fix decode error

[hanul93]

In my execution environment, I get the following error. So I fixed the decoding part.

Traceback (most recent call last):
  File "test\test_idb.py", line 3, in <module>
    with idb.from_file('NetBase.dll.i64') as db:
  File "c:\Python310\lib\contextlib.py", line 135, in __enter__
    return next(self.gen)
  File "test\venv\lib\site-packages\idb\__init__.py", line 33, in from_file
    db.vsParse(buf)
  File "test\venv\lib\site-packages\vstruct\__init__.py", line 145, in vsParse
    self._vsFireCallbacks(fname)
  File "test\venv\lib\site-packages\vstruct\__init__.py", line 88, in _vsFireCallbacks
    callback()
  File "test\venv\lib\site-packages\idb\fileformat.py", line 1199, in pcb_header
    s.inf = Root(self).idainfo
  File "test\venv\lib\site-packages\idb\analysis.py", line 365, in __getattr__
    return field.cast(bytes(v), wordsize=self.idb.wordsize)
  File "test\venv\lib\site-packages\idb\analysis.py", line 96, in inner
    return cast(buf, V, wordsize=wordsize)
  File "test\venv\lib\site-packages\idb\analysis.py", line 74, in cast
    v.vsParse(buf)
  File "test\venv\lib\site-packages\idb\analysis.py", line 636, in vsParse
    self.procname = reader.str(16)
  File "test\venv\lib\site-packages\idb\analysis.py", line 427, in str
    return self.read(size).decode(encoding)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x82 in position 8: invalid start byte

[williballenthin]

this exception indicates that the encountered data isn't what we expect (utf-8 string). the proposed fix hides the error, rather than fixing it. i would rather address the underlying bug.

can you share the idb?

[hanul93]

You are right.
Here is the idb file.
360NetBase.dll.zip

[hanul93]

I have discovered the cause of this problem.
This problem was due to incorrectly interpreting the structure while analyzing idainfo.
However, the source code in your GitHub repository had no issues.
The problem is that the code in version 0.7.1 uploaded to PyPI is different.

[PyPI] ida/analysis.py:625
if self.version == 700 and self.tag == "IDA":

[GitHub] ida/analysis.py:625
if self.version >= 700 and self.tag == "IDA":

The idb file I sent you was analyzed with IDA Pro v7.7.
Therefore, errors were occurring in my project environment installed through PyPI.

[williballenthin]

ah great, thanks for the explanation. i'll push another release to PyPI.

[williballenthin]

v0.8.0 released here: https://github.com/williballenthin/python-idb/releases/tag/v0.8.0
and on PyPI here: https://pypi.org/manage/project/python-idb/release/0.8.0/