pwnlib.tubes.ssh — SSH

class pwnlib.tubes.ssh.ssh(user=None, host=None, port=22, password=None, key=None, keyfile=None, proxy_command=None, proxy_sock=None, level=None, cache=True, ssh_agent=False, ignore_config=False, raw=False, auth_none=False, *a, **kw)

Creates a new ssh connection.

Parameters:

• user (str) – The username to log in with

• host (str) – The hostname to connect to

• port (int) – The port to connect to

• password (str) – Try to authenticate using this password

• key (str) – Try to authenticate using this private key. The string should be the actual private key.

• keyfile (str) – Try to authenticate using this private key. The string should be a filename.

• proxy_command (str) – Use this as a proxy command. It has approximately the same semantics as ProxyCommand from ssh(1).

• proxy_sock (str) – Use this socket instead of connecting to the host.

• timeout – Timeout, in seconds

• level – Log level

• cache (bool) – Cache downloaded files (by hash/size/timestamp)

• ssh_agent (bool) – If True, enable usage of keys via ssh-agent

• ignore_config (bool) – If True, disable usage of ~/.ssh/config and ~/.ssh/authorized_keys

• raw (bool) – If True, assume a non-standard shell and don’t probe the environment

• auth_none (bool) – If True, try to authenticate with no authentication methods

NOTE: The proxy_command and proxy_sock arguments is only available if a fairly new version of paramiko is used.

Example proxying:

 >>> s1 = ssh(host='example.pwnme')
 >>> r1 = s1.remote('localhost', 22)
 >>> s2 = ssh(host='example.pwnme', proxy_sock=r1.sock)
 >>> r2 = s2.remote('localhost', 22) # and so on...
 >>> for x in r2, s2, r1, s1: x.close()

__call__(attr)

Permits function-style access to run commands over SSH

Examples

>>> s =  ssh(host='example.pwnme')
>>> print(repr(s('echo hello')))
b'hello'

__getattr__(attr)

Permits member access to run commands over SSH

Examples

>>> s =  ssh(host='example.pwnme')
>>> s.echo('hello')
b'hello'
>>> s.whoami()
b'travis'
>>> s.echo(['huh','yay','args'])
b'huh yay args'

__getitem__(attr)

Permits indexed access to run commands over SSH

Examples

>>> s =  ssh(host='example.pwnme')
>>> print(repr(s['echo hello']))
b'hello'

__init__(user=None, host=None, port=22, password=None, key=None, keyfile=None, proxy_command=None, proxy_sock=None, level=None, cache=True, ssh_agent=False, ignore_config=False, raw=False, auth_none=False, *a, **kw)

Creates a new ssh connection.

Parameters:

• user (str) – The username to log in with

• host (str) – The hostname to connect to

• port (int) – The port to connect to

• password (str) – Try to authenticate using this password

• key (str) – Try to authenticate using this private key. The string should be the actual private key.

• keyfile (str) – Try to authenticate using this private key. The string should be a filename.

• proxy_command (str) – Use this as a proxy command. It has approximately the same semantics as ProxyCommand from ssh(1).

• proxy_sock (str) – Use this socket instead of connecting to the host.

• timeout – Timeout, in seconds

• level – Log level

• cache (bool) – Cache downloaded files (by hash/size/timestamp)

• ssh_agent (bool) – If True, enable usage of keys via ssh-agent

• ignore_config (bool) – If True, disable usage of ~/.ssh/config and ~/.ssh/authorized_keys

• raw (bool) – If True, assume a non-standard shell and don’t probe the environment

• auth_none (bool) – If True, try to authenticate with no authentication methods

NOTE: The proxy_command and proxy_sock arguments is only available if a fairly new version of paramiko is used.

Example proxying:

 >>> s1 = ssh(host='example.pwnme')
 >>> r1 = s1.remote('localhost', 22)
 >>> s2 = ssh(host='example.pwnme', proxy_sock=r1.sock)
 >>> r2 = s2.remote('localhost', 22) # and so on...
 >>> for x in r2, s2, r1, s1: x.close()

__repr__()

Return repr(self).

