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util/me_cleaner: Pull the latest changes from upstream 

Relevant changes (commit 250b2ec):
 * Fix a bug for ME6 Ignition images.
 * Fix signature checking for ME11 and later.
 * Add command line arguments.
 * Add an option to relocate the FTPR partition to the top of the
    ME region, recovering most of the ME region space.
 * Print the image minimum size.
 * Add write boundary checks, to prevent writes on other regions
    in case of bugs.

The new changes have been tested on multiple platforms by the
me_cleaner users. They have been tested also on the author's
X220T with coreboot, where the ME region has been shrinked up to
84 kB without any issue.

Change-Id: I3bd6b4cba9f5eebc3cd4892dd9f188744a06c42b
Signed-off-by: Nicola Corna <nicola@corna.info>
Reviewed-on: https://review.coreboot.org/18473
Tested-by: build bot (Jenkins)
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
This commit is contained in:
Nicola Corna 2017-02-22 10:16:32 +01:00 committed by Martin Roth
parent 4f4fc1891b
commit e38f85915f
2 changed files with 312 additions and 119 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
util/me_cleaner/README.md
View File

@ -12,7 +12,8 @@ Currently this tool:
* Removes any partition except for the fundamental one (FTPR)
* Removes the EFFS presence flag
* Corrects the FPT checksum
* Removes any non-essential LZMA or Huffman compressed module (pre-Skylake only)
* Removes any non-essential LZMA or Huffman compressed module from the FTPR partition (pre-Skylake only)
* Relocates the remaining parts of the FTPR partition to the top of the ME region (pre-Skylake only)
* Checks the validity of the RSA signature of the FTPR partition
Don't forget to power cycle your PC after flashing the modified ME/TXE image

428
util/me_cleaner/me_cleaner.py
View File

@ -18,12 +18,70 @@ import sys
import itertools
import binascii
import hashlib
import argparse
import shutil
from struct import pack, unpack
min_ftpr_offset = 0x400
spared_blocks = 4
unremovable_modules = ("BUP", "ROMP")
class OutOfRegionException(Exception):
pass
class regionFile:
def __init__(self, f, region_start, region_end):
self.f = f
self.region_start = region_start
self.region_end = region_end
def read(self, n):
return self.f.read(n)
def readinto(self, b):
return self.f.readinto(b)
def seek(self, offset):
return self.f.seek(offset)
def write_to(self, offset, data):
if offset >= self.region_start and \
offset + len(data) <= self.region_end:
self.f.seek(offset)
return self.f.write(data)
else:
raise OutOfRegionException()
def fill_range(self, start, end, fill):
if start >= self.region_start and end <= self.region_end:
if start < end:
block = fill * 4096
self.f.seek(start)
self.f.writelines(itertools.repeat(block,
(end - start) // 4096))
self.f.write(block[:(end - start) % 4096])
else:
raise OutOfRegionException()
def move_range(self, offset_from, size, offset_to, fill):
if offset_from >= self.region_start and \
offset_from + size <= self.region_end and \
offset_to >= self.region_start and \
offset_to + size <= self.region_end:
for i in range(0, size, 4096):
self.f.seek(offset_from + i, 0)
block = self.f.read(4096 if size - i >= 4096 else size - i)
self.f.seek(offset_from + i, 0)
self.f.write(fill * len(block))
self.f.seek(offset_to + i, 0)
self.f.write(block)
else:
raise OutOfRegionException()
def get_chunks_offsets(llut, me_start):
chunk_count = unpack("<I", llut[0x04:0x08])[0]
huffman_stream_end = sum(unpack("<II", llut[0x10:0x18])) + me_start
@ -50,19 +108,13 @@ def get_chunks_offsets(llut, me_start):
return offsets
def fill_range(f, start, end, fill):
block = fill * 4096
f.seek(start)
f.writelines(itertools.repeat(block, (end - start) // 4096))
f.write(block[:(end - start) % 4096])
def remove_modules(f, mod_headers, ftpr_offset):
def remove_modules(f, mod_headers, ftpr_offset, me_end):
