git-lfs/subprocess/subprocess_windows.go

// +build windows

package subprocess

import (
	"os/exec"
	"syscall"
)

// ExecCommand is a small platform specific wrapper around os/exec.Command
func ExecCommand(name string, arg ...string) *Cmd {
	cmd := exec.Command(name, arg...)
	cmd.Path, _ = LookPath(name)
	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
	cmd.Env = fetchEnvironment()
	return newCmd(cmd)
}
Refactor execCommand and simpleExec into separate package 2016-03-02 15:16:06 +00:00			`// +build windows`

			`package subprocess`

			`import (`
			`"os/exec"`
			`"syscall"`
			`)`

			`// ExecCommand is a small platform specific wrapper around os/exec.Command`
Fix for #1874 Created subprocess.Cmd wrapper to autoclose any created pipes Removing original fix for #1860 2017-01-17 23:41:38 +00:00			`func ExecCommand(name string, arg ...string) *Cmd {`
Refactor execCommand and simpleExec into separate package 2016-03-02 15:16:06 +00:00			`cmd := exec.Command(name, arg...)`
subprocess: avoid using relative program names When Go runs a program with os.exec, it uses the LookPath function to look up the path name if the path does not contain a path separator. On Unix, this provides the standard Unix semantics by looking in PATH. However, on Windows, it also looks in the current directory as well to emulate the behavior of CMD. Unfortunately, this is a well-known security flaw on Windows and similar behavior there is the source for several whole classes of security vulnerabilities. This leads to an untrusted repository being able to create a git.bat file that gets executed in preference to our trusted path for the git binary. Since we don't want to rely on Go fixing this behavior, let's import some code from Go to provide the Unix semantics for LookPath, which are secure if the user hasn't put the current directory in PATH. That should provide secure behavior in this case. Fortunately, our code goes through one particular place to run all commands, so this is a relatively simple fix. Update the various copyright and license files to reflect our imported code. 2020-10-28 14:27:33 +00:00			`cmd.Path, _ = LookPath(name)`
Refactor execCommand and simpleExec into separate package 2016-03-02 15:16:06 +00:00			`cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}`
subprocess: don't initialize environment at startup Currently, the subprocess package reads from the environment as it's created at startup when the init function is called. However, we'll soon want to modify the environment in this case before it gets processed, so let's change the code to use a mutex to initialize the environment once before using it and simply call that before using the environment we've set up. We'll want to reset the environment as well in a future commit, so let's be sure to add a function for that. We reuse the same internal function and just ignore the return value to make our code paths simpler. 2020-10-02 16:50:06 +00:00			`cmd.Env = fetchEnvironment()`
Fix for #1874 Created subprocess.Cmd wrapper to autoclose any created pipes Removing original fix for #1860 2017-01-17 23:41:38 +00:00			`return newCmd(cmd)`
Refactor execCommand and simpleExec into separate package 2016-03-02 15:16:06 +00:00			`}`