Add partial support for encrypted lmpro archives

- Archive extraction now supported
- lmpatch does not yet support inserting encrypted files into an
  archive, if the original file was encrypted and uncompressed, the
  patched file will be inserted as uncompressed and unencrypted, if the
  original file was encrypted and compressed, the patched file will be
  inserted as compressed and unencrypted
- Scrambled LM Pro GAL image conversion is not yet supported

See also: #3

livemaker/archive.py

@@ -25,11 +25,6 @@
 with the exception that archives cannot be modified in-place (i.e. mode ``'a'``
 is unavailable).
 
-Note:
-    Reading (and writing) files which are encrypted via LiveMaker Pro is not
-    supported, but any non-encrypted files from a LiveMaker Pro archive can
-    be extracted.
-
 """
 
 import enum
@@ -45,6 +40,7 @@
 import construct
 
 from .exceptions import BadLiveMakerArchive, UnsupportedLiveMakerCompression
+from .scramble import decrypt
 
 
 log = logging.getLogger(__name__)
@@ -60,7 +56,9 @@ class LMCompressType(enum.IntEnum):
 
 SUPPORTED_COMPRESSIONS = [
     LMCompressType.NONE,
-    LMCompressType.ZLIB
+    LMCompressType.ZLIB,
+    LMCompressType.ENCRYPTED,
+    LMCompressType.ENCRYPTED_ZLIB,
 ]
 
 # LM3 seed for TpRandom
@@ -722,8 +720,14 @@ def read(self, name, decompress=True, skip_checksum=True):
             if info.checksum != LMArchiveDirectory.checksum(data):
                 log.warn('Bad checksum for file {}.'.format(info.name))
         if decompress:
-            if info.compress_type == LMCompressType.ZLIB:
-                data = zlib.decompress(data)
+            if info.compress_type in (LMCompressType.ENCRYPTED, LMCompressType.ENCRYPTED_ZLIB):
+                data = decrypt(data)
+
+            if info.compress_type in (LMCompressType.ZLIB, LMCompressType.ENCRYPTED_ZLIB):
+                try:
+                    data = zlib.decompress(data)
+                except zlib.error as e:
+                    raise UnsupportedLiveMakerCompression(str(e))
         return data
 
     def read_exe(self):

livemaker/cli.py

@@ -34,7 +34,7 @@
 from . import GalImagePlugin
 
 from .archive import LMArchive
-from .exceptions import LiveMakerException, BadLsbError
+from .exceptions import LiveMakerException, BadLsbError, UnsupportedLiveMakerCompression
 from .lsb import LMScript
 from .lsb.command import BaseComponentCommand, Calc, CommandType, Jump
 from .lsb.core import OpeData, OpeDataType, OpeFuncType, Param, ParamType
@@ -86,7 +86,11 @@ def x(dry_run, image_format, output_dir, verbose, input_file):
         for info in lm.infolist():
             if str(info.path).lower().endswith('.gal'):
                 if not dry_run:
-                    data = lm.read(info)
+                    try:
+                        data = lm.read(info)
+                    except UnsupportedLiveMakerCompression as e:
+                        print('  Error extracting {}: {}'.format(info.path, e))
+                        continue
                 if image_format in ('gal', 'both'):
                     if not dry_run:
                         path = Path.joinpath(output_dir, info.path).expanduser().resolve()
@@ -115,7 +119,10 @@ def x(dry_run, image_format, output_dir, verbose, input_file):
                                 print(info.path)
             else:
                 if not dry_run:
-                    lm.extract(info, output_dir)
+                    try:
+                        lm.extract(info, output_dir)
+                    except UnsupportedLiveMakerCompression as e:
+                        print('  Error extracting {}: {}'.format(info.path, e))
                 if verbose or dry_run:
                     print(info.path)
 

livemaker/patch.py

@@ -28,7 +28,7 @@
 
 import click
 
-from livemaker import LMArchive
+from livemaker import LMArchive, LMCompressType
 from livemaker.exceptions import LiveMakerException
 
 
@@ -116,9 +116,16 @@ def bar_show(item):
             with click.progressbar(orig_lm.infolist(), item_show_func=bar_show) as bar:
                 for info in bar:
                     if info.path == lsb_path:
-                        # replace existing with patch version, use original
-                        # compress type
-                        new_lm.write(lsb_path, compress_type=info.compress_type, unk1=info.unk1)
+                        # replace existing with patch version
+                        #
+                        # TODO: support writing encrypted files
+                        if info.compress_type == LMCompressType.ENCRYPTED:
+                            compress_type = LMCompressType.NONE
+                        elif info.compress_type == LMCompressType.ENCRYPTED_ZLIB:
+                            compress_type = LMCompressType.ZLIB
+                        else:
+                            compress_type = info.compress_type
+                        new_lm.write(lsb_path, compress_type=compress_type, unk1=info.unk1)
                         log.info('patched {}'.format(lsb_path))
                         # print('patched')
                     else: