system::call crypt32::CertNameToStr

Hi,

I want a function from the field crypt32 benefit.

From these links i have the suggestions.




I would like to use this function: crypt32::CertNameToStr

here is this function in c :

//-----------------------------------------------------------
// Convert the subject name to an ASN.1 encoded
// string and print the octets in that string.

// First : Get the number of bytes that must
// be allocated for the string.

cbSize = CertNameToStr(
pCertContext->dwCertEncodingType,
&(pCertContext->pCertInfo->Subject),
MY_STRING_TYPE,
NULL,
0);

Here's my attempt with system::call functions

; $2 pointer to the next certificate
;
; extracted from struct # http://msdn.microsoft.com/en-us/libr...8VS.85%29.aspx
;
System::Call "*$2(i .r5,,,i .r6,)"
; extracted from struct # http://msdn.microsoft.com/en-us/libr...8VS.85%29.aspx
;
System::Call "*$6(,,,,,,i .r7,,,,,,)"
System::Call "crypt32::CertNameToStr(i r5,i r7, i 3,i 0,i 0) i.r3"

unfortunately without success.

Any hints are very wellcome.
(sorry for my poor english)
Uwe

/sigh...

I doubt many people will help you since your request very suspicious.

Your forum account is brand new and your asking to perform a task that exploits a known security vulnerability in Windows.

http://www.microsoft.com/technet/sec.../ms09-056.mspx
http://www.microsoft.com/technet/security/bulletin/ms09-056.mspx

Re: system::call crypt32::CertNameToStr

Hallo Zinthose,

Thank you for your notice.My question is, in this respect quite harmless.
I want my current NSIS script easier.

This is my current way, to read the issuer from the certificate store.

; snip
!define RegCertKey "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\My\Certificates"
GetTempFileName $9
ExecDos::exec 'regedit /e $9 ${RegCertKey}' "" ""
; snip

Then search with "BinStrSearch" in this file to find the issuer name.
This whole to simplify is my goal.

Uwe

This could be done like shown in the following script (based on the script referred by you in your first post of this thread):

OutFile "cert.exe"
!include "LogicLib.nsh"
!define CERT_STORE_CERTIFICATE_CONTEXT  1
!define CERT_NAME_ISSUER_FLAG           1
!define CERT_NAME_SIMPLE_DISPLAY_TYPE   4
Function display_certs
  ; Save registers
  Push $0
  Push $1
  Push $2
  Push $3
  Push $4
  ; Open system certificate store of certification authorities
  System::Call "crypt32::CertOpenSystemStore(i 0, t 'MY') i.r1" 
  ${If} $1 != 0
     StrCpy $2 0
     ; Loop through certificate store
     ${Do}
         System::Call "crypt32::CertEnumCertificatesInStore(i r1, i r2) i.r2"
         ${If} $2 != 0
            ; Get subject of certificate
            System::Call "crypt32::CertGetNameString(i r2, \\
               i ${CERT_NAME_SIMPLE_DISPLAY_TYPE}, i 0, i 0, \\
               t .r4, i ${NSIS_MAX_STRLEN}) i.r3"
            ${If} $3 != 0
               StrCpy $0 "Subject: $4$\\r$\\n"
               ; Get issuer of certificate
               System::Call "crypt32::CertGetNameString(i r2, \\
                  i ${CERT_NAME_SIMPLE_DISPLAY_TYPE}, \\
                  i ${CERT_NAME_ISSUER_FLAG}, i 0, \\
                  t .r4, i ${NSIS_MAX_STRLEN}) i.r3"
               ${If} $3 != 0
                  StrCpy $0 "$0Issuer: $4"
               ${EndIf}
               MessageBox MB_OK "$0"
            ${EndIf} 
         ${Else}
            ${ExitDo}
         ${EndIf}
     ${Loop}
     System::Call "crypt32::CertCloseStore(i r1, i 0)"
  ${EndIf}
  
  ; Restore registers
  Pop $4
  Pop $3
  Pop $2
  Pop $1
  Pop $0
FunctionEnd
Function .onInit
  InitPluginsDir
  Call display_certs
  Quit
FunctionEnd
Section
SectionEnd