README
¶
golisten
Privilege de-escalation listen in Go.
Overview
golisten expects to be root. If it is not, it will error.
As root, perform a net.Listen(). Once this is done, we can perform the
privilege de-escalation.
Because of the Go thread model, it is not safe to do so with a "simple" syscall.Setuid().
In order to ensure that the whole process (all threads) are de-escalated, golsiten will
fork itself as the requested user while inheriting the privileged listened file descriptor.
golisten.ListenAndServe works just like http.ListenAndServe but expect the target user
to be run as.
Example
ListenAndServe
package main
import (
"fmt"
"log"
"net/http"
"os/user"
"github.com/creack/golisten"
)
func handler(w http.ResponseWriter, req *http.Request) {
u, err := user.Current()
if err != nil {
log.Printf("Error getting user: %s", err)
return
}
fmt.Fprintf(w, "%s\n", u.Uid)
}
func main() {
http.HandleFunc("/", handler)
log.Fatal(golisten.ListenAndServe("guillaume", ":80", nil))
}
Listen
package main
import (
"fmt"
"log"
"net/http"
"os/user"
"github.com/creack/golisten"
)
func handler(w http.ResponseWriter, req *http.Request) {
u, err := user.Current()
if err != nil {
log.Printf("Error getting user: %s", err)
return
}
fmt.Fprintf(w, "%s\n", u.Uid)
}
func ExampleListenAndServe() {
ln, err := golisten.Listen("guillaume", "tcp", ":80")
if err != nil {
log.Fatal(err)
}
http.HandleFunc("/", handler)
log.Fatal(http.Serve(ln, nil))
}
TODO
- ListenAndServeTLS
- Benchmarks
- Tests
- Use environment instead of command-line flag for fd passing
Documentation
¶
Overview ¶
Package golisten allows a user to user http.ListenAndServe with any port as root and effectively accept the incomming connection as an other un-privileged user.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func ListenAndServe ¶
ListenAndServe wraps `http.ListenAndServe`. Listen as root and accept as `targetUser`.
Example ¶
package main
import (
"fmt"
"log"
"net/http"
"os/user"
)
func handler(w http.ResponseWriter, req *http.Request) {
u, err := user.Current()
if err != nil {
log.Printf("Error getting user: %s", err)
return
}
fmt.Fprintf(w, "%s\n", u.Uid)
}
func main() {
ln, err := Listen("guillaume", "tcp", ":80")
if err != nil {
log.Fatal(err)
}
http.HandleFunc("/", handler)
log.Fatal(http.Serve(ln, nil))
}
Output:
Example ¶
package main
import (
"fmt"
"log"
"net/http"
"os/user"
)
func handler(w http.ResponseWriter, req *http.Request) {
u, err := user.Current()
if err != nil {
log.Printf("Error getting user: %s", err)
return
}
fmt.Fprintf(w, "%s\n", u.Uid)
}
func main() {
http.HandleFunc("/", handler)
log.Fatal(ListenAndServe("guillaume", ":80", nil))
}
Output:
Types ¶
This section is empty.
Source Files