Passing /C to command.com for custom URL handler

[Albert Chin-A-Young]

I have a custom URL handler that calls a .bat file which then launches PuTTY. When the .bat file executes, a cmd.exe window appears which then launches PuTTY. I know I can pass /c to cmd.exe to avoid the creation of the cmd.exe window. Can I tell KeePass to invoke cmd.exe with /C?

[wellread1]

Can I tell KeePass to invoke cmd.exe with /C?

Use cmd://cmd.exe /C

For more information see Executing command lines in the KeePass URL Field Capabilities documentation.

[Paul]

Put exit at the end of your batch file.

cheers, Paul

[Albert Chin-A-Young]

Thanks. I modified my URL-handler to:

cmd://cmd.exe /C "H:\pamssh.bat" {BASE:RMVSCM}

but the command window still appears followed by the Putty window. Is there a way to avoid the command window appearing? I presume cmd://cmd.exe has Keepass invoking cmd.exe with /C rather than the initial cmd.exe being passed /C to avoid the command window.

[wellread1]

Did you add the exit to the end of your batch file?

[Albert Chin-A-Young]

I have EXIT /b at the end of the file.

[wellread1]

When you run your batch file outside of KeePass, does the console window stay open until you exit PuTTY?

[Albert Chin-A-Young]

If I execute my script from the cmd promp as above, only the Putty window appears.

[Albert Chin-A-Young]

Attached is the .bat script. It just launches putty with a temporary file that contains "root@<servername>". This temporary file is removed once putty terminates.</servername>

@ECHO off

SETLOCAL EnableExtensions EnableDelayedExpansion

SET pamSSHRelayServer=SERVERNAME
SET pamSSHRelayPort=PORT

IF "%~1" == "" ECHO No server name specified
IF "%~1" == "" EXIT /b

SET "usernameUpper=%USERNAME%"

CALL :toUpper usernameUpper

REM Get unique file name
:uniqLoop
SET "uniqueFileName=%tmp%\putty~%RANDOM%.tmp"
IF EXIST "%uniqueFileName%" GOTO :uniqLoop

ECHO root@%1 >%uniqueFileName%
putty -ssh -t -P %pamSSHRelayPort% %usernameUpper%@%pamSSHRelayServer%^
 -m %uniqueFileName%
DEL %uniqueFileName%
EXIT /b

REM Functions
:toUpper str -- converts lowercase character to uppercase
::           -- str [in,out] - valref of string variable to be converted
:$created 20060101 :$changed 20080219 :$categories StringManipulation
:$source https://www.dostips.com
IF NOT DEFINED %~1 EXIT /b
FOR %%a IN ("a=A" "b=B" "c=C" "d=D" "e=E" "f=F" "g=G" "h=H" "i=I"
            "j=J" "k=K" "l=L" "m=M" "n=N" "o=O" "p=P" "q=Q" "r=R"
            "s=S" "t=T" "u=U" "v=V" "w=W" "x=X" "y=Y" "z=Z") do (
    CALL SET %~1=%%%~1:%%~a%%
)
EXIT /b

[Paul]

Have you tried just:
cmd://H:\pamssh.bat {BASE:RMVSCM}

cheers, Paul

[Albert Chin-A-Young]

Yes. I did that initially. I get the cmd window and then the Putty window. Both windows remain open until Putty terminates.

[wellread1]

When you run a batch file, the console window is going to stay open until the job is finished. There is nothing KeePass can do about that.

[Dominik Reichl]

The /C command line option tells cmd.exe to execute the command that follows and terminate afterwards. It doesn't hide the cmd.exe window.

PowerShell scripts and commands can more easily be executed invisibly (by running PowerShell.exe with the -WindowStyle Hidden command line parameter); maybe you could convert your batch file to a PowerShell script or run your batch file using PowerShell.

Another solution would be to use the {CMD:...} placeholder (which can run applications with a hidden window, see [1] for details) together with running a GUI dummy executable (like consent.exe), e.g.
cmd://consent.exe {CMD:!"H:\pamssh.bat" {BASE:RMVSCM}!W=0,WS=H!}
(that's a bit of a hack; the PowerShell way is cleaner).

Best regards,
Dominik

[1] https://keepass.info/help/base/placeholders.html#cmd

[Albert Chin-A-Young]

Ok, thanks.

