DevWarningPatch.bat

<# :
@echo off
copy/b "%~f0" "%temp%\%~n0.ps1" >nul
powershell -v 2 -ep bypass -noprofile "%temp%\%~n0.ps1" "'%cd% '" "'%~1'"
del "%temp%\%~n0.ps1"
echo: & pause
exit /b
#>
param([string]$cwd='.', [string]$dll)

function main {
  write-host -f white -b black `
    "Chrome 'developer mode extensions' warning disabler 2017.12.08"
  $pathsDone = @{}
  if ($dll -and (gi -literal $dll)) {
    doPatch "DRAG'n'DROPPED" ((gi -literal $dll).directoryName + '\')
    exit
  }
  doPatch 'CURRENT DIRECTORY' ((gi -literal $cwd).fullName + '\')
  ('HKLM', 'HKCU') | %{ $hive = $_
    ('', '\Wow6432Node') | %{
      $key = "${hive}:\SOFTWARE$_\Google\Update\Clients"
      gci -ea silentlycontinue $key -r | gp | ?{ $_.CommandLine } | %{
        $path = $_.CommandLine -replace '"(.+?\\\d+\.\d+\.\d+\.\d+\\).+', '$1'
        if (!$pathsDone[$path.toLower()]) {
          doPatch REGISTRY $path
          $pathsDone[$path.toLower()] = $true
        }
      }
    }
  }
}

function doPatch([string]$pathLabel, [string]$path) {
  $dll = Join-Path $path chrome.dll
  if (!(Test-Path -literal $dll)) {
    return
  }
  ''
  $localAppData = [Environment]::GetFolderPath('LocalApplicationData')
  "$pathLabel $((split-path $dll).Replace($localAppData, '%LocalAppData%'))"

  "`tREADING Chrome.dll..."
  $bin = [IO.BinaryReader][IO.File]::OpenRead($dll)
  $bytes = $bin.ReadBytes(1MB)

  # process PE headers
  $BC = [BitConverter]
  $coff = $BC::ToUInt32($bytes,0x3C) + 4
  $is64 = $BC::ToUInt16($bytes,$coff) -eq 0x8664
  $opthdr = $coff+20
  $codesize = $BC::ToUInt32($bytes,$opthdr+4)
  $imagebase32 = $BC::ToUInt32($bytes,$opthdr+28)

  # patch the flag in data section
  $bin.BaseStream.Position = $codesize
  $data = $BC::ToString($bin.ReadBytes($bin.BaseStream.Length - $codesize))
  $bin.Close()
  $flag = 'ExtensionDeveloperModeWarning'
  $stroffs = $data.IndexOf($BC::ToString($flag[1..99]))
  if ($stroffs -lt 0) {
    write-host -f red "`t$flag not found"
    return
  }
  if ($data.substring($stroffs-3, 2) -eq '00') {
    write-host -f darkgreen "`tALREADY PATCHED"
    return
  }
  $stroffs = $stroffs/3 - 1 + $codesize

  $centbrowser = $data.indexOf($BC::ToString('CentBrowser'[0..99])) -gt 0

  $EA = $ErrorActionPreference
  $ErrorActionPreference = 'silentlyContinue'
  $exe = join-path (split-path $path) chrome.exe
  while ((get-process chrome -module | ?{ $_.FileName -eq $exe })) {
    forEach ($timeout in 15..0) {
      write-host -n -b yellow -f black `
        "`rChrome is running and will be terminated in $timeout sec. "
      write-host -n -b yellow -f darkyellow "Press ENTER to do it now. "
      if ([console]::KeyAvailable) {
        $key = $Host.UI.RawUI.ReadKey("AllowCtrlC,IncludeKeyDown,NoEcho")
        if ($key.virtualKeyCode -eq 13) { break }
        if ($key.virtualKeyCode -eq 27) { write-host; exit }
      }
      sleep 1
    }
    write-host
    get-process chrome | ?{
      $_.MainWindowHandle.toInt64() -and ($_ | gps -file).FileName -eq $exe
    } | %{
      "`tTrying to exit gracefully..."
      if ($_.CloseMainWindow()) {
        sleep 1
      }
    }
    $killLabelShown = 0
    get-process chrome | ?{
      ($_ | gps -file | select -expand FileName) -eq $exe
    } | %{
      if (!$killLabelShown++) {
        "`tTerminating background chrome processes..."
      }
      stop-process $_ -force
    }
    sleep -milliseconds 200
  }
  $ErrorActionPreference = $EA

  $bytes = [IO.File]::ReadAllBytes($dll)
  $bytes[$stroffs] = 0
  "`tPATCHED $flag flag"

