then ShowMessage ('wrong username or password') else
if Pos('server',E.Message) > 0 then ShowMessage ('Connected') else
ShowMessage('Unhandled case');
memLog.Lines.Add(E.Message);
end;
end
end;
The reason why i set "Connected" if the message contain "server" is that on my
local machine (on my company ldap server in fact) in case all is fine (domain, user and password) the server replies "The server requires a safer authentication", so the "server" word is in there, while in other cases it says "wrong user or password". SInce this must work on itlian and english servers i set "server" and "pasword" as reliable words. Anyway i tested on another server that gives differente errors.
I started from a reply to this question to do the above.
How can i check if the user set the correct password or not in a more reliable way using a similar technique?
UPDATE (found solution)
Thanks to the replies i managed to write this function that does what i need. It seems quite reliable up to now, I write here to share, hoping it can help others:
// This function returns True if the provided parameters are correct
// login credentials for a user in the specified Domain
// From empirical tests it seems reliable
function UserCanLogin(aDomain, aUser, aPassword: string): Boolean;
var
hToken: THandle;
begin
Result := False;
if (LogonUser(pChar(aUser), pChar(aDomain), pChar(aPassword), LOGON32_LOGON_INTERACTIVE,
LOGON32_PROVIDER_DEFAULT, hToken)) then
begin
CloseHandle(hToken);
Result := True;
end;
end;
You need to check the error code that ADsOpenObject returns. do not base your error checking on the returned exception messages.
if the function succeeded it will return S_OK, otherwise you need to refer to ADSI Error Codes, specifically, the LDAP error codes for ADSI
When an LDAP server generates an error and passes the error to the
client, the error is then translated into a string by the LDAP client.
This method is similar to Win32 error codes for ADSI. In this example,
the client error code is the WIN32 error 0x80072020.
To Determine the LDAP error codes for ADSI
Drop the 8007 from the WIN32 error code. In the example, the remaining hex value is 2020.
Convert the remaining hex value to a decimal value. In the example, the remaining hex value 2020 converts to the decimal value
8224.
Search in the WinError.h file for the definition of the decimal value. In the example, 8224L corresponds to the error
ERROR_DS_OPERATIONS_ERROR.
Replace the prefix ERROR_DS with LDAP_. In the example, the new definition is LDAP_OPERATIONS_ERROR.
Search in the Winldap.h file for the value of the LDAP error definition. In the example, the value of LDAP_OPERATIONS_ERROR in
the Winldap.h file is 0x01.
For a 0x8007052e result (0x052e = 1326) for example you will get ERROR_LOGON_FAILURE
From your comment:
Since the function always raises an exception i am not able to read
the code
You are getting an EOleException because your ADsOpenObject function is defined with safecall calling convention. while other implementations might be using stdcall. when using safecall Delphi will raise an EOleException and the HResult will be reflected in the EOleException.ErrorCode, otherwise (stdcall) will not raise an exception and the HResult will be returned by the ADsOpenObject function.
i would like to know whether a user inputs the correct combination of
Domain, User and Password for his Active Directory user.
You can use LogonUser function to validate user login e.g. :
if (LogonUser(pChar(_Username), pChar(_ADServer), pChar(_Password), LOGON32_LOGON_INTERACTIVE,
LOGON32_PROVIDER_DEFAULT, hToken)) then
begin
CloseHandle(hToken);
//...
//DoSomething
end
else raise Exception.Create(SysErrorMessage(GetLastError));
Note: You must use LogonUser within a domain machine to be able to use the domain login or the function will always return The user name or password is incorrect
The alternative is using TLDAPSend e.g. :
function _IsAuthenticated(const lpszUsername, lpszDomain, lpszPassword: string): Boolean;
var
LDAP : TLDAPSend;
begin
Result := False;
if ( (Length(lpszUsername) = 0) or (Length(lpszPassword) = 0) )then Exit;
LDAP := TLDAPSend.Create;
try
LDAP.TargetHost := lpszDomain;
LDAP.TargetPort := '389';
....
LDAP.UserName := lpszUsername + #64 + lpszDomain;;
LDAP.Password := lpszPassword;
Result := LDAP.Login;
finally
LDAP.Free;
end;
end;
How can i check if the user set the correct password or not in a more
reliable way using a similar technique?
Try to use FormatMessage function
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER or FORMAT_MESSAGE_FROM_SYSTEM,
nil,
myResult,
LANG_ENGLISH or SUBLANG_ENGLISH_US,
lpMsg,
0,
nil);
MessageBox(0, lpMsg, 'Msg', 0);
I get (HRESULT) 0x8007052e (2147943726) "unknown user name or bad password" when I use a wrong password. And there is no EOleException, try:
hr := ADsOpenObject('LDAP://'+ ADomain + '/OU=Domain Controllers,' + APath,
AUser, APwd,
ADS_SECURE_AUTHENTICATION or ADS_READONLY_SERVER,
IID_IADs, pObject);
if (hr=HRESULT(2147943726)) then ShowMessage ('wrong username or password')

