Module: Puppet::Util::Windows::Process

Extended by:
FFI::Library, String
Defined in:
lib/puppet/util/windows/process.rb

Defined Under Namespace

Classes: LUID, LUID_AND_ATTRIBUTES, OSVERSIONINFO, TOKEN_ELEVATION, TOKEN_PRIVILEGES

Constant Summary collapse

WAIT_TIMEOUT = 
0x102
WAIT_INTERVAL = 
200
CREATE_NO_WINDOW =

docs.microsoft.com/en-us/windows/desktop/ProcThread/process-creation-flags

0x08000000
PROCESS_QUERY_INFORMATION =

docs.microsoft.com/en-us/windows/desktop/ProcThread/process-security-and-access-rights

0x0400
MAX_PATH_LENGTH =

docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file#maximum-path-length-limitation

32767
TOKEN_ALL_ACCESS = 
0xF01FF
ERROR_NO_SUCH_PRIVILEGE = 
1313
TOKEN_QUERY = 
0x0008
ABOVE_NORMAL_PRIORITY_CLASS = 
0x0008000
BELOW_NORMAL_PRIORITY_CLASS = 
0x0004000
HIGH_PRIORITY_CLASS = 
0x0000080
IDLE_PRIORITY_CLASS = 
0x0000040
NORMAL_PRIORITY_CLASS = 
0x0000020
REALTIME_PRIORITY_CLASS = 
0x0000010
TOKEN_INFORMATION_CLASS =

msdn.microsoft.com/en-us/library/windows/desktop/aa379626(v=vs.85).aspx

enum(
    :TokenUser, 1,
    :TokenGroups,
    :TokenPrivileges,
    :TokenOwner,
    :TokenPrimaryGroup,
    :TokenDefaultDacl,
    :TokenSource,
    :TokenType,
    :TokenImpersonationLevel,
    :TokenStatistics,
    :TokenRestrictedSids,
    :TokenSessionId,
    :TokenGroupsAndPrivileges,
    :TokenSessionReference,
    :TokenSandBoxInert,
    :TokenAuditPolicy,
    :TokenOrigin,
    :TokenElevationType,
    :TokenLinkedToken,
    :TokenElevation,
    :TokenHasRestrictions,
    :TokenAccessInformation,
    :TokenVirtualizationAllowed,
    :TokenVirtualizationEnabled,
    :TokenIntegrityLevel,
    :TokenUIAccess,
    :TokenMandatoryPolicy,
    :TokenLogonSid,
    :TokenIsAppContainer,
    :TokenCapabilities,
    :TokenAppContainerSid,
    :TokenAppContainerNumber,
    :TokenUserClaimAttributes,
    :TokenDeviceClaimAttributes,
    :TokenRestrictedUserClaimAttributes,
    :TokenRestrictedDeviceClaimAttributes,
    :TokenDeviceGroups,
    :TokenRestrictedDeviceGroups,
    :TokenSecurityAttributes,
    :TokenIsRestricted,
    :MaxTokenInfoClass
)

Class Method Summary collapse

Methods included from FFI::Library

attach_function_private

Methods included from String

wide_string

Class Method Details

.elevated_security? ⇒ Boolean

Returns whether or not the owner of the current process is running with elevated security privileges.

Only supported on Windows Vista or later.


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# File 'lib/puppet/util/windows/process.rb', line 252

def elevated_security?
  # default / pre-Vista
  elevated = false
  handle = nil

  begin
    handle = get_current_process
    open_process_token(handle, TOKEN_QUERY) do |token_handle|
      get_token_information(token_handle, :TokenElevation) do |token_info|
        token_elevation = parse_token_information_as_token_elevation(token_info)
        # TokenIsElevated member of the TOKEN_ELEVATION struct
        elevated = token_elevation[:TokenIsElevated] != 0
      end
    end

    elevated
  rescue Puppet::Util::Windows::Error => e
    raise e if e.code != ERROR_NO_SUCH_PRIVILEGE
  ensure
    FFI::WIN32.CloseHandle(handle) if handle
  end
end

