mirror of
https://github.com/smaeul/u-boot.git
synced 2025-10-25 01:58:13 +01:00
4961ceefbf
Unused variables should be called '_'. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
384 lines
14 KiB
Python
Executable File
384 lines
14 KiB
Python
Executable File
#!/usr/bin/env python3
|
|
## SPDX-License-Identifier: GPL-2.0-only
|
|
#
|
|
# EFI variable store utilities.
|
|
#
|
|
# (c) 2020 Paulo Alcantara <palcantara@suse.de>
|
|
#
|
|
|
|
import os
|
|
import struct
|
|
import uuid
|
|
import time
|
|
import zlib
|
|
import argparse
|
|
from OpenSSL import crypto
|
|
|
|
# U-Boot variable store format (version 1)
|
|
UBOOT_EFI_VAR_FILE_MAGIC = 0x0161566966456255
|
|
|
|
# UEFI variable attributes
|
|
EFI_VARIABLE_NON_VOLATILE = 0x1
|
|
EFI_VARIABLE_BOOTSERVICE_ACCESS = 0x2
|
|
EFI_VARIABLE_RUNTIME_ACCESS = 0x4
|
|
EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS = 0x10
|
|
EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS = 0x20
|
|
EFI_VARIABLE_READ_ONLY = 1 << 31
|
|
NV_BS = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS
|
|
NV_BS_RT = NV_BS | EFI_VARIABLE_RUNTIME_ACCESS
|
|
NV_BS_RT_AT = NV_BS_RT | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
|
|
DEFAULT_VAR_ATTRS = NV_BS_RT
|
|
|
|
# vendor GUIDs
|
|
EFI_GLOBAL_VARIABLE_GUID = '8be4df61-93ca-11d2-aa0d-00e098032b8c'
|
|
EFI_IMAGE_SECURITY_DATABASE_GUID = 'd719b2cb-3d3a-4596-a3bc-dad00e67656f'
|
|
EFI_CERT_TYPE_PKCS7_GUID = '4aafd29d-68df-49ee-8aa9-347d375665a7'
|
|
WIN_CERT_TYPE_EFI_GUID = 0x0ef1
|
|
WIN_CERT_REVISION = 0x0200
|
|
|
|
var_attrs = {
|
|
'NV': EFI_VARIABLE_NON_VOLATILE,
|
|
'BS': EFI_VARIABLE_BOOTSERVICE_ACCESS,
|
|
'RT': EFI_VARIABLE_RUNTIME_ACCESS,
|
|
'AT': EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS,
|
|
'RO': EFI_VARIABLE_READ_ONLY,
|
|
'AW': EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS,
|
|
}
|
|
|
|
var_guids = {
|
|
'EFI_GLOBAL_VARIABLE_GUID': EFI_GLOBAL_VARIABLE_GUID,
|
|
'EFI_IMAGE_SECURITY_DATABASE_GUID': EFI_IMAGE_SECURITY_DATABASE_GUID,
|
|
}
|
|
|
|
class EfiStruct:
|
|
# struct efi_var_file
|
|
var_file_fmt = '<QQLL'
|
|
var_file_size = struct.calcsize(var_file_fmt)
|
|
# struct efi_var_entry
|
|
var_entry_fmt = '<LLQ16s'
|
|
var_entry_size = struct.calcsize(var_entry_fmt)
|
|
# struct efi_time
|
|
var_time_fmt = '<H6BLh2B'
|
|
var_time_size = struct.calcsize(var_time_fmt)
|
|
# WIN_CERTIFICATE
|
|
var_win_cert_fmt = '<L2H'
|
|
var_win_cert_size = struct.calcsize(var_win_cert_fmt)
|
|
# WIN_CERTIFICATE_UEFI_GUID
|
|
var_win_cert_uefi_guid_fmt = var_win_cert_fmt+'16s'
|
|
var_win_cert_uefi_guid_size = struct.calcsize(var_win_cert_uefi_guid_fmt)
|
|
|
|
class EfiVariable:
|
|
def __init__(self, size, attrs, time, guid, name, data):
|
|
self.size = size
|
|
self.attrs = attrs
|
|
self.time = time
|
|
self.guid = guid
|
|
self.name = name
|
|
self.data = data
|
|
|
|
def calc_crc32(buf):
|
|
return zlib.crc32(buf) & 0xffffffff
|
|
|
|
class EfiVariableStore:
|
|
def __init__(self, infile):
|
|
self.infile = infile
|
|
self.efi = EfiStruct()
|
|
if os.path.exists(self.infile) and os.stat(self.infile).st_size > self.efi.var_file_size:
|
|
with open(self.infile, 'rb') as f:
|
|
buf = f.read()
|
|
self._check_header(buf)
|
|
self.ents = buf[self.efi.var_file_size:]
|
|
else:
|
|
self.ents = bytearray()
|
|
|
|
def _check_header(self, buf):
|
|
