92 lines
3.4 KiB
Python
92 lines
3.4 KiB
Python
# SPDX-License-Identifier: GPL-2.0+
|
|
# Copyright (c) 2018 Google, Inc
|
|
# Written by Simon Glass <sjg@chromium.org>
|
|
#
|
|
|
|
# Support for a Chromium OS verified boot block, used to sign a read-write
|
|
# section of the image.
|
|
|
|
from collections import OrderedDict
|
|
import os
|
|
|
|
from binman.entry import Entry, EntryArg
|
|
|
|
from dtoc import fdt_util
|
|
from patman import tools
|
|
|
|
class Entry_vblock(Entry):
|
|
"""An entry which contains a Chromium OS verified boot block
|
|
|
|
Properties / Entry arguments:
|
|
- content: List of phandles to entries to sign
|
|
- keydir: Directory containing the public keys to use
|
|
- keyblock: Name of the key file to use (inside keydir)
|
|
- signprivate: Name of provide key file to use (inside keydir)
|
|
- version: Version number of the vblock (typically 1)
|
|
- kernelkey: Name of the kernel key to use (inside keydir)
|
|
- preamble-flags: Value of the vboot preamble flags (typically 0)
|
|
|
|
Output files:
|
|
- input.<unique_name> - input file passed to futility
|
|
- vblock.<unique_name> - output file generated by futility (which is
|
|
used as the entry contents)
|
|
|
|
Chromium OS signs the read-write firmware and kernel, writing the signature
|
|
in this block. This allows U-Boot to verify that the next firmware stage
|
|
and kernel are genuine.
|
|
"""
|
|
def __init__(self, section, etype, node):
|
|
super().__init__(section, etype, node)
|
|
self.content = fdt_util.GetPhandleList(self._node, 'content')
|
|
if not self.content:
|
|
self.Raise("Vblock must have a 'content' property")
|
|
(self.keydir, self.keyblock, self.signprivate, self.version,
|
|
self.kernelkey, self.preamble_flags) = self.GetEntryArgsOrProps([
|
|
EntryArg('keydir', str),
|
|
EntryArg('keyblock', str),
|
|
EntryArg('signprivate', str),
|
|
EntryArg('version', int),
|
|
EntryArg('kernelkey', str),
|
|
EntryArg('preamble-flags', int)])
|
|
|
|
def GetVblock(self):
|
|
# Join up the data files to be signed
|
|
input_data = b''
|
|
for entry_phandle in self.content:
|
|
data = self.section.GetContentsByPhandle(entry_phandle, self)
|
|
if data is None:
|
|
# Data not available yet
|
|
return False
|
|
input_data += data
|
|
|
|
uniq = self.GetUniqueName()
|
|
output_fname = tools.GetOutputFilename('vblock.%s' % uniq)
|
|
input_fname = tools.GetOutputFilename('input.%s' % uniq)
|
|
tools.WriteFile(input_fname, input_data)
|
|
prefix = self.keydir + '/'
|
|
args = [
|
|
'vbutil_firmware',
|
|
'--vblock', output_fname,
|
|
'--keyblock', prefix + self.keyblock,
|
|
'--signprivate', prefix + self.signprivate,
|
|
'--version', '%d' % self.version,
|
|
'--fv', input_fname,
|
|
'--kernelkey', prefix + self.kernelkey,
|
|
'--flags', '%d' % self.preamble_flags,
|
|
]
|
|
#out.Notice("Sign '%s' into %s" % (', '.join(self.value), self.label))
|
|
stdout = tools.Run('futility', *args)
|
|
return tools.ReadFile(output_fname)
|
|
|
|
def ObtainContents(self):
|
|
data = self.GetVblock()
|
|
if data is False:
|
|
return False
|
|
self.SetContents(data)
|
|
return True
|
|
|
|
def ProcessContents(self):
|
|
# The blob may have changed due to WriteSymbols()
|
|
data = self.GetVblock()
|
|
return self.ProcessContentsUpdate(data)
|