def attack(self, block):
"""Attack a given Range Query with a distinguishable first block
This function can only be used under specific circumstances, which is why it is not the default function.
To use it, change the Dictionary of the getAttackerFor-function in DRQPatternAttack.py to point to
DFBPatternBRQ instead of DFBPatternPRQ, but be aware that it will not always work on small data sets.
@param fb: The first block, as set
@param rq: The remaining range query, as set
@return: List of possible results
"""
fb, rq = block
res = []
suspected_n = float(len(fb))
rq.update(fb)
rqlen = len(rq)
pattern_length_max = math.ceil(rqlen / suspected_n)
pattern_length_max += 2 * math.ceil(pattern_length_max / suspected_n)
# Increase maximum pattern length, because duplicates could lead to a miscalculation of up to floor(real_pattern_length/real_N).
# We are using ceil() to avoid border cases where the real M would lead to x in that calculation, while our detected M
# only leads to x-1. Those cases would be few and far between, considering the chances of actually getting so many duplicates,
# but nevertheless, they should be dealt with.
pattern_length_min = math.floor(rqlen / (suspected_n+1))
for key in fb: # Iterate through all elements of the first block
if DB.isValidTarget(key) and (pattern_length_min <= DB.getPatternLengthForHost(key) <= pattern_length_max):
# if the current element is a beginning of a pattern with the correct length...
if DB.getPatternForHost(key) <= rq: # Check if the pattern is a subset of the remaining range query.
res.append(key)
return res
def generateBaseDRQ(self, domain):
"""Generator for Basic DNS Range Queries (randomly generated query sets)
Queries are unique inside their respective sets, but may appear more than once across different
query blocks.
@param domain: Domain for which a DNS Range Query should be generated
@return: List of Sets, in order, each set representing a query block
"""
if not DB.isValidTarget(domain):
Error.printErrorAndExit(domain + " is not a valid target")
patlen = DB.getPatternLengthForHost(domain)
block = [set()]
pattern = DB.getPatternForHost(domain) # Get the actual pattern of the target
randoms = DB.getRandomHosts((Config.RQSIZE-1)*len(pattern)) # Get random hosts (dummies)
pattern.remove(domain)
block[0].add(domain)
i = 1
for subquery in pattern: # Create the blocks that will hold dummies and actual queries
block.append(set())
block[i].add(subquery) # Add the actual query to its respective block
i += 1
for query, index in zip(randoms, cycle(range(patlen))):
# distribute the randomly chosen dummy queries as evenly as possible across the blocks
block[index].add(query)
return block
def attack(self, rq):
"""Attack a given Range Query using the assumption from the class description.
@param rq: A Range Query, as returned by generate.DRQ
@return: list of possible results
"""
res = []
for element in rq: # Iterate through all elements (queries) of the given range query
if DB.isValidTarget(element): # If the current element is the beginning of a pattern...
# This checks if the pattern of the current element is a subset of the range query
inter = rq & DB.getPatternForHost(element)
if len(inter) == DB.getPatternLengthForHost(element):
res.append(element)
return res
def attack(self, block):
"""Attack a given Range Query with a distinguishable first block
@param fb: The first block, as set
@param rq: The remaining range query, as set
@return: List of possible results
"""
fb, rq = block
res = []
rq.update(fb)
for key in fb: # Iterate through all queries in the first block
if DB.isValidTarget(key): # If the current query is a valid beginning of a pattern...
if DB.getPatternForHost(key) <= rq: # Check if the pattern is a subset of the second block.
res.append(key)
return res
def attack(self, blocklist):
"""Attack a given range query with fully distinguishable blocks
@param blocklist: A list of sets, each set representing a block, the main target in the first block.
@return: List of possible results
"""
res = []
length = len(blocklist)
for key in blocklist[0]: # Iterate through all candidates for the main target (as it must be in the first block)
if DB.isValidTarget(key) and DB.getPatternLengthForHost(key) == length: # If it is the beginning of a pattern of the correct length...