_init_remote_platform_info()

Fills _platform_info, e.g.:

{'distro': 'Ubuntu\n',
 'distro_ver': '14.04\n',
 'machine': 'x86_64',
 'node': 'pwnable.kr',
 'processor': 'x86_64',
 'release': '3.11.0-12-generic',
 'system': 'linux',
 'version': '#19-ubuntu smp wed oct 9 16:20:46 utc 2013'}

_libs_remote(remote)

Return a dictionary of the libraries used by a remote file.

checksec()

Prints a helpful message about the remote system.

Parameters:

banner (bool) – Whether to print the path to the ELF binary.

close()

Close the connection.

connect_remote(host, port, timeout=Timeout.default) → ssh_connecter

Connects to a host through an SSH connection. This is equivalent to using the -L flag on ssh.

Returns a pwnlib.tubes.ssh.ssh_connecter object.

Examples

>>> from pwn import *
>>> l = listen()
>>> s =  ssh(host='example.pwnme')
>>> a = s.connect_remote(s.host, l.lport)
>>> a=a; b = l.wait_for_connection()  # a=a; prevents hangs
>>> a.sendline(b'Hello')
>>> print(repr(b.recvline()))
b'Hello\n'

connected()

Returns True if we are connected.

Example

>>> s =  ssh(host='example.pwnme')
>>> s.connected()
True
>>> s.close()
>>> s.connected()
False

download(file_or_directory, local=None)

Download a file or directory from the remote host.

Parameters:

• file_or_directory (str) – Path to the file or directory to download.

• local (str) – Local path to store the data. By default, uses the current directory.

Examples

>>> with open('/tmp/foobar','w+') as f:
...     _ = f.write('Hello, world')
>>> s =  ssh(host='example.pwnme',
...         cache=False)
>>> _ = s.set_working_directory('/tmp')
>>> _ = s.download('foobar', 'barfoo')
>>> with open('barfoo','r') as f:
...     print(f.read())
Hello, world

download_data(remote, fingerprint=True)

Downloads a file from the remote server and returns it as a string.

Parameters:

remote (str) – The remote filename to download.

Examples

>>> with open('/tmp/bar','w+') as f:
...     _ = f.write('Hello, world')
>>> s =  ssh(host='example.pwnme',
...         cache=False)
>>> s.download_data('/tmp/bar')
b'Hello, world'
>>> s._sftp = None
>>> s._tried_sftp = True
>>> s.download_data('/tmp/bar')
b'Hello, world'

download_dir(remote=None, local=None, ignore_failed_read=False)

Recursively downloads a directory from the remote server

Parameters:

• local – Local directory

• remote – Remote directory

download_file(remote, local=None)

Downloads a file from the remote server.

The file is cached in /tmp/pwntools-ssh-cache using a hash of the file, so calling the function twice has little overhead.

Parameters:

• remote (str/bytes) – The remote filename to download

• local (str) – The local filename to save it to. Default is to infer it from the remote filename.

Examples

>>> with open('/tmp/foobar','w+') as f:
...     _ = f.write('Hello, world')
>>> s =  ssh(host='example.pwnme',
...         cache=False)
>>> _ = s.set_working_directory(wd='/tmp')
>>> _ = s.download_file('foobar', 'barfoo')
>>> with open('barfoo','r') as f:
...     print(f.read())
Hello, world

get(file_or_directory, local=None)

download(file_or_directory, local=None)

Download a file or directory from the remote host.

Parameters:

• file_or_directory (str) – Path to the file or directory to download.

• local (str) – Local path to store the data. By default, uses the current directory.

Examples

>>> with open('/tmp/foobar','w+') as f:
...     _ = f.write('Hello, world')
>>> s =  ssh(host='example.pwnme',
...         cache=False)
>>> _ = s.set_working_directory('/tmp')
>>> _ = s.download('foobar', 'barfoo')
>>> with open('barfoo','r') as f:
...     print(f.read())
Hello, world

getenv(variable, **kwargs)

Retrieve the address of an environment variable on the remote system.

Note

The exact address will differ based on what other environment variables are set, as well as argv[0]. In order to ensure that the path is exactly the same, it is recommended to invoke the process with argv=[].

interactive(shell=None)

Create an interactive session.

