util/me_cleaner/me_cleaner.py

   1 #!/usr/bin/env python
   2 # me_cleaner - Tool for partial deblobbing of Intel ME/TXE firmware images
   3 # SPDX-License-Identifier: GPL-3.0-or-later
   4
   5 from __future__ import division, print_function
   6
   7 import argparse
   8 import binascii
   9 import hashlib
  10 import itertools
  11 import shutil
  12 import sys
  13 from struct import pack, unpack
  14
  15
  16 min_ftpr_offset = 0x400
  17 spared_blocks = 4
  18 unremovable_modules = ("ROMP", "BUP")
  19 unremovable_modules_me11 = ("rbe", "kernel", "syslib", "bup")
  20 unremovable_partitions = ("FTPR",)
  21
  22 pubkeys_md5 = {
  23     "763e59ebe235e45a197a5b1a378dfa04": ("ME",  ("6.x.x.x",)),
  24     "3a98c847d609c253e145bd36512629cb": ("ME",  ("6.0.50.x",)),
  25     "0903fc25b0f6bed8c4ed724aca02124c": ("ME",  ("7.x.x.x", "8.x.x.x")),
  26     "2011ae6df87c40fba09e3f20459b1ce0": ("ME",  ("9.0.x.x", "9.1.x.x")),
  27     "e8427c5691cf8b56bc5cdd82746957ed": ("ME",  ("9.5.x.x", "10.x.x.x")),
  28     "986a78e481f185f7d54e4af06eb413f6": ("ME",  ("11.x.x.x",)),
  29     "bda0b6bb8ca0bf0cac55ac4c4d55e0f2": ("TXE", ("1.x.x.x",)),
  30     "b726a2ab9cd59d4e62fe2bead7cf6997": ("TXE", ("1.x.x.x",)),
  31     "0633d7f951a3e7968ae7460861be9cfb": ("TXE", ("2.x.x.x",)),
  32     "1d0a36e9f5881540d8e4b382c6612ed8": ("TXE", ("3.x.x.x",)),
  33     "be900fef868f770d266b1fc67e887e69": ("SPS", ("2.x.x.x",)),
  34     "4622e3f2cb212a89c90a4de3336d88d2": ("SPS", ("3.x.x.x",)),
  35     "31ef3d950eac99d18e187375c0764ca4": ("SPS", ("4.x.x.x",))
  36 }
  37
  38
  39 class OutOfRegionException(Exception):
  40     pass
  41
  42
  43 class RegionFile:
  44     def __init__(self, f, region_start, region_end):
  45         self.f = f
  46         self.region_start = region_start
  47         self.region_end = region_end
  48
  49     def read(self, n):
  50         if f.tell() + n <= self.region_end:
  51             return self.f.read(n)
  52         else:
  53             raise OutOfRegionException()
  54
  55     def readinto(self, b):
  56         if f.tell() + len(b) <= self.region_end:
  57             return self.f.readinto(b)
  58         else:
  59             raise OutOfRegionException()
  60
  61     def seek(self, offset):
  62         if self.region_start + offset <= self.region_end:
  63             return self.f.seek(self.region_start + offset)
  64         else:
  65             raise OutOfRegionException()
  66
  67     def write_to(self, offset, data):
  68         if self.region_start + offset + len(data) <= self.region_end:
  69             self.f.seek(self.region_start + offset)
  70             return self.f.write(data)
  71         else:
  72             raise OutOfRegionException()
  73
  74     def fill_range(self, start, end, fill):
  75         if self.region_start + end <= self.region_end:
  76             if start < end:
  77                 block = fill * 4096
  78                 self.f.seek(self.region_start + start)
  79                 self.f.writelines(itertools.repeat(block,
  80                                                    (end - start) // 4096))
  81                 self.f.write(block[:(end - start) % 4096])
  82         else:
  83             raise OutOfRegionException()
  84
  85     def fill_all(self, fill):
  86         self.fill_range(0, self.region_end - self.region_start, fill)
  87
  88     def move_range(self, offset_from, size, offset_to, fill):
  89         if self.region_start + offset_from + size <= self.region_end and \
  90            self.region_start + offset_to + size <= self.region_end:
  91             for i in range(0, size, 4096):
  92                 self.f.seek(self.region_start + offset_from + i, 0)
  93                 block = self.f.read(min(size - i, 4096))
  94                 self.f.seek(self.region_start + offset_from + i, 0)
  95                 self.f.write(fill * len(block))
  96                 self.f.seek(self.region_start + offset_to + i, 0)
  97                 self.f.write(block)
  98         else:
  99             raise OutOfRegionException()
 100
 101     def save(self, filename, size):
 102         if self.region_start + size <= self.region_end:
 103             self.f.seek(self.region_start)
 104             copyf = open(filename, "w+b")
 105             for i in range(0, size, 4096):
 106                 copyf.write(self.f.read(min(size - i, 4096)))
 107             return copyf
 108         else:
 109             raise OutOfRegionException()
 110
 111
 112 def get_chunks_offsets(llut):
 113     chunk_count = unpack("<I", llut[0x04:0x08])[0]
 114     huffman_stream_end = sum(unpack("<II", llut[0x10:0x18]))
 115     nonzero_offsets = [huffman_stream_end]
 116     offsets = []
 117
 118     for i in range(0, chunk_count):
 119         chunk = llut[0x40 + i * 4:0x44 + i * 4]
 120         offset = 0
 121
 122         if chunk[3] != 0x80:
 123             offset = unpack("<I", chunk[0:3] + b"\x00")[0]
 124
 125         offsets.append([offset, 0])
 126         if offset != 0:
