Release 3.10.0

* Fix corefile environment variables and speed up ELF.string()

* Even more doctests

* Fix doctest arch

* No longer split on = since it isn't necessary

* Fix arch again

* Delete intermediate corefiles

* Do not flag for extended testing when the commit SHA is what matches

CHANGELOG.md

@@ -9,9 +9,10 @@ The table below shows which release corresponds to each branch, and what date th
 
 | Version          | Branch   | Release Date           |
 | ---------------- | -------- | ---------------------- |
-| [3.11.0](#3110)  | `dev`    | Dec 2, 2017 (planned)
-| [3.10.0](#3100)  | `beta`   | Oct 21, 2017 (planned)
-| [3.9.2](#392)    | `stable` | Oct 5, 2017
+| [3.12.0](#3120)  | `dev`    | Jan 13, 2018 (planned)
+| [3.11.0](#3110)  | `beta`   | Dec 2, 2017 (planned)
+| [3.10.0](#3100)  | `stable` | Oct 25, 2017
+| [3.9.2](#392)    |          | Oct 5, 2017
 | [3.9.1](#391)    |          | Sep 28, 2017
 | [3.9.0](#390)    |          | Sep 11, 2017
 | [3.8.0](#380)    |          | Jul 29, 2017
@@ -39,13 +40,39 @@ 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
+
+To be released on Jan 13, 2018.
+
 ## 3.11.0
 
 To be released on Dec 2, 2017.
 
+- [#1044][1044] Enhancements to ROP
+    + Much better support for 64-bit Intel (amd64) ROP
+    + ROP gadget selection is optimized to favor multi-pops instead of multiple single-pop gadgets
+    + Added support for blacklisting byte values in ROP gadget addresses
+- [#1049][1049] Enhancements to `cyclic`
+    + `context` now has two additional attributes, `cyclic_alphabet` and `cyclic_length`, which correspond to the arguments `alphabet` and `n` to `cyclic()` and `cyclic_find()` and related routines.
+    + The motivation for this change is to allow setting the `alphabet` globally, so that any padding / patterns generated internally to pwntools can be controlled.  The specific motivation is blacklisting values in ROP padding.
+- [#1052][1052] Enhancements for detecting `QEMU_LD_PREFIX` used by QEMU user-mode emulation for sysroots
+
+[1044]: https://github.com/Gallopsled/pwntools/pull/1044
+[1049]: https://github.com/Gallopsled/pwntools/pull/1049
+[1052]: https://github.com/Gallopsled/pwntools/pull/1052
+
 ## 3.10.0
 
-To be released on Oct 21, 2017.
+- [#1007][1007] Add support for setting a `gdbinit` file in the context
+- [#1055][1055] Fixes for `Corefile` stack parsing, speed up `ELF.string()`
+- [#1057][1057] Fix a variable name typo in `DynELF` logging which results in an exception being thrown
+- [#1058][1058] Fix an edge case in `ssh_process.exe`
+
+[1007]: https://github.com/Gallopsled/pwntools/pull/1007
+[1055]: https://github.com/Gallopsled/pwntools/pull/1055
+[1057]: https://github.com/Gallopsled/pwntools/pull/1057
+[1058]: https://github.com/Gallopsled/pwntools/pull/1058
+
 
 ## 3.9.2
 

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-v3.9.2-green.svg?style=flat)](https://pypi.python.org/pypi/pwntools/)
+[![PyPI](https://img.shields.io/badge/pypi-v3.10.0-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)

pwnlib/context/__init__.py

@@ -150,7 +150,7 @@ class _Tls_DictStack(threading.local, _DictStack):
 
 def _validator(validator):
     """
-    Validator that tis tightly coupled to the implementation
+    Validator that is tightly coupled to the implementation
     of the classes here.
 
     This expects that the object has a ._tls property which
@@ -340,6 +340,7 @@ class ContextType(object):
         'delete_corefiles': False,
         'device': os.getenv('ANDROID_SERIAL', None) or None,
         'endian': 'little',
+        'gdbinit': "",
         'kernel': None,
         'log_level': logging.INFO,
         'log_file': _devnull(),
@@ -1231,6 +1232,23 @@ class ContextType(object):
         """
         return bool(v)
 
+
+    @_validator
+    def gdbinit(self, value):
+        """Path to the gdbinit that is used when running GDB locally.
+
+        This is useful if you want pwntools-launched GDB to include some additional modules,
+        like PEDA but you do not want to have GDB include them by default.
+
+        The setting will only apply when GDB is launched locally since remote hosts may not have
+        the necessary requirements for the gdbinit.
+
+        If set to an empty string, GDB will use the default `~/.gdbinit`.
+
+        Default value is ``""``.
+        """
+        return str(value)
+
     #*************************************************************************
     #                               ALIASES
     #*************************************************************************

pwnlib/dynelf.py

@@ -447,7 +447,7 @@ class DynELF(object):
             if debug:
                 w.status("r_debug.linkmap")
                 linkmap = self.leak.field(debug, r_debug.r_map)
-                w.status("r_debug.linkmap %#x" % result)
+                w.status("r_debug.linkmap %#x" % linkmap)
 
         if not linkmap:
             w.failure("Could not find DT_PLTGOT or DT_DEBUG")

pwnlib/elf/corefile.py

@@ -389,7 +389,7 @@ class Corefile(ELF):
 
         >>> core.vdso.data[:4]
         '\x7fELF'
-        >>> core.libc # docteset: +ELLIPSIS
+        >>> core.libc # doctest: +ELLIPSIS
         Mapping('/lib/x86_64-linux-gnu/libc-...', ...)
 