hdr = struct.unpack_from(self.efi.var_file_fmt, buf, 0)
|
|
magic, crc32 = hdr[1], hdr[3]
|
|
|
|
if magic != UBOOT_EFI_VAR_FILE_MAGIC:
|
|
print("err: invalid magic number: %s"%hex(magic))
|
|
exit(1)
|
|
if crc32 != calc_crc32(buf[self.efi.var_file_size:]):
|
|
print("err: invalid crc32: %s"%hex(crc32))
|
|
exit(1)
|
|
|
|
def _get_var_name(self, buf):
|
|
name = ''
|
|
for i in range(0, len(buf) - 1, 2):
|
|
if not buf[i] and not buf[i+1]:
|
|
break
|
|
name += chr(buf[i])
|
|
return ''.join([chr(x) for x in name.encode('utf_16_le') if x]), i + 2
|
|
|
|
def _next_var(self, offs=0):
|
|
size, attrs, time, guid = struct.unpack_from(self.efi.var_entry_fmt, self.ents, offs)
|
|
data_fmt = str(size)+"s"
|
|
offs += self.efi.var_entry_size
|
|
name, namelen = self._get_var_name(self.ents[offs:])
|
|
offs += namelen
|
|
data = struct.unpack_from(data_fmt, self.ents, offs)[0]
|
|
# offset to next 8-byte aligned variable entry
|
|
offs = (offs + len(data) + 7) & ~7
|
|
return EfiVariable(size, attrs, time, uuid.UUID(bytes_le=guid), name, data), offs
|
|
|
|
def __iter__(self):
|
|
self.offs = 0
|
|
return self
|
|
|
|
def __next__(self):
|
|
if self.offs < len(self.ents):
|
|
var, noffs = self._next_var(self.offs)
|
|
self.offs = noffs
|
|
return var
|
|
else:
|
|
raise StopIteration
|
|
|
|
def __len__(self):
|
|
return len(self.ents)
|
|
|
|
def _set_var(self, guid, name_data, size, attrs, tsec):
|
|
ent = struct.pack(self.efi.var_entry_fmt,
|
|
size,
|
|
attrs,
|
|
tsec,
|
|
uuid.UUID(guid).bytes_le)
|
|
ent += name_data
|
|
self.ents += ent
|
|
|
|
def del_var(self, guid, name, attrs):
|
|
offs = 0
|
|
while offs < len(self.ents):
|
|
var, loffs = self._next_var(offs)
|
|
if var.name == name and str(var.guid) == guid:
|
|
if var.attrs != attrs:
|
|
print("err: attributes don't match")
|
|
exit(1)
|
|
self.ents = self.ents[:offs] + self.ents[loffs:]
|
|
return
|
|
offs = loffs
|
|
print("err: variable not found")
|
|
exit(1)
|
|
|
|
def set_var(self, guid, name, data, size, attrs):
|
|
offs = 0
|
|
while offs < len(self.ents):
|
|
var, loffs = self._next_var(offs)
|
|
if var.name == name and str(var.guid) == guid:
|
|
if var.attrs != attrs:
|
|
print("err: attributes don't match")
|
|
exit(1)
|
|
# make room for updating var
|
|
self.ents = self.ents[:offs] + self.ents[loffs:]
|
|
break
|
|
offs = loffs
|
|
|
|
tsec = int(time.time()) if attrs & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS else 0
|
|
nd = name.encode('utf_16_le') + b"\x00\x00" + data
|
|
# U-Boot variable format requires the name + data blob to be 8-byte aligned
|
|
pad = ((len(nd) + 7) & ~7) - len(nd)
|
|
nd += bytes([0] * pad)
|
|
|
|
return self._set_var(guid, nd, size, attrs, tsec)
|
|
|
|
def save(self):
|
|
hdr = struct.pack(self.efi.var_file_fmt,
|
|
0,
|
|
UBOOT_EFI_VAR_FILE_MAGIC,
|
|
len(self.ents) + self.efi.var_file_size,
|
|
calc_crc32(self.ents))
|
|
|
|
with open(self.infile, 'wb') as f:
|
|
f.write(hdr)
|
|
f.write(self.ents)
|
|
|
|
def parse_attrs(attrs):
|
|
v = DEFAULT_VAR_ATTRS
|
|
if attrs:
|
|
v = 0
|
|
for i in attrs.split(','):
|
|
v |= var_attrs[i.upper()]
|
|
return v
|
|
|
|
def parse_data(val, vtype):
|
|
if not val or not vtype:
|
|
return None, 0
|
|
fmt = { 'u8': '<B', 'u16': '<H', 'u32': '<L', 'u64': '<Q' }
|
|
if vtype.lower() == 'file':
|
|
with open(val, 'rb') as f:
|
|
data = f.read()
|
|