 127             nonzero_offsets.append(offset)
 128
 129     nonzero_offsets.sort()
 130
 131     for i in offsets:
 132         if i[0] != 0:
 133             i[1] = nonzero_offsets[nonzero_offsets.index(i[0]) + 1]
 134
 135     return offsets
 136
 137
 138 def remove_modules(f, mod_headers, ftpr_offset, me_end):
 139     comp_str = ("uncomp.", "Huffman", "LZMA")
 140     unremovable_huff_chunks = []
 141     chunks_offsets = []
 142     base = 0
 143     chunk_size = 0
 144     end_addr = 0
 145
 146     for mod_header in mod_headers:
 147         name = mod_header[0x04:0x14].rstrip(b"\x00").decode("ascii")
 148         offset = unpack("<I", mod_header[0x38:0x3C])[0] + ftpr_offset
 149         size = unpack("<I", mod_header[0x40:0x44])[0]
 150         flags = unpack("<I", mod_header[0x50:0x54])[0]
 151         comp_type = (flags >> 4) & 7
 152
 153         print(" {:<16} ({:<7}, ".format(name, comp_str[comp_type]), end="")
 154
 155         if comp_type == 0x00 or comp_type == 0x02:
 156             print("0x{:06x} - 0x{:06x}       ): "
 157                   .format(offset, offset + size), end="")
 158
 159             if name in unremovable_modules:
 160                 end_addr = max(end_addr, offset + size)
 161                 print("NOT removed, essential")
 162             else:
 163                 end = min(offset + size, me_end)
 164                 f.fill_range(offset, end, b"\xff")
 165                 print("removed")
 166
 167         elif comp_type == 0x01:
 168             if not chunks_offsets:
 169                 f.seek(offset)
 170                 llut = f.read(4)
 171                 if llut == b"LLUT":
 172                     llut += f.read(0x3c)
 173
 174                     chunk_count = unpack("<I", llut[0x4:0x8])[0]
 175                     base = unpack("<I", llut[0x8:0xc])[0] + 0x10000000
 176                     chunk_size = unpack("<I", llut[0x30:0x34])[0]
 177
 178                     llut += f.read(chunk_count * 4)
 179                     chunks_offsets = get_chunks_offsets(llut)
 180                 else:
 181                     sys.exit("Huffman modules found, but LLUT is not present")
 182
 183             module_base = unpack("<I", mod_header[0x34:0x38])[0]
 184             module_size = unpack("<I", mod_header[0x3c:0x40])[0]
 185             first_chunk_num = (module_base - base) // chunk_size
 186             last_chunk_num = first_chunk_num + module_size // chunk_size
 187             huff_size = 0
 188
 189             for chunk in chunks_offsets[first_chunk_num:last_chunk_num + 1]:
 190                 huff_size += chunk[1] - chunk[0]
 191
 192             print("fragmented data, {:<9}): "
 193                   .format("~" + str(int(round(huff_size / 1024))) + " KiB"),
 194                   end="")
 195
 196             if name in unremovable_modules:
 197                 print("NOT removed, essential")
 198
 199                 unremovable_huff_chunks += \
 200                     [x for x in chunks_offsets[first_chunk_num:
 201                      last_chunk_num + 1] if x[0] != 0]
 202             else:
 203                 print("removed")
 204
 205         else:
 206             print("0x{:06x} - 0x{:06x}): unknown compression, skipping"
 207                   .format(offset, offset + size), end="")
 208
 209     if chunks_offsets:
 210         removable_huff_chunks = []
 211
 212         for chunk in chunks_offsets:
 213             if all(not(unremovable_chk[0] <= chunk[0] < unremovable_chk[1] or
 214                        unremovable_chk[0] < chunk[1] <= unremovable_chk[1])
 215                    for unremovable_chk in unremovable_huff_chunks):
 216                 removable_huff_chunks.append(chunk)
 217
 218         for removable_chunk in removable_huff_chunks:
 219             if removable_chunk[1] > removable_chunk[0]:
 220                 end = min(removable_chunk[1], me_end)
 221                 f.fill_range(removable_chunk[0], end, b"\xff")
 222
 223         end_addr = max(end_addr,
 224                        max(unremovable_huff_chunks, key=lambda x: x[1])[1])
 225
 226     return end_addr
 227
 228
 229 def check_partition_signature(f, offset):
 230     f.seek(offset)
 231     header = f.read(0x80)
 232     modulus = int(binascii.hexlify(f.read(0x100)[::-1]), 16)
 233     public_exponent = unpack("<I", f.read(4))[0]
 234     signature = int(binascii.hexlify(f.read(0x100)[::-1]), 16)
 235
 236     header_len = unpack("<I", header[0x4:0x8])[0] * 4
 237     manifest_len = unpack("<I", header[0x18:0x1c])[0] * 4
 238     f.seek(offset + header_len)
 239
 240     sha256 = hashlib.sha256()
 241     sha256.update(header)
 242     sha256.update(f.read(manifest_len - header_len))
 243
 244     decrypted_sig = pow(signature, public_exponent, modulus)
 245
 246     return "{:#x}".format(decrypted_sig).endswith(sha256.hexdigest())   # FIXME
 247
 248
 249 def print_check_partition_signature(f, offset):
 250     if check_partition_signature(f, offset):
 251         print("VALID")
 252     else:
 253         print("INVALID!!")
