def _key(self):
key = self.args.key
if len(key) != 0x10:
raise ValueError(
F'Key length of {len(key)} bytes is invalid; XXTEA only supports 16 byte keys'
)
return chunks.unpack(key, 4)
def _ripemd128_blocks(msg):
N = len(msg)
P = (56 - N) % 64
msg += b'\x80' + b'\x00' * (P - 1) + (N << 3).to_bytes(8, 'little')
it = iter(chunks.unpack(msg, 4))
while True:
block = list(itertools.islice(it, 16))
if not block:
break
assert len(block) == 16
yield block
def _checksum(self, data):
from refinery.lib import chunks
checksum = 0
it = chunks.unpack(data, 4)
if len(data) % 4:
import itertools
it = itertools.chain(it, (int.from_bytes(data[-4:], 'little'), ))
for chunk in it:
checksum += chunk
checksum ^= ((chunk & 0x7FFFFFFF) << 1) + (chunk >> 31) + 1
checksum &= 0xFFFFFFFF
return checksum
def chunk(self, data, raw=False):
if not raw:
return chunks.unpack(data, self.args.blocksize,
self.args.bigendian)
def chunkraw(data, b: int):
stop = len(data)
stop = stop - stop % b
for k in range(0, stop, b):
yield data[k:k + b]
return chunkraw(data, self.args.blocksize)
def block_encrypt(self, block) -> BufferType:
u = self._u
w = self._w
g = self._g
r = self._r
M = self._m
S = self._S
A, B, C, D = chunks.unpack(block, u)
B = B + S[0] & M
D = D + S[1] & M
for i in range(1, r + 1):
t = rotl(w, B * (2 * B + 1) & M, g)
v = rotl(w, D * (2 * D + 1) & M, g)
A = rotl(w, A ^ t, v) + S[2 * i + 0] & M
C = rotl(w, C ^ v, t) + S[2 * i + 1] & M
A, B, C, D = B, C, D, A
A = A + S[2 * r + 2] & M
C = C + S[2 * r + 3] & M
return chunks.pack((A, B, C, D), u)
def block_decrypt(self, block) -> BufferType:
u = self._u
w = self._w
g = self._g
r = self._r
M = self._m
S = self._S
A, B, C, D = chunks.unpack(block, u)
C = C - S[2 * r + 3] & M
A = A - S[2 * r + 2] & M
for i in range(r, 0, -1):
A, B, C, D = D, A, B, C
t = rotl(w, B * (2 * B + 1) & M, g)
v = rotl(w, D * (2 * D + 1) & M, g)
C = rotr(w, C - S[2 * i + 1] & M, t) ^ v
A = rotr(w, A - S[2 * i + 0] & M, v) ^ t
D = D - S[1] & M
B = B - S[0] & M
return chunks.pack((A, B, C, D), u)
def key(self, key):
w = self._w # word size
u = self._u # length of a word in bytes
r = self._r # round count
M = self._m # bit mask
L = list(chunks.unpack(key + (-len(key) % u) * B'\0', u))
c = len(L)
t = 2 * (r + 2)
P, Q = rc5constants(w)
S = [P]
while len(S) < t:
S.append(S[~0] + Q & M)
i = j = 0
A = B = 0
for _ in range(3 * max(t, c)):
A = S[i] = rotl(w, S[i] + A + B & M, 3)
B = L[j] = rotl(w, L[j] + A + B & M, A + B)
i = (i + 1) % t
j = (j + 1) % c
self._S = S
def keystream(self) -> Iterable[int]:
key = self.args.key
A: int = 0
B: int = 0
C: int = 0
S: List[int] = [0x9E3779B9] * 8
T: List[int] = []
K = list(
chunks.unpack(key + bytearray(0x400 - len(key)),
4,
bigendian=False))
U = 0xFFFFFFFF
def _mix_state():
a, b, c, d, e, f, g, h = S
a ^= (b << 0x0B) & U
d = d + a & U
b = b + c & U # noqa
b ^= (c >> 0x02) & U
e = e + b & U
c = c + d & U # noqa
