124 lines
3.0 KiB

#!/usr/bin/env python
from XmlMutatorMin import XmlMutatorMin
# Default settings (production mode)
__mutator__ = None
__seed__ = "RANDOM"
__log__ = False
__log_file__ = "wrapper.log"
# AFL functions
def log(text):
"""
Logger
"""
global __seed__
global __log__
global __log_file__
if __log__:
with open(__log_file__, "a") as logf:
logf.write("[%s] %s\n" % (__seed__, text))
def init(seed):
"""
Called once when AFL starts up. Seed is used to identify the AFL instance in log files
"""
global __mutator__
global __seed__
# Get the seed
__seed__ = seed
# Create a global mutation class
try:
__mutator__ = XmlMutatorMin(__seed__, verbose=__log__)
log("init(): Mutator created")
except RuntimeError as e:
log("init(): Can't create mutator: %s" % e.message)
def fuzz(buf, add_buf, max_size):
"""
Called for each fuzzing iteration.
"""
global __mutator__
# Do we have a working mutator object?
if __mutator__ is None:
log("fuzz(): Can't fuzz, no mutator available")
return buf
# Try to use the AFL buffer
via_buffer = True
# Interpret the AFL buffer (an array of bytes) as a string
if via_buffer:
try:
buf_str = str(buf)
log("fuzz(): AFL buffer converted to a string")
except Exception:
via_buffer = False
log("fuzz(): Can't convert AFL buffer to a string")
# Load XML from the AFL string
if via_buffer:
try:
__mutator__.init_from_string(buf_str)
log(
"fuzz(): Mutator successfully initialized with AFL buffer (%d bytes)"
% len(buf_str)
)
except Exception:
via_buffer = False
log("fuzz(): Can't initialize mutator with AFL buffer")
# If init from AFL buffer wasn't succesful
if not via_buffer:
log("fuzz(): Returning unmodified AFL buffer")
return buf
# Sucessful initialization -> mutate
try:
__mutator__.mutate(max=5)
log("fuzz(): Input mutated")
except Exception:
log("fuzz(): Can't mutate input => returning buf")
return buf
# Convert mutated data to a array of bytes
try:
data = bytearray(__mutator__.save_to_string())
log("fuzz(): Mutated data converted as bytes")
except Exception:
log("fuzz(): Can't convert mutated data to bytes => returning buf")
return buf
# Everything went fine, returning mutated content
log("fuzz(): Returning %d bytes" % len(data))
return data
# Main (for debug)
if __name__ == "__main__":
__log__ = True
__log_file__ = "/dev/stdout"
__seed__ = "RANDOM"
init(__seed__)
in_1 = bytearray(
"<foo ddd='eeee'>ffff<a b='c' d='456' eee='ffffff'>zzzzzzzzzzzz</a><b yyy='YYY' zzz='ZZZ'></b></foo>"
)
in_2 = bytearray("<abc abc123='456' abcCBA='ppppppppppppppppppppppppppppp'/>")
out = fuzz(in_1, in_2)
print(out)