This is a simple wrapper for creating a new pwnlib.tubes.ssh.ssh_channel object and calling pwnlib.tubes.ssh.ssh_channel.interactive() on it.

libs(remote, directory=None, flatten=False)

Downloads the libraries referred to by a file.

This is done by running ldd on the remote server, parsing the output and downloading the relevant files.

The directory argument specified where to download the files. This defaults to ‘./$HOSTNAME’ where $HOSTNAME is the hostname of the remote server.

Parameters:

• remote (str) – Remote file path

• directory (str) – Output directory

• flatten (bool) – Flatten the file tree if True (defaults to False) and ignore the remote directory structure. If there are duplicate filenames, an error will be raised.

listen(port=0, bind_address='', timeout=pwnlib.timeout.Timeout.default)

listen_remote(port = 0, bind_address = ‘’, timeout = Timeout.default) -> ssh_connecter

Listens remotely through an SSH connection. This is equivalent to using the -R flag on ssh.

Returns a pwnlib.tubes.ssh.ssh_listener object.

Examples

>>> from pwn import *
>>> s =  ssh(host='example.pwnme')
>>> l = s.listen_remote()
>>> a = remote(s.host, l.port)
>>> a=a; b = l.wait_for_connection()  # a=a; prevents hangs
>>> a.sendline(b'Hello')
>>> print(repr(b.recvline()))
b'Hello\n'

listen_remote(port=0, bind_address='', timeout=Timeout.default) → ssh_connecter

Listens remotely through an SSH connection. This is equivalent to using the -R flag on ssh.

Returns a pwnlib.tubes.ssh.ssh_listener object.

Examples

>>> from pwn import *
>>> s =  ssh(host='example.pwnme')
>>> l = s.listen_remote()
>>> a = remote(s.host, l.port)
>>> a=a; b = l.wait_for_connection()  # a=a; prevents hangs
>>> a.sendline(b'Hello')
>>> print(repr(b.recvline()))
b'Hello\n'

process(argv=None, executable=None, tty=True, cwd=None, env=None, ignore_environ=None, timeout=pwnlib.timeout.Timeout.default, run=True, stdin=0, stdout=1, stderr=2, preexec_fn=None, preexec_args=(), raw=True, aslr=None, setuid=None, shell=False)

Executes a process on the remote server, in the same fashion as pwnlib.tubes.process.process.

To achieve this, a Python script is created to call os.execve with the appropriate arguments.

As an added bonus, the ssh_channel object returned has a pid property for the process pid.

Parameters:

• argv (list) – List of arguments to pass into the process

• executable (str) – Path to the executable to run. If None, argv[0] is used.

• tty (bool) – Request a tty from the server. This usually fixes buffering problems by causing libc to write data immediately rather than buffering it. However, this disables interpretation of control codes (e.g. Ctrl+C) and breaks .shutdown.

• cwd (str) – Working directory. If None, uses the working directory specified on cwd or set via set_working_directory().

• env (dict) – 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) – Set to True to run the program (default). If False, returns the path to an executable Python script on the remote server which, when executed, will do it.

• stdin (int, str) – If an integer, replace stdin with the numbered file descriptor. If a string, a open a file with the specified path and replace stdin with its file descriptor. May also be one of sys.stdin, sys.stdout, sys.stderr. If None, the file descriptor is closed.

• stdout (int, str) – See stdin.

• stderr (int, str) – See stdin.

• preexec_fn (callable) – Function which is executed on the remote side before execve(). This MUST be a self-contained function – it must perform all of its own imports, and cannot refer to variables outside its scope.

• preexec_args (object) – Argument passed to preexec_fn. This MUST only consist of native Python objects.

• raw (bool) – If True, disable TTY control code interpretation.

• aslr (bool) – See pwnlib.tubes.process.process for more information.

• setuid (bool) – See pwnlib.tubes.process.process for more information.

• shell (bool) – Pass the command-line arguments to the shell.

Returns:

A new SSH channel, or a path to a script if run=False.

Notes

Requires Python on the remote server.

Examples

>>> s = ssh(host='example.pwnme')
>>> sh = s.process('/bin/sh', env={'PS1':''})
>>> sh.sendline(b'echo Hello; exit')
>>> sh.recvall()
b'Hello\n'
>>> s.process(['/bin/echo', b'\xff']).recvall()
b'\xff\n'
>>> s.process(['readlink', '/proc/self/exe']).recvall() 
b'.../bin/readlink\n'
>>> s.process(['LOLOLOL', '/proc/self/exe'], executable='readlink').recvall() 
b'.../bin/readlink\n'
>>> s.process(['LOLOLOL\x00', '/proc/self/cmdline'], executable='cat').recvall()
b'LOLOLOL\x00/proc/self/cmdline\x00'
>>> sh = s.process(executable='/bin/sh')
>>> str(sh.pid).encode() in s.pidof('sh') 
True
>>> io = s.process(['pwd'], cwd='/tmp')
>>> io.recvall()
b'/tmp\n'
>>> io.cwd
'/tmp'
>>> p = s.process(['python','-c','import os; os.write(1, os.read(2, 1024))'], stderr=0)
>>> p.send(b'hello')
>>> p.recv()
b'hello'
>>> s.process(['/bin/echo', 'hello']).recvall()
b'hello\n'
>>> s.process(['/bin/echo', 'hello'], stdout='/dev/null').recvall()
b''
>>> s.process(['/usr/bin/env'], env={}).recvall()
b''
>>> s.process('/usr/bin/env', env={'A':'B'}).recvall()
b'A=B\n'

>>> s.process('false', preexec_fn=1234)
Traceback (most recent call last):
...
PwnlibException: preexec_fn must be a function

>>> s.process('false', preexec_fn=lambda: 1234)
Traceback (most recent call last):
...
PwnlibException: preexec_fn cannot be a lambda

>>> def uses_globals():
...     foo = bar
>>> print(s.process('false', preexec_fn=uses_globals).recvall().strip().decode()) 
Traceback (most recent call last):
...
NameError: ...name 'bar' is not defined

>>> s.process('echo hello', shell=True).recvall()
b'hello\n'

>>> io = s.process(['cat'], timeout=5)
>>> io.recvline()
b''

>>> # Testing that empty argv works
>>> io = s.process([], executable='sh')
>>> io.sendline(b'echo $0')
>>> io.recvline()
b'$ \n'
>>> # Make sure that we have a shell
>>> io.sendline(b'echo hello')
>>> io.recvline()
b'$ hello\n'

>>> # Testing that empty argv[0] works
>>> io = s.process([''], executable='sh')
>>> io.sendline(b'echo $0')
>>> io.recvline()
b'$ \n'

put(file_or_directory, remote=None)

upload(file_or_directory, remote=None)

Upload a file or directory to the remote host.

Parameters:

• file_or_directory (str) – Path to the file or directory to download.

• remote (str) – Local path to store the data. By default, uses the working directory.

read(path)

Wrapper around download_data to match pwnlib.util.misc.read()

remote(host, port, timeout=pwnlib.timeout.Timeout.default)

connect_remote(host, port, timeout = Timeout.default) -> ssh_connecter

Connects to a host through an SSH connection. This is equivalent to using the -L flag on ssh.

Returns a pwnlib.tubes.ssh.ssh_connecter object.

Examples

>>> from pwn import *
>>> l = listen()
>>> s =  ssh(host='example.pwnme')
>>> a = s.connect_remote(s.host, l.lport)
>>> a=a; b = l.wait_for_connection()  # a=a; prevents hangs
>>> a.sendline(b'Hello')
>>> print(repr(b.recvline()))
b'Hello\n'

run(process, tty=True, cwd=None, env=None, timeout=None, raw=True, wd=None)

Backward compatibility. Use system()

run_to_end(process, tty=False, cwd=None, env=None, timeout=Timeout.default) → str

Run a command on the remote server and return a tuple with (data, exit_status). If tty is True, then the command is run inside a TTY on the remote server.