 254         sys.exit("The FTPR partition signature is not valid. Is the input "
 255                  "ME/TXE image valid?")
 256
 257
 258 def relocate_partition(f, me_end, partition_header_offset,
 259                        new_offset, mod_headers):
 260
 261     f.seek(partition_header_offset)
 262     name = f.read(4).rstrip(b"\x00").decode("ascii")
 263     f.seek(partition_header_offset + 0x8)
 264     old_offset, partition_size = unpack("<II", f.read(0x8))
 265
 266     llut_start = 0
 267     for mod_header in mod_headers:
 268         if (unpack("<I", mod_header[0x50:0x54])[0] >> 4) & 7 == 0x01:
 269             llut_start = unpack("<I", mod_header[0x38:0x3C])[0] + old_offset
 270             break
 271
 272     if mod_headers and llut_start != 0:
 273         # Bytes 0x9:0xb of the LLUT (bytes 0x1:0x3 of the AddrBase) are added
 274         # to the SpiBase (bytes 0xc:0x10 of the LLUT) to compute the final
 275         # start of the LLUT. Since AddrBase is not modifiable, we can act only
 276         # on SpiBase and here we compute the minimum allowed new_offset.
 277         f.seek(llut_start + 0x9)
 278         lut_start_corr = unpack("<H", f.read(2))[0]
 279         new_offset = max(new_offset,
 280                          lut_start_corr - llut_start - 0x40 + old_offset)
 281         new_offset = ((new_offset + 0x1f) // 0x20) * 0x20
 282
 283     offset_diff = new_offset - old_offset
 284     print("Relocating {} from {:#x} - {:#x} to {:#x} - {:#x}..."
 285           .format(name, old_offset, old_offset + partition_size,
 286                   new_offset, new_offset + partition_size))
 287
 288     print(" Adjusting FPT entry...")
 289     f.write_to(partition_header_offset + 0x8,
 290                pack("<I", new_offset))
 291
 292     if mod_headers:
 293         if llut_start != 0:
 294             f.seek(llut_start)
 295             if f.read(4) == b"LLUT":
 296                 print(" Adjusting LUT start offset...")
 297                 lut_offset = llut_start + offset_diff + 0x40 - lut_start_corr
 298                 f.write_to(llut_start + 0x0c, pack("<I", lut_offset))
 299
 300                 print(" Adjusting Huffman start offset...")
 301                 f.seek(llut_start + 0x14)
 302                 old_huff_offset = unpack("<I", f.read(4))[0]
 303                 f.write_to(llut_start + 0x14,
 304                            pack("<I", old_huff_offset + offset_diff))
 305
 306                 print(" Adjusting chunks offsets...")
 307                 f.seek(llut_start + 0x4)
 308                 chunk_count = unpack("<I", f.read(4))[0]
 309                 f.seek(llut_start + 0x40)
 310                 chunks = bytearray(chunk_count * 4)
 311                 f.readinto(chunks)
 312                 for i in range(0, chunk_count * 4, 4):
 313                     if chunks[i + 3] != 0x80:
 314                         chunks[i:i + 3] = \
 315                             pack("<I", unpack("<I", chunks[i:i + 3] +
 316                                  b"\x00")[0] + offset_diff)[0:3]
 317                 f.write_to(llut_start + 0x40, chunks)
 318             else:
 319                 sys.exit("Huffman modules present but no LLUT found!")
 320         else:
 321             print(" No Huffman modules found")
 322
 323     print(" Moving data...")