comp_str = ("Uncomp.", "Huffman", "LZMA")
unremovable_huff_chunks = []
chunks_offsets = []
base = 0
chunk_size = 0
end_addr = 0
for mod_header in mod_headers:
name = mod_header[0x04:0x14].rstrip(b"\x00").decode("ascii")
@ -78,9 +130,11 @@ def remove_modules(f, mod_headers, ftpr_offset):
.format(offset, offset + size))
if name in unremovable_modules:
end_addr = max(end_addr, offset + size)
print("NOT removed, essential")
else:
fill_range(f, offset, offset + size, b"\xff")
end = min(offset + size, me_end)
f.fill_range(offset, end, b"\xff")
print("removed")
elif comp_type == 0x01:
@ -93,10 +147,9 @@ def remove_modules(f, mod_headers, ftpr_offset):
chunk_count = unpack("<I", llut[0x4:0x8])[0]
base = unpack("<I", llut[0x8:0xc])[0] + 0x10000000
huff_data_len = unpack("<I", llut[0x10:0x14])[0]
chunk_size = unpack("<I", llut[0x30:0x34])[0]
llut += f.read(chunk_count * 4 + huff_data_len)
llut += f.read(chunk_count * 4)
chunks_offsets = get_chunks_offsets(llut, me_start)
else:
sys.exit("Huffman modules found, but LLUT is not present")
@ -129,14 +182,20 @@ def remove_modules(f, mod_headers, ftpr_offset):
for removable_chunk in removable_huff_chunks:
if removable_chunk[1] > removable_chunk[0]:
fill_range(f, removable_chunk[0], removable_chunk[1], b"\xff")
end = min(removable_chunk[1], me_end)
f.fill_range(removable_chunk[0], end, b"\xff")
end_addr = max(end_addr,
max(unremovable_huff_chunks, key=lambda x: x[1])[1])
return end_addr
def check_partition_signature(f, offset):
f.seek(offset)
header = f.read(0x80)
modulus = int(binascii.hexlify(f.read(0x100)[::-1]), 16)
public_exponent = int(binascii.hexlify(f.read(0x4)[::-1]), 16)
public_exponent = unpack("<I", f.read(4))[0]
signature = int(binascii.hexlify(f.read(0x100)[::-1]), 16)
header_len = unpack("<I", header[0x4:0x8])[0] * 4
@ -152,144 +211,274 @@ def check_partition_signature(f, offset):
return "{:#x}".format(decrypted_sig).endswith(sha256.hexdigest()) # FIXME
if len(sys.argv) != 2 or sys.argv[1] == "-h" or sys.argv[1] == "--help":
print("Usage: \n"
" me_cleaner.py me_or_txe_image.bin\n"
"or\n"
" me_cleaner.py full_dump.bin")
else:
with open(sys.argv[1], "r+b") as f:
f.seek(0x10)
magic = f.read(4)
def relocate_partition(f, me_start, me_end, partition_header_offset,
new_offset, mod_headers):
if magic == b"$FPT":
print("ME/TXE image detected")
me_start = 0
f.seek(0, 2)
me_end = f.tell()
f.seek(partition_header_offset)
name = f.read(4).rstrip(b"\x00").decode("ascii")
f.seek(partition_header_offset + 0x8)
old_offset, partition_size = unpack("<II", f.read(0x8))
old_offset += me_start
elif magic == b"\x5a\xa5\xf0\x0f":
print("Full image detected")
f.seek(0x14)
flmap0 = unpack("<I", f.read(4))[0]
nr = flmap0 >> 24 & 0x7
frba = flmap0 >> 12 & 0xff0
if nr >= 2:
f.seek(frba + 0x8)
flreg2 = unpack("<I", f.read(4))[0]
me_start = (flreg2 & 0x1fff) << 12
me_end = flreg2 >> 4 & 0x1fff000 | 0xfff
llut_start = 0
for mod_header in mod_headers:
if (unpack("<I", mod_header[0x50:0x54])[0] >> 4) & 7 == 0x01:
llut_start = unpack("<I", mod_header[0x38:0x3C])[0] + old_offset
break
if me_start >= me_end:
sys.exit("The ME/TXE region in this image has been "
"disabled")
if llut_start != 0:
# Bytes 0x9:0xb of the LLUT (bytes 0x1:0x3 of the AddrBase) are added
# to the SpiBase (bytes 0xc:0x10 of the LLUT) to compute the final
# start of the LLUT. Since AddrBase is not modifiable, we can act only
# on SpiBase and here we compute the minimum allowed new_offset.
f.seek(llut_start + 0x9)
lut_start_corr = unpack("<H", f.read(2))[0]
new_offset = max(new_offset,
lut_start_corr + me_start - llut_start - 0x40 +
old_offset)
new_offset = ((new_offset + 0x1f) // 0x20) * 0x20
f.seek(me_start + 0x10)
if f.read(4) != b"$FPT":
sys.exit("The ME/TXE region is corrupted or missing")
offset_diff = new_offset - old_offset
print("Relocating {} to {:#x} - {:#x}..."