Examples

>>> s =  ssh(host='example.pwnme')
>>> print(s.run_to_end('echo Hello; exit 17'))
(b'Hello\n', 17)

set_working_directory(wd=None, symlink=False)

Sets the working directory in which future commands will be run (via ssh.run) and to which files will be uploaded/downloaded from if no path is provided

Note

This uses mktemp -d under the covers, sets permissions on the directory to 0700. This means that setuid binaries will not be able to access files created in this directory.

In order to work around this, we also chmod +x the directory.

Parameters:

• wd (string) – Working directory. Default is to auto-generate a directory based on the result of running ‘mktemp -d’ on the remote machine.

• symlink (bool,str) –

  Create symlinks in the new directory.

  The default value, False, implies that no symlinks should be created.

  A string value is treated as a path that should be symlinked. It is passed directly to the shell on the remote end for expansion, so wildcards work.

  Any other value is treated as a boolean, where True indicates that all files in the “old” working directory should be symlinked.

Examples

>>> s =  ssh(host='example.pwnme')
>>> cwd = s.set_working_directory()
>>> s.ls()
b''
>>> packing._decode(s.pwd()) == cwd
True

>>> s =  ssh(host='example.pwnme')
>>> homedir = s.pwd()
>>> _=s.touch('foo')

>>> _=s.set_working_directory()
>>> assert s.ls() == b''

>>> _=s.set_working_directory(homedir)
>>> assert b'foo' in s.ls().split(), s.ls().split()

>>> _=s.set_working_directory(symlink=True)
>>> assert b'foo' in s.ls().split(), s.ls().split()
>>> assert homedir != s.pwd()

>>> symlink=os.path.join(homedir,b'*')
>>> _=s.set_working_directory(symlink=symlink)
>>> assert b'foo' in s.ls().split(), s.ls().split()
>>> assert homedir != s.pwd()

>>> _=s.set_working_directory()
>>> io = s.system('pwd')
>>> io.recvallS().strip() == io.cwd
True
>>> io.cwd == s.cwd
True

shell(shell=None, tty=True, timeout=Timeout.default) → ssh_channel

Open a new channel with a shell inside.

Parameters:

• shell (str) – Path to the shell program to run. If None, uses the default shell for the logged in user.

• tty (bool) – If True, then a TTY is requested on the remote server.

Returns:

Return a pwnlib.tubes.ssh.ssh_channel object.

Examples

>>> s =  ssh(host='example.pwnme')
>>> sh = s.shell('/bin/sh')
>>> sh.sendline(b'echo Hello; exit')
>>> print(b'Hello' in sh.recvall())
True

system(process, tty=True, cwd=None, env=None, timeout=Timeout.default, raw=True) → ssh_channel

Open a new channel with a specific process inside. If tty is True, then a TTY is requested on the remote server.

If raw is True, terminal control codes are ignored and input is not echoed back.

Return a pwnlib.tubes.ssh.ssh_channel object.

Examples

>>> s =  ssh(host='example.pwnme')
>>> py = s.system('python3 -i')
>>> _ = py.recvuntil(b'>>> ')
>>> py.sendline(b'print(2+2)')
>>> py.sendline(b'exit()')
>>> print(repr(py.recvline()))
b'4\n'
>>> s.system('env | grep -a AAAA', env={'AAAA': b'\x90'}).recvall()
b'AAAA=\x90\n'
>>> io = s.system('pwd', cwd='/tmp')
>>> io.recvall()
b'/tmp\n'
>>> io.cwd
'/tmp'

unlink(file)

Delete the file on the remote host

Parameters:

file (str) – Path to the file

upload(file_or_directory, remote=None)

Upload a file or directory to the remote host.

Parameters:

• file_or_directory (str) – Path to the file or directory to download.

• remote (str) – Local path to store the data. By default, uses the working directory.

upload_data(data, remote)

Uploads some data into a file on the remote server.

Parameters:

• data (str) – The data to upload.

• remote (str) – The filename to upload it to.

