First Commit

tools/release/fix-pg-map-id.py

@@ -0,0 +1,227 @@
+#!/usr/bin/python3
+# encoding: utf-8
+# SPDX-FileCopyrightText: 2024 FC (Fay) Stegerman <flx@obfusk.net>
+# SPDX-License-Identifier: GPL-3.0-or-later.
+
+import hashlib
+import os
+import re
+import struct
+import zipfile
+import zlib
+
+from binascii import hexlify
+from typing import Any, Dict, Match, Tuple
+
+DEX_MAGIC = b"dex\n"
+DEX_MAGIC_RE = re.compile(rb"dex\n(\d{3})\x00")
+
+PROF_MAGIC = b"pro\x00"
+PROF_010_P = b"010\x00"
+
+CLASSES_DEX_RE = re.compile(r"classes\d*\.dex")
+ASSET_PROF = "assets/dexopt/baseline.prof"
+
+PG_MAP_ID_RE = re.compile(rb'(~~R8{"backend":"dex".*?"pg-map-id":")([0-9a-f]{7})(")')
+
+ATTRS = ("compress_type", "create_system", "create_version", "date_time",
+         "external_attr", "extract_version", "flag_bits")
+LEVELS = (9, 6, 4, 1)
+
+
+class Error(RuntimeError):
+    pass
+
+
+# FIXME: is there a better alternative?
+class ReproducibleZipInfo(zipfile.ZipInfo):
+    """Reproducible ZipInfo hack."""
+
+    if "_compresslevel" not in zipfile.ZipInfo.__slots__:       # type: ignore[attr-defined]
+        if "compress_level" not in zipfile.ZipInfo.__slots__:   # type: ignore[attr-defined]
+            raise Error("zipfile.ZipInfo has no ._compresslevel")
+
+    _compresslevel: int
+    _override: Dict[str, Any] = {}
+
+    def __init__(self, zinfo: zipfile.ZipInfo, **override: Any) -> None:
+        # pylint: disable=W0231
+        if override:
+            self._override = {**self._override, **override}
+        for k in self.__slots__:
+            if hasattr(zinfo, k):
+                setattr(self, k, getattr(zinfo, k))
+
+    def __getattribute__(self, name: str) -> Any:
+        if name != "_override":
+            try:
+                return self._override[name]
+            except KeyError:
+                pass
+        return object.__getattribute__(self, name)
+
+
+def fix_pg_map_id(input_dir: str, output_dir: str, map_id: str) -> None:
+    file_data = {}
+    for filename in [ASSET_PROF] + sorted(os.listdir(input_dir)):
+        if re.fullmatch(CLASSES_DEX_RE, filename) or filename == ASSET_PROF:
+            print(f"reading {filename!r}...")
+            with open(os.path.join(input_dir, *filename.split("/")), "rb") as fh:
+                file_data[filename] = fh.read()
+    _fix_pg_map_id(file_data, map_id)
+    for filename, data in file_data.items():
+        print(f"writing {filename!r}...")
+        if "/" in filename:
+            os.makedirs(os.path.join(output_dir, *filename.split("/")[:-1]), exist_ok=True)
+        with open(os.path.join(output_dir, *filename.split("/")), "wb") as fh:
+            fh.write(data)
+
+
+def fix_pg_map_id_apk(input_apk: str, output_apk: str, map_id: str) -> None:
+    with open(input_apk, "rb") as fh_raw:
+        with zipfile.ZipFile(input_apk) as zf_in:
+            with zipfile.ZipFile(output_apk, "w") as zf_out:
+                file_data = {}
+                for info in zf_in.infolist():
+                    if re.fullmatch(CLASSES_DEX_RE, info.filename) or info.filename == ASSET_PROF:
+                        print(f"reading {info.filename!r}...")
+                        file_data[info.filename] = zf_in.read(info)
+                _fix_pg_map_id(file_data, map_id)
+                for info in zf_in.infolist():
+                    attrs = {attr: getattr(info, attr) for attr in ATTRS}
+                    zinfo = ReproducibleZipInfo(info, **attrs)
+                    if info.compress_type == 8:
+                        fh_raw.seek(info.header_offset)
+                        n, m = struct.unpack("<HH", fh_raw.read(30)[26:30])
+                        fh_raw.seek(info.header_offset + 30 + m + n)
+                        ccrc = 0
+                        size = info.compress_size
+                        while size > 0:
+                            ccrc = zlib.crc32(fh_raw.read(min(size, 4096)), ccrc)
+                            size -= 4096
+                        with zf_in.open(info) as fh_in:
+                            comps = {lvl: zlib.compressobj(lvl, 8, -15) for lvl in LEVELS}
+                            ccrcs = {lvl: 0 for lvl in LEVELS}
+                            while True:
+                                data = fh_in.read(4096)
+                                if not data:
+                                    break
+                                for lvl in LEVELS:
+                                    ccrcs[lvl] = zlib.crc32(comps[lvl].compress(data), ccrcs[lvl])
+                            for lvl in LEVELS:
+                                if ccrc == zlib.crc32(comps[lvl].flush(), ccrcs[lvl]):
+                                    zinfo._compresslevel = lvl
+                                    break
+                            else:
+                                raise Error(f"Unable to determine compresslevel for {info.filename!r}")
+                    elif info.compress_type != 0:
+                        raise Error(f"Unsupported compress_type {info.compress_type}")
+                    if re.fullmatch(CLASSES_DEX_RE, info.filename) or info.filename == ASSET_PROF:
+                        print(f"writing {info.filename!r}...")
