Release 3.12.0

* Fix test breakage caused by Sphinx deprecation

* Fix missing import in RST

Closes #1112

CHANGELOG.md

@@ -9,9 +9,10 @@ The table below shows which release corresponds to each branch, and what date th
 
 | Version          | Branch   | Release Date           |
 | ---------------- | -------- | ---------------------- |
-| [3.13.0](#3130)  | `dev`    | Mar 31, 2018 (planned)
-| [3.12.0](#3120)  | `beta`   | Feb 17, 2018 (planned)
-| [3.11.0](#3110)  | `stable` | Jan 3, 2018
+| [3.14.0](#3130)  | `dev`    | Jun 12, 2018 (planned)
+| [3.13.0](#3130)  | `beta`   | Mar 31, 2018 (planned)
+| [3.12.0](#3120)  | `stable` | Feb 22, 2018
+| [3.11.0](#3110)  |          | Jan 3, 2018
 | [3.10.0](#3100)  |          | Oct 25, 2017
 | [3.9.2](#392)    |          | Oct 5, 2017
 | [3.9.1](#391)    |          | Sep 28, 2017
@@ -41,9 +42,31 @@ The table below shows which release corresponds to each branch, and what date th
 | [3.0.0](#300)    |          | Aug 20, 2016
 | [2.2.0](#220)    |          | Jan 5, 2015
 
-## 3.12.0
+## 3.14.0
 
-To be released on Feb 17, 2018.
+To be released on Jun 12, 2018.
+
+## 3.13.0
+
+To be released on Mar 31, 2018.
+
+- [#1104][1104] Add `DynELF.dump()` for dumping remote ELF files
+- [#1101][1101] Set `context.os` via `context.binary`, useful for Android exploitation
+- [5fdc08][5fdc08] Work around broken `pidof` on Android
+- [63dfed][63dfed] Print warning when Corefile deletion fails instead of throwing an exception
+- [#1094][1094] Make hexdump output alignment more consistent
+- [#1096][1096] `flat()` and `fit()` are now the same function
+- [#1068][1068] Work around very old OpenSSL versions which don't have sha256 support *AND* don't exit with an error code when trying to use it
+
+[1104]: https://github.com/Gallopsled/pwntools/pull/1104
+[1101]: https://github.com/Gallopsled/pwntools/pull/1101
+[1094]: https://github.com/Gallopsled/pwntools/pull/1094
+[1096]: https://github.com/Gallopsled/pwntools/pull/1096
+[1068]: https://github.com/Gallopsled/pwntools/pull/1068
+[5fdc08]: https://github.com/Gallopsled/pwntools/commit/5fdc08
+[63dfed]: https://github.com/Gallopsled/pwntools/commit/63dfed
+
+## 3.12.0
 
 - [#1083][1083] Better error messages for `gdb` when `LD_PRELOAD` is incorrect
 - [#1085][1085] Add support for extracting Android `BOOTLDR!` images
@@ -59,7 +82,6 @@ To be released on Feb 17, 2018.
 [1067]: https://github.com/Gallopsled/pwntools/pull/1067
 [1063]: https://github.com/Gallopsled/pwntools/pull/1063
 
-
 ## 3.11.0
 
 - [#1044][1044] Enhancements to ROP
@@ -95,7 +117,6 @@ To be released on Feb 17, 2018.
 [1057]: https://github.com/Gallopsled/pwntools/pull/1057
 [1058]: https://github.com/Gallopsled/pwntools/pull/1058
 
-
 ## 3.9.2
 
 - [#1043][1043] Do not attempt to populate the libraries used by statically-linked binaries

README.md

@@ -2,7 +2,7 @@
 ![pwntools logo](https://github.com/Gallopsled/pwntools/blob/stable/docs/source/logo.png?raw=true)
 
 [![Docs](https://readthedocs.org/projects/pwntools/badge/?version=stable)](https://docs.pwntools.com/)
-[![PyPI](https://img.shields.io/badge/pypi-v3.11.0-green.svg?style=flat)](https://pypi.python.org/pypi/pwntools/)
+[![PyPI](https://img.shields.io/badge/pypi-v3.12.0-green.svg?style=flat)](https://pypi.python.org/pypi/pwntools/)
 [![Travis](https://travis-ci.org/Gallopsled/pwntools.svg)](https://travis-ci.org/Gallopsled/pwntools)
 [![Coveralls](https://img.shields.io/coveralls/Gallopsled/pwntools/dev.svg)](https://coveralls.io/github/Gallopsled/pwntools?branch=dev)
 [![Twitter](https://img.shields.io/badge/twitter-pwntools-4099FF.svg?style=flat)](https://twitter.com/pwntools)

docs/source/conf.py

@@ -24,6 +24,27 @@ sys.path.insert(0, os.path.abspath('../..'))
 