Example

>>> s =  ssh(host='example.pwnme')
>>> s.upload_data(b'Hello, world', '/tmp/upload_foo')
>>> print(open('/tmp/upload_foo').read())
Hello, world
>>> s._sftp = False
>>> s._tried_sftp = True
>>> s.upload_data(b'Hello, world', '/tmp/upload_bar')
>>> print(open('/tmp/upload_bar').read())
Hello, world

upload_dir(local, remote=None)

Recursively uploads a directory onto the remote server

Parameters:

• local – Local directory

• remote – Remote directory

upload_file(filename, remote=None)

Uploads a file to the remote server. Returns the remote filename.

Arguments: filename(str): The local filename to download remote(str): The remote filename to save it to. Default is to infer it from the local filename.

which(program) → str

Minor modification to just directly invoking which on the remote system which adds the current working directory to the end of $PATH.

write(path, data)

Wrapper around upload_data to match pwnlib.util.misc.write()

property arch

CPU Architecture of the remote machine.

Type:

str

property aslr

Whether ASLR is enabled on the system.

Example

>>> s = ssh("travis", "example.pwnme")
>>> s.aslr
True

Type:

bool

property aslr_ulimit

Whether the entropy of 32-bit processes can be reduced with ulimit.

Type:

bool

property bits

Pointer size of the remote machine.

Type:

str

cache = True

Enable caching of SSH downloads (bool)

client = None

Paramiko SSHClient which backs this object

property distro

Linux distribution name and release.

Type:

tuple

host = None

Remote host name (str)

property ibt

Whether kernel indirect branch tracking is supported on the system.

Example

>>> s = ssh("travis", "example.pwnme")
>>> s.ibt
False

Type:

bool

key = None

Remote private key (str)

keyfile = None

Remote private key file (str)

property os

Operating System of the remote machine.

Type:

str

password = None

Remote password (str)

pid = None

PID of the remote sshd process servicing this connection.

port = None

Remote port (int)

raw = False

Enable raw mode and don’t probe the environment (bool)

property sftp

Paramiko SFTPClient object which is used for file transfers. Set to None to disable sftp.

user = None

Remote username (str)

property user_shstk

Whether userspace shadow stack is supported on the system.

Example

>>> s = ssh("travis", "example.pwnme")
>>> s.user_shstk 
False

Type:

bool

property version

Kernel version of the remote machine.

Type:

tuple

class pwnlib.tubes.ssh.ssh_channel

Bases: sock

interactive(prompt=pwnlib.term.text.bold_red('$') + ' ')

If not in TTY-mode, this does exactly the same as meth:pwnlib.tubes.tube.tube.interactive, otherwise it does mostly the same.

An SSH connection in TTY-mode will typically supply its own prompt, thus the prompt argument is ignored in this case. We also have a few SSH-specific hacks that will ideally be removed once the pwnlib.term is more mature.

kill()

Kills the process.

poll() → int

Poll the exit code of the process. Will return None, if the process has not yet finished and the exit code otherwise.

class pwnlib.tubes.ssh.ssh_process(parent, process=None, tty=False, cwd=None, env=None, raw=True, *args, **kwargs)

Bases: ssh_channel

getenv(variable, **kwargs)

Retrieve the address of an environment variable in the remote process.

Examples

>>> s = ssh(host='example.pwnme')
>>> p = s.process(['python', '-c', 'import time; time.sleep(10)'])
>>> hex(p.getenv('PATH'))  
'0x...'

libs() → dict

Returns a dictionary mapping the address of each loaded library in the process’s address space.

If /proc/$PID/maps cannot be opened, the output of ldd is used verbatim, which may be different than the actual addresses if ASLR is enabled.

argv = None

Arguments passed to the process Only valid when instantiated through ssh.process()

cwd = None

Working directory

property elf

Returns an ELF file for the executable that launched the process.

executable = None

Executable of the procesks Only valid when instantiated through ssh.process()

property libc

Returns an ELF for the libc for the current process. If possible, it is adjusted to the correct address automatically.

Examples

>>> s =  ssh(host='example.pwnme')
>>> p = s.process('true')
>>> p.libc  
ELF(.../libc.so.6')

pid = None

PID of the process Only valid when instantiated through ssh.process()

class pwnlib.tubes.ssh.ssh_connecter

Bases: sock

class pwnlib.tubes.ssh.ssh_listener

Bases: sock