win32utils devel - Jun 2009 - Debugging Segmentation Faults

All, I''m attempting to perform a remote registry query using win32- 
api. For some reason the last call to "RegQueryValueEx" is causing a  
segmentation fault. Any suggestions on how to resolve and/or debug  
this issue?

 >ruby win32.rb
win32.rb:127: [BUG] Segmentation fault
ruby 1.8.6 (2008-08-11) [i386-mswin32]


This application has requested the Runtime to terminate it in an  
unusual way.
Please contact the application''s support team for more information.
 >Exit code: 3

<!-- START CODE SNIPPET -->
require "win32/api"
require "windows/registry"
include Win32
require "dl"

class Win32APIExample
         def initialize
  	    @aKEY_QUERY_VALUE = 0x1
   	    @aKEY_SET_VALUE = 0x2
     	    @aKEY_ALL_ACCESS = 0x3
         end

         def remotereg
           machine = "\\\\myhost"

           #http://support.microsoft.com/kb/315586

           ############################
           ## Connect to the remote registry service
           #RegConnectRegistry
           # http://msdn.microsoft.com/en-us/library/ms724840(VS. 
85).aspx
           phkResult = 0.chr * 4
           regConnectRegistry =  
API.new(''RegConnectRegistry'',''PLP'',''L'',''advapi32'')
           returncode = regConnectRegistry.call(machine,  
Windows::Registry::HKEY_LOCAL_MACHINE, phkResult)

           if returncode != Windows::Error::ERROR_SUCCESS
             puts "AN ERROR OCCURRED"
             return
           end

           phkResult = phkResult.unpack(''L'').first

           ###########################
           ## Open a handle to the specified Registry node
           #RegOpenKeyEx
           #http://msdn.microsoft.com/en-us/library/ms724897(VS.85).aspx
           hKey = 0.chr * 4
           regOpenKeyEx =
API.new(''RegOpenKeyEx'',''PSLLP'',''L'',''advapi32'')
           returncode = regOpenKeyEx.call(phkResult,"HARDWARE\ 
\DESCRIPTION\\System",0, at aKEY_QUERY_VALUE, hKey)

           if returncode != Windows::Error::ERROR_SUCCESS
             puts "AN ERROR OCCURRED"
             return
           end

           hKey = hKey.unpack(''L'').first


           ###########################
           ## GET the value of the specificed registry key
           #RegQueryValueEx
           #http://msdn.microsoft.com/en-us/library/ms724911(VS.85).aspx
           lpData = 0.chr * 8192
           lpcbData = [lpData.length].pack(''L'')

           regQueryValueEx = API.new(''
'',''PSVLPP'',''L'',''advapi32'')
           returncode = regQueryValueEx.call(hKey,  
"SystemBIOSVersion", nil, Windows::Registry::REG_MULTI_SZ, lpData,  
lpcbData)

         end
end

if __FILE__ == $0
         b = Win32APIExample.new()
         puts b.remotereg
end
<!-- END CODE SNIPPET -->