         The corefile also contains a :attr:`.Corefile.stack` property, which gives
@@ -421,7 +421,7 @@ class Corefile(ELF):
 
         >>> s = ssh('travis', 'example.pwnme')
         >>> _ = s.set_working_directory()
-        >>> elf = ELF.from_assembly('int3')
+        >>> elf = ELF.from_assembly(shellcraft.trap())
         >>> path = s.upload(elf.path)
         >>> _ =s.chmod('+x', path)
         >>> io = s.process(path)
@@ -429,6 +429,46 @@ class Corefile(ELF):
         -1
         >>> io.corefile.signal == signal.SIGTRAP # doctest: +SKIP
         True
+
+    Tests:
+
+        These are extra tests not meant to serve as examples.
+
+        Corefile.getenv() works correctly, even if the environment variable's
+        value contains embedded '='. Corefile is able to find the stack, even
+        if the stack pointer doesn't point at the stack.
+
+        >>> elf = ELF.from_assembly(shellcraft.crash())
+        >>> io = elf.process(env={'FOO': 'BAR=BAZ'})
+        >>> io.wait()
+        >>> core = io.corefile
+        >>> core.getenv('FOO')
+        'BAR=BAZ'
+        >>> core.sp == 0
+        True
+        >>> core.sp in core.stack
+        False
+
+        Corefile gracefully handles the stack being filled with garbage, including
+        argc / argv / envp being overwritten.
+
+        >>> context.clear(arch='i386')
+        >>> assembly = '''
+        ... LOOP:
+        ...   mov dword ptr [esp], 0x41414141
+        ...   pop eax
+        ...   jmp LOOP
+        ... '''
+        >>> elf = ELF.from_assembly(assembly)
+        >>> io = elf.process()
+        >>> io.wait()
+        >>> core = io.corefile
+        >>> core.argc, core.argv, core.env
+        (0, [], {})
+        >>> core.stack.data.endswith('AAAA')
+        True
+        >>> core.fault_addr == core.sp
+        True
     """
 
     _fill_gaps = False
@@ -454,6 +494,9 @@ class Corefile(ELF):
         #: variable.
         #:
         #: Note: Use with the :meth:`.ELF.string` method to extract them.
+        #:
+        #: Note: If FOO=BAR is in the environment, self.env['FOO'] is the
+        #:       address of the string "BAR\x00".
         self.env = {}
 
         #: :class:`list`: List of addresses of arguments on the stack.
@@ -664,7 +707,22 @@ class Corefile(ELF):
 
     @property
     def signal(self):
-        """:class:`int`: Signal which caused the core to be dumped."""
+        """:class:`int`: Signal which caused the core to be dumped.
+
+        Example:
+
+            >>> elf = ELF.from_assembly(shellcraft.trap())
+            >>> io = elf.process()
+            >>> io.wait()
+            >>> io.corefile.signal == signal.SIGTRAP
+            True
+
+            >>> elf = ELF.from_assembly(shellcraft.crash())
+            >>> io = elf.process()
+            >>> io.wait()
+            >>> io.corefile.signal == signal.SIGSEGV
+            True
+        """
         if self.siginfo:
             return int(self.siginfo.si_signo)
         if self.prstatus:
@@ -675,7 +733,17 @@ class Corefile(ELF):
         """:class:`int`: Address which generated the fault, for the signals
             SIGILL, SIGFPE, SIGSEGV, SIGBUS.  This is only available in native
             core dumps created by the kernel.  If the information is unavailable,
-            this returns the address of the instruction pointer."""
+            this returns the address of the instruction pointer.
+
+
+        Example:
+
+            >>> elf = ELF.from_assembly('mov eax, 0xdeadbeef; jmp eax', arch='i386')
+            >>> io = elf.process()
+            >>> io.wait()
+            >>> io.corefile.fault_addr == io.corefile.eax == 0xdeadbeef
+            True
+        """
         if self.siginfo:
             return int(self.siginfo.sigfault_addr)
 
@@ -848,11 +916,31 @@ class Corefile(ELF):
         # Now we can fill in the environment
         env_pointer_data = stack[start_of_envp:p_last_env_addr+self.bytes]
         for pointer in unpack_many(env_pointer_data):
-            end = stack.find('=', last_env_addr)
 