.execute(command, arguments, stdin, stdout, stderr) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 18

def execute(command, arguments, stdin, stdout, stderr)
  create_args = {
    :command_line => command,
    :startup_info => {
      :stdin => stdin,
      :stdout => stdout,
      :stderr => stderr
    },
    :close_handles => false,
  }
  if arguments[:suppress_window]
    create_args[:creation_flags] = CREATE_NO_WINDOW
  end
  if arguments[:cwd]
    create_args[:cwd] = arguments[:cwd]
  end
  Process.create(create_args)
end

.get_current_process ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 61

def get_current_process
  # this pseudo-handle does not require closing per MSDN docs
  GetCurrentProcess()
end

.get_environment_strings ⇒ Object

Returns a hash of the current environment variables encoded as UTF-8 The memory block returned from GetEnvironmentStringsW is double-null terminated and the vars are paired as below; Var1=Value10 Var2=Value20 VarX=ValueX00 Note - Some env variable names start with '=' and are excluded from the return value Note - The env_ptr MUST be freed using the FreeEnvironmentStringsW function Note - There is no technical limitation to the size of the environment block returned.

However a practical limit of 64K is used as no single environment variable can exceed 32KB


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# File 'lib/puppet/util/windows/process.rb', line 305

def get_environment_strings
  env_ptr = GetEnvironmentStringsW()

  # pass :invalid => :replace to the Ruby String#encode to use replacement characters
  pairs = env_ptr.read_arbitrary_wide_string_up_to(65534, :double_null, { :invalid => :replace })
    .split(?\x00)
    .reject { |env_str| env_str.nil? || env_str.empty? || env_str[0] == '=' }
    .reject do |env_str|
      # reject any string containing the Unicode replacement character
      if env_str.include?("\uFFFD")
        Puppet.warning(_("Discarding environment variable %{string} which contains invalid bytes") % { string: env_str })
        true
      end
    end
    .map { |env_pair| env_pair.split('=', 2) }
  Hash[ pairs ]
ensure
  if env_ptr && ! env_ptr.null?
    if FreeEnvironmentStringsW(env_ptr) == FFI::WIN32_FALSE
      Puppet.debug "FreeEnvironmentStringsW memory leak"
    end
  end
end

.get_process_image_name_by_pid(pid) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 122

def get_process_image_name_by_pid(pid)
  image_name = ""

  Puppet::Util::Windows::Security.with_privilege(Puppet::Util::Windows::Security::SE_DEBUG_NAME) do
    open_process(PROCESS_QUERY_INFORMATION, false, pid) do |phandle|
      FFI::MemoryPointer.new(:dword, 1) do |exe_name_length_ptr|
        # UTF is 2 bytes/char:
        max_chars = MAX_PATH_LENGTH + 1
        exe_name_length_ptr.write_dword(max_chars)
        FFI::MemoryPointer.new(:wchar, max_chars) do |exe_name_ptr|
          use_win32_path_format = 0
          result = QueryFullProcessImageNameW(phandle, use_win32_path_format, exe_name_ptr, exe_name_length_ptr)
          if result == FFI::WIN32_FALSE
            raise Puppet::Util::Windows::Error.new(
                    "QueryFullProcessImageNameW(phandle, #{use_win32_path_format}, " +
                    "exe_name_ptr, #{max_chars}")
          end
          image_name = exe_name_ptr.read_wide_string(exe_name_length_ptr.read_dword)
        end
      end
    end
  end

  image_name
end

.get_system_default_ui_language ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 349

def get_system_default_ui_language
  GetSystemDefaultUILanguage()
end

.get_token_information(token_handle, token_information, &block) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 170

def get_token_information(token_handle, token_information, &block)
  # to determine buffer size
  FFI::MemoryPointer.new(:dword, 1) do |return_length_ptr|
    result = GetTokenInformation(token_handle, token_information, nil, 0, return_length_ptr)
    return_length = return_length_ptr.read_dword

    if return_length <= 0
      raise Puppet::Util::Windows::Error.new(
        "GetTokenInformation(#{token_handle}, #{token_information}, nil, 0, #{return_length_ptr})")
    end