[Albert Chin-A-Young]

I modified my URL handler to:

cmd://powershell.exe -WindowStyle Hidden "H:\pamssh.bat" {BASE:RMVSCM}

A cmd window appears (to run powershell) but then disappears and then Putty is launched. Wish the cmd window never appeared but that's probably the best that can be achieved with trying to execute a .bat file. Might try to rewrite in .vbs to eliminate this window all-together. Thanks everyone for the help.

[Paul]

Here's a PowerShell version for you.
I've not tested the whole thing together but the parts are all OK. Comment the test command and un-comment the real command when you've tested it.

cheers, Paul

# PS variables are local by default
# check command line argument
if (-Not ($Args[0])) {Break}

# set required values
$pamSSHRelayServer = SERVERNAME
$pamSSHRelayPort = PORT
$usernameUpper = "$env:USERNAME".ToUpper()

# create a random file name; Get-Random -Maximum 99999 -minimum 1000
do {$uniqueFileName = $env:tmp + "\putty~" + (Get-Random -Maximum 99999 -minimum 1000) + ".tmp"} While (Test-Path "$uniqueFileName")

# create command file
Write-Output "root@" + $Args[0] | Add-Content $uniqueFileName

# test command. comment out these 2 lines after testing
Write-Output "putty -ssh -t -P $pamSSHRelayPort $usernameUpper@$pamSSHRelayServer^  -m $uniqueFileName"
pause

# run puTTY
##& putty -ssh -t -P $pamSSHRelayPort $usernameUpper@$pamSSHRelayServer^  -m $uniqueFileName

#clean up
DEL $uniqueFileName

[Albert Chin-A-Young]

Wow! Thanks. Seems simpler than the vbscript version I wrote yesterday::

Dim userName
Dim fso, tmp, absTmpPath
Dim objArgs, destServer
Dim objShell

Const pamSSHRelayServer = SERVERNAME
Const pamSSHRelayPort = PORT

' Class for temporary file. Contains folder and name of temporary
' file so we can remove once PuTTY terminates.
Class TmpFile
  public Folder
  public Name
  public fh
End Class

' Function to create temporary file and return TmpFile class. File
' object not returned because we cannot remove the file based on
' the file object. Rather, we need the full path to the temporary
' file.
Function CreateTempFile
  Dim tmp
  Const tmpFolderType = 2

  Set tmp = new TmpFile
  Set tmp.Folder = fso.GetSpecialFolder (tmpFolderType)
  tmp.Name = fso.GetTempName
  Set tmp.fh = tmp.Folder.CreateTextFile (tmp.Name)
  Set CreateTempFile = tmp
End Function

Set fso = CreateObject ("Scripting.FileSystemObject")

' Only allowable argument is server name to ssh to. Error
' otherwise and display usage informatiopn.
Set objArgs = WScript.Arguments
If objArgs.Count <> 1 Then
  MsgBox "No server name specified" & vbCrLf & vbCrLf & _
    WScript.ScriptName & ": " & WScript.ScriptName & " <server name>"
  WScript.Quit
End If
destServer = objArgs (0)

' Take username from login session
userName = UCase (CreateObject ("WScript.Network").UserName)

Set tmp = CreateTempFile
tmp.fh.WriteLine "root@" & destServer
tmp.fh.Close
absTmpPath = fso.BuildPath (tmp.Folder, tmp.Name)

Set fso = CreateObject ("Scripting.FileSystemObject")
Dim strPath

Set objShell = CreateObject ("WScript.shell")
strPath = "putty -ssh -t "
strPath = strPath + "-P " & pamSSHRelayPort & " "
strPath = strPath + userName & "@" & pamSSHRelayServer & " "
strPath = strPath + "-m " & absTmpPath
objShell.Run strPath

' Wait for process to finish before removing temp file by
' scanning list of processes for one with temp file on the
' command line. Continue looping until process exits. When
' Putty is invoked, control is returned to this script so
' need to loop until Putty terminates.
Dim objWMIService
Dim proc, procs
Dim puttyIsDone

Set objWMIService = GetObject ("winmgmts:\\.\root\cimv2")

puttyIsDone = False
Do While (Not puttyIsDone)
  ' Check every second if Putty still running
  WScript.Sleep (1000)

  Set procs = objWMIService.ExecQuery(_
    "Select * from Win32_Process",,48)

  puttyIsDone = True
  For Each proc in procs
    If InStr (proc.CommandLine, absTmpPath) > 0 Then
      puttyIsDone = False
      Exit For
    End If
  Next
Loop

' Remove tmp file after Putty terminates
fso.DeleteFile (absTmpPath)