-            if pointer in stack and end in stack:
-                name = stack[pointer:end]
-                self.env[name] = pointer
+            # If the stack is corrupted, the pointer will be outside of
+            # the stack.
+            if pointer not in stack:
+                continue
+
+            try:
+                name_value = self.string(pointer)
+            except Exception:
+                continue
+
+            name, value = name_value.split('=', 1)
+
+            # "end" points at the byte after the null terminator
+            end = pointer + len(name_value) + 1
+
+            # Do not mark things as environment variables if they point
+            # outside of the stack itself, or we had to cross into a different
+            # mapping (after the stack) to read it.
+            # This may occur when the entire stack is filled with non-NUL bytes,
+            # and we NULL-terminate on a read failure in .string().
+            if end not in stack:
+                continue
+
+            self.env[name] = pointer + len(name) + len('=')
 
         # May as well grab the arguments off the stack as well.
         # argc comes immediately before argv[0] on the stack, but
@@ -904,15 +992,32 @@ class Corefile(ELF):
 
         Returns:
             :class:`str`: The contents of the environment variable.
+
+        Example:
+
+            >>> elf = ELF.from_assembly(shellcraft.trap())
+            >>> io = elf.process(env={'GREETING': 'Hello!'})
+            >>> io.wait()
+            >>> io.corefile.getenv('GREETING')
+            'Hello!'
         """
         if name not in self.env:
             log.error("Environment variable %r not set" % name)
 
-        return self.string(self.env[name]).split('=',1)[-1]
+        return self.string(self.env[name])
 
     @property
     def registers(self):
-        """:class:`dict`: All available registers in the coredump."""
+        """:class:`dict`: All available registers in the coredump.
+
+        Example:
+
+            >>> elf = ELF.from_assembly('mov eax, 0xdeadbeef;' + shellcraft.trap(), arch='i386')
+            >>> io = elf.process()
+            >>> io.wait()
+            >>> io.corefile.registers['eax'] == 0xdeadbeef
+            True
+        """
         if not self.prstatus:
             return {}
 
@@ -1020,6 +1125,7 @@ class CorefileFinder(object):
             new_path = 'core.%i' % core_pid
             if core_pid > 0 and new_path != self.core_path:
                 write(new_path, self.read(self.core_path))
+                self.unlink(self.core_path)
                 self.core_path = new_path
 
         # Check the PID

pwnlib/elf/elf.py

@@ -1686,16 +1686,33 @@ class ELF(ELFFile):
         return packing.unpack(self.read(address, context.bytes), *a, **kw)
 
     def string(self, address):
-        """Reads a null-terminated string from the specified ``address``"""
+        """string(address) -> str
+
+        Reads a null-terminated string from the specified ``address``
+
+        Returns:
+            A ``str`` with the string contents (NUL terminator is omitted),
+            or an empty string if no NUL terminator could be found.
+        """
         data = ''
         while True:
-            c = self.read(address, 1)
+            read_size = 0x1000
+            partial_page = address & 0xfff
+
+            if partial_page:
+                read_size -= partial_page
+
+            c = self.read(address, read_size)
+
             if not c:
                 return ''
-            if c == '\x00':
-                return data
+
             data += c
-            address += 1
+
+            if '\x00' in c:
+                return data[:data.index('\x00')]
+
+            address += len(c)
 
     def flat(self, address, *a, **kw):
         """Writes a full array of values to the specified address.

pwnlib/gdb.py

@@ -646,6 +646,10 @@ def attach(target, gdbscript = None, exe = None, need_ptrace_scope = True, gdb_a
         cmd += ' '
         cmd += ' '.join(gdb_args)
 
+    if context.gdbinit:
+        cmd += ' -nh '                     # ignore ~/.gdbinit
+        cmd += ' -x %s ' % context.gdbinit # load custom gdbinit
+
     cmd += ' -q '
 
     if exe and context.native:

pwnlib/tubes/ssh.py

@@ -341,7 +341,8 @@ class ssh_process(ssh_channel):
         libs = self.parent.libs(self.executable)
 
         for lib in libs:
-            if self.executable in lib:
+            # Cannot just check "executable in lib", see issue #1047
+            if lib.endswith(self.executable):
                 return pwnlib.elf.elf.ELF(lib)
 
 

pwnlib/version.py

@@ -1 +1 @@
-__version__ = '3.9.2'
+__version__ = '3.10.0'

setup.py

@@ -86,7 +86,7 @@ except Exception as e:
 setup(
     name                 = 'pwntools',
     packages             = find_packages(),
-    version              = '3.9.2',
+    version              = '3.10.0',
     data_files           = [('',
                              glob.glob('*.md') + glob.glob('*.txt')),
                             ],

travis/install.sh

@@ -90,7 +90,7 @@ setup_android_emulator()
         elif [[ -n "$TRAVIS_TAG" ]]; then
             echo "TRAVIS_TAG ($TRAVIS_TAG) indicates a new relase"
             echo "Forcing Android Emulator installation"
-        elif (git log --stat "$TRAVIS_COMMIT_RANGE" | grep -iE "android|adb"); then
+        elif (git log --stat "$TRAVIS_COMMIT_RANGE" | grep -iE "android|adb" | grep -v "commit "); then
             echo "Found Android-related commits, forcing Android Emulator installation"
         else
             # In order to avoid running the doctests that require the Android