 324     partition_size = min(partition_size, me_end - old_offset)
 325     f.move_range(old_offset, partition_size, new_offset, b"\xff")
 326
 327     return new_offset
 328
 329
 330 def check_and_remove_modules(f, me_end, offset, min_offset,
 331                              relocate, keep_modules):
 332
 333     f.seek(offset + 0x20)
 334     num_modules = unpack("<I", f.read(4))[0]
 335     f.seek(offset + 0x290)
 336     data = f.read(0x84)
 337
 338     mod_header_size = 0
 339     if data[0x0:0x4] == b"$MME":
 340         if data[0x60:0x64] == b"$MME" or num_modules == 1:
 341             mod_header_size = 0x60
 342         elif data[0x80:0x84] == b"$MME":
 343             mod_header_size = 0x80
 344
 345     if mod_header_size != 0:
 346         f.seek(offset + 0x290)
 347         data = f.read(mod_header_size * num_modules)
 348         mod_headers = [data[i * mod_header_size:(i + 1) * mod_header_size]
 349                        for i in range(0, num_modules)]
 350
 351         if all(hdr.startswith(b"$MME") for hdr in mod_headers):
 352             if args.keep_modules:
 353                 end_addr = offset + ftpr_length
 354             else:
 355                 end_addr = remove_modules(f, mod_headers, offset, me_end)
 356
 357             if args.relocate:
 358                 new_offset = relocate_partition(f, me_end, 0x30, min_offset,
 359                                                 mod_headers)
 360                 end_addr += new_offset - offset
 361                 offset = new_offset
 362
 363             return end_addr, offset
 364
 365         else:
 366             print("Found less modules than expected in the FTPR "
 367                   "partition; skipping modules removal")
 368     else:
 369         print("Can't find the module header size; skipping "
 370               "modules removal")
 371
 372     return -1, offset
 373
 374
 375 def check_and_remove_modules_me11(f, me_end, partition_offset,
 376                                   partition_length, min_offset, relocate,
 377                                   keep_modules):
 378
 379     comp_str = ("LZMA/uncomp.", "Huffman")
 380
 381     if keep_modules:
 382         end_data = partition_offset + partition_length
 383     else:
 384         end_data = 0
 385
 386         f.seek(partition_offset + 0x4)
 387         module_count = unpack("<I", f.read(4))[0]
 388
 389         modules = []
 390         modules.append(("end", partition_length, 0))
 391
 392         f.seek(partition_offset + 0x10)
 393         for i in range(0, module_count):
 394             data = f.read(0x18)
 395             name = data[0x0:0xc].rstrip(b"\x00").decode("ascii")
 396             offset_block = unpack("<I", data[0xc:0x10])[0]
 397             offset = offset_block & 0x01ffffff
 398             comp_type = (offset_block & 0x02000000) >> 25
 399
 400             modules.append((name, offset, comp_type))
 401
 402         modules.sort(key=lambda x: x[1])
 403
 404         for i in range(0, module_count):
 405             name = modules[i][0]
 406             offset = partition_offset + modules[i][1]
 407             end = partition_offset + modules[i + 1][1]
 408             removed = False
 409
 410             if name.endswith(".man") or name.endswith(".met"):
 411                 compression = "uncompressed"
 412             else:
 413                 compression = comp_str[modules[i][2]]
 414
 415             print(" {:<12} ({:<12}, 0x{:06x} - 0x{:06x}): "
 416                   .format(name, compression, offset, end), end="")
 417
 418             if name.endswith(".man"):
 419                 print("NOT removed, partition manif.")