.format(name, new_offset, new_offset + partition_size))
print("The ME/TXE region goes from {:#x} to {:#x}"
.format(me_start, me_end))
else:
sys.exit("This image does not contains a ME/TXE firmware "
"(NR = {})".format(nr))
print(" Adjusting FPT entry...")
f.write_to(partition_header_offset + 0x8,
pack("<I", new_offset - me_start))
if llut_start != 0:
f.seek(llut_start)
if f.read(4) == b"LLUT":
print(" Adjusting LUT start offset...")
lut_offset = llut_start + offset_diff + 0x40 - \
lut_start_corr - me_start
f.write_to(llut_start + 0x0c, pack("<I", lut_offset))
print(" Adjusting Huffman start offset...")
f.seek(llut_start + 0x14)
old_huff_offset = unpack("<I", f.read(4))[0]
f.write_to(llut_start + 0x14,
pack("<I", old_huff_offset + offset_diff))
print(" Adjusting chunks offsets...")
f.seek(llut_start + 0x4)
chunk_count = unpack("<I", f.read(4))[0]
f.seek(llut_start + 0x40)
chunks = bytearray(chunk_count * 4)
f.readinto(chunks)
for i in range(0, chunk_count * 4, 4):
if chunks[i + 3] != 0x80:
chunks[i:i + 3] = \
pack("<I", unpack("<I", chunks[i:i + 3] +
b"\x00")[0] + offset_diff)[0:3]
f.write_to(llut_start + 0x40, chunks)
else:
sys.exit("Unknown image")
sys.exit("Huffman modules present but no LLUT found!")
else:
print(" No Huffman modules found")
print("Found FPT header at {:#x}".format(me_start + 0x10))
print(" Moving data...")
partition_size = min(partition_size, me_end - old_offset)
f.move_range(old_offset, partition_size, new_offset, b"\xff")
f.seek(me_start + 0x14)
entries = unpack("<I", f.read(4))[0]
print("Found {} partition(s)".format(entries))
return new_offset
f.seek(me_start + 0x14)
header_len = unpack("B", f.read(1))[0]
f.seek(me_start + 0x30)
partitions = f.read(entries * 0x20)
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Tool to remove as much code "
"as possible from Intel ME/TXE firmwares")
parser.add_argument("file", help="ME/TXE image or full dump")
parser.add_argument("-O", "--output", help="save the modified image in a "
"separate file, instead of modifying the original "
"file")
parser.add_argument("-r", "--relocate", help="relocate the FTPR partition "
"to the top of the ME region", action="store_true")
parser.add_argument("-k", "--keep-modules", help="don't remove the FTPR "
"modules, even when possible", action="store_true")
parser.add_argument("-d", "--descriptor", help="remove the ME/TXE "
"Read/Write permissions to the other regions on the "
"flash from the Intel Flash Descriptor (requires a "
"full dump)", action="store_true")
parser.add_argument("-c", "--check", help="verify the integrity of the "
"fundamental parts of the firmware and exit",
action="store_true")
args = parser.parse_args()
ftpr_header = b""
f = open(args.file, "rb" if args.check or args.output else "r+b")
f.seek(0x10)
magic = f.read(4)
for i in range(entries):
if partitions[i * 0x20:(i * 0x20) + 4] == b"FTPR":
ftpr_header = partitions[i * 0x20:(i + 1) * 0x20]
break
if magic == b"$FPT":
print("ME/TXE image detected")
me_start = 0
f.seek(0, 2)
me_end = f.tell()
if ftpr_header == b"":
sys.exit("FTPR header not found, this image doesn't seem to be "
"valid")
if args.descriptor:
sys.exit("-d requires a full dump")
