Uncaught exceptions on generic file containing 'startxref' string #626
Description
Bug report
Several issues were spotted in the PdfFileReader class.
The following code was used during tests:
import sys
from PyPDF2 import PdfFileReader
from PyPDF2.utils import PyPdfError
if __name__ == "__main__":
with open(sys.argv[1], "rb") as f:
try:
r = PdfFileReader(f)
except PyPdfError:
passoutput - bug1.pdf :
Traceback (most recent call last):
File "/usr/local/lib/python3.8/dist-packages/PyPDF2/pdf.py", line 1768, in read
startxref = int(line)
ValueError: invalid literal for int() with base 10: b'startxref'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "main.py", line 13, in <module>
r = PdfFileReader(f)
File "/usr/local/lib/python3.8/dist-packages/PyPDF2/pdf.py", line 1148, in __init__
self.read(stream)
File "/usr/local/lib/python3.8/dist-packages/PyPDF2/pdf.py", line 1773, in read
startxref = int(line[9:].strip())
ValueError: invalid literal for int() with base 10: b''
output - bug2.pdf :
Traceback (most recent call last):
File "main.py", line 13, in <module>
r = PdfFileReader(f)
File "/usr/local/lib/python3.8/dist-packages/PyPDF2/pdf.py", line 1148, in __init__
self.read(stream)
File "/usr/local/lib/python3.8/dist-packages/PyPDF2/pdf.py", line 1948, in read
stream.seek(-11, 1)
OSError: [Errno 22] Invalid argument
Solution
Validate the signature of the input file, that should be %PDF- and alike, ref:https://en.wikipedia.org/wiki/List_of_file_signatures