#!/usr/bin/python # me_cleaner - Tool for partial deblobbing of Intel ME/TXE firmware images # Copyright (C) 2016-2018 Nicola Corna <nicola@corna.info> # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # from __future__ import division, print_function import argparse import binascii import hashlib import itertools import shutil import sys from struct import pack, unpack min_ftpr_offset = 0x400 spared_blocks = 4 unremovable_modules = ("ROMP", "BUP") unremovable_modules_me11 = ("rbe", "kernel", "syslib", "bup") unremovable_partitions = ("FTPR",) pubkeys_md5 = { "763e59ebe235e45a197a5b1a378dfa04": ("ME", ("6.x.x.x",)), "3a98c847d609c253e145bd36512629cb": ("ME", ("6.0.50.x",)), "0903fc25b0f6bed8c4ed724aca02124c": ("ME", ("7.x.x.x", "8.x.x.x")), "2011ae6df87c40fba09e3f20459b1ce0": ("ME", ("9.0.x.x", "9.1.x.x")), "e8427c5691cf8b56bc5cdd82746957ed": ("ME", ("9.5.x.x", "10.x.x.x")), "986a78e481f185f7d54e4af06eb413f6": ("ME", ("11.x.x.x",)), "bda0b6bb8ca0bf0cac55ac4c4d55e0f2": ("TXE", ("1.x.x.x",)), "b726a2ab9cd59d4e62fe2bead7cf6997": ("TXE", ("1.x.x.x",)), "0633d7f951a3e7968ae7460861be9cfb": ("TXE", ("2.x.x.x",)), "1d0a36e9f5881540d8e4b382c6612ed8": ("TXE", ("3.x.x.x",)), "be900fef868f770d266b1fc67e887e69": ("SPS", ("2.x.x.x",)), "4622e3f2cb212a89c90a4de3336d88d2": ("SPS", ("3.x.x.x",)), "31ef3d950eac99d18e187375c0764ca4": ("SPS", ("4.x.x.x",)) } 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): if f.tell() + n <= self.region_end: return self.f.read(n) else: raise OutOfRegionException() def readinto(self, b): if f.tell() + len(b) <= self.region_end: return self.f.readinto(b) else: raise OutOfRegionException() def seek(self, offset): if self.region_start + offset <= self.region_end: return self.f.seek(self.region_start + offset) else: raise OutOfRegionException() def write_to(self, offset, data): if self.region_start + offset + len(data) <= self.region_end: self.f.seek(self.region_start + offset) return self.f.write(data) else: raise OutOfRegionException() def fill_range(self, start, end, fill): if self.region_start + end <= self.region_end: if start < end: block = fill * 4096 self.f.seek(self.region_start + start) self.f.writelines(itertools.repeat(block, (end - start) // 4096)) self.f.write(block[:(end - start) % 4096]) else: raise OutOfRegionException() def fill_all(self, fill): self.fill_range(0, self.region_end - self.region_start, fill) def move_range(self, offset_from, size, offset_to, fill): if self.region_start + offset_from + size <= self.region_end and \ self.region_start + offset_to + size <= self.region_end: for i in range(0, size, 4096): self.f.seek(self.region_start + offset_from + i, 0) block = self.f.read(min(size - i, 4096)) self.f.seek(self.region_start + offset_from + i, 0) self.f.write(fill * len(block)) self.f.seek(self.region_start + offset_to + i, 0) self.f.write(block) else: raise OutOfRegionException() def save(self, filename, size): if self.region_start + size <= self.region_end: self.f.seek(self.region_start) copyf = open(filename, "w+b") for i in range(0, size, 4096): copyf.write(self.f.read(min(size - i, 4096))) return copyf else: raise OutOfRegionException() def get_chunks_offsets(llut): chunk_count = unpack("<I", llut[0x04:0x08])[0] huffman_stream_end = sum(unpack("<II", llut[0x10:0x18])) nonzero_offsets = [huffman_stream_end] offsets = [] for i in range(0, chunk_count): chunk = llut[0x40 + i * 4:0x44 + i * 4] offset = 0 if chunk[3] != 0x80: offset = unpack("<I", chunk[0:3] + b"\x00")[0] offsets.append([offset, 0]) if offset != 0: nonzero_offsets.append(offset) nonzero_offsets.sort() for i in offsets: if i[0] != 0: i[1] = nonzero_offsets[nonzero_offsets.index(i[0]) + 1] return offsets 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") offset = unpack("<I", mod_header[0x38:0x3C])[0] + ftpr_offset size = unpack("<I", mod_header[0x40:0x44])[0] flags = unpack("<I", mod_header[0x50:0x54])[0] comp_type = (flags >> 4) & 7 print(" {:<16} ({:<7}, ".format(name, comp_str[comp_type]), end="") if comp_type == 0x00 or comp_type == 0x02: print("0x{:06x} - 0x{:06x} ): " .format(offset, offset + size), end="") if name in unremovable_modules: end_addr = max(end_addr, offset + size) print("NOT removed, essential") else: end = min(offset + size, me_end) f.fill_range(offset, end, b"\xff") print("removed") elif comp_type == 0x01: if not chunks_offsets: f.seek(offset) llut = f.read(4) if llut == b"LLUT": llut += f.read(0x3c) chunk_count = unpack("<I", llut[0x4:0x8])[0] base = unpack("<I", llut[0x8:0xc])[0] + 0x10000000 chunk_size = unpack("<I", llut[0x30:0x34])[0] llut += f.read(chunk_count * 4) chunks_offsets = get_chunks_offsets(llut) else: sys.exit("Huffman modules found, but LLUT is not present") module_base = unpack("<I", mod_header[0x34:0x38])[0] module_size = unpack("<I", mod_header[0x3c:0x40])[0] first_chunk_num = (module_base - base) // chunk_size last_chunk_num = first_chunk_num + module_size // chunk_size huff_size = 0 for chunk in chunks_offsets[first_chunk_num:last_chunk_num + 1]: huff_size += chunk[1] - chunk[0] print("fragmented data, {:<9}): " .format("~" + str(int(round(huff_size / 1024))) + " KiB"), end="") if name in unremovable_modules: print("NOT removed, essential") unremovable_huff_chunks += \ [x for x in chunks_offsets[first_chunk_num: last_chunk_num + 1] if x[0] != 0] else: print("removed") else: print("0x{:06x} - 0x{:06x}): unknown compression, skipping" .format(offset, offset + size), end="") if chunks_offsets: removable_huff_chunks = [] for chunk in chunks_offsets: if all(not(unremovable_chk[0] <= chunk[0] < unremovable_chk[1] or unremovable_chk[0] < chunk[1] <= unremovable_chk[1]) for unremovable_chk in unremovable_huff_chunks): removable_huff_chunks.append(chunk) for removable_chunk in removable_huff_chunks: if removable_chunk[1] > removable_chunk[0]: 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 = unpack("<I", f.read(4))[0] signature = int(binascii.hexlify(f.read(0x100)[::-1]), 16) header_len = unpack("<I", header[0x4:0x8])[0] * 4 manifest_len = unpack("<I", header[0x18:0x1c])[0] * 4 f.seek(offset + header_len) sha256 = hashlib.sha256() sha256.update(header) sha256.update(f.read(manifest_len - header_len)) decrypted_sig = pow(signature, public_exponent, modulus) return "{:#x}".format(decrypted_sig).endswith(sha256.hexdigest()) # FIXME def print_check_partition_signature(f, offset): if check_partition_signature(f, offset): print("VALID") else: print("INVALID!!") sys.exit("The FTPR partition signature is not valid. Is the input " "ME/TXE image valid?") def relocate_partition(f, me_end, partition_header_offset, new_offset, mod_headers): 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)) 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 mod_headers and 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 - llut_start - 0x40 + old_offset) new_offset = ((new_offset + 0x1f) // 0x20) * 0x20 offset_diff = new_offset - old_offset print("Relocating {} from {:#x} - {:#x} to {:#x} - {:#x}..." .format(name, old_offset, old_offset + partition_size, new_offset, new_offset + partition_size)) print(" Adjusting FPT entry...") f.write_to(partition_header_offset + 0x8, pack("<I", new_offset)) if mod_headers: 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 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("Huffman modules present but no LLUT found!") else: print(" No Huffman modules found") print(" Moving data...") partition_size = min(partition_size, me_end - old_offset) f.move_range(old_offset, partition_size, new_offset, b"\xff") return new_offset def check_and_remove_modules(f, me_end, offset, min_offset, relocate, keep_modules): f.seek(offset + 0x20) num_modules = unpack("<I", f.read(4))[0] f.seek(offset + 0x290) data = f.read(0x84) mod_header_size = 0 if data[0x0:0x4] == b"$MME": if data[0x60:0x64] == b"$MME" or num_modules == 1: mod_header_size = 0x60 elif data[0x80:0x84] == b"$MME": mod_header_size = 0x80 if mod_header_size != 0: f.seek(offset + 0x290) data = f.read(mod_header_size * num_modules) mod_headers = [data[i * mod_header_size:(i + 1) * mod_header_size] for i in range(0, num_modules)] if all(hdr.startswith(b"$MME") for hdr in mod_headers): if args.keep_modules: end_addr = offset + ftpr_length else: end_addr = remove_modules(f, mod_headers, offset, me_end) if args.relocate: new_offset = relocate_partition(f, me_end, 0x30, min_offset, mod_headers) end_addr += new_offset - offset offset = new_offset return end_addr, offset else: print("Found less modules than expected in the FTPR " "partition; skipping modules removal") else: print("Can't find the module header size; skipping " "modules removal") return -1, offset def check_and_remove_modules_me11(f, me_end, partition_offset, partition_length, min_offset, relocate, keep_modules): comp_str = ("LZMA/uncomp.", "Huffman") if keep_modules: end_data = partition_offset + partition_length else: end_data = 0 f.seek(partition_offset + 0x4) module_count = unpack("<I", f.read(4))[0] modules = [] modules.append(("end", partition_length, 0)) f.seek(partition_offset + 0x10) for i in range(0, module_count): data = f.read(0x18) name = data[0x0:0xc].rstrip(b"\x00").decode("ascii") offset_block = unpack("<I", data[0xc:0x10])[0] offset = offset_block & 0x01ffffff comp_type = (offset_block & 0x02000000) >> 25 modules.append((name, offset, comp_type)) modules.sort(key=lambda x: x[1]) for i in range(0, module_count): name = modules[i][0] offset = partition_offset + modules[i][1] end = partition_offset + modules[i + 1][1] removed = False if name.endswith(".man") or name.endswith(".met"): compression = "uncompressed" else: compression = comp_str[modules[i][2]] print(" {:<12} ({:<12}, 0x{:06x} - 0x{:06x}): " .format(name, compression, offset, end), end="") if name.endswith(".man"): print("NOT removed, partition manif.") elif name.endswith(".met"): print("NOT removed, module metadata") elif any(name.startswith(m) for m in unremovable_modules_me11): print("NOT removed, essential") else: removed = True f.fill_range(offset, min(end, me_end), b"\xff") print("removed") if not removed: end_data = max(end_data, end) if relocate: new_offset = relocate_partition(f, me_end, 0x30, min_offset, []) end_data += new_offset - partition_offset partition_offset = new_offset return end_data, partition_offset def check_mn2_tag(f, offset): f.seek(offset + 0x1c) tag = f.read(4) if tag != b"$MN2": sys.exit("Wrong FTPR manifest tag ({}), this image may be corrupted" .format(tag)) def flreg_to_start_end(flreg): return (flreg & 0x7fff) << 12, (flreg >> 4 & 0x7fff000 | 0xfff) + 1 def start_end_to_flreg(start, end): return (start & 0x7fff000) >> 12 | ((end - 1) & 0x7fff000) << 4 if __name__ == "__main__": parser = argparse.ArgumentParser(description="Tool to remove as much code " "as possible from Intel ME/TXE firmware " "images") softdis = parser.add_mutually_exclusive_group() bw_list = parser.add_mutually_exclusive_group() parser.add_argument("-v", "--version", action="version", version="%(prog)s 1.2") parser.add_argument("file", help="ME/TXE image or full dump") parser.add_argument("-O", "--output", metavar='output_file', help="save " "the modified image in a separate file, instead of " "modifying the original file") softdis.add_argument("-S", "--soft-disable", help="in addition to the " "usual operations on the ME/TXE firmware, set the " "MeAltDisable bit or the HAP bit to ask Intel ME/TXE " "to disable itself after the hardware initialization " "(requires a full dump)", action="store_true") softdis.add_argument("-s", "--soft-disable-only", help="instead of the " "usual operations on the ME/TXE