A file integrity verifier based on the format of the file.
Project description
integv
integv is a file integrity verifier based on the format of the file. It's capable of checking the integrity of multiple types of files without any additional information like Content-Length or checksum. The main goal of integv is to detect file corruption (mostly shortened) during file download caused by network glitch. But integv still can be used for many other purposes as well.
Installation
pip install integv
Quick Start
import integv
# load a test mp4 file
file_path = "./test/sample/video/sample.mp4"
with open(file_path, "rb") as f:
file = f.read()
# initiate a verifier
verifier = integv.FileIntegrityVerifier()
# verify using the file and file_type
# file_type can be a simple filename extension like "mp4" or "jpg"
# or you can provide a full MIME type like "video/mp4" or "image/jpeg"
verifier.verify(file, file_type="mp4") # True
# a corrupted file (in this case, shortened by one byte) will not pass the verification
verifier.verify(file[:-1], file_type="mp4") # False
# the file input for the verifier can be bytes or a binary file like object
verifier.verify(open(file_path, "rb"), file_type="mp4") # True
# it can also be a string representing a file path
# if the file path contains a proper filename extension, the file_type is not needed.
verifier.verify(file_path) # True
Supported types
Video
- mp4:
video/mp4
- mkv:
video/x-matroska
- webm:
video/webm
- avi:
video/vnd.avi
Image
- jpeg:
image/jpeg
- png:
image/png
- gif:
image/gif
- webp
image/webp
Audio
- wav:
audio/x-wav
- ogg:
audio/ogg
Limitation of integv
The integv verifier only checks the file by the format information embedded in file like file size in header, chuck size in chuck header, end of file markers, etc. It does not try to decode the file which makes integv fast and simple. But that also means the possibility of false negative (corrupted files can't be detected). The baseline of all integv file integrity verifiers must be extremely sensitive to shortened files, which is very common in file downloaded from the network. Some types of files like png contain checksum inside, which is less error-prone. By all means, do not use integv for any kind of security verification. As a bad file which passes the verification can be simply forged.
Advanced Usage
Specialized File Integrity Verifier
There are some specialized file integrity verifier for different types of files.
You can find them in integv.video
, integv.image
and integv.audio
. They are
used exactly like the FileIntegrityVerifier
except file_type
are not needed.
from integv.video import MP4IntegrityVerifier
verifier = MP4IntegrityVerifier()
verifier.verify("./test/sample/video/sample.mp4") # True
Optional slow
argument in verifier initialization
A boolean argument slow
can be provided in verifier initialization. It will
enable some sophisticated verification to eliminate false negatives. And that
will consume more time. The default value of slow
is False
. For now, only
one verifier, OGGIntegrityVerifier
has a slow
method of verification.
from integv import FileIntegrityVerifier
verifier = FileIntegrityVerifier()
slow_verifier = FileIntegrityVerifier(slow=True)
file_path = "./test/sample/audio/sample.ogg"
verifier.verify(file_path) # True
slow_verifier.verify(file_path) # also True, but slower
Project details
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