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Tested unveiling CGI dirs and globs as executable.

This commit is contained in:
kvothe 2020-09-15 22:14:12 -04:00
parent 03ca12d0c1
commit 69a253f820

View file

@ -3,44 +3,29 @@ package main
import (
"golang.org/x/sys/unix"
"log"
"path/filepath"
)
// Restrict access to the files specified in config in an OS-dependent way.
// The OpenBSD implementation uses pledge(2) and unveil(2) to restrict the
// operations available to the molly brown executable.
func enableSecurityRestrictions(config Config, errorLog *log.Logger) {
// Pledge to only use stdio, inet, rpath, and unveil syscalls.
// If (S)CGI paths have been specified, also allow exec syscalls.
// Please note that execpromises haven't been specified, meaning that
// (S)CGI applications spawned by molly brown should pledge their own
// restrictions.
promises := "stdio inet rpath unveil"
if len(config.CGIPaths) > 0 || len(config.SCGIPaths) > 0 {
promises += " exec"
}
err := unix.PledgePromises(promises)
if err != nil {
errorLog.Println("Could not pledge: " + err.Error())
log.Fatal(err)
}
// Unveil a specific list of files that we are allowed to access.
err = unix.Unveil(config.DocBase, "r")
err := unix.Unveil(config.DocBase, "r")
if err != nil {
errorLog.Println("Could not unveil DocBase: " + err.Error())
log.Fatal(err)
}
for _, cgiPath := range config.CGIPaths {
err = unix.Unveil(cgiPath, "rx")
if err != nil {
errorLog.Println("Could not unveil CGIPath: " + err.Error())
log.Fatal(err)
}
}
for _, scgiPath := range config.SCGIPaths {
err = unix.Unveil(scgiPath, "rx")
if err != nil {
errorLog.Println("Could not unveil SCGIPaths: " + err.Error())
log.Fatal(err)
cgiGlobbedPaths, err := filepath.Glob(cgiPath)
for _, cgiGlobbedPath := range cgiGlobbedPaths {
log.Println("Unveiling \"" + cgiGlobbedPath + "\" as executable.")
err = unix.Unveil(cgiGlobbedPath, "rx")
if err != nil {
errorLog.Println("Could not unveil CGIPaths: " + err.Error())
log.Fatal(err)
}
}
}
err = unix.UnveilBlock()
@ -48,4 +33,19 @@ func enableSecurityRestrictions(config Config, errorLog *log.Logger) {
errorLog.Println("Could not block unveil: " + err.Error())
log.Fatal(err)
}
// Pledge to only use stdio, inet, and rpath syscalls.
// If CGI paths have been specified, also allow exec syscalls.
// Please note that execpromises haven't been specified, meaning that
// CGI applications spawned by molly brown should pledge their own
// restrictions and unveil their own files.
promises := "stdio inet rpath"
if len(config.CGIPaths) > 0 {
promises += " exec proc"
}
err = unix.PledgePromises(promises)
if err != nil {
errorLog.Println("Could not pledge: " + err.Error())
log.Fatal(err)
}
}