Client Application Name in DataSnap

I have client-server system that uses DataSnap. I want to log the client application data so I use the TDSServer - OnConnect Event. In this event I can access what I want with the following code:
IP:= DSConnectEventObject.ChannelInfo.ClientInfo.IpAddress
ClientPort:= DSConnectEventObject.ChannelInfo.ClientInfo.ClientPort
Protocol:= DSConnectEventObject.ChannelInfo.ClientInfo.Protocol
AppName:= DSConnectEventObject.ChannelInfo.ClientInfo.AppName
first 3 lines are OK but AppName is empty!!!
(I run server and client on the same computer i.e. localhost)
I have been unable to find any online information about how to specify the AppName when the client connects via TCP/IP. If you look at the code
procedure TDSTCPChannel.Open;
var
ClientInfo: TDBXClientInfo;
begin
inherited;
FreeAndNil(FChannelInfo);
FChannelInfo := TDBXSocketChannelInfo.Create(IntPtr(FContext.Connection), FContext.Connection.Socket.Binding.PeerIP);
ClientInfo := FChannelInfo.ClientInfo;
ClientInfo.IpAddress := FContext.Connection.Socket.Binding.PeerIP;
ClientInfo.ClientPort := IntToStr(FContext.Connection.Socket.Binding.PeerPort);
ClientInfo.Protocol := 'tcp/ip';
FChannelInfo.ClientInfo := ClientInfo;
end;
in DataSnap.DSTCPServerTransport.Pas it is evident that the ClientInfo.AppName is not set.
However, the following work-around works with the Seattle demo DataSnap Basic Server + Client:
In the client, add a Param 'AppName' to the SqlConnection1 component's Params and
set its value to something like 'MyTestApp'. Recompile the client.
Open the server in the IDE and modify the ServerContainerForm's code as shown below.
Code:
uses
[...], DBXTransport;
procedure TForm8.DSServer1Connect(DSConnectEventObject: TDSConnectEventObject);
var
S : String; // added
Info : TDBXClientInfo; // added
begin
ActiveConnections.Insert;
if DSConnectEventObject.ChannelInfo <> nil then
begin
ActiveConnections['ID'] := DSConnectEventObject.ChannelInfo.Id;
ActiveConnections['Info'] := DSConnectEventObject.ChannelInfo.Info;
end;
ActiveConnections['UserName'] := DSConnectEventObject.ConnectProperties[TDBXPropertyNames.UserName];
ActiveConnections['ServerConnection'] := DSConnectEventObject.ConnectProperties[TDBXPropertyNames.ServerConnection];
ActiveConnections.Post;
InsertEvent('Connect');
// following added to get AppName from client
S := DSConnectEventObject.ConnectProperties['AppName'];
Info := DSConnectEventObject.ChannelInfo.ClientInfo;
Info.AppName := S;
DSConnectEventObject.ChannelInfo.ClientInfo := Info;
Caption := DSConnectEventObject.ChannelInfo.ClientInfo.AppName;
end;
As you can see, it works by picking up the value set for AppName in the client's
SqlConnection1.Params in the call to `DSConnectEventObject.ConnectProperties['AppName']'
and then display it on the Caption of the ServerContainerForm.
Obviously, you could pass any other name/value pair by adding them to the SqlConnection's Params on the client and then pick them up on the server by calling DSConnectEventObject.ConnectProperties[].