 import pwnlib
 
+# -- WORK-AROUNDS FOR DEPRECATION ----------------------------------------------
+# Deprecated
+# 1.6b1
+# sphinx.util.compat.Directive class is now deprecated.
+# Please use instead docutils.parsers.rst.Directive
+#
+# Pwntools Note:
+#   Can't just "do the right thing" since we have dependencies that
+#   are also affected by this, specifically sphinxcontrib.autoprogram
+try:
+    import sphinx.util.compat
+except ImportError:
+    import sys
+    import types
+    import sphinx.util
+    import docutils.parsers.rst
+    class compat(types.ModuleType):
+        Directive = docutils.parsers.rst.Directive
+    sphinx.util.compat = compat('sphinx.util.compat')
+    sys.modules['sphinx.util.compat'] = sphinx.util.compat
+
 # -- General configuration -----------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.

docs/source/elf/corefile.rst

@@ -1,5 +1,6 @@
 .. testsetup:: *
 
+   from glob import glob
    from pwn import *
 
 :mod:`pwnlib.elf.corefile` --- Core Files

docs/source/tubes/sockets.rst

@@ -1,6 +1,7 @@
 .. testsetup:: *
 
    from pwn import *
+   from pwnlib.tubes.server import server
 
 :mod:`pwnlib.tubes.sock` --- Sockets
 ===========================================================
@@ -23,3 +24,9 @@
    .. autoclass:: pwnlib.tubes.listen.listen
       :members:
       :show-inheritance:
+
+.. automodule:: pwnlib.tubes.server
+
+   .. autoclass:: pwnlib.tubes.server.server
+      :members:
+      :show-inheritance:

pwn/toplevel.py

@@ -43,6 +43,7 @@ from pwnlib.tubes.listen import listen
 from pwnlib.tubes.process import process, PTY, PIPE, STDOUT
 from pwnlib.tubes.remote import remote, tcp, udp, connect
 from pwnlib.tubes.serialtube import serialtube
+from pwnlib.tubes.server import server
 from pwnlib.tubes.ssh import ssh
 from pwnlib.tubes.tube import tube
 from pwnlib.ui import *

pwnlib/abi.py

@@ -124,8 +124,3 @@ linux_aarch64_sigreturn = SigreturnABI('sp', ['x8'], 16, 0)
 
 windows_i386  = ABI('esp', [], 4, 0)
 windows_amd64 = ABI('rsp', ['rcx','rdx','r8','r9'], 32, 32)
-
-# Fake ABIs used by SROP
-linux_i386_srop = ABI('esp', ['eax'], 4, 0)
-linux_amd64_srop = ABI('rsp', ['rax'], 4, 0)
-linux_arm_srop = ABI('sp', ['r7'], 4, 0)

pwnlib/adb/adb.py

@@ -820,6 +820,7 @@ echo $PATH | while read -d: directory; do
     [ -x "$directory/{name}" ] || continue;
     echo -n "$directory/{name}\\x00";
 done
+[ -x "{name}" ] && echo -n "$PWD/{name}\\x00"
 '''.format(name=name)
 
     which_cmd = which_cmd.strip()