elif magic == b"\x5a\xa5\xf0\x0f":
print("Full image detected")
f.seek(0x14)
flmap0, flmap1 = unpack("<II", f.read(8))
nr = flmap0 >> 24 & 0x7
frba = flmap0 >> 12 & 0xff0
fmba = (flmap1 & 0xff) << 4
if nr >= 2:
f.seek(frba)
flreg0, flreg1, flreg2 = unpack("<III", f.read(12))
fd_start = (flreg0 & 0x1fff) << 12
fd_end = flreg0 >> 4 & 0x1fff000 | 0xfff + 1
me_start = (flreg2 & 0x1fff) << 12
me_end = flreg2 >> 4 & 0x1fff000 | 0xfff + 1
if me_start >= me_end:
sys.exit("The ME/TXE region in this image has been disabled")
f.seek(me_start + 0x10)
if f.read(4) != b"$FPT":
sys.exit("The ME/TXE region is corrupted or missing")
print("The ME/TXE region goes from {:#x} to {:#x}"
.format(me_start, me_end))
else:
sys.exit("This image does not contains a ME/TXE firmware NR = {})"
.format(nr))
else:
sys.exit("Unknown image")
print("Found FPT header at {:#x}".format(me_start + 0x10))
f.seek(me_start + 0x14)
entries = unpack("<I", f.read(4))[0]
print("Found {} partition(s)".format(entries))
f.seek(me_start + 0x14)
header_len = unpack("B", f.read(1))[0]
f.seek(me_start + 0x30)
partitions = f.read(entries * 0x20)
ftpr_header = b""
for i in range(entries):
if partitions[i * 0x20:(i * 0x20) + 4] == b"FTPR":
ftpr_header = partitions[i * 0x20:(i + 1) * 0x20]
break
if ftpr_header == b"":
sys.exit("FTPR header not found, this image doesn't seem to be valid")
ftpr_offset, ftpr_lenght = unpack("<II", ftpr_header[0x08:0x10])
ftpr_offset += me_start
print("Found FTPR header: FTPR partition spans from {:#x} to {:#x}"
.format(ftpr_offset, ftpr_offset + ftpr_lenght))
f.seek(ftpr_offset)
if f.read(4) == b"$CPD":
me11 = True
num_entries = unpack("<I", f.read(4))[0]
ftpr_mn2_offset = 0x10 + num_entries * 0x18
else:
me11 = False
ftpr_mn2_offset = 0
f.seek(ftpr_offset + ftpr_mn2_offset + 0x24)
version = unpack("<HHHH", f.read(0x08))
print("ME/TXE firmware version {}"
.format('.'.join(str(i) for i in version)))
if not args.check:
if args.output:
f.close()
shutil.copy(args.file, args.output)
f = open(args.output, "r+b")
mef = regionFile(f, me_start, me_end)
ftpr_offset, ftpr_lenght = unpack("<II", ftpr_header[0x08:0x10])
ftpr_offset += me_start
print("Found FTPR header: FTPR partition spans from {:#x} to {:#x}"
.format(ftpr_offset, ftpr_offset + ftpr_lenght))
print("Removing extra partitions...")
fill_range(f, me_start + 0x30, ftpr_offset, b"\xff")
fill_range(f, ftpr_offset + ftpr_lenght, me_end, b"\xff")
mef.fill_range(me_start + 0x30, ftpr_offset, b"\xff")
mef.fill_range(ftpr_offset + ftpr_lenght, me_end, b"\xff")
print("Removing extra partition entries in FPT...")
f.seek(me_start + 0x30)
f.write(ftpr_header)
f.seek(me_start + 0x14)
f.write(pack("<I", 1))
mef.write_to(me_start + 0x30, ftpr_header)
mef.write_to(me_start + 0x14, pack("<I", 1))
print("Removing EFFS presence flag...")
f.seek(me_start + 0x24)
flags = unpack("<I", f.read(4))[0]
mef.seek(me_start + 0x24)
flags = unpack("<I", mef.read(4))[0]
flags &= ~(0x00000001)
f.seek(me_start + 0x24)
f.write(pack("<I", flags))
mef.write_to(me_start + 0x24, pack("<I", flags))
f.seek(me_start, 0)
header = bytearray(f.read(0x30))
if args.descriptor:
print("Removing ME/TXE R/W access to the other flash regions...")