return data, len(data)
|
|
if vtype.lower() == 'str':
|
|
data = val.encode('utf-8')
|
|
return data, len(data)
|
|
if vtype.lower() == 'nil':
|
|
return None, 0
|
|
i = fmt[vtype.lower()]
|
|
return struct.pack(i, int(val)), struct.calcsize(i)
|
|
|
|
def parse_args(args):
|
|
name = args.name
|
|
attrs = parse_attrs(args.attrs)
|
|
guid = args.guid if args.guid else EFI_GLOBAL_VARIABLE_GUID
|
|
|
|
if name.lower() == 'db' or name.lower() == 'dbx':
|
|
name = name.lower()
|
|
guid = EFI_IMAGE_SECURITY_DATABASE_GUID
|
|
attrs = NV_BS_RT_AT
|
|
elif name.lower() == 'pk' or name.lower() == 'kek':
|
|
name = name.upper()
|
|
guid = EFI_GLOBAL_VARIABLE_GUID
|
|
attrs = NV_BS_RT_AT
|
|
|
|
data, size = parse_data(args.data, args.type)
|
|
return guid, name, attrs, data, size
|
|
|
|
def cmd_set(args):
|
|
env = EfiVariableStore(args.infile)
|
|
guid, name, attrs, data, size = parse_args(args)
|
|
env.set_var(guid=guid, name=name, data=data, size=size, attrs=attrs)
|
|
env.save()
|
|
|
|
def print_var(var):
|
|
print(var.name+':')
|
|
print(" "+str(var.guid)+' '+''.join([x for x in var_guids if str(var.guid) == var_guids[x]]))
|
|
print(" "+'|'.join([x for x in var_attrs if var.attrs & var_attrs[x]])+", DataSize = %s"%hex(var.size))
|
|
hexdump(var.data)
|
|
|
|
def cmd_print(args):
|
|
env = EfiVariableStore(args.infile)
|
|
if not args.name and not args.guid and not len(env):
|
|
return
|
|
|
|
found = False
|
|
for var in env:
|
|
if not args.name:
|
|
if args.guid and args.guid != str(var.guid):
|
|
continue
|
|
print_var(var)
|
|
found = True
|
|
else:
|
|
if args.name != var.name or (args.guid and args.guid != str(var.guid)):
|
|
continue
|
|
print_var(var)
|
|
found = True
|
|
|
|
if not found:
|
|
print("err: variable not found")
|
|
exit(1)
|
|
|
|
def cmd_del(args):
|
|
env = EfiVariableStore(args.infile)
|
|
attrs = parse_attrs(args.attrs)
|
|
guid = args.guid if args.guid else EFI_GLOBAL_VARIABLE_GUID
|
|
env.del_var(guid, args.name, attrs)
|
|
env.save()
|
|
|
|
def pkcs7_sign(cert, key, buf):
|
|
with open(cert, 'r') as f:
|
|
crt = crypto.load_certificate(crypto.FILETYPE_PEM, f.read())
|
|
with open(key, 'r') as f:
|
|
pkey = crypto.load_privatekey(crypto.FILETYPE_PEM, f.read())
|
|
|
|
PKCS7_BINARY = 0x80
|
|
PKCS7_DETACHED = 0x40
|
|
PKCS7_NOATTR = 0x100
|
|
|
|
bio_in = crypto._new_mem_buf(buf)
|
|
p7 = crypto._lib.PKCS7_sign(crt._x509, pkey._pkey, crypto._ffi.NULL, bio_in,
|
|
PKCS7_BINARY|PKCS7_DETACHED|PKCS7_NOATTR)
|
|
bio_out = crypto._new_mem_buf()
|
|
crypto._lib.i2d_PKCS7_bio(bio_out, p7)
|
|
return crypto._bio_to_string(bio_out)
|
|
|
|
# UEFI 2.8 Errata B "8.2.2 Using the EFI_VARIABLE_AUTHENTICATION_2 descriptor"
|
|
def cmd_sign(args):
|
|
guid, name, attrs, data, _ = parse_args(args)
|
|
attrs |= EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
|
|
efi = EfiStruct()
|
|
|
|
tm = time.localtime()
|
|
etime = struct.pack(efi.var_time_fmt,
|
|
tm.tm_year, tm.tm_mon, tm.tm_mday,
|
|
tm.tm_hour, tm.tm_min, tm.tm_sec,
|
|
0, 0, 0, 0, 0)
|
|
|
|
buf = name.encode('utf_16_le') + uuid.UUID(guid).bytes_le + attrs.to_bytes(4, byteorder='little') + etime
|
|
if data:
|
|
buf += data
|
|
sig = pkcs7_sign(args.cert, args.key, buf)
|
|
|
|
desc = struct.pack(efi.var_win_cert_uefi_guid_fmt,
|
|
efi.var_win_cert_uefi_guid_size + len(sig),
|
|
WIN_CERT_REVISION,
|
|