  # patch the channel restriction code for stable/beta
  $rxChannel = '(?!<41-)83-F8-(?:03-7D|02-7F|02-0F-8F)'
  # old code: cmp eax,3; jge ...
  # new code: cmp eax,2; jg ... (jg can be 2-byte)
  function patch64 {
    $patterns = @(
      "(?<ch>$rxChannel)-.{1,100}-(?<flag>48-8D-)"
      # 48-8D-15-F3-78-87-00 first flag ref
      # 48-8D-15-A4-78-87-00 second flag ref
      "(?<flag>4[8C]-8D-).{9}(.{6}).{100,600}4[8C]-8D-.{9}\1.{600,2000}(?<ch>$rxChannel)"
      "84-C0.{18,48}(?<ch>$rxChannel)-.{30,60}84-C0"
    )
    forEach ($pattern in $patterns) {
      $pos = 0
      $rx = [regex]$pattern
      $patternDisplay = $pattern -replace '^(.{40}).+', '$1'
      write-host -n -f darkgray "`tLooking for $patternDisplay"
      do {
        $m = $rx.match($code, $pos)
        write-host -n -f darkgray .
        if (!$m.success) { break }
        $chanpos = $searchBase + $m.groups['ch'].index/3 + 2
        $pos = $m.groups['flag'].index + $m.groups['flag'].length
        $offs = $BC::ToUInt32($bytes, $searchBase + $pos/3+1)
        $diff = $searchBase + $pos/3+5+$offs - $stroffs
        #write-host ("`n{0,16:x}`t{1}" -f ($offs, $diff))
      } until ($diff -ge 0 -and $diff -le 6000 -and $diff % 256 -eq 0)
      write-host
      #write-host ("{0,16:x}" -f ($searchBase + $pos/3))
      if ($m.success) { break }
      $chanpos = 0
    }
    $chanpos
  }
  function patch86 {
    $flagOffs = [uint32]$stroffs + [uint32]$imagebase32
    $flagOffsStr = $BC::ToString($BC::GetBytes($flagOffs))
    #write-host $flagOffsStr
    $variants = "(?<ch>$rxChannel-.{1,300})-(68-(?<flag>`$1-.{6}`$2.{100,200})){2}",
                "68-(?<flag>`$1-.{6}`$2).{300,500}E8.{12,32}(?<ch>$rxChannel)",
                "E8.{12,32}(?<ch>$rxChannel).{300,500}68-(?<flag>`$1-.{6}`$2)"
    forEach ($variant in $variants) {
      $pattern = $flagOffsStr -replace '^(..)-.{6}(..)', $variant
      $patternDisplay = $pattern -replace '^(.{40}).+', '$1'
      write-host -f darkgray "`tLooking for $patternDisplay..."
      $minDiff = 65536
      foreach ($m in [regex]::matches($code, $pattern)) {
        $maybeFlagOffs = $BC::toUInt32($bytes, $searchBase + $m.groups['flag'].index/3)
        $diff = [Math]::abs($maybeFlagOffs - $flagOffs)
        #write-host ("`n{0,16:x}`t{1}" -f ($maybeFlagOffs, $diff))
        if ($diff % 256 -eq 0 -and $diff -lt $minDiff) {
          $minDiff = $diff
          $chanpos = $searchBase + $m.groups['ch'].index/3 + 2
        }
      }
    }
    $chanpos
  }
  $passes = 3
  foreach ($pass in $passes..1) {
    if ($centbrowser) { break }
    $searchBase = [int]($codesize/$passes * ($pass-1))
    $code = $BC::ToString($bytes, $searchBase, [int]($codesize/$passes) + 2000)
    $chanpos = if ($is64) { patch64 } else { patch86 }
    if ($chanpos) { break }
    $searchBase = 0
  }
  if ($chanpos) {
    #write-host ('{0:x}' -f $chanpos)
    $bytes[$chanpos] = 9
    "`tPATCHED Chrome release channel restriction"
  } elseif (!$centbrowser) {
    write-host -f red "`tUnable to find the channel code, try updating me"
    write-host -f red "`thttp://stackoverflow.com/a/30361260"
    return
  }

  "`tWriting to a temporary dll..."
  [IO.File]::WriteAllBytes("$dll.new",$bytes)

  "`tBacking up the original dll..."
  move -literal $dll "$dll.bak" -force

  "`tRenaming the temporary dll as the original dll..."
  move -literal "$dll.new" $dll -force

  write-host -f green "`tDONE.`n"
  [GC]::Collect()
}

main