    # re-call API with properly sized buffer for all results
    FFI::MemoryPointer.new(return_length) do |token_information_buf|
      result = GetTokenInformation(token_handle, token_information,
        token_information_buf, return_length, return_length_ptr)

      if result == FFI::WIN32_FALSE
        raise Puppet::Util::Windows::Error.new(
          "GetTokenInformation(#{token_handle}, #{token_information}, #{token_information_buf}, " +
            "#{return_length}, #{return_length_ptr})")
      end

      yield token_information_buf
    end
  end

  # GetTokenInformation buffer has been cleaned up by this point, nothing to return
  nil
end

.lookup_privilege_value(name, system_name = '', &block) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 149

def lookup_privilege_value(name, system_name = '', &block)
  FFI::MemoryPointer.new(LUID.size) do |luid_ptr|
    result = LookupPrivilegeValueW(
      wide_string(system_name),
      wide_string(name.to_s),
      luid_ptr
      )

    if result == FFI::WIN32_FALSE
      raise Puppet::Util::Windows::Error.new(
        "LookupPrivilegeValue(#{system_name}, #{name}, #{luid_ptr})")
    end

    yield LUID.new(luid_ptr)
  end

  # the underlying MemoryPointer for LUID is cleaned up by this point
  nil
end

.open_process(desired_access, inherit_handle, process_id, &block) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 67

def open_process(desired_access, inherit_handle, process_id, &block)
  phandle = nil
  inherit = inherit_handle ? FFI::WIN32_TRUE : FFI::WIN32_FALSE
  begin
    phandle = OpenProcess(desired_access, inherit, process_id)
    if phandle == FFI::Pointer::NULL_HANDLE
      raise Puppet::Util::Windows::Error.new(
        "OpenProcess(#{desired_access.to_s(8)}, #{inherit}, #{process_id})")
    end

    yield phandle
  ensure
    FFI::WIN32.CloseHandle(phandle) if phandle
  end

  # phandle has had CloseHandle called against it, so nothing to return
  nil
end

.open_process_token(handle, desired_access, &block) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 87

def open_process_token(handle, desired_access, &block)
  token_handle = nil
  begin
    FFI::MemoryPointer.new(:handle, 1) do |token_handle_ptr|
      result = OpenProcessToken(handle, desired_access, token_handle_ptr)
      if result == FFI::WIN32_FALSE
        raise Puppet::Util::Windows::Error.new(
          "OpenProcessToken(#{handle}, #{desired_access.to_s(8)}, #{token_handle_ptr})")
      end

      yield token_handle = token_handle_ptr.read_handle
    end

    token_handle
  ensure
    FFI::WIN32.CloseHandle(token_handle) if token_handle
  end

  # token_handle has had CloseHandle called against it, so nothing to return
  nil
end

.parse_token_information_as_token_elevation(token_information_buf) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 217

def parse_token_information_as_token_elevation(token_information_buf)
  TOKEN_ELEVATION.new(token_information_buf)
end

.parse_token_information_as_token_privileges(token_information_buf) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 201

def parse_token_information_as_token_privileges(token_information_buf)
  raw_privileges = TOKEN_PRIVILEGES.new(token_information_buf)
  privileges = { :count => raw_privileges[:PrivilegeCount], :privileges => [] }

  offset = token_information_buf + TOKEN_PRIVILEGES.offset_of(:Privileges)
  privilege_ptr = FFI::Pointer.new(LUID_AND_ATTRIBUTES, offset)

