# Volatility Framework plugin: bitlocker # # # Author: # Marcin Ulikowski # # # Based on research by: # Jesse Kornblum # # AES key schedule crypto code dervied from SlowAES project: # https://code.google.com/p/slowaes/ # Modified to verify a key schedule, not just compare them. # # Special thanks: # Piotr Chmylkowski # Romain Coltel # # This plugin is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This plugin is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this plugin. If not, see . """ @author: Marcin Ulikowski @license: GNU General Public License 2.0 @contact: marcin@ulikowski.pl @organization: http://ulikowski.pl """ import os import volatility.plugins.common as common import volatility.utils as utils import volatility.obj as obj import volatility.poolscan as poolscan import volatility.debug as debug class bitlocker(common.AbstractWindowsCommand): '''Extracts BitLocker FVEK (Full Volume Encryption Key)''' sbox = [0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16] Rcon = [0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb ] def __init__(self, config, *args, **kwargs): common.AbstractWindowsCommand.__init__(self, config, *args, **kwargs) config.add_option('DUMP-DIR', default = None, help = 'Directory in which to dump FVEK') @staticmethod def is_valid_profile(profile): return profile.metadata.get('major', 0) >= 6 def rotate(self, word): return word[1:] + word[:1] def core(self, word, iteration): word = self.rotate(word) for i in range(4): word[i] = self.sbox[word[i]] word[0] = word[0] ^ self.Rcon[iteration] return word def validSchedule(self, keySchedule, size, expandedKeySize): keySchedule = map(ord, keySchedule) key = keySchedule[:size] currentSize = 0 rconIteration = 1 expandedKey = [0] * expandedKeySize for j in range(size): expandedKey[j] = key[j] currentSize += size while currentSize < expandedKeySize: t = expandedKey[currentSize-4:currentSize] if currentSize % size == 0: t = self.core(t, rconIteration) rconIteration += 1 if size == 32 and ((currentSize % size) == 16): for l in range(4): t[l] = self.sbox[t[l]] for m in range(4): expandedKey[currentSize] = expandedKey[currentSize - size] ^ t[m] if expandedKey[currentSize] != keySchedule[currentSize]: return False currentSize += 1 return True def calculate(self): addr_space = utils.load_as(self._config) windows_version = (addr_space.profile.metadata.get('major', 0), addr_space.profile.metadata.get('minor', 0)) if windows_version <= (6, 1): pool_tag = 'FVEc' else: pool_tag = 'Cngb' scanner = poolscan.SinglePoolScanner() scanner.checks = [ ('PoolTagCheck', dict(tag = pool_tag)), ('CheckPoolSize', dict(condition = lambda x: x > 184)), ] for addr in scanner.scan(addr_space): pool = obj.Object('_POOL_HEADER', offset = addr, vm = addr_space) pool_alignment = obj.VolMagic(pool.obj_vm).PoolAlignment.v() pool_size = int(pool.BlockSize * pool_alignment) debug.debug('Scanning potential BitLocker pool @ {0:#010x}'.format(pool.obj_offset)) aes = [] buf = addr_space.zread(addr, pool_size) for i in range(8, pool_size - 176): if self.validSchedule(buf[i:i+176], 16, 176): aes.append(buf[i:i+16]) for i in range(8, pool_size - 240): if self.validSchedule(buf[i:i+240], 32, 240): aes.append(buf[i:i+32]) debug.debug('AES keys found: {}'.format(len(aes))) if 0 < len(aes) <= 2: yield pool, aes[0], aes[1] if len(aes) > 1 else '' def render_text(self, outfd, data): data = sorted(data, key = lambda x: x[1]) outfd.write('\n') for pool, fvek, tweak in data: outfd.write('Address : {0:#010x}\n'.format(pool.obj_offset)) outfd.write('Cipher : AES-{}\n'.format(len(fvek) * 8)) outfd.write('FVEK : {}\n'.format(''.join('{:02x}'.format(ord(i)) for i in fvek))) if tweak: outfd.write('TWEAK : {}\n'.format(''.join('{:02x}'.format(ord(i)) for i in tweak))) if self._config.DUMP_DIR: full_path = os.path.join(self._config.DUMP_DIR, '{0:#010x}.fvek'.format(pool.obj_offset)) with open(full_path, "wb") as fvek_file: fvek_file.write(fvek + tweak) outfd.write('FVEK dumped to file: {}\n'.format(full_path)) outfd.write('\n')