Add pwnlib.config module and documentation

docs/source/config.rst

@@ -0,0 +1,4 @@
+:mod:`pwnlib.config` --- Pwntools Configuration File
+====================================================
+
+.. automodule:: pwnlib.config

docs/source/index.rst

@@ -48,6 +48,7 @@ Each of the ``pwntools`` modules is documented here.
    atexception
    atexit
    constants
+   config
    context
    dynelf
    encoders

pwn/__init__.py

@@ -5,6 +5,7 @@
 
 pwnlib.args.initialize()
 pwnlib.log.install_default_handler()
+pwnlib.config.initialize()
 
 log = pwnlib.log.getLogger('pwnlib.exploit')
 args = pwnlib.args.args

pwnlib/config.py

@@ -0,0 +1,60 @@
+# -*- coding: utf-8 -*-
+"""Allows per-user and per-host configuration of Pwntools settings.
+
+The list of configurable options includes all of the logging symbols
+and colors, as well as all of the default values on the global context
+object.
+
+The configuration file is read from ``~/.pwn.conf`` and ``/etc/pwn.conf``.
+
+The configuration file is only read in ``from pwn import *`` mode, and not
+when used in library mode (``import pwnlib``).  To read the configuration
+file in library mode, invoke :func:`.config.initialize`.
+
+The ``context`` section supports complex types, at least as far as is
+supported by ``pwnlib.util.safeeval.expr``.
+
+::
+
+    [log]
+    success.symbol=😎
+    error.symbol=☠
+    info.color=blue
+
+    [context]
+    adb_port=4141
+    randomize=1
+    timeout=60
+    terminal=['x-terminal-emulator', '-e']
+"""
+from __future__ import absolute_import
+
+import ConfigParser
+import os
+
+registered_configs = {}
+
+def register_config(section, function):
+    """Registers a configuration section.
+
+    Arguments:
+        section(str): Named configuration section
+        function(callable): Function invoked with a dictionary of
+            ``{option: value}`` for the entries in the section.
+    """
+    registered_configs[section] = function
+
+def initialize():
+    """Read the configuration files."""
+    from pwnlib.log import getLogger
+    log = getLogger(__name__)
+
+    c = ConfigParser.ConfigParser()
+    c.read(['/etc/pwn.conf', os.path.expanduser('~/.pwn.conf')])
+
+    for section in c.sections():
+        if section not in registered_configs:
+            log.warn("Unknown configuration section %r" % section)
+            continue
+        settings = dict(c.items(section))
+        registered_configs[section](settings)

pwnlib/context/__init__.py

@@ -21,9 +21,11 @@
 
 import socks
 
+from pwnlib.config import register_config
 from pwnlib.device import Device
 from pwnlib.timeout import Timeout
 
+
 _original_socket = socket.socket
 
 class _devnull(object):
@@ -1343,3 +1345,20 @@ def setter(*a, **kw):
         with context.local(**{k:kw.pop(k) for k,v in kw.items() if isinstance(getattr(ContextType, k, None), property)}):
             return function(*a, **kw)
     return setter
+
+# Read configuration options from the context section
+def update_context_defaults(section):
+    # Circular imports FTW!
+    from pwnlib.util import safeeval
+    from pwnlib.log import getLogger
+    log = getLogger(__name__)
+    for key, value in section.items():
+        if key not in ContextType.defaults:
+            log.warn("Unknown configuration option %r in section %r" % (key, 'context'))
+            continue
+        if isinstance(ContextType.defaults[key], (str, unicode)):
+            value = safeeval.expr(value)
+
+        ContextType.defaults[key] = value
+
+register_config('context', update_context_defaults)

pwnlib/log.py

@@ -103,6 +103,7 @@
 import time
 
 from pwnlib import term
+from pwnlib.config import register_config
 from pwnlib.context import Thread
 from pwnlib.context import context
 from pwnlib.exception import PwnlibException
@@ -132,26 +133,26 @@
     }
 
 
-# permit setting logging colors from a configuration file
-config = os.path.expanduser('~/.pwn.conf')
-if os.path.exists(config):
-    c = ConfigParser.ConfigParser()
-    c.read([config])
-
-    for section in c.sections():
-        if section not in _msgtype_prefixes:
+def read_log_config(settings):
+    log = getLogger(__name__)
+    for key, value in settings.items():
+        if '.' not in key:
+            log.warn("Invalid configuration option %r in section %r" % (key, 'log'))
             continue
 
-        for key, value in c.items(section):
-            if key == 'color':
-                try:
-                    _msgtype_prefixes[section][0] = getattr(text, value)
-                except AttributeError:
-                    pass
+        msgtype, key = key.split('.', 1)
+
+        if key == 'color':
+            current = _msgtype_prefixes[msgtype][0]
+            _msgtype_prefixes[msgtype][0] = getattr(text, value, current)
 
-            elif key == 'symbol':
-                _msgtype_prefixes[section][1] = value
+        elif key == 'symbol':
+            _msgtype_prefixes[msgtype][1] = value
+
+        else:
+            log.warn("Unknown configuration option %r in section %r" % (key, 'log'))
 
+register_config('log', read_log_config)
 
 # the text decoration to use for spinners.  the spinners themselves can be found
 # in the `pwnlib.term.spinners` module