Fix need for tiocsti workaround

Fixes bug #77
Use a subprocess to provide the same behaviour.
Fix the termios calls when the keyboard is proccess to exit a run part
way through (existing issue).

arsenal/app.py

@@ -1,9 +1,9 @@
 import argparse
 import json
 import os
-import fcntl
-import termios
 import re
+import subprocess
+import termios
 import time
 from curses import wrapper
 
@@ -18,7 +18,8 @@
 class App:
 
     def __init__(self):
-        pass
+        self.stdin = 0
+        self.oldattr = None
 
     def get_args(self):
         examples = '''examples:
@@ -168,39 +169,36 @@ def start(self, args, cheatsheets):
                 break
 
     def prefil_shell_cmd(self, cmd):
-        stdin = 0
         # save TTY attribute for stdin
-        oldattr = termios.tcgetattr(stdin)
+        self.oldattr = termios.tcgetattr(self.stdin)
         # create new attributes to fake input
-        newattr = termios.tcgetattr(stdin)
+        newattr = termios.tcgetattr(self.stdin)
         # disable echo in stdin -> only inject cmd in stdin queue (with TIOCSTI)
         newattr[3] &= ~termios.ECHO
         # enable non canonical mode -> ignore special editing characters
         newattr[3] &= ~termios.ICANON
         # use the new attributes
-        termios.tcsetattr(stdin, termios.TCSANOW, newattr)
+        termios.tcsetattr(self.stdin, termios.TCSANOW, newattr)
         # write the selected command in stdin queue
-        try:
-            for c in cmd.cmdline:
-                fcntl.ioctl(stdin, termios.TIOCSTI, c)
-        except OSError:
-            message = "========== OSError ============\n"
-            message += "Arsenal needs TIOCSTI enable for running\n"
-            message += "Please run the following commands as root to fix this issue on the current session :\n"
-            message += "sysctl -w dev.tty.legacy_tiocsti=1\n"
-            message += "If you want this workaround to survive a reboot,\n" 
-            message += "add the following configuration to sysctl.conf file and reboot :\n"
-            message += "echo \"dev.tty.legacy_tiocsti=1\" >> /etc/sysctl.conf\n"
-            message += "More details about this bug here: https://github.com/Orange-Cyberdefense/arsenal/issues/77"
-            print(message)
-        # restore TTY attribute for stdin
-        termios.tcsetattr(stdin, termios.TCSADRAIN, oldattr)
+        print(cmd.cmdline, end=" ")
+        input()
+        print("")
+        # run command and pipe to stdin
+        subprocess.run([cmd.cmdline], shell=True)
+        self.restore_tty()
+
+    def restore_tty(self):
+        # restore TTY attribute for stdin if they have been saved
+        if self.oldattr:
+            termios.tcsetattr(self.stdin, termios.TCSADRAIN, self.oldattr)
 
 
 def main():
+    app = App()
     try:
-        App().run()
+        app.run()
     except KeyboardInterrupt:
+        app.restore_tty()
         exit(0)