Update `RarHeaderFactoryTests` and `GZipArchiveTests` to open the test
readers as `FileAccess.Read` and `FileShare.Read` to prevent issues with
multiple test from trying to open exclusive access to files.
The `TestBase` is not always able to delete the scratch folder in
`Dispose()` because sometimes the files are still in use.
This problem appears to be leaked file handles (likely due to incorrect
handling of `IDisposable`). To avoid the problem for now, force a
garbage collection prior to deleting the scratch folder.
Tests fail in Visual Studio because they try to reuse the same scratch
working space, and each test is responsible for resetting the space. To
simplify the test code:
1. Make `TestBase` `IDisposable` and have it create the scratch space
2. Remove `ResetScratch()` as it is now handled by the base class
3. Add a unique ID to each scrach space folder to prevent collisions
This PR is meant to fix an arbitrary file write vulnerability, that can be
achieved using a specially crafted zip archive, that holds path traversal
filenames. When the filename gets concatenated to the target extraction
directory, the final path ends up outside of the target folder.
A sample malicious zip file named Zip.Evil.zip was used,
and when running the code below, resulted in the creation of C:/Temp/evil.txt
outside of the intended target directory.
There are various possible ways to avoid this issue, some include checking
for .. (dot dot) characters in the filename, but the best solution in our
opinion is to check if the final target filename, starts with the target
folder (after both are resolved to their absolute path).
Stay secure,
Snyk Team
* Add netstandard 2.0 target and netcoreapp2.0 tests
* Update xunit
* set tests explicitly to netcore2
* update travis
* Don't say build as netcoreapp1.0
* try adding dotnet 1 too
* Remove .NET Core 1 support
* switch to circle
* update cake
* fix circle build
* try fix file ending test again
* Fix casing on files
* Another casing fix
* Add back netstandard1.0
* Finish adding netstandard 1.0 back
* Add netstandard1.3 back