pwnlib/adb/bootloader.py

@@ -0,0 +1,103 @@
+from __future__ import unicode_literals
+
+import ctypes
+import io
+import os
+import sys
+
+class img_info(ctypes.Structure):
+    _fields_ = [
+        ('name', ctypes.c_char * 64),
+        ('size', ctypes.c_uint32)
+    ]
+
+class bootloader_images_header(ctypes.Structure):
+    _fields_ = [
+        ('magic', ctypes.c_char * 8),
+        ('num_images', ctypes.c_uint32),
+        ('start_offset', ctypes.c_uint32),
+        ('bootldr_size', ctypes.c_uint32),
+    ]
+
+    def __init__(self, *a, **kw):
+        super(bootloader_images_header, self).__init__(*a, **kw)
+        if self.magic != self.MAGIC:
+            raise ValueError("Incorrect magic (%r, expected %r)" % (self.magic, self.MAGIC))
+    MAGIC = 'BOOTLDR!'
+
+class BootloaderImage(object):
+    def __init__(self, data):
+        """Android Bootloader image
+
+        Arguments:
+            data(str): Binary data from the image file.
+        """
+        self.data = data
+        self.header = bootloader_images_header.from_buffer_copy(data)
+
+        imgarray = ctypes.ARRAY(img_info, self.header.num_images)
+        self.img_info = imgarray.from_buffer_copy(data, ctypes.sizeof(self.header))
+
+    def extract(self, index_or_name):
+        """extract(index_or_name) -> bytes
+
+        Extract the contents of an image.
+
+        Arguments:
+            index_or_name(str,int): Either an image index or name.
+
+        Returns:
+            Contents of the image.
+        """
+        if isinstance(index_or_name, int):
+            index = index_or_name
+        else:
+            for i in range(len(self.img_info)):
+                if self.img_info[i].name == index_or_name:
+                    index = i
+                    break
+            else:
+                raise ValueError("Invalid img name: %r" % index_or_name)
+
+        if index >= len(self.img_info):
+            raise ValueError("index out of range (%s, max %s)" % (index, len(self.img_info)))
+
+        offset = self.header.start_offset
+
+        for i in range(index):
+            offset += self.img_info[i].size
+
+        return self.data[offset:offset + self.img_info[index].size]
+
+    def extract_all(self, path):
+        """extract_all(path)
+
+        Extracts all images to the provided path.  The filenames are taken
+        from the image name, with '.img' appended.
+        """
+        if not os.path.isdir(path):
+            raise ValueError("%r does not exist or is not a directory" % path)
+
+        for img in self.img_info:
+            imgpath = os.path.join(path, img.name + '.img')
+            with open(imgpath, 'wb+') as f:
+                data = self.extract(img.name)
+                f.write(data)
+
+    def __str__(self):
+        rv = []
+        rv.append("Bootloader")
+        rv.append("  Magic:  %r" % self.header.magic)
+        rv.append("  Offset: %#x" % self.header.start_offset)
+        rv.append("  Size:   %#x" % self.header.bootldr_size)
+        rv.append("  Images: %s" % self.header.num_images)
+        for img in self.img_info:
+            rv.append("    Name: %s" % img.name)
+            rv.append("    Size: %#x" % img.size)
+            rv.append("    Data: %r..." % self.extract(img.name)[:32])
+        return '\n'.join(rv)
+
+if __name__ == '__main__':
+    # Easy sanity checking
+    b = BootloaderImage(open(sys.argv[1]).read())
+    print(b)

pwnlib/commandline/debug.py

@@ -30,13 +30,25 @@ parser.add_argument(
     help = 'The os/architecture/endianness/bits the shellcode will run in (default: linux/i386), choose from: %s' % common.choices,
 )
 parser.add_argument(
-    '--exec', type=file, dest='executable',
+    '--exec',
+
+    # NOTE: Type cannot be "file" because we may be referring to a remote
+    #       file, or a file on an Android device.
+    type=str,
+
+    dest='executable',
     help='File to debug'
 )
 parser.add_argument(
     '--process', metavar='PROCESS_NAME',
     help='Name of the process to attach to (e.g. "bash")'
 )
+parser.add_argument(
+    '--sysroot', metavar='SYSROOT',
+    type=str,
+    default='',
+    help="GDB sysroot path"
+)
 
 def main(args):
     gdbscript = ''
@@ -47,23 +59,41 @@ def main(args):
         context.device = adb.wait_for_device()
 
     if args.executable:
-        context.binary = ELF(args.executable.name)
-        target = context.binary.path
+        if os.path.exists(args.executable):
+            context.binary = ELF(args.executable)
+            target = context.binary.path
+
+        # This path does nothing, but avoids the "print_usage()"
+        # path below.
+        elif context.os == 'android':
+            target = args.executable
     elif args.pid:
         target = int(args.pid)
     elif args.process:
         if context.os == 'android':
-            target = adb.pidof(process)
+            target = adb.pidof(args.process)
         else:
-            target = pidof(process)
+            target = pidof(args.process)
+
+        # pidof() returns a list
+        if not target:
+            log.error("Could not find a PID for %r", args.process)
+        target = target[0]
     else:
         parser.print_usage()
         return 1
 
     if args.pid or args.process:
-        gdb.attach(target, gdbscript=gdbscript)
+        pid = gdb.attach(target, gdbscript=gdbscript, sysroot=args.sysroot)
+
+        # Since we spawned the gdbserver process, and process registers an
+        # atexit handler to close itself, gdbserver will be terminated when
+        # we exit.  This will manifest as a "remote connected ended" or
+        # similar error message.  Hold it open for the user.
+        log.info("GDB connection forwarding will terminate when you press enter")
+        pause()
     else:
-        gdb.debug(target, gdbscript=gdbscript).interactive()
+        gdb.debug(target, gdbscript=gdbscript, sysroot=args.sysroot).interactive()
 
 if __name__ == '__main__':
     pwnlib.commandline.common.main(__file__)

pwnlib/elf/corefile.py

@@ -753,30 +753,38 @@ class Corefile(ELF):
             >>> io.corefile.fault_addr == io.corefile.eax == 0xdeadbeef
             True
         """
-        fault_addr = 0
-        if self.siginfo:
-            fault_addr = int(self.siginfo.sigfault_addr)
+        if not self.siginfo:
+            return getattr(self, 'pc', 0)
 
-            # The fault_addr on AMD64 is zero if the crash occurs
-            # after a "ret" instruction, if the "ret" would return
-            # to an invalid address.  We need to extract the address
-            # manually, as a convenience.
-            if fault_addr == 0 and self.arch == 'amd64' and self.pc and self.sp:
-                try:
-                    code = self.read(self.pc, 1)
-                    if code != '\xc3':
-                        return fault_addr
-                    address = self.unpack(self.sp)
-                    return address
-                except Exception:
-                    # Could not read $rsp or $rip
-                    pass
+        fault_addr = int(self.siginfo.sigfault_addr)
 
-            return fault_addr
+        # The fault_addr is zero if the crash occurs due to a
+        # "protection fault", e.g. a dereference of 0x4141414141414141
+        # because this is technically a kernel address.
+        #
+        # A protection fault does not set "fault_addr" in the siginfo.
+        # (http://elixir.free-electrons.com/linux/v4.14-rc8/source/kernel/signal.c#L1052)
+        #
+        # Since a common use for corefiles is to spray the stack with a
+        # cyclic pattern to find the offset to get control of $PC,
+        # check for a "ret" instruction ("\xc3").
+        #
+        # If we find a RET at $PC, extract the "return address" from the
+        # top of the stack.
+        if fault_addr == 0 and self.siginfo.si_code == 0x80:
+            try:
+                code = self.read(self.pc, 1)
+                RET = '\xc3'
+                if code == RET:
+                    fault_addr = self.unpack(self.sp)
+            except Exception:
+                # Could not read $rsp or $rip
+                pass
+
+        return fault_addr
 
         # No embedded siginfo structure, so just return the
         # current instruction pointer.
-        return getattr(self, 'pc', 0)
 
     @property
     def _pc_register(self):
@@ -819,8 +827,8 @@ class Corefile(ELF):
         fields = [
             repr(self.path),
             '%-10s %s' % ('Arch:', gnu_triplet),
-            '%-10s %#x' % ('%s:' % self._pc_register.upper(), getattr(self, 'pc', 0)),
-            '%-10s %#x' % ('%s:' % self._sp_register.upper(), getattr(self, 'sp', 0)),
+            '%-10s %#x' % ('%s:' % self._pc_register.upper(), self.pc or 0),
+            '%-10s %#x' % ('%s:' % self._sp_register.upper(), self.sp or 0),
         ]
 
         if self.exe and self.exe.name:

pwnlib/elf/elf.py

@@ -262,9 +262,13 @@ class ELF(ELFFile):
                 self.bits = 64
 
         # Is this a native binary? Should we be checking QEMU?
-        with context.local(arch=self.arch):
-            #: Whether this ELF should be able to run natively
-            self.native = context.native
+        try:
+            with context.local(arch=self.arch):
+                #: Whether this ELF should be able to run natively
+                self.native = context.native
+        except AttributeError:
+            # The architecture may not be supported in pwntools
+            self.native = False
 
         self._address = 0
         if self.elftype != 'DYN':

pwnlib/gdb.py

@@ -229,7 +229,7 @@ def _gdbserver_args(pid=None, path=None, args=None, which=None):
 
     orig_args = args
 
-    gdbserver_args = [gdbserver]
+    gdbserver_args = [gdbserver, '--multi']
     if context.aslr:
         gdbserver_args += ['--no-disable-randomization']
     else:
@@ -249,6 +249,12 @@ def _gdbserver_port(gdbserver, ssh):
     # Process /bin/bash created; pid = 14366
     # Listening on port 34816
     process_created = gdbserver.recvline()
+
+    if process_created.startswith('ERROR:'):
+        raise ValueError(
+            'Failed to spawn process under gdbserver. gdbserver error message: %s' % process_created
+        )
+
     gdbserver.pid   = int(process_created.split()[-1], 0)
 
     listening_on = ''
@@ -287,7 +293,7 @@ def _get_runner(ssh=None):
     else:                          return tubes.process.process
 
 @LocalContext
-def debug(args, gdbscript=None, exe=None, ssh=None, env=None, **kwargs):
+def debug(args, gdbscript=None, exe=None, ssh=None, env=None, sysroot=None, **kwargs):
     """debug(args) -> tube
 
     Launch a GDB server with the specified command line,
@@ -299,6 +305,8 @@ def debug(args, gdbscript=None, exe=None, ssh=None, env=None, **kwargs):
         exe(str): Path to the executable on disk
         env(dict): Environment to start the binary in
         ssh(:class:`.ssh`): Remote ssh session to use to launch the process.
+        sysroot(str): Foreign-architecture sysroot, used for QEMU-emulated binaries
+            and Android targets.
 