  # extract each instance of LUID_AND_ATTRIBUTES
  0.upto(privileges[:count] - 1) do |i|
    privileges[:privileges] <<  LUID_AND_ATTRIBUTES.new(privilege_ptr[i])
  end

  privileges
end

.process_privilege_symlink? ⇒ Boolean 


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# File 'lib/puppet/util/windows/process.rb', line 224

def process_privilege_symlink?
  privilege_symlink = false
  handle = get_current_process
  open_process_token(handle, TOKEN_ALL_ACCESS) do |token_handle|
    lookup_privilege_value('SeCreateSymbolicLinkPrivilege') do |luid|
      get_token_information(token_handle, :TokenPrivileges) do |token_info|
        token_privileges = parse_token_information_as_token_privileges(token_info)
        privilege_symlink = token_privileges[:privileges].any? { |p| p[:Luid].values == luid.values }
      end
    end
  end

  privilege_symlink
rescue Puppet::Util::Windows::Error => e
  if e.code == ERROR_NO_SUCH_PRIVILEGE
    false # pre-Vista
  else
    raise e
  end
end

.set_environment_variable(name, val) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 330

def set_environment_variable(name, val)
  raise Puppet::Util::Windows::Error(_('environment variable name must not be nil or empty')) if ! name || name.empty?

  FFI::MemoryPointer.from_string_to_wide_string(name) do |name_ptr|
    if (val.nil?)
      if SetEnvironmentVariableW(name_ptr, FFI::MemoryPointer::NULL) == FFI::WIN32_FALSE
        raise Puppet::Util::Windows::Error.new(_("Failed to remove environment variable: %{name}") % { name: name })
      end
    else
      FFI::MemoryPointer.from_string_to_wide_string(val) do |val_ptr|
        if SetEnvironmentVariableW(name_ptr, val_ptr) == FFI::WIN32_FALSE
          raise Puppet::Util::Windows::Error.new(_("Failed to set environment variable: %{name}") % { name: name })
        end
      end
    end
  end
end

.supports_elevated_security? ⇒ Boolean

Returns whether or not the OS has the ability to set elevated token information.

Returns true on Windows Vista or later, otherwise false


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# File 'lib/puppet/util/windows/process.rb', line 359

def supports_elevated_security?
  windows_major_version >= 6
end

.wait_process(handle) ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 38

def wait_process(handle)
  while WaitForSingleObject(handle, WAIT_INTERVAL) == WAIT_TIMEOUT
    sleep(0)
  end

  exit_status = -1
  FFI::MemoryPointer.new(:dword, 1) do |exit_status_ptr|
    if GetExitCodeProcess(handle, exit_status_ptr) == FFI::WIN32_FALSE
      raise Puppet::Util::Windows::Error.new(_("Failed to get child process exit code"))
    end
    exit_status = exit_status_ptr.read_dword

    # $CHILD_STATUS is not set when calling win32/process Process.create
    # and since it's read-only, we can't set it. But we can execute a
    # a shell that simply returns the desired exit status, which has the
    # desired effect.
    %x{#{ENV['COMSPEC']} /c exit #{exit_status}}
  end

  exit_status
end

.windows_major_version ⇒ Object 


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# File 'lib/puppet/util/windows/process.rb', line 276

def windows_major_version
  ver = 0

  FFI::MemoryPointer.new(OSVERSIONINFO.size) do |os_version_ptr|
    os_version = OSVERSIONINFO.new(os_version_ptr)
    os_version[:dwOSVersionInfoSize] = OSVERSIONINFO.size

    result = GetVersionExW(os_version_ptr)

    if result == FFI::WIN32_FALSE
      raise Puppet::Util::Windows::Error.new(_("GetVersionEx failed"))
    end

    ver = os_version[:dwMajorVersion]
  end

  ver
end

.with_process_token(access, &block) ⇒ Object

Execute a block with the current process token


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# File 'lib/puppet/util/windows/process.rb', line 111

def with_process_token(access, &block)
  handle = get_current_process
  open_process_token(handle, access) do |token_handle|
    yield token_handle
  end

  # all handles have been closed, so nothing to safely return
  nil
end