FireDac connection issue

I was using an example from here :
establishing connection
Did it this way :
procedure TDataModule2.DataModuleCreate(Sender: TObject);
begin
with FDGUIxLoginDialog1.VisibleItems do begin
Clear;
Add('Server=Strežnik');
Add('User_name=Uporabnik');
Add('Password=Geslo');
Add('Database=Baza');
end;
try
FDConnection1.Connected := True;
except
on E: EAbort do
application.terminate; // user pressed Cancel button in Login dialog
on E:EFDDBEngineException do
case E.Kind of
ekUserPwdInvalid: ; // user name or password are incorrect
//ekUserPwdExpired: ; // user password is expired
ekServerGone: ; // DBMS is not accessible due to some reason
else
// other issues
end;
end;
end;
However, application will not terminate after hitting cancel in the login dialog but shows my main form. What should I do to correct this ?
Also, how can I flash a message if the password was wrong, in this scenario ?
Firedac is connecting to SQL Server.
ps
Even this will not work :
.....
except
on E: EFDDBEngineException do
if E.Kind = ekUserPwdInvalid then
begin
ShowMessage('A user name or a password are invalid');
Abort;
end;
An application usually quits by closing its main form.
You should never let an application quit by issuing an exception; it's bad form.
EAbort is not an exception that gets issued by the login dialog. In fact under normal circumstances te login dialog will not issue any exception.
If the user presses Cancel then the connection will not get ehm.. connected, you can test that.
Here's a list of all the errors TFDConnection can generate.
The following code should work:
type
TAction = (aSuccess, aGiveup, aWrongPassword, aPasswordExpired);
procedure TDataModule2.DataModuleCreate(Sender: TObject);
var
VI: TStrings;
WhatToDo: TAction;
begin
WhatToDo:= aSuccess;
VI:= FDGUIxLoginDialog1.VisibleItems;
VI.Clear;
VI.Add('Server=Strežnik');
VI.Add('User_name=Uporabnik');
VI.Add('Password=Geslo');
VI.Add('Database=Baza');
try
FDConnection1.Connected := True;
except
on E:EFDDBEngineException do case E.Kind of
ekUserPwdInvalid: WhatToDo:= aWrongPassword;
ekUserPwdExpired: WhatToDo:= aPasswordExpired;
else WhatToDo:= aGiveUp;
end; {case}
end;
if Not(FDConnection1.Connected) then WhatToDo:= aGiveUp;
case Action of
aWrongPassword: begin
ShowMessage('You've entered a wrong username or password please try again');
DataModuleCreate(Sender);
Action:= aSuccess;
end;
aPasswordExpired: ShowMessage('You password has expired, please request a new one from the PHB');
end;
if Action <> aSuccess then Application.Terminate;
end;
Comments about coding style
Do not use with. With is evil use a temporary variable instead and use that to reference the nested variable(s).
Terminating on an error without issuing an error is really silly.
No user is going to be happy having an application die on them without any explanation why.
You should never terminate on a wrong password or username.
As least give the user the change to try again 3 or 4 times.
If he doesn't get it right by then issue the "wrong username or password" error message and quit.
Never tell the user which (username or password) is wrong, an attacker can use that to generate a list of usernames.

ADSI can't open object using ADsOpenObject. Delphi

I have a program that allows to login by using the windows login information, and I am trying to get the windows groups members when the user enter his password, I wrote a small function similar to my code :
procedure ShowADSPath(UserName, Password: widestring);
var Group : IADs;
begin
try
OleCheck(ADsOpenObject('WinNT://Server/Group1',
UserName,
Password, ADS_SECURE_AUTHENTICATION, IADs, Group));
if (Group <> nil) and (Group.Class_ = 'Group') then
ShowMessage(Group.ADsPath);
Group.release;
Group:= nil;
except
ShowMessage('NOT ACCESSDE');
end;
end;
so when the entered username and password are right the program returns the path for the group
when wrong 'NOT ACCESSED' appears.
the function works well if I enter the right username and password for the first time, or if I enter wrong username and password data it works fine too.
the problem is when I call the function second time it doesn't work as expected like:
when I run my program and first I enter wrong password and call my function 'NOT ACCESSED' will appear as expected, but if I recall the function even with the right password it returns 'NOT ACCESSED' too.
Also when I run my program and first I enter right password and call my function the groups path appears as expected, but if I recall the function with the wrong password it returns the path too.
it looks like my connection data became saved, and I need to free the memory but I don't know how.
any body can help?
Finally I could find a solution for my issue, which looks like a Microsoft API issue described in this article:
http://support.microsoft.com/kb/218497
actually the API function ADsOpenObject is opening a connection with the server using the credentials you pass but it never close that connection, I tried to close it but it doesn't became close in the session, so I used another API to check the existence of the object first, check out this function it worked for me:
procedure ShowADSPath(UserName, Password: widestring);
function CheckObject(APath: String): IDispatch;
var
Moniker: IMoniker;
Eaten: integer;
BindContext: IBindCtx;
Dispatch: IDispatch;
begin
Result := nil;
OleCheck(CreateBindCtx(0, BindContext));
OleCheck(MkParseDisplayName(BindContext, PWideChar(WideString(APath)),
Eaten, Moniker));
OleCheck(Moniker.BindToObject(BindContext, nil, IDispatch, Dispatch));
Result := Dispatch;
end;
var Group : IADs;
begin
try
if CheckObject('WinNT://Server/Group1,group') <> nil then
OleCheck(ADsOpenObject('WinNT://Server/Group1,group',
UserName,
Password, ADS_SECURE_AUTHENTICATION, IADs, Group));
if (Group <> nil) and (Group.Class_ = 'Group') then
begin
ShowMessage(Group.ADsPath);
Group.release;
Group:= nil;
end;
except
ShowMessage('NOT ACCESSDE');
end;
end;

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