     Returns:
         :class:`.process` or :class:`.ssh_channel`: A tube connected to the target process
@@ -404,7 +412,6 @@ def debug(args, gdbscript=None, exe=None, ssh=None, env=None, **kwargs):
 
     runner = _get_runner(ssh)
     which  = _get_which(ssh)
-    sysroot = None
     gdbscript = gdbscript or ''
 
     if context.noptrace:
@@ -416,11 +423,15 @@ def debug(args, gdbscript=None, exe=None, ssh=None, env=None, **kwargs):
     else:
         qemu_port = random.randint(1024, 65535)
         qemu_user = qemu.user_path()
-        sysroot = qemu.ld_prefix(env)
+        sysroot = sysroot or qemu.ld_prefix(env)
         if not qemu_user:
             log.error("Cannot debug %s binaries without appropriate QEMU binaries" % context.arch)
         args = [qemu_user, '-g', str(qemu_port)] + args
 
+    # Use a sane default sysroot for Android
+    if not sysroot and context.os == 'android':
+        sysroot = 'remote:/'
+
     # Make sure gdbserver/qemu is installed
     if not which(args[0]):
         log.error("%s is not installed" % args[0])
@@ -478,7 +489,7 @@ def binary():
         >>> gdb.binary() # doctest: +SKIP
         '/usr/bin/gdb'
     """
-    gdb = misc.which('gdb')
+    gdb = misc.which('pwntools-gdb') or misc.which('gdb')
 
     if not context.native:
         multiarch = misc.which('gdb-multiarch')
@@ -508,6 +519,7 @@ def attach(target, gdbscript = None, exe = None, need_ptrace_scope = True, gdb_a
           detect the architechture automatically (if it is supported).
         gdb_args(list): List of additional arguments to pass to GDB.
         sysroot(str): Foreign-architecture sysroot, used for QEMU-emulated binaries
+            and Android targets.
 
     Returns:
         PID of the GDB process (or the window which it is running in).
@@ -607,6 +619,10 @@ def attach(target, gdbscript = None, exe = None, need_ptrace_scope = True, gdb_a
     if gdbscript and not gdbscript.endswith('\n'):
         gdbscript += '\n'
 
+    # Use a sane default sysroot for Android
+    if not sysroot and context.os == 'android':
+        sysroot = 'remote:/'
+
     # gdb script to run before `gdbscript`
     pre = ''
     if not context.native:
@@ -671,7 +687,15 @@ def attach(target, gdbscript = None, exe = None, need_ptrace_scope = True, gdb_a
         exe = exe or target.executable
     elif isinstance(target, tuple) and len(target) == 2:
         host, port = target
-        pre += 'target remote %s:%d\n' % (host, port)
+
+        if context.os != 'android':
+            pre += 'target remote %s:%d\n' % (host, port)
+        else:
+            # Android debugging is done over gdbserver, which can't follow
+            # new inferiors (tldr; follow-fork-mode child) unless it is run
+            # in extended-remote mode.
+            pre += 'target extended-remote %s:%d\n' % (host, port)
+            pre += 'set detach-on-fork off\n'
 
         def findexe():
             for spid in proc.pidof(target):
@@ -699,7 +723,8 @@ def attach(target, gdbscript = None, exe = None, need_ptrace_scope = True, gdb_a
         log.error('could not find target process')
 
     if exe:
-        pre += 'file %s\n' % exe
+        # The 'file' statement should go first
+        pre = 'file %s\n%s' % (exe, pre)
 
     cmd = binary()
 
@@ -731,7 +756,11 @@ def attach(target, gdbscript = None, exe = None, need_ptrace_scope = True, gdb_a
         gdbserver = runner(gdb_cmd)
         port    = _gdbserver_port(gdbserver, None)
         host    = context.adb_host
-        pre    += 'target remote %s:%i' % (context.adb_host, port)
+        pre    += 'target extended-remote %s:%i\n' % (context.adb_host, port)
+
+        # gdbserver on Android sets 'detach-on-fork on' which breaks things
+        # when you're trying to debug anything that forks.
+        pre += 'set detach-on-fork off\n'
 
     gdbscript = pre + (gdbscript or '')
 
@@ -759,7 +788,7 @@ def ssh_gdb(ssh, argv, gdbscript = None, arch = None, **kwargs):
         argv = [argv]
 
     exe = argv[0]
-    argv = ["gdbserver", "127.0.0.1:0"] + argv
+    argv = ["gdbserver", "--multi", "127.0.0.1:0"] + argv
 
