def load(fp, _isa, base=0, offset=0):
"""load a single executable extent from a file"""
_isa = isa.correlate(copy.deepcopy(_isa))
# first, assemble
fp.seek(offset, os.SEEK_CUR)
assembled = bytes(
keystone.Ks(
_isa["keystone"]["arch"], _isa["keystone"]["endianness"] +
_isa["keystone"]["mode"]).asm(fp.read())[0])
# disassemble
return MachineCodeIO.load(io.BytesIO(assembled), _isa, base)
def dump(fp, extent):
"""load a single executable extent to a file"""
_isa = isa.correlate(copy.deepcopy(extent["isa"]))
# dump assembly
b = io.BytesIO()
AssemblyIO.dump(b, extent)
# assemble
fp.write(
bytes(
keystone.Ks(
_isa["keystone"]["arch"], _isa["keystone"]["endianness"] +
_isa["keystone"]["mode"]).asm(b.getvalue())[0]))
def loadall(fp, base=0, extents=None):
"""load all executable extents from a file"""
# load the binary
binary = analyze.Binary(fp.read())
# compute the complete _isa
_isa = isa.correlate({
"capstone": {
"arch": binary.arch,
"endianness": binary.endianess,
"mode": binary.mode
}
})
# load extents
extents = dict(extents) if isinstance(extents, dict) \
else {".text": None}
extents = {k: {"base": v} for k, v in extents.items()}
for extent in binary.executable_sections:
_base = extents[extent.name] \
if isinstance(extents.get(extent.name, None), int) \
else extent.addr
code = io.BytesIO(extent.code)
for offset in range(
min(16, extent.size)
): # Intel-specific##############################################################
print(
"Loading extent from object (extent \"%s\", offset %u)..."
% (extent.name, offset))
code.seek(0, os.SEEK_SET)
extents[(extent.name,
offset)] = MachineCodeIO.load(io.BytesIO(code.read()),
_isa, base + _base,
offset)
# filter out unmatched extents
return {k: v for k, v in extents.items() if len(v.keys()) > 1}
def load(fp, _isa, base=0, offset=0):
"""load a single executable extent from a file"""
_isa = isa.correlate(copy.deepcopy(_isa))
# load
fp.seek(offset, os.SEEK_CUR)
return {
"base":
base,
"instructions":
capstone.Cs(
_isa["capstone"]["arch"], _isa["capstone"]["endianness"] +
_isa["capstone"]["mode"]).disasm(fp.read(), base + offset),
"isa":
_isa,
"offset":
offset
}
def chain(which="mprotect", *objs, **kwargs):
"""establish a predefined ROP chain"""
chains = {"mprotect": Transpiler.mprotect}
if Transpiler._isa_mismatch(*objs):
raise TypeError("ISA mismatch")
_isa = None
for o in objs:
for e in o.values():
if "isa" in e:
_isa = e["isa"]
break
if _isa is not None:
break
if _isa is None:
raise ValueError("no ISA")
_isa = isa.correlate(copy.deepcopy(_isa))
if which in chains:
print("Generating the \"%s\" chain..." % which)
chain = chains[which](*objs, **kwargs)
if chain is None:
print("Failed!")
return
print("Packing the chain...")
packer = '>' if _isa["capstone"]["endianness"] \
== capstone.CS_MODE_BIG_ENDIAN else '<'
packer += 'I' if _isa["capstone"]["mode"] == capstone.CS_MODE_32 \
else 'L'
for i, e in enumerate(chain):
if isinstance(e, bytes):
continue
else:
# treat as a machine word
chain[i] = struct.pack(packer, e)
return b"".join(chain)
raise ValueError("unsupported chain \"%s\"" % which)
def pload(path, _isa, base=0, offset=0):
"""load a single executable extent at a path"""
_isa = isa.correlate(copy.deepcopy(_isa))
with open(path, "rb") as fp:
return MachineCodeIO.load(fp, base, offset)
def pdump(path, extent):
"""load a single executable extent to a path"""
_isa = isa.correlate(copy.deepcopy(extent["isa"]))
with open(path, "wb") as fp:
MachineCodeIO.dump(fp, extent)