 420             elif name.endswith(".met"):
 421                 print("NOT removed, module metadata")
 422             elif any(name.startswith(m) for m in unremovable_modules_me11):
 423                 print("NOT removed, essential")
 424             else:
 425                 removed = True
 426                 f.fill_range(offset, min(end, me_end), b"\xff")
 427                 print("removed")
 428
 429             if not removed:
 430                 end_data = max(end_data, end)
 431
 432     if relocate:
 433         new_offset = relocate_partition(f, me_end, 0x30, min_offset, [])
 434         end_data += new_offset - partition_offset
 435         partition_offset = new_offset
 436
 437     return end_data, partition_offset
 438
 439
 440 def check_mn2_tag(f, offset):
 441     f.seek(offset + 0x1c)
 442     tag = f.read(4)
 443     if tag != b"$MN2":
 444         sys.exit("Wrong FTPR manifest tag ({}), this image may be corrupted"
 445                  .format(tag))
 446
 447
 448 def flreg_to_start_end(flreg):
 449     return (flreg & 0x7fff) << 12, (flreg >> 4 & 0x7fff000 | 0xfff) + 1
 450
 451
 452 def start_end_to_flreg(start, end):
 453     return (start & 0x7fff000) >> 12 | ((end - 1) & 0x7fff000) << 4
 454
 455
 456 if __name__ == "__main__":
 457     parser = argparse.ArgumentParser(description="Tool to remove as much code "
 458                                      "as possible from Intel ME/TXE firmware "
 459                                      "images")
 460     softdis = parser.add_mutually_exclusive_group()
 461     bw_list = parser.add_mutually_exclusive_group()
 462
 463     parser.add_argument("-v", "--version", action="version",
 464                         version="%(prog)s 1.2")
 465
 466     parser.add_argument("file", help="ME/TXE image or full dump")
 467     parser.add_argument("-O", "--output", metavar='output_file', help="save "
 468                         "the modified image in a separate file, instead of "
 469                         "modifying the original file")
 470     softdis.add_argument("-S", "--soft-disable", help="in addition to the "
 471                          "usual operations on the ME/TXE firmware, set the "
 472                          "MeAltDisable bit or the HAP bit to ask Intel ME/TXE "
 473                          "to disable itself after the hardware initialization "
 474                          "(requires a full dump)", action="store_true")
 475     softdis.add_argument("-s", "--soft-disable-only", help="instead of the "
 476                          "usual operations on the ME/TXE firmware, just set "
 477                          "the MeAltDisable bit or the HAP bit to ask Intel "
 478                          "ME/TXE to disable itself after the hardware "
 479                          "initialization (requires a full dump)",
 480                          action="store_true")
 481     parser.add_argument("-r", "--relocate", help="relocate the FTPR partition "
 482                         "to the top of the ME region to save even more space",
 483                         action="store_true")
 484     parser.add_argument("-t", "--truncate", help="truncate the empty part of "
 485                         "the firmware (requires a separated ME/TXE image or "
 486                         "--extract-me)", action="store_true")
 487     parser.add_argument("-k", "--keep-modules", help="don't remove the FTPR "
 488                         "modules, even when possible", action="store_true")
 489     bw_list.add_argument("-w", "--whitelist", metavar="whitelist",
 490                          help="Comma separated list of additional partitions "
 491                          "to keep in the final image. This can be used to "
 492                          "specify the MFS partition for example, which stores "
 493                          "PCIe and clock settings.")
 494     bw_list.add_argument("-b", "--blacklist", metavar="blacklist",
 495                          help="Comma separated list of partitions to remove "
 496                          "from the image. This option overrides the default "
 497                          "removal list.")
 498     parser.add_argument("-d", "--descriptor", help="remove the ME/TXE "
 499                         "Read/Write permissions to the other regions on the "
 500                         "flash from the Intel Flash Descriptor (requires a "
 501                         "full dump)", action="store_true")
 502     parser.add_argument("-D", "--extract-descriptor",
 503                         metavar='output_descriptor', help="extract the flash "
 504                         "descriptor from a full dump; when used with "
 505                         "--truncate save a descriptor with adjusted regions "
 506                         "start and end")
 507     parser.add_argument("-M", "--extract-me", metavar='output_me_image',
 508                         help="extract the ME firmware from a full dump; when "
 509                         "used with --truncate save a truncated ME/TXE image")
 510     parser.add_argument("-c", "--check", help="verify the integrity of the "
 511                         "fundamental parts of the firmware and exit",