     # Download the executable
     local_exe = os.path.basename(exe)

pwnlib/rop/call.py

@@ -233,4 +233,12 @@ class Call(object):
                 args.extend(map(repr, arg.values))
             else:
                 args.append(arg)
-        return '%s(%s)' % (self.name or fmt % self.target, ', '.join(map(str, args)))
+
+        name = self.name or fmt & self.target
+        arg_str = []
+        for arg in args:
+            if isinstance(arg, (int,long)) and arg > 0x100:
+                arg_str.append(hex(arg))
+            else:
+                arg_str.append(str(arg))
+        return '%s(%s)' % (name, ', '.join(arg_str))

pwnlib/rop/rop.py

@@ -105,7 +105,7 @@ Finally, let's build our ROP stack
     >>> rop.write(c.STDOUT_FILENO, binary.symbols['flag'], 8)
     >>> rop.exit()
     >>> print rop.dump()
-    0x0000:       0x10000012 write(STDOUT_FILENO, 268435494, 8)
+    0x0000:       0x10000012 write(STDOUT_FILENO, 0x10000026, 8)
     0x0004:       0x1000000e <adjust @0x18> add esp, 0x10; ret
     0x0008:              0x1 arg0
     0x000c:       0x10000026 flag
@@ -1156,6 +1156,8 @@ class ROP(object):
         regs = set(regs or ())
 
         for addr, gadget in self.gadgets.items():
+            addr_bytes = set(pack(gadget.address))
+            if addr_bytes & self._badchars:     continue
             if gadget.insns[-1] != 'ret':        continue
             if gadget.move < move:               continue
             if not (regs <= set(gadget.regs)):   continue

pwnlib/shellcraft/templates/aarch64/linux/open.asm

@@ -1,7 +1,7 @@
 <%
   from pwnlib import shellcraft
 %>
-<%page args="filename, mode='O_RDONLY'"/>
+<%page args="filename, flags='O_RDONLY', mode=0"/>
 <%docstring>
 Opens a file
 </%docstring>
@@ -9,4 +9,4 @@ Opens a file
   AT_FDCWD=-100
 %>
     ${shellcraft.pushstr(filename)}
-    ${shellcraft.syscall('SYS_openat', AT_FDCWD, 'sp', mode, 0)}
+    ${shellcraft.syscall('SYS_openat', AT_FDCWD, 'sp', flags, mode)}

pwnlib/shellcraft/templates/amd64/linux/cat.asm

@@ -8,5 +8,5 @@ Opens a file and writes its contents to the specified file descriptor.
 </%docstring>
 
     ${pushstr(filename)}
-    ${syscall('SYS_open', 'rsp', 0, 'O_RDONLY')}
+    ${syscall('SYS_open', 'rsp', 'O_RDONLY', 0)}
     ${syscall('SYS_sendfile', fd, 'rax', 0, 0x7fffffff)}

pwnlib/shellcraft/templates/amd64/linux/dup.asm

@@ -10,7 +10,7 @@ Args: [sock (imm/reg) = rbp]
   after     = common.label("after")
 %>
 
-
+    /* dup() file descriptor ${sock} into stdin/stdout/stderr */
 ${dup}:
     ${amd64.mov('rbp', sock)}
 

pwnlib/shellcraft/templates/arm/linux/cat.asm

@@ -15,5 +15,5 @@ Example:
 
 </%docstring>
     ${arm.pushstr(filename)}
-    ${arm.linux.open('sp', 0, int(constants.O_RDONLY))}
+    ${arm.linux.open('sp', int(constants.O_RDONLY), 0)}
     ${arm.linux.sendfile(fd, 'r0', 0, 0x7fffffff)}

pwnlib/shellcraft/templates/i386/linux/cat.asm

@@ -19,5 +19,5 @@ label = common.label("sendfile_loop")
 %>
 
     ${sc.pushstr(filename)}
-    ${sc.open('esp', 0, 'O_RDONLY')}
+    ${sc.open('esp', 'O_RDONLY', 0)}
     ${sc.sendfile(fd, 'eax', 0, 0x7fffffff)}

pwnlib/shellcraft/templates/i386/linux/dupio.asm

@@ -11,6 +11,7 @@ Args: [sock (imm/reg) = ebp]
   looplabel = common.label("loop")
 %>
 
+    /* dup() file descriptor ${sock} into stdin/stdout/stderr */
 ${dup}:
     ${mov('ebx', sock)}
     ${mov('ecx', 3)}

pwnlib/shellcraft/templates/mips/linux/cat.asm

@@ -22,5 +22,5 @@ label = common.label("sendfile_loop")
 %>
 
     ${mips.pushstr(filename)}
-    ${mips.open('$sp', 0, int(constants.O_RDONLY))}
+    ${mips.open('$sp', int(constants.O_RDONLY), 0)}
     ${mips.sendfile(fd, '$v0', 0, 0x7fffffff)}

pwnlib/shellcraft/templates/thumb/linux/cat.asm

@@ -20,6 +20,6 @@ label = common.label("sendfile_loop")
 %>
 
     ${thumb.pushstr(filename)}
-    ${thumb.linux.open('sp', 0, constants.O_RDONLY)}
+    ${thumb.linux.open('sp', constants.O_RDONLY, 0)}
     ${thumb.mov('r5', 'r0')}
     ${thumb.linux.sendfile(fd, 'r5', 0, 0x7fffffff)}