Hi,

2009/6/26 Robert Clugston <waldo1979 at
gmail.com>:
> All, I''m attempting to perform a remote registry query using
win32-api. For
> some reason the last call to "RegQueryValueEx" is causing a
segmentation
> fault. Any suggestions on how to resolve and/or debug this issue?
>
>>ruby win32.rb
> win32.rb:127: [BUG] Segmentation fault
> ruby 1.8.6 (2008-08-11) [i386-mswin32]
>
>
> This application has requested the Runtime to terminate it in an unusual
> way.
> Please contact the application''s support team for more
information.
>>Exit code: 3
>
> <!-- START CODE SNIPPET -->
> require "win32/api"
> require "windows/registry"
> include Win32
> require "dl"
>
> class Win32APIExample
> ? ? ? ?def initialize
> ? ? ? ? ? ?@aKEY_QUERY_VALUE = 0x1
> ? ? ? ? ? ?@aKEY_SET_VALUE = 0x2
> ? ? ? ? ? ?@aKEY_ALL_ACCESS = 0x3
> ? ? ? ?end
>
> ? ? ? ?def remotereg
> ? ? ? ? ?machine = "\\\\myhost"
>
> ? ? ? ? ?#http://support.microsoft.com/kb/315586
>
> ? ? ? ? ?############################
> ? ? ? ? ?## Connect to the remote registry service
> ? ? ? ? ?#RegConnectRegistry
> ? ? ? ? ?# http://msdn.microsoft.com/en-us/library/ms724840(VS.85).aspx
> ? ? ? ? ?phkResult = 0.chr * 4
> ? ? ? ? ?regConnectRegistry >
API.new(''RegConnectRegistry'',''PLP'',''L'',''advapi32'')
> ? ? ? ? ?returncode = regConnectRegistry.call(machine,
> Windows::Registry::HKEY_LOCAL_MACHINE, phkResult)
>
> ? ? ? ? ?if returncode != Windows::Error::ERROR_SUCCESS
> ? ? ? ? ? ?puts "AN ERROR OCCURRED"
> ? ? ? ? ? ?return
> ? ? ? ? ?end
>
> ? ? ? ? ?phkResult = phkResult.unpack(''L'').first
>
> ? ? ? ? ?###########################
> ? ? ? ? ?## Open a handle to the specified Registry node
> ? ? ? ? ?#RegOpenKeyEx
> ? ? ? ? ?#http://msdn.microsoft.com/en-us/library/ms724897(VS.85).aspx
> ? ? ? ? ?hKey = 0.chr * 4
> ? ? ? ? ?regOpenKeyEx =
API.new(''RegOpenKeyEx'',''PSLLP'',''L'',''advapi32'')
> ? ? ? ? ?returncode >
regOpenKeyEx.call(phkResult,"HARDWARE\\DESCRIPTION\\System",0, at
aKEY_QUERY_VALUE,
> hKey)
>
> ? ? ? ? ?if returncode != Windows::Error::ERROR_SUCCESS
> ? ? ? ? ? ?puts "AN ERROR OCCURRED"
> ? ? ? ? ? ?return
> ? ? ? ? ?end
>
> ? ? ? ? ?hKey = hKey.unpack(''L'').first
>
>
> ? ? ? ? ?###########################
> ? ? ? ? ?## GET the value of the specificed registry key
> ? ? ? ? ?#RegQueryValueEx
> ? ? ? ? ?#http://msdn.microsoft.com/en-us/library/ms724911(VS.85).aspx
> ? ? ? ? ?lpData = 0.chr * 8192
> ? ? ? ? ?lpcbData = [lpData.length].pack(''L'')
>
> ? ? ? ? ?regQueryValueEx = API.new('' ?
'',''PSVLPP'',''L'',''advapi32'')
> ? ? ? ? ?returncode = regQueryValueEx.call(hKey,
"SystemBIOSVersion", nil,
> Windows::Registry::REG_MULTI_SZ, lpData, lpcbData)
>
> ? ? ? ?end
> end
>
> if __FILE__ == $0
> ? ? ? ?b = Win32APIExample.new()
> ? ? ? ?puts b.remotereg
> end
> <!-- END CODE SNIPPET -->
The 4th parameter is not an input but a ouput parameter.

The following line
         regQueryValueEx = API.new(''  
'',''PSVLPP'',''L'',''advapi32'')
         returncode = regQueryValueEx.call(hKey, "SystemBIOSVersion",
nil, Windows::Registry::REG_MULTI_SZ, lpData, lpcbData)
should be
         regQueryValueEx =
API.new(''RegQueryValueEx'',''PSPPPP'',''L'',''advapi32'')
         returncode = regQueryValueEx.call(hKey, "SystemBIOSVersion",
nil, nil, lpData, lpcbData)
	 lpData[0,lpcbData.unpack(''L'').first].strip


Regards,

Park Heesob