 512                         action="store_true")
 513
 514     args = parser.parse_args()
 515
 516     if args.check and (args.soft_disable_only or args.soft_disable or
 517        args.relocate or args.descriptor or args.truncate or args.output):
 518         sys.exit("-c can't be used with -S, -s, -r, -d, -t or -O")
 519
 520     if args.soft_disable_only and (args.relocate or args.truncate):
 521         sys.exit("-s can't be used with -r or -t")
 522
 523     if (args.whitelist or args.blacklist) and args.relocate:
 524         sys.exit("Relocation is not yet supported with custom whitelist or "
 525                  "blacklist")
 526
 527     f = open(args.file, "rb" if args.check or args.output else "r+b")
 528     f.seek(0x10)
 529     magic = f.read(4)
 530
 531     if magic == b"$FPT":
 532         print("ME/TXE image detected")
 533
 534         if args.descriptor or args.extract_descriptor or args.extract_me or \
 535            args.soft_disable or args.soft_disable_only:
 536             sys.exit("-d, -D, -M, -S and -s require a full dump")
 537
 538         f.seek(0, 2)
 539         me_start = 0
 540         me_end = f.tell()
 541         mef = RegionFile(f, me_start, me_end)
 542
 543     elif magic == b"\x5a\xa5\xf0\x0f":
 544         print("Full image detected")
 545
 546         if args.truncate and not args.extract_me:
 547             sys.exit("-t requires a separated ME/TXE image (or --extract-me)")
 548
 549         f.seek(0x14)
 550         flmap0, flmap1 = unpack("<II", f.read(8))
 551         frba = flmap0 >> 12 & 0xff0
 552         fmba = (flmap1 & 0xff) << 4
 553         fpsba = flmap1 >> 12 & 0xff0
 554
 555         f.seek(frba)
 556         flreg = unpack("<III", f.read(12))
 557
 558         fd_start, fd_end = flreg_to_start_end(flreg[0])
 559         bios_start, bios_end = flreg_to_start_end(flreg[1])
 560         me_start, me_end = flreg_to_start_end(flreg[2])
 561
 562         if me_start >= me_end:
 563             sys.exit("The ME/TXE region in this image has been disabled")
 564
 565         mef = RegionFile(f, me_start, me_end)
 566
 567         mef.seek(0x10)
 568         if mef.read(4) != b"$FPT":
 569             sys.exit("The ME/TXE region is corrupted or missing")
 570
 571         print("The ME/TXE region goes from {:#x} to {:#x}"
 572               .format(me_start, me_end))
 573     else:
 574         sys.exit("Unknown image")
 575
 576     end_addr = me_end
 577
 578     print("Found FPT header at {:#x}".format(mef.region_start + 0x10))
 579
 580     mef.seek(0x14)
 581     entries = unpack("<I", mef.read(4))[0]
 582     print("Found {} partition(s)".format(entries))
 583
 584     mef.seek(0x30)
 585     partitions = mef.read(entries * 0x20)
 586
 587     ftpr_header = b""
 588
 589     for i in range(entries):
 590         if partitions[i * 0x20:(i * 0x20) + 4] == b"FTPR":
 591             ftpr_header = partitions[i * 0x20:(i + 1) * 0x20]
 592             break
 593
 594     if ftpr_header == b"":
 595         sys.exit("FTPR header not found, this image doesn't seem to be valid")
 596
 597     ftpr_offset, ftpr_length = unpack("<II", ftpr_header[0x08:0x10])
 598     print("Found FTPR header: FTPR partition spans from {:#x} to {:#x}"
 599           .format(ftpr_offset, ftpr_offset + ftpr_length))
 600
 601     mef.seek(ftpr_offset)
 602     if mef.read(4) == b"$CPD":
 603         me11 = True
 604         num_entries = unpack("<I", mef.read(4))[0]
 605
 606         mef.seek(ftpr_offset + 0x10)
 607         ftpr_mn2_offset = -1
 608
 609         for i in range(0, num_entries):
 610             data = mef.read(0x18)
 611             name = data[0x0:0xc].rstrip(b"\x00").decode("ascii")
 612             offset = unpack("<I", data[0xc:0xf] + b"\x00")[0]
 613
 614             if name == "FTPR.man":
 615                 ftpr_mn2_offset = offset
 616                 break
 617
 618         if ftpr_mn2_offset >= 0:
 619             check_mn2_tag(mef, ftpr_offset + ftpr_mn2_offset)
 620             print("Found FTPR manifest at {:#x}"
 621                   .format(ftpr_offset + ftpr_mn2_offset))
 622         else:
 623             sys.exit("Can't find the manifest of the FTPR partition")
 624
 625     else:
 626         check_mn2_tag(mef, ftpr_offset)
 627         me11 = False
 628         ftpr_mn2_offset = 0
 629
 630     mef.seek(ftpr_offset + ftpr_mn2_offset + 0x24)
 631     version = unpack("<HHHH", mef.read(0x08))
 632     print("ME/TXE firmware version {}"
 633           .format('.'.join(str(i) for i in version)))
 634
 635     mef.seek(ftpr_offset + ftpr_mn2_offset + 0x80)
 636     pubkey_md5 = hashlib.md5(mef.read(0x104)).hexdigest()
 637
 638     if pubkey_md5 in pubkeys_md5:
 639         variant, pubkey_versions = pubkeys_md5[pubkey_md5]
 640         print("Public key match: Intel {}, firmware versions {}"
 641               .format(variant, ", ".join(pubkey_versions)))
 642     else:
 643         if version[0] >= 6:
 644             variant = "ME"
 645         else:
 646             variant = "TXE"
 647         print("WARNING Unknown public key {}\n"
 648               "        Assuming Intel {}\n"
 649               "        Please report this warning to the project's maintainer!"
