def _set_value(self, varnode: Varnode, value: BV) -> None:
"""
Store a value for a given varnode.
This method stores to the appropriate register, or unique space,
depending on the space indicated by the varnode.
:param varnode: Varnode to store into.
:param value: Value to store.
"""
space_name = varnode.space.name
# FIXME: Consider moving into behavior.py
value = self._adjust_value_size(varnode.size * 8, value)
assert varnode.size * 8 == value.size()
l.debug("Storing %s %x %s %d", space_name, varnode.offset, value,
varnode.size)
if space_name == "register":
self.state.registers.store(self._map_register_name(varnode),
value,
size=varnode.size)
elif space_name == "unique":
self._pcode_tmps[varnode.offset] = value
elif space_name in ("ram", "mem"):
l.debug("Storing %s to offset %s", value, varnode.offset)
self.state.memory.store(varnode.offset,
value,
endness=self.project.arch.memory_endness)
else:
raise NotImplementedError()
def _adjust_value_size(num_bits: int, v_in: BV) -> BV:
"""
Ensure given bv is num_bits bits long by either zero extending or truncating.
"""
if v_in.size() > num_bits:
v_out = v_in[num_bits - 1:0]
l.debug('Truncating value %s (%d bits) to %s (%d bits)', v_in,
v_in.size(), v_out, num_bits)
return v_out
elif v_in.size() < num_bits:
v_out = v_in.zero_extend(num_bits - v_in.size())
l.debug('Extending value %s (%d bits) to %s (%d bits)', v_in,
v_in.size(), v_out, num_bits)
return v_out
else:
return v_in
def evaluate_binary(self, size_out: int, size_in: int, in1: BV,
in2: BV) -> BV:
if in2.size() < in1.size():
in2 = in2.sign_extend(in1.size() - in2.size())
return (in1 >> (in2 * 8)) & (2**(size_out * 8) - 1)
def booleanize(cls, in1: BV) -> BV:
"""
Reduce input BV to a single bit of truth: out <- 1 if (in1 != 0) else 0.
"""
return cls.generic_compare((in1, claripy.BVV(0, in1.size())),
operator.ne)
def evaluate_unary(self, size_out: int, size_in: int, in1: BV) -> BV:
return self.generic_compare((in1, claripy.BVV(0, in1.size())),
operator.eq)
def evaluate_binary(self, size_out: int, size_in: int, in1: BV,
in2: BV) -> BV:
in1, in2 = make_bv_sizes_equal(in1, in2)
return in1.LShR(in2)
def evaluate_unary(self, size_out: int, size_in: int, in1: BV) -> BV:
return in1.sign_extend((size_out - size_in) * 8)
def evaluate_binary(self, size_out: int, size_in: int, in1: BV,
in2: BV) -> BV:
if in2.size() < in1.size():
in2 = in2.sign_extend(in1.size() - in2.size())
return in1.LShR(in2)