pwnlib/shellcraft/templates/thumb/linux/dup.asm

@@ -9,6 +9,7 @@ Args: [sock (imm/reg) = r6]
   dup       = common.label("dup")
   looplabel = common.label("loop")
 %>
+    /* dup() file descriptor ${sock} into stdin/stdout/stderr */
 ${dup}:
         ${mov('r1', 2)}
         ${mov('r7', 'SYS_dup2')}

pwnlib/tubes/__init__.py

@@ -15,8 +15,9 @@ from pwnlib.tubes import listen
 from pwnlib.tubes import process
 from pwnlib.tubes import remote
 from pwnlib.tubes import serialtube
+from pwnlib.tubes import server
 from pwnlib.tubes import sock
 from pwnlib.tubes import ssh
 from pwnlib.tubes import tube
 
-__all__ = ['tube', 'sock', 'remote', 'listen', 'process', 'serialtube', 'ssh']
+__all__ = ['tube', 'sock', 'remote', 'listen', 'process', 'serialtube', 'server', 'ssh']

pwnlib/tubes/process.py

@@ -565,7 +565,7 @@ class process(tube):
         #
 
         # Create a duplicate so we can modify it safely
-        env = dict(os.environ if env is None else env)
+        env = (os.environ if env is None else env).copy()
 
         for k,v in env.items():
             if not isinstance(k, (str, unicode)):

pwnlib/tubes/server.py

@@ -0,0 +1,162 @@
+from __future__ import absolute_import
+
+import errno
+import socket
+import threading
+
+from pwnlib.context import context
+from pwnlib.log import getLogger
+from pwnlib.tubes.sock import sock
+from pwnlib.tubes.remote import remote
+
+log = getLogger(__name__)
+
+class server(sock):
+    r"""Creates an TCP or UDP-server to listen for connections. It supports
+    both IPv4 and IPv6.
+
+    Arguments:
+        port(int): The port to connect to.
+            Defaults to a port auto-selected by the operating system.
+        bindaddr(str): The address to bind to.
+            Defaults to ``0.0.0.0`` / `::`.
+        fam: The string "any", "ipv4" or "ipv6" or an integer to pass to :func:`socket.getaddrinfo`.
+        typ: The string "tcp" or "udp" or an integer to pass to :func:`socket.getaddrinfo`.
+        callback: A function to be started on incoming connections. It should take a :class:`pwnlib.tubes.remote` as its only argument.
+
+    Examples:
+
+        >>> s = server(8888)
+        >>> client_conn = remote('localhost', s.lport)
+        >>> server_conn = s.next_connection()
+        >>> client_conn.sendline('Hello')
+        >>> server_conn.recvline()
+        'Hello\n'
+        >>> def cb(r):
+        ...     client_input = r.readline()
+        ...     r.send(client_input[::-1])
+        ...
+        >>> t = server(8889, callback=cb)
+        >>> client_conn = remote('localhost', t.lport)
+        >>> client_conn.sendline('callback')
+        >>> client_conn.recv()
+        '\nkcabllac'
+    """
+
+    #: Local port
+    lport = 0
+
+    #: Local host
+    lhost = None
+
+    #: Socket type (e.g. socket.SOCK_STREAM)
+    type = None
+
+    #: Socket family
+    family = None
+
+    #: Socket protocol
+    protocol = None
+
+    #: Canonical name of the listening interface
+    canonname = None
+
+    #: Sockaddr structure that is being listened on
+    sockaddr = None
+
+    _accepter = None
+
+    def __init__(self, port=0, bindaddr = "0.0.0.0", fam = "any", typ = "tcp",
+                 callback = None, blocking = False, *args, **kwargs):
+        super(server, self).__init__(*args, **kwargs)
+
+        port = int(port)
+        fam  = {socket.AF_INET: 'ipv4',
+                socket.AF_INET6: 'ipv6'}.get(fam, fam)
+
+        fam = self._get_family(fam)
+        typ = self._get_type(typ)
+
+        if fam == socket.AF_INET6 and bindaddr == '0.0.0.0':
+            bindaddr = '::'
+
+        h = self.waitfor('Trying to bind to %s on port %d' % (bindaddr, port))
+
+        for res in socket.getaddrinfo(bindaddr, port, fam, typ, 0, socket.AI_PASSIVE):
+            self.family, self.type, self.proto, self.canonname, self.sockaddr = res
+
+            if self.type not in [socket.SOCK_STREAM, socket.SOCK_DGRAM]:
+                continue
+
+            h.status("Trying %s" % self.sockaddr[0])
+            listen_sock = socket.socket(self.family, self.type, self.proto)
+            listen_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            listen_sock.bind(self.sockaddr)
+            self.lhost, self.lport = listen_sock.getsockname()[:2]
+            if self.type == socket.SOCK_STREAM:
+                listen_sock.listen(1)
+            break
+        else:
+            h.failure()
+            self.error("Could not bind to %s on port %d" % (bindaddr, port))
+
+        h.success()
+
+        self.sock = listen_sock
+        self.connections_waiting = threading.Event()
+        self.connections = []
+        def accepter():
+            while True:
+                h = self.waitfor('Waiting for connections on %s:%s' % (self.lhost, self.lport))
+                while True:
+                    try:
+                        if self.type == socket.SOCK_STREAM:
+                            sock, rhost = listen_sock.accept()
+                        else:
+                            data, rhost = listen_sock.recvfrom(4096)
+                            listen_sock.connect(rhost)
+                            sock = listen_sock
+                            sock.unrecv(data)
+                        sock.settimeout(self.timeout)
+                        break
+                    except socket.error as e:
+                        if e.errno == errno.EINTR:
+                            continue
+                        h.failure()
+                        self.exception("Socket failure while waiting for connection")
+                        sock = None
+                        return
+
+                self.rhost, self.rport = rhost[:2]
+                r = remote(self.rhost, self.rport, sock = sock)
+                h.success('Got connection from %s on port %d' % (self.rhost, self.rport))
+                if callback:
+                    if not blocking:
+                        t = context.Thread(target = callback, args = (r,))
+                        t.daemon = True
+                        t.start()
+                    else:
+                        callback(r)
+                else:
+                    self.connections.append(r)
+                    if not self.connections_waiting.is_set():
+                        self.connections_waiting.set()
+
+        self._accepter = context.Thread(target = accepter)
+        self._accepter.daemon = True
+        self._accepter.start()
+
+    def next_connection(self):
+        if not self.connections_waiting.is_set():
+            self.connections_waiting.wait()
+        conn = self.connections.pop(0)
+        if not self.connections:
+            self.connections_waiting.clear()
+        return conn
+
+    def close(self):
+        # since `close` is scheduled to run on exit we must check that we got
+        # a connection or the program will hang in the `join` call above
+        if self._accepter and self._accepter.is_alive():
+            return
+        super(server, self).close()

