755 permissions when creating directory

[vshah23]

Context

[CI-763] A customer pointed out that our plugin executables have 777 permissions which was triggering their security scanner and recommended us to change permissions to 755.

We also thought why not change the directory permissions to 755 to be on the safe side as a proactive security measure.

Changes

• Set directory permissions to 755 as a proactive security measure

Investigation

We found that directories already have 755 permission, but we don’t know how 😳

Upon further inspection we found from the bitrise-cli we are calling the EnsureDirExist function in pathutil.go which calls os.MkdirAll(dir, 0777) so we’re explicitly saying to use 777 permission, but the ~/.bitrise directory is still being created with 755 permission.

We thought there was something happening during the image creation process, but it turns out it’s due to umask that the folder permissions are defaulting to 755.

Decisions

We decided to avoid setting the umask using syscall.Umask() and instead just set the file permissions here. This will not have much of an affect since the directories are already set with 755 permissions, but we want to be explicit about it.