 650               .format(pubkey_md5, variant))
 651
 652     if not args.check and args.output:
 653         f.close()
 654         shutil.copy(args.file, args.output)
 655         f = open(args.output, "r+b")
 656
 657     mef = RegionFile(f, me_start, me_end)
 658
 659     if me_start > 0:
 660         fdf = RegionFile(f, fd_start, fd_end)
 661
 662         if me11:
 663             fdf.seek(fpsba)
 664             pchstrp0 = unpack("<I", fdf.read(4))[0]
 665             print("The HAP bit is " +
 666                   ("SET" if pchstrp0 & 1 << 16 else "NOT SET"))
 667         else:
 668             fdf.seek(fpsba + 0x28)
 669             pchstrp10 = unpack("<I", fdf.read(4))[0]
 670             print("The AltMeDisable bit is " +
 671                   ("SET" if pchstrp10 & 1 << 7 else "NOT SET"))
 672
 673     # ME 6 Ignition: wipe everything
 674     me6_ignition = False
 675     if not args.check and not args.soft_disable_only and \
 676        variant == "ME" and version[0] == 6:
 677         mef.seek(ftpr_offset + 0x20)
 678         num_modules = unpack("<I", mef.read(4))[0]
 679         mef.seek(ftpr_offset + 0x290 + (num_modules + 1) * 0x60)
 680         data = mef.read(0xc)
 681
 682         if data[0x0:0x4] == b"$SKU" and data[0x8:0xc] == b"\x00\x00\x00\x00":
 683             print("ME 6 Ignition firmware detected, removing everything...")
 684             mef.fill_all(b"\xff")
 685             me6_ignition = True
 686
 687     if not args.check:
 688         if not args.soft_disable_only and not me6_ignition:
 689             print("Reading partitions list...")
 690             unremovable_part_fpt = b""
 691             extra_part_end = 0
 692             whitelist = []
 693             blacklist = []
 694
 695             whitelist += unremovable_partitions
 696
 697             if args.blacklist:
 698                 blacklist = args.blacklist.split(",")
 699             elif args.whitelist:
 700                 whitelist += args.whitelist.split(",")
 701
 702             for i in range(entries):
 703                 partition = partitions[i * 0x20:(i + 1) * 0x20]
 704                 flags = unpack("<I", partition[0x1c:0x20])[0]
 705
 706                 try:
 707                     part_name = \
 708                         partition[0x0:0x4].rstrip(b"\x00").decode("ascii")
 709                 except UnicodeDecodeError:
 710                     part_name = "????"
 711
 712                 part_start, part_length = unpack("<II", partition[0x08:0x10])
 713
 714                 # ME 6: the last partition has 0xffffffff as size
 715                 if variant == "ME" and version[0] == 6 and \
 716                    i == entries - 1 and part_length == 0xffffffff:
 717                     part_length = me_end - me_start - part_start
 718
 719                 part_end = part_start + part_length
 720
 721                 if flags & 0x7f == 2:
 722                     print(" {:<4} ({:^24}, 0x{:08x} total bytes): nothing to "
 723                           "remove"
 724                           .format(part_name, "NVRAM partition, no data",
 725                                   part_length))
 726                 elif part_start == 0 or part_length == 0 or part_end > me_end:
 727                     print(" {:<4} ({:^24}, 0x{:08x} total bytes): nothing to "
 728                           "remove"
 729                           .format(part_name, "no data here", part_length))
 730                 else:
 731                     print(" {:<4} (0x{:08x} - 0x{:09x}, 0x{:08x} total bytes): "
 732                           .format(part_name, part_start, part_end, part_length),
 733                           end="")
 734                     if part_name in whitelist or (blacklist and
 735                        part_name not in blacklist):
 736                         unremovable_part_fpt += partition
 737                         if part_name != "FTPR":
 738                             extra_part_end = max(extra_part_end, part_end)
 739                         print("NOT removed")
 740                     else:
 741                         mef.fill_range(part_start, part_end, b"\xff")
 742                         print("removed")
 743
 744             print("Removing partition entries in FPT...")
 745             mef.write_to(0x30, unremovable_part_fpt)
 746             mef.write_to(0x14,
 747                          pack("<I", len(unremovable_part_fpt) // 0x20))
 748
 749             mef.fill_range(0x30 + len(unremovable_part_fpt),
 750                            0x30 + len(partitions), b"\xff")
 751
 752             if (not blacklist and "EFFS" not in whitelist) or \
 753                "EFFS" in blacklist:
 754                 print("Removing EFFS presence flag...")
 755                 mef.seek(0x24)
 756                 flags = unpack("<I", mef.read(4))[0]
 757                 flags &= ~(0x00000001)
 758                 mef.write_to(0x24, pack("<I", flags))
 759
 760             if me11:
 761                 mef.seek(0x10)
 762                 header = bytearray(mef.read(0x20))
 763                 header[0x0b] = 0x00
 764             else:
 765                 mef.seek(0)
 766                 header = bytearray(mef.read(0x30))
 767                 header[0x1b] = 0x00
 768             checksum = (0x100 - sum(header) & 0xff) & 0xff
 769
 770             print("Correcting checksum (0x{:02x})...".format(checksum))
 771             # The checksum is just the two's complement of the sum of the first
 772             # 0x30 bytes in ME < 11 or bytes 0x10:0x30 in ME >= 11 (except for
 773             # 0x1b, the checksum itself). In other words, the sum of those
 774             # bytes must be always 0x00.
 775             mef.write_to(0x1b, pack("B", checksum))
 776
 777             print("Reading FTPR modules list...")