pwnlib/tubes/ssh.py

@@ -874,6 +874,8 @@ os.chdir(%(cwd)r)
 if env is not None:
     os.environ.clear()
     os.environ.update(env)
+else:
+    env = os.environ
 
 def is_exe(path):
     return os.path.isfile(path) and os.access(path, os.X_OK)
@@ -961,7 +963,7 @@ except Exception:
 %(func_src)s
 apply(%(func_name)s, %(func_args)r)
 
-os.execve(exe, argv, os.environ)
+os.execve(exe, argv, env)
 """ % locals()
 
         script = script.strip()
@@ -1302,7 +1304,7 @@ from ctypes import *; libc = CDLL('libc.so.6'); print(libc.getenv(%r))
         return misc.parse_ldd_output(data)
 
     def _get_fingerprint(self, remote):
-        cmd = '(openssl sha256 || sha256 || sha256sum) 2>/dev/null < '
+        cmd = '(sha256 || sha256sum || openssl sha256) 2>/dev/null < '
         cmd = cmd + sh_string(remote)
         data, status = self.run_to_end(cmd)
 

pwnlib/util/misc.py

@@ -190,6 +190,8 @@ def run_in_new_terminal(command, terminal = None, args = None):
           variable), ``x-terminal-emulator`` is used.
         - If tmux is detected (by the presence of the ``$TMUX`` environment
           variable), a new pane will be opened.
+        - If GNU Screen is detected (by the presence of the ``$STY`` environment
+          variable), a new screen will be opened.
 
     Arguments:
         command (str): The command to run.
@@ -219,6 +221,9 @@ def run_in_new_terminal(command, terminal = None, args = None):
         elif 'TMUX' in os.environ and which('tmux'):
             terminal = 'tmux'
             args     = ['splitw']
+        elif 'STY' in os.environ and which('screen'):
+            terminal = 'screen'
+            args     = ['-t','pwntools-gdb','bash','-c']
 
     if not terminal:
         log.error('Could not find a terminal binary to use. Set context.terminal to your terminal.')

pwnlib/version.py

@@ -1 +1 @@
-__version__ = '3.11.0'
+__version__ = '3.12.0'

setup.py

@@ -86,7 +86,7 @@ except Exception as e:
 setup(
     name                 = 'pwntools',
     packages             = find_packages(),
-    version              = '3.11.0',
+    version              = '3.12.0',
     data_files           = [('',
                              glob.glob('*.md') + glob.glob('*.txt')),
                             ],