WIN_CERT_TYPE_EFI_GUID,
|
|
uuid.UUID(EFI_CERT_TYPE_PKCS7_GUID).bytes_le)
|
|
|
|
with open(args.outfile, 'wb') as f:
|
|
if data:
|
|
f.write(etime + desc + sig + data)
|
|
else:
|
|
f.write(etime + desc + sig)
|
|
|
|
def main():
|
|
ap = argparse.ArgumentParser(description='EFI variable store utilities')
|
|
subp = ap.add_subparsers(help="sub-command help")
|
|
|
|
printp = subp.add_parser('print', help='get/list EFI variables')
|
|
printp.add_argument('--infile', '-i', required=True, help='file to save the EFI variables')
|
|
printp.add_argument('--name', '-n', help='variable name')
|
|
printp.add_argument('--guid', '-g', help='vendor GUID')
|
|
printp.set_defaults(func=cmd_print)
|
|
|
|
setp = subp.add_parser('set', help='set EFI variable')
|
|
setp.add_argument('--infile', '-i', required=True, help='file to save the EFI variables')
|
|
setp.add_argument('--name', '-n', required=True, help='variable name')
|
|
setp.add_argument('--attrs', '-a', help='variable attributes (values: nv,bs,rt,at,ro,aw)')
|
|
setp.add_argument('--guid', '-g', help="vendor GUID (default: %s)"%EFI_GLOBAL_VARIABLE_GUID)
|
|
setp.add_argument('--type', '-t', help='variable type (values: file|u8|u16|u32|u64|str)')
|
|
setp.add_argument('--data', '-d', help='data or filename')
|
|
setp.set_defaults(func=cmd_set)
|
|
|
|
delp = subp.add_parser('del', help='delete EFI variable')
|
|
delp.add_argument('--infile', '-i', required=True, help='file to save the EFI variables')
|
|
delp.add_argument('--name', '-n', required=True, help='variable name')
|
|
delp.add_argument('--attrs', '-a', help='variable attributes (values: nv,bs,rt,at,ro,aw)')
|
|
delp.add_argument('--guid', '-g', help="vendor GUID (default: %s)"%EFI_GLOBAL_VARIABLE_GUID)
|
|
delp.set_defaults(func=cmd_del)
|
|
|
|
signp = subp.add_parser('sign', help='sign time-based EFI payload')
|
|
signp.add_argument('--cert', '-c', required=True, help='x509 certificate filename in PEM format')
|
|
signp.add_argument('--key', '-k', required=True, help='signing certificate filename in PEM format')
|
|
signp.add_argument('--name', '-n', required=True, help='variable name')
|
|
signp.add_argument('--attrs', '-a', help='variable attributes (values: nv,bs,rt,at,ro,aw)')
|
|
signp.add_argument('--guid', '-g', help="vendor GUID (default: %s)"%EFI_GLOBAL_VARIABLE_GUID)
|
|
signp.add_argument('--type', '-t', required=True, help='variable type (values: file|u8|u16|u32|u64|str|nil)')
|
|
signp.add_argument('--data', '-d', help='data or filename')
|
|
signp.add_argument('--outfile', '-o', required=True, help='output filename of signed EFI payload')
|
|
signp.set_defaults(func=cmd_sign)
|
|
|
|
args = ap.parse_args()
|
|
if hasattr(args, "func"):
|
|
args.func(args)
|
|
else:
|
|
ap.print_help()
|
|
|
|
def group(a, *ns):
|
|
for n in ns:
|
|
a = [a[i:i+n] for i in range(0, len(a), n)]
|
|
return a
|
|
|
|
def join(a, *cs):
|
|
return [cs[0].join(join(t, *cs[1:])) for t in a] if cs else a
|
|
|
|
def hexdump(data):
|
|
toHex = lambda c: '{:02X}'.format(c)
|
|
toChr = lambda c: chr(c) if 32 <= c < 127 else '.'
|
|
make = lambda f, *cs: join(group(list(map(f, data)), 8, 2), *cs)
|
|
hs = make(toHex, ' ', ' ')
|
|
cs = make(toChr, ' ', '')
|
|
for i, (h, c) in enumerate(zip(hs, cs)):
|
|
print (' {:010X}: {:48} {:16}'.format(i * 16, h, c))
|
|
|
|
if __name__ == '__main__':
|
|
main()
|