fdf = regionFile(f, fd_start, fd_end)
fdf.write_to(fmba + 0x4, pack("<I", 0x04040000))
if me11:
mef.seek(me_start + 0x10)
header = bytearray(mef.read(0x20))
else:
mef.seek(me_start)
header = bytearray(mef.read(0x30))
checksum = (0x100 - (sum(header) - header[0x1b]) & 0xff) & 0xff
print("Correcting checksum (0x{:02x})...".format(checksum))
# The checksum is just the two's complement of the sum of the first
# 0x30 bytes (except for 0x1b, the checksum itself). In other words,
# the sum of the first 0x30 bytes must be always 0x00.
f.seek(me_start + 0x1b)
f.write(pack("B", checksum))
f.seek(ftpr_offset)
if f.read(4) == b"$CPD":
me11 = True
num_entries = unpack("<I", f.read(4))[0]
f.seek(ftpr_offset + 0x10 + num_entries * 0x18 + 0x24)
else:
me11 = False
f.seek(ftpr_offset + 0x24)
version = unpack("<HHHH", f.read(0x08))
print("ME/TXE firmware version {}"
.format('.'.join(str(i) for i in version)))
# 0x30 bytes in ME < 11 or bytes 0x10:0x30 in ME >= 11 (except for
# 0x1b, the checksum itself). In other words, the sum of those bytes
# must be always 0x00.
mef.write_to(me_start + 0x1b, pack("B", checksum))
if not me11:
print("Reading FTPR modules list...")
f.seek(ftpr_offset + 0x1c)
tag = f.read(4)
mef.seek(ftpr_offset + 0x1c)
tag = mef.read(4)
if tag == b"$MN2":
f.seek(ftpr_offset + 0x20)
num_modules = unpack("<I", f.read(4))[0]
f.seek(ftpr_offset + 0x290)
data = f.read(0x84)
mef.seek(ftpr_offset + 0x20)
num_modules = unpack("<I", mef.read(4))[0]
mef.seek(ftpr_offset + 0x290)
data = mef.read(0x84)
module_header_size = 0
if data[0x0:0x4] == b"$MME":
if data[0x60:0x64] == b"$MME":
if data[0x60:0x64] == b"$MME" or num_modules == 1:
module_header_size = 0x60
elif data[0x80:0x84] == b"$MME":
module_header_size = 0x80
if module_header_size != 0:
f.seek(ftpr_offset + 0x290)
mod_headers = [f.read(module_header_size)
mef.seek(ftpr_offset + 0x290)
mod_headers = [mef.read(module_header_size)
for i in range(0, num_modules)]
if all(mod_h.startswith(b"$MME") for mod_h in mod_headers):
remove_modules(f, mod_headers, ftpr_offset)
if all(hdr.startswith(b"$MME") for hdr in mod_headers):
if args.keep_modules:
end_addr = ftpr_offset + ftpr_lenght
else:
end_addr = remove_modules(mef, mod_headers,
ftpr_offset, me_end)
if args.relocate:
new_ftpr_offset = relocate_partition(mef,
me_start, me_end,
me_start + 0x30,
min_ftpr_offset + me_start,
mod_headers)
end_addr += new_ftpr_offset - ftpr_offset
ftpr_offset = new_ftpr_offset
end_addr = (end_addr // 0x1000 + 1) * 0x1000
end_addr += spared_blocks * 0x1000
print("The ME minimum size should be {0} bytes "
"({0:#x} bytes)".format(end_addr - me_start))
if me_start > 0:
print("The ME region can be reduced up to:\n"
" {:08x}:{:08x} me"
.format(me_start, end_addr - 1))
else:
print("Found less modules than expected in the FTPR "
"partition; skipping modules removal")
@ -302,12 +491,15 @@ else:
else:
print("Modules removal in ME v11 or greater is not yet supported")
sys.stdout.write("Checking FTPR RSA signature... ")
if check_partition_signature(f, ftpr_offset):
print("VALID")
else:
print("INVALID!!")
sys.exit("The FTPR partition signature is not valid. Is the input "
"ME/TXE image valid?")
sys.stdout.write("Checking FTPR RSA signature... ")
if check_partition_signature(f, ftpr_offset + ftpr_mn2_offset):
print("VALID")
else:
print("INVALID!!")
sys.exit("The FTPR partition signature is not valid. Is the input "
"ME/TXE image valid?")
f.close()
if not args.check:
print("Done! Good luck!")