[Vol-dev] Plugin input mechanism

Hiya guys, I'm pretty new here, so forgive me for bursting in and asking lots of questions, but I'm trying to get used to the codebase (I've had some fun running pylint across this, which helped a *lot* with trying to figure out what went where). I'd really like to add a layer that allows the existing volatility tools to be run against a live system, directly via firewire (ie, without having to completely image the system first). I should probably mention now that I'm from a penetration testing background, rather than a forensics background, but that I've been investigating the firewire technique metlstorm developed for a while now. My hope is that some of the hash dumping tools and similar might be much quicker when run directly, rather than having to image the entire system first, and that it might also help the volatility suite be used as a live debugging aide for people trying to learn about memory and how it works. It seemed as though everything was laid out nicely, so I'd just need to implement a FirewireAddressSpace object (which I've done, and attached, although I have yet to test it). The problem I found was that all forensics.commands.command subclasses appear to accept an optparse parser result, and then manually open their own image based on the filename. Since most of the functions seem to operate on an AddressSpace rather than on a filename string, it seemed as though it should be possible to pass that into the plugins/commands. So that leads me to a few questions: * Would it be worthwhile reworking the module system to allow modules to specify their requirements more abstractly (I need a memory image, I need a set of registry keys, etc)? * Would it need to be that abstract, or do pretty much all modules always act on an AddressSpace? * How are you guys intending to deal with upgrading plugins after a major enhancement (I noticed plugins are already getting a bit out of hand, since Andreas' plugins require overwriting bits of volatility with his own versions)? * Would it be a major version number bump with an API break, and if so are there any other changes that would be worthwhile addressing at the same time? * Should I investigate allowing multiple plugin versions to co-exist? In implementing a new AddressSpace, I also spotted this fast variable, that appears simply to open a new handle, and I can't figure out how that helps or makes it faster? Was this a place holder for a possible address space enhancement, or is there really some kind of speed-up which I'm missing? Sorry to kind of drop all this here, but it seemed the most appropriate place for it. I've joined the IRC channel as well, so if you want to poke me for not doing things sensibly, you'll find me on there as ikelos... 5:) Thanks, Mike 5:) diff --git a/Volatility/forensics/addrspace.py b/Volatility/forensics/addrspace.py index d0c0dee..8697f71 100755 --- a/Volatility/forensics/addrspace.py +++ b/Volatility/forensics/addrspace.py @@ -30,6 +30,7 @@ """ Alias for all address spaces """ import os +import sys import struct try: @@ -73,7 +74,7 @@ class FileAddressSpace: return False return addr < self.fsize - 1 - def close(): + def close(self): self.fhandle.close() class BufferAddressSpace(FileAddressSpace): @@ -85,3 +86,103 @@ class BufferAddressSpace(FileAddressSpace): if fast == True: self.fast_fhandle = StringIO(buf) + +try: + import firewire +except: + pass + +if 'firewire' in sys.modules: + + def intervals(exclusions, start, end): + """Returns a list of intervals, from start to end, that do not include the exclusions""" + return _intervals(sorted(exclusions), start, end, []) + + def _intervals(exclusions, start, end, accumulator): + """Accepts a sorted list of intervals and a start and end + + This will return a list of intervals between start and length + that does not contain any of the intervals in the list of exclusions. + """ + if not len(exclusions): + # We're done + return accumulator + [(start, end)] + + e = exclusions[0] + estart = e[0] + eend = e[1] + + # e and range overlap + if not (eend < start or estart > end): + # Ignore this exclusions + return intervals(exclusions[1:], start, end, accumulator) + if estart < start: + if eend < end: + # Covers the start of the remaining length + return intervals(exclusions[1:], eend, end, accumulator) + else: + # Covers the entire remaining area + return accumulator + else: + if eend < end: + # Covers a section of the remaining length + return intervals(exclusions[1:], eend, end, accumulator + [(start, estart)]) + else: + # Covers the end of the remaining length + return accumulator + [(start, estart)] + + class FirewireIO(object): + """File-like interface for Firewire devices""" + def __init__(self, bus, node): + self.offset = 0 + self.fsize = 4 * 1024 * 1024 * 1024 + self.closed = False + self._exclusions = [(0xa0000, 0xfffff, "Upper Memory Area")] + try: + h = firewire.Host() + self._node = h[bus][node] + except IndexError: + raise IOError, "Firewire node " + str(node) + " on bus " + str(bus) + " was not accessible" + + def close(self): + """Close function for file-like interface""" + self.closed = True + + def flush(self): + """Flush function for file-like interface""" + pass + + def read(self, size = -1): + if size < 0: + size = self.fsize + ints = intervals(self._exclusions, self.offset, self.offset + size) + output = "\x00" * size + for i in ints: + output = output[: i[0] - self.offset] + self._node.read(i[1] - i[0], i[0]) + output[i[1] - self.offset:] + return output + + def seek(self, offset, whence = os.SEEK_SET): + """Seek function for file-like interface""" + self.offset = offset + if (whence == os.SEEK_CUR): + self.offset += offset + elif (whence == os.SEEK_END): + self.offset = self.fsize - offset + + def tell(self): + """Tell function for file-like interface""" + return self.offset + + def write(self, string): + pass + + class FirewireAddressSpace(FileAddressSpace): + def __init__(self, bus, node, fast=False): + self.fname = "Firewire on bus " + bus + " node " + node + self.name = self.fname + self.fhandle = FirewireIO(bus, node) + # Theoretical limit + self.fsize = self.fhandle.fsize + + if fast == True: + raise RuntimeError("Fast mode for firewire not implemented") \ No newline at end of file