# The following is a method of determining if every block contains exactly one element of the pattern of the current candidate.
tmp = blocklist[1:]
cnt = {}
for i in range(length-1):
cnt[i] = 0
for query in DB.getPatternForHost(key):
if query != key:
for i in range(len(tmp)):
if query in tmp[i]:
cnt[i] += 1
if not 0 in cnt.values():
res.append(key)
return res
def generateBaseDRQ(self, domain):
"""Generator for Pattern-Based DNS Range Queries (trying to fill the query blocks with patterns)
Queries are unique inside their respective sets, but may appear more than once across different
query blocks.
@param domain: Domain for which a DNS Range Query should be generated
@return: List of Sets, in order, each set representing a query block
"""
if not DB.isValidTarget(domain):
Error.printErrorAndExit(domain + " is not a valid target")
pattern_length = len(DB.PATTERNS[domain])
block = [set()]
num_of_available_patterns = DB.getNumberOfHostsWithPatternLength(pattern_length) - 1
if num_of_available_patterns >= Config.RQSIZE:
hosts = set([domain])
hosts.update(set(DB.getRandomHostsByPatternLengthB(pattern_length, Config.RQSIZE-1, hosts)))
pattern_copy = {}
for host in hosts:
pattern_copy[host] = DB.getPatternForHost(host)
pattern_copy[host].remove(host)
block[0].add(host)
for i in range(1, pattern_length, 1):
block.append(set())
for host in pattern_copy:
block[i].add(pattern_copy[host].pop())
else:
num_of_needed_patterns = Config.RQSIZE - (num_of_available_patterns+1)
padding = []
for i in range(num_of_needed_patterns):
# Find patterns whose lengths sum to pattern_length (if any exist that have not been chosen yet)
pad1_len = pad2_len = -1
for pad1_len, pad2_len in zip(range(1, pattern_length/2+1, 1), range(pattern_length-1, pattern_length/2-1, -1)):
# This is a construct that generates numbers that sum to pattern_length. It is used instead of truly random
# numbers because it will not get stuck when no more patterns are available.
if ((DB.getNumberOfHostsWithPatternLengthB(pad1_len, block[0]) > 0) and \
(DB.getNumberOfHostsWithPatternLength(pad2_len) > 0)):
break
elif pad1_len == pattern_length/2: # No patterns of the correct length have been found, abort
pad1_len = -1
if (pad1_len == -1): # Break out of loop as no further patterns can be found.
break
# The following few lines get the dummy patterns from the database and saves them to the list of dummy-patterns
pad1_host = DB.getRandomHostsByPatternLengthB(pad1_len, 1, block[0])[0]
pad1_pattern = DB.getPatternForHost(pad1_host)
pad1_pattern.remove(pad1_host)
block[0].add(pad1_host)
padding.append([pad1_host])
for host in pad1_pattern:
padding[i].append(host)
pad2_host = DB.getRandomHostsByPatternLength(pad2_len, 1)[0]
pad2_pattern = DB.getPatternForHost(pad2_host)
pad2_pattern.remove(pad2_host)
padding[i].append(pad2_host)
for host in pad2_pattern:
padding[i].append(host)
# We now have as many dummy patterns as we will get. Start distributing them.
pattern_copy = {}
block[0].add(domain)
pattern_copy[domain] = DB.getPatternForHost(domain)
pattern_copy[domain].remove(domain)
for element in DB.getRandomHostsByPatternLengthB(pattern_length, num_of_available_patterns, block[0]):
# Get all patterns with the correct length and add them to the range query
pattern_copy[element] = DB.getPatternForHost(element)
pattern_copy[element].remove(element)
block[0].add(element)
for i in range(1, pattern_length, 1):
# Distribute the remaining patterns (those whose lengths sum to the correct length)
block.append(set())
for host in pattern_copy:
block[i].add(pattern_copy[host].pop())
for pattern in padding:
block[i].add(pattern[i])
return block