 778             if me11:
 779                 end_addr, ftpr_offset = \
 780                     check_and_remove_modules_me11(mef, me_end,
 781                                                   ftpr_offset, ftpr_length,
 782                                                   min_ftpr_offset,
 783                                                   args.relocate,
 784                                                   args.keep_modules)
 785             else:
 786                 end_addr, ftpr_offset = \
 787                     check_and_remove_modules(mef, me_end, ftpr_offset,
 788                                              min_ftpr_offset, args.relocate,
 789                                              args.keep_modules)
 790
 791             if end_addr > 0:
 792                 end_addr = max(end_addr, extra_part_end)
 793                 end_addr = (end_addr // 0x1000 + 1) * 0x1000
 794                 end_addr += spared_blocks * 0x1000
 795
 796                 print("The ME minimum size should be {0} bytes "
 797                       "({0:#x} bytes)".format(end_addr))
 798
 799                 if me_start > 0:
 800                     print("The ME region can be reduced up to:\n"
 801                           " {:08x}:{:08x} me"
 802                           .format(me_start, me_start + end_addr - 1))
 803                 elif args.truncate:
 804                     print("Truncating file at {:#x}...".format(end_addr))
 805                     f.truncate(end_addr)
 806
 807         if args.soft_disable or args.soft_disable_only:
 808             if me11:
 809                 print("Setting the HAP bit in PCHSTRP0 to disable Intel ME...")
 810                 pchstrp0 |= (1 << 16)
 811                 fdf.write_to(fpsba, pack("<I", pchstrp0))
 812             else:
 813                 print("Setting the AltMeDisable bit in PCHSTRP10 to disable "
 814                       "Intel ME...")
 815                 pchstrp10 |= (1 << 7)
 816                 fdf.write_to(fpsba + 0x28, pack("<I", pchstrp10))
 817
 818     if args.descriptor:
 819         print("Removing ME/TXE R/W access to the other flash regions...")
 820         if me11:
 821             flmstr2 = 0x00400500
 822         else:
 823             fdf.seek(fmba + 0x4)
 824             flmstr2 = (unpack("<I", fdf.read(4))[0] | 0x04040000) & 0x0404ffff
 825
 826         fdf.write_to(fmba + 0x4, pack("<I", flmstr2))
 827
 828     if args.extract_descriptor:
 829         if args.truncate:
 830             print("Extracting the descriptor to \"{}\"..."
 831                   .format(args.extract_descriptor))
 832             fdf_copy = fdf.save(args.extract_descriptor, fd_end - fd_start)
 833
 834             if bios_start == me_end:
 835                 print("Modifying the regions of the extracted descriptor...")
 836                 print(" {:08x}:{:08x} me   --> {:08x}:{:08x} me"
 837                       .format(me_start, me_end - 1,
 838                               me_start, me_start + end_addr - 1))
 839                 print(" {:08x}:{:08x} bios --> {:08x}:{:08x} bios"
 840                       .format(bios_start, bios_end - 1,
 841                               me_start + end_addr, bios_end - 1))
 842
 843                 flreg1 = start_end_to_flreg(me_start + end_addr, bios_end)
 844                 flreg2 = start_end_to_flreg(me_start, me_start + end_addr)
 845
 846                 fdf_copy.seek(frba + 0x4)
 847                 fdf_copy.write(pack("<II", flreg1, flreg2))
 848             else:
 849                 print("\nWARNING:\n The start address of the BIOS region "
 850                       "isn't equal to the end address of the ME\n region: if "
 851                       "you want to recover the space from the ME region you "
 852                       "have to\n manually modify the descriptor.\n")
 853         else:
 854             print("Extracting the descriptor to \"{}\"..."
 855                   .format(args.extract_descriptor))
 856             fdf_copy = fdf.save(args.extract_descriptor, fd_end - fd_start)
 857
 858         fdf_copy.close()
 859
 860     if args.extract_me:
 861         if args.truncate:
 862             print("Extracting and truncating the ME image to \"{}\"..."
 863                   .format(args.extract_me))
 864             mef_copy = mef.save(args.extract_me, end_addr)
 865         else:
 866             print("Extracting the ME image to \"{}\"..."
 867                   .format(args.extract_me))
 868             mef_copy = mef.save(args.extract_me, me_end - me_start)
 869
 870         if not me6_ignition:
 871             print("Checking the FTPR RSA signature of the extracted ME "
 872                   "image... ", end="")
 873             print_check_partition_signature(mef_copy,
 874                                             ftpr_offset + ftpr_mn2_offset)
 875         mef_copy.close()
 876
 877     if not me6_ignition:
 878         print("Checking the FTPR RSA signature... ", end="")
 879         print_check_partition_signature(mef, ftpr_offset + ftpr_mn2_offset)
 880
 881     f.close()
 882
 883     if not args.check:
 884         print("Done! Good luck!")