+                        zf_out.writestr(zinfo, file_data[info.filename])
+                    else:
+                        with zf_in.open(info) as fh_in:
+                            with zf_out.open(zinfo, "w") as fh_out:
+                                while True:
+                                    data = fh_in.read(4096)
+                                    if not data:
+                                        break
+                                    fh_out.write(data)
+
+
+def _fix_pg_map_id(file_data: Dict[str, bytes], map_id: str) -> None:
+    crcs = {}
+    for filename in file_data:
+        if re.fullmatch(CLASSES_DEX_RE, filename):
+            print(f"fixing {filename!r}...")
+            data = _fix_dex_id_checksum(file_data[filename], map_id.encode())
+            file_data[filename] = data
+            crcs[filename] = zlib.crc32(data)
+    if ASSET_PROF in file_data:
+        print(f"fixing {ASSET_PROF!r}...")
+        file_data[ASSET_PROF] = _fix_prof_checksum(file_data[ASSET_PROF], crcs)
+
+
+def _fix_dex_id_checksum(data: bytes, map_id: bytes) -> bytes:
+    def repl(m: Match[bytes]) -> bytes:
+        print(f"fixing pg-map-id: {m.group(2)!r} -> {map_id!r}")
+        return m.group(1) + map_id + m.group(3)
+
+    magic = data[:8]
+    if magic[:4] != DEX_MAGIC or not DEX_MAGIC_RE.fullmatch(magic):
+        raise Error(f"Unsupported magic {magic!r}")
+    print(f"dex version={int(magic[4:7]):03d}")
+    checksum, signature = struct.unpack("<I20s", data[8:32])
+    fixed_data = re.sub(PG_MAP_ID_RE, repl, data[32:])
+    if fixed_data == data[32:]:
+        print("(not modified)")
+        return data
+    fixed_sig = hashlib.sha1(fixed_data).digest()
+    print(f"fixing signature: {hexlify(signature).decode()} -> {hexlify(fixed_sig).decode()}")
+    fixed_data = fixed_sig + fixed_data
+    fixed_checksum = zlib.adler32(fixed_data)
+    print(f"fixing checksum: 0x{checksum:x} -> 0x{fixed_checksum:x}")
+    return magic + int.to_bytes(fixed_checksum, 4, "little") + fixed_data
+
+
+def _fix_prof_checksum(data: bytes, crcs: Dict[str, int]) -> bytes:
+    magic, data = _split(data, 4)
+    version, data = _split(data, 4)
+    if magic == PROF_MAGIC:
+        if version == PROF_010_P:
+            print("prof version=010 P")
+            return PROF_MAGIC + PROF_010_P + _fix_prof_010_p_checksum(data, crcs)
+        else:
+            raise Error(f"Unsupported prof version {version!r}")
+    else:
+        raise Error(f"Unsupported magic {magic!r}")
+
+
+def _fix_prof_010_p_checksum(data: bytes, crcs: Dict[str, int]) -> bytes:
+    num_dex_files, uncompressed_data_size, compressed_data_size, data = _unpack("<BII", data)
+    dex_data_headers = []
+    if len(data) != compressed_data_size:
+        raise Error("Compressed data size does not match")
+    data = zlib.decompress(data)
+    if len(data) != uncompressed_data_size:
+        raise Error("Uncompressed data size does not match")
+    for i in range(num_dex_files):
+        profile_key_size, num_type_ids, hot_method_region_size, \
+            dex_checksum, num_method_ids, data = _unpack("<HHIII", data)
+        profile_key, data = _split(data, profile_key_size)
+        filename = profile_key.decode()
+        fixed_checksum = crcs[filename]
+        if fixed_checksum != dex_checksum:
+            print(f"fixing {filename!r} checksum: 0x{dex_checksum:x} -> 0x{fixed_checksum:x}")
+        dex_data_headers.append(struct.pack(
+            "<HHIII", profile_key_size, num_type_ids, hot_method_region_size,
+            fixed_checksum, num_method_ids) + profile_key)
+    fixed_data = b"".join(dex_data_headers) + data
+    fixed_cdata = zlib.compress(fixed_data, 1)
+    fixed_hdr = struct.pack("<BII", num_dex_files, uncompressed_data_size, len(fixed_cdata))
+    return fixed_hdr + fixed_cdata
+
+
+def _unpack(fmt: str, data: bytes) -> Any:
+    assert all(c in "<BHI" for c in fmt)
+    size = fmt.count("B") + 2 * fmt.count("H") + 4 * fmt.count("I")
+    return struct.unpack(fmt, data[:size]) + (data[size:],)
+
+
+def _split(data: bytes, size: int) -> Tuple[bytes, bytes]:
+    return data[:size], data[size:]
+
+
+if __name__ == "__main__":
+    import argparse
+    parser = argparse.ArgumentParser(prog="fix-pg-map-id.py")
+    parser.add_argument("input_dir_or_apk", metavar="INPUT_DIR_OR_APK")
+    parser.add_argument("output_dir_or_apk", metavar="OUTPUT_DIR_OR_APK")
+    parser.add_argument("pg_map_id", metavar="PG_MAP_ID")
+    args = parser.parse_args()
+    if os.path.isdir(args.input_dir_or_apk):
+        fix_pg_map_id(args.input_dir_or_apk, args.output_dir_or_apk, args.pg_map_id)
+    else:
+        fix_pg_map_id_apk(args.input_dir_or_apk, args.output_dir_or_apk, args.pg_map_id)
+
+# vim: set tw=80 sw=4 sts=4 et fdm=marker :