firmware, just set " "the MeAltDisable bit or the HAP bit to ask Intel " "ME/TXE to disable itself after the hardware " "initialization (requires a full dump)", action="store_true") parser.add_argument("-r", "--relocate", help="relocate the FTPR partition " "to the top of the ME region to save even more space", action="store_true") parser.add_argument("-t", "--truncate", help="truncate the empty part of " "the firmware (requires a separated ME/TXE image or " "--extract-me)", action="store_true") parser.add_argument("-k", "--keep-modules", help="don't remove the FTPR " "modules, even when possible", action="store_true") bw_list.add_argument("-w", "--whitelist", metavar="whitelist", help="Comma separated list of additional partitions " "to keep in the final image. This can be used to " "specify the MFS partition for example, which stores " "PCIe and clock settings.") bw_list.add_argument("-b", "--blacklist", metavar="blacklist", help="Comma separated list of partitions to remove " "from the image. This option overrides the default " "removal list.") 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("-D", "--extract-descriptor", metavar='output_descriptor', help="extract the flash " "descriptor from a full dump; when used with " "--truncate save a descriptor with adjusted regions " "start and end") parser.add_argument("-M", "--extract-me", metavar='output_me_image', help="extract the ME firmware from a full dump; when " "used with --truncate save a truncated ME/TXE image") 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() if args.check and (args.soft_disable_only or args.soft_disable or args.relocate or args.descriptor or args.truncate or args.output): sys.exit("-c can't be used with -S, -s, -r, -d, -t or -O") if args.soft_disable_only and (args.relocate or args.truncate): sys.exit("-s can't be used with -r or -t") if (args.whitelist or args.blacklist) and args.relocate: sys.exit("Relocation is not yet supported with custom whitelist or " "blacklist") f = open(args.file, "rb" if args.check or args.output else "r+b") f.seek(0x10) magic = f.read(4) if magic == b"$FPT": print("ME/TXE image detected") if args.descriptor or args.extract_descriptor or args.extract_me or \ args.soft_disable or args.soft_disable_only: sys.exit("-d, -D, -M, -S and -s require a full dump") f.seek(0, 2) me_start = 0 me_end = f.tell() mef = RegionFile(f, me_start, me_end) elif magic == b"\x5a\xa5\xf0\x0f": print("Full image detected") if args.truncate and not args.extract_me: sys.exit("-t requires a separated ME/TXE image (or --extract-me)") f.seek(0x14) flmap0, flmap1 = unpack("<II", f.read(8)) frba = flmap0 >> 12 & 0xff0 fmba = (flmap1 & 0xff) << 4 fpsba = flmap1 >> 12 & 0xff0 f.seek(frba) flreg = unpack("<III", f.read(12)) fd_start, fd_end = flreg_to_start_end(flreg[0]) bios_start, bios_end = flreg_to_start_end(flreg[1]) me_start, me_end = flreg_to_start_end(flreg[2]) if me_start >= me_end: sys.exit("The ME/TXE region in this image has been disabled") mef = RegionFile(f, me_start, me_end) mef.seek(0x10) if mef.read(4) != b"$FPT": sys.exit("The ME/TXE region is corrupted or missing") print("The ME/TXE region goes from {:#x} to {:#x}" .format(me_start, me_end)) else: sys.exit("Unknown image") end_addr = me_end print("Found FPT header at {:#x}".format(mef.region_start + 0x10)) mef.seek(0x14) entries = unpack("<I", mef.read(4))[0] print("Found {} partition(s)".format(entries)) mef.seek(0x30) partitions = mef.read(entries * 0x20) ftpr_header = b"" for i in range(entries): if partitions[i * 0x20:(i * 0x20) + 4] == b"FTPR": ftpr_header = partitions[i * 0x20:(i + 1) * 0x20] break if ftpr_header == b"": sys.exit("FTPR header not found, this image doesn't seem to be valid") ftpr_offset, ftpr_length = unpack("<II", ftpr_header[0x08:0x10]) print("Found FTPR header: FTPR partition spans from {:#x} to {:#x}" .format(ftpr_offset, ftpr_offset + ftpr_length)) mef.seek(ftpr_offset) if mef.read(4) == b"$CPD": me11 = True num_entries = unpack("<I", mef.read(4))[0] mef.seek(ftpr_offset + 0x10) ftpr_mn2_offset = -1 for i in range(0, num_entries): data = mef.read(0x18) name = data[0x0:0xc].rstrip(b"\x00").decode("ascii") offset = unpack("<I", data[0xc:0xf] + b"\x00")[0] if name == "FTPR.man": ftpr_mn2_offset = offset break if ftpr_mn2_offset >= 0: check_mn2_tag(mef, ftpr_offset + ftpr_mn2_offset) print("Found FTPR manifest at {:#x}" .format(ftpr_offset + ftpr_mn2_offset)) else: sys.exit("Can't find the manifest of the FTPR partition") else: check_mn2_tag(mef, ftpr_offset) me11 = False ftpr_mn2_offset = 0 mef.seek(ftpr_offset + ftpr_mn2_offset + 0x24) version = unpack("<HHHH", mef.read(0x08)) print("ME/TXE firmware version {}" .format('.'.join(str(i) for i in version))) mef.seek(ftpr_offset + ftpr_mn2_offset + 0x80) pubkey_md5 = hashlib.md5(mef.read(0x104)).hexdigest() if pubkey_md5 in pubkeys_md5: variant, pubkey_versions = pubkeys_md5[pubkey_md5] print("Public key match: Intel {}, firmware versions {}" .format(variant, ", ".join(pubkey_versions))) else: if version[0] >= 6: variant = "ME" else: variant = "TXE" print("WARNING Unknown public key {}\n" " Assuming Intel {}\n" " Please report this warning to the project's maintainer!" .format(pubkey_md5, variant)) if not args.check and args.output: f.close() shutil.copy(args.file, args.output) f = open(args.output, "r+b") mef = RegionFile(f, me_start, me_end) if me_start > 0: fdf = RegionFile(f, fd_start, fd_end) if me11: fdf.seek(fpsba) pchstrp0 = unpack("<I", fdf.read(4))[0] print("The HAP bit is " + ("SET" if pchstrp0 & 1 << 16 else "NOT SET")) else: fdf.seek(fpsba + 0x28) pchstrp10 = unpack("<I", fdf.read(4))[0] print("The AltMeDisable bit is " + ("SET" if pchstrp10 & 1 << 7 else "NOT SET")) # ME 6 Ignition: wipe everything me6_ignition = False if not args.check and not args.soft_disable_only and \ variant == "ME" and version[0] == 6: mef.seek(ftpr_offset + 0x20) num_modules = unpack("<I", mef.read(4))[0] mef.seek(ftpr_offset + 0x290 + (num_modules + 1) * 0x60) data = mef.read(0xc) if data[0x0:0x4] == b"$SKU" and data[0x8:0xc] == b"\x00\x00\x00\x00": print("ME 6 Ignition firmware detected, removing everything...") mef.fill_all(b"\xff") me6_ignition = True if not args.check: if not args.soft_disable_only and not me6_ignition: print("Reading partitions list...") unremovable_part_fpt = b"" extra_part_end = 0 whitelist = [] blacklist = [] whitelist += unremovable_partitions if args.blacklist: blacklist = args.blacklist.split(",") elif args.whitelist: whitelist += args.whitelist.split(",") for i in range(entries): partition = partitions[i * 0x20:(i + 1) * 0x20] flags = unpack("<I", partition[0x1c:0x20])[0] try: part_name = \ partition[0x0:0x4].rstrip(b"\x00").decode("ascii") except UnicodeDecodeError: part_name = "????" part_start, part_length = unpack("<II", partition[0x08:0x10]) # ME 6: the last partition has 0xffffffff as size if variant == "ME" and version[0] == 6 and \ i == entries - 1 and part_length == 0xffffffff: part_length = me_end - me_start - part_start part_end = part_start + part_length if flags & 0x7f == 2: print(" {:<4} ({:^24}, 0x{:08x} total bytes): nothing to " "remove" .format(part_name, "NVRAM partition, no data", part_length)) elif part_start == 0 or part_length == 0 or part_end > me_end: print(" {:<4} ({:^24}, 0x{:08x} total bytes): nothing to " "remove" .format(part_name, "no data here", part_length)) else: print(" {:<4} (0x{:08x} - 0x{:09x}, 0x{:08x} total bytes): " .format(part_name, part_start, part_end, part_length), end="") if part_name in whitelist or (blacklist and part_name not in blacklist): unremovable_part_fpt += partition if part_name != "FTPR": extra_part_end = max(extra_part_end, part_end) print("NOT removed") else: mef.fill_range(part_start, part_end, b"\xff") print("removed") print("Removing partition entries in FPT...") mef.write_to(0x30, unremovable_part_fpt) mef.write_to(0x14, pack("<I", len(unremovable_part_fpt) // 0x20)) mef.fill_range(0x30 + len(unremovable_part_fpt), 0x30 + len(partitions), b"\xff") if (not blacklist and "EFFS" not in whitelist) or \ "EFFS" in blacklist: print("Removing EFFS presence flag...") mef.seek(0x24) flags = unpack("<I", mef.read(4))[0] flags &= ~(0x00000001) mef.write_to(0x24, pack("<I", flags)) if me11: mef.seek(0x10) header = bytearray(mef.read(0x20)) header[0x0b] = 0x00 else: mef.seek(0) header = bytearray(mef.read(0x30)) header[0x1b] = 0x00 checksum = (0x100 - sum(header) & 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 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(0x1b, pack("B", checksum)) print("Reading FTPR modules list...") if me11: end_addr, ftpr_offset = \ check_and_remove_modules_me11(mef, me_end, ftpr_offset, ftpr_length, min_ftpr_offset, args.relocate, args.keep_modules) else: end_addr, ftpr_offset = \ check_and_remove_modules(mef, me_end, ftpr_offset, min_ftpr_offset, args.relocate, args.keep_modules) if end_addr > 0: end_addr = max(end_addr, extra_part_end) 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)) if me_start > 0: print("The ME region can be reduced up to:\n" " {:08x}:{:08x} me" .format(me_start, me_start + end_addr - 1)) elif args.truncate: print("Truncating file at {:#x}...".format(end_addr)) f.truncate(end_addr) if args.soft_disable or args.soft_disable_only: if me11: print("Setting the HAP bit in PCHSTRP0 to disable Intel ME...") pchstrp0 |= (1 << 16) fdf.write_to(fpsba, pack("<I", pchstrp0)) else: print("Setting the AltMeDisable bit in PCHSTRP10 to disable " "Intel ME...") pchstrp10 |= (1 << 7) fdf.write_to(fpsba + 0x28, pack("<I", pchstrp10)) if args.descriptor: print("Removing ME/TXE R/W access to the other flash regions...") if me11: flmstr2 = 0x00400500 else: fdf.seek(fmba + 0x4) flmstr2 = (unpack("<I", fdf.read(4))[0] | 0x04040000) & 0x0404ffff fdf.write_to(fmba + 0x4, pack("<I", flmstr2)) if args.extract_descriptor: if args.truncate: print("Extracting the descriptor to \"{}\"..." .format(args.extract_descriptor)) fdf_copy = fdf.save(args.extract_descriptor, fd_end - fd_start) if bios_start == me_end: print("Modifying the regions of the extracted descriptor...") print(" {:08x}:{:08x} me --> {:08x}:{:08x} me" .format(me_start, me_end - 1, me_start, me_start + end_addr - 1)) print(" {:08x}:{:08x} bios --> {:08x}:{:08x} bios" .format(bios_start, bios_end - 1, me_start + end_addr, bios_end - 1)) flreg1 = start_end_to_flreg(me_start + end_addr, bios_end) flreg2 = start_end_to_flreg(me_start, me_start + end_addr) fdf_copy.seek(frba + 0x4) fdf_copy.write(pack("<II", flreg1, flreg2)) else: print("\nWARNING:\n The start address of the BIOS region " "isn't equal to the end address of the ME\n region: if " "you want to recover the space from the ME region you " "have to\n manually modify the descriptor.\n") else: print("Extracting the descriptor to \"{}\"..." .format(args.extract_descriptor)) fdf_copy = fdf.save(args.extract_descriptor, fd_end - fd_start) fdf_copy.close() if args.extract_me: if args.truncate: print("Extracting and truncating the ME image to \"{}\"..." .format(args.extract_me)) mef_copy = mef.save(args.extract_me, end_addr) else: print("Extracting the ME image to \"{}\"..." .format(args.extract_me)) mef_copy = mef.save(args.extract_me, me_end - me_start) if not me6_ignition: print("Checking the FTPR RSA signature of the extracted ME " "image... ", end="") print_check_partition_signature(mef_copy, ftpr_offset + ftpr_mn2_offset) mef_copy.close() if not me6_ignition: print("Checking the FTPR RSA signature... ", end="") print_check_partition_signature(mef, ftpr_offset + ftpr_mn2_offset) f.close() if not args.check: print("Done! Good luck!")