Allow to add to the existing environment in ssh instead of replacing it (Gallopsled#1764)

* Add env_add to the ssh module

* Use ignore_environ like process

---------

Co-authored-by: peace-maker <[email protected]>
Co-authored-by: Arusekk <[email protected]>

Author: 3 people

pwnlib/tubes/ssh.py

@@ -760,7 +760,7 @@ def shell(self, shell = None, tty = True, timeout = Timeout.default):
         """
         return self.run(shell, tty, timeout = timeout)
 
-    def process(self, argv=None, executable=None, tty=True, cwd=None, env=None, timeout=Timeout.default, run=True,
+    def process(self, argv=None, executable=None, tty=True, cwd=None, env=None, ignore_environ=None, timeout=Timeout.default, run=True,
                 stdin=0, stdout=1, stderr=2, preexec_fn=None, preexec_args=(), raw=True, aslr=None, setuid=None,
                 shell=False):
         r"""
@@ -788,8 +788,9 @@ def process(self, argv=None, executable=None, tty=True, cwd=None, env=None, time
                 Working directory.  If :const:`None`, uses the working directory specified
                 on :attr:`cwd` or set via :meth:`set_working_directory`.
             env(dict):
-                Environment variables to set in the child.  If :const:`None`, inherits the
-                default environment.
+                Environment variables to add to the environment.
+            ignore_environ(bool):
+                Ignore default environment.  By default use default environment iff env not specified.
             timeout(int):
                 Timeout to set on the `tube` created to interact with the process.
             run(bool):
@@ -909,6 +910,9 @@ def process(self, argv=None, executable=None, tty=True, cwd=None, env=None, time
 
         aslr      = aslr if aslr is not None else context.aslr
 
+        if ignore_environ is None:
+            ignore_environ = env is not None  # compat
+
         argv, env = misc.normalize_argv_env(argv, env, self)
 
         if shell:
@@ -959,11 +963,12 @@ def func(): pass
 
 os.chdir(%(cwd)r)
 
+if %(ignore_environ)r:
+    os.environ.clear()
 environ = getattr(os, 'environb', os.environ)
 
 if env is not None:
     env = OrderedDict((bytes(k), bytes(v)) for k,v in env)
-    os.environ.clear()
     environ.update(env)
 else:
     env = environ