c ^= (d << 0x08) & U
f = f + c & U
d = d + e & U # noqa
d ^= (e >> 0x10) & U
g = g + d & U
e = e + f & U # noqa
e ^= (f << 0x0A) & U
h = h + e & U
f = f + g & U # noqa
f ^= (g >> 0x04) & U
a = a + f & U
g = g + h & U # noqa
g ^= (h << 0x08) & U
b = b + g & U
h = h + a & U # noqa
h ^= (a >> 0x09) & U
c = c + h & U
a = a + b & U # noqa
S[:] = a, b, c, d, e, f, g, h
return S
def _initialize_with(R: List[int]):
for i in range(0, 0x100, 8):
S[:] = (x + R[j] & U for j, x in enumerate(S, i))
T[i:i + 8] = _mix_state()
for _ in range(4):
_mix_state()
_initialize_with(K)
_initialize_with(T)
operations = [
(__lshift__, 0x0D),
(__rshift__, 0x06),
(__lshift__, 0x02),
(__rshift__, 0x10),
]
while True:
C = (C + 1) & U
B = (B + C) & U
for i in range(0x100):
X = T[i]
shift, k = operations[i % 4]
A = (A ^ shift(A, k)) & U
A = (A + T[i ^ 0x80]) & U
Y = T[+i] = T[X // 4 & 0xFF] + A + B & U
B = K[~i] = X + T[Y // 1024 & 0xFF] & U
yield from chunks.pack(K, 4, True)
def hexdump(data: ByteString,
metrics: HexDumpMetrics,
colorize=False) -> Iterable[str]:
separator = metrics.hex_char_spacer
hex_width = metrics.hex_column_width
addr_width = metrics.address_width
columns = metrics.hex_columns
hexformat = metrics.hex_char_format
printable = range(0x21, 0x7F)
from colorama import Fore as FG, Style as S
if columns <= 0:
raise RuntimeError('Requested width is too small.')
def pieces(data):
view = memoryview(data)
step = columns * metrics.block_size
for lno, offset in enumerate(range(0, len(data), step)):
if metrics.line_count and lno >= metrics.line_count:
break
yield lno, view[offset:offset + step]
previous = None
repetitions = 0
for last, (lno, chunk) in lookahead(pieces(data)):
if not metrics.expand:
if chunk == previous and not last:
repetitions += 1
continue
elif repetitions > 0:
line = F' repeats {repetitions} times '
line = F'{line:/^{hex_width*columns-1}} {"":/<{columns}}'
if colorize:
line = F'{FG.LIGHTBLACK_EX}{line}{S.RESET_ALL}'
if addr_width:
line = F'{".":.>{addr_width}}{metrics.hex_addr_spacer}{line}'
yield line
repetitions = 0
blocks = chunks.unpack(chunk, metrics.block_size, metrics.big_endian)
if not colorize:
dump = separator.join(hexformat.format(b) for b in blocks)
ascii_preview = re.sub(B'[^!-~]', B'.', chunk).decode('ascii')
line = (F'{dump:<{hex_width*columns-len(separator)}}'
F'{metrics.txt_separator}{ascii_preview:<{columns}}')
else:
def byte_color(value: int):
if not value:
return FG.LIGHTBLACK_EX
elif value in B'\x20\t\n\r\v\f':
return FG.LIGHTYELLOW_EX
elif value not in printable:
return FG.LIGHTRED_EX
else:
return S.RESET_ALL
with io.StringIO() as _hex, io.StringIO() as _asc:
current_color = S.RESET_ALL
block_size = metrics.block_size
prefix = metrics.hex_char_prefix
remaining_hex_width = hex_width * columns - len(separator)
for k, b in enumerate(chunk):
if k % block_size == 0:
if k != 0:
_hex.write(separator)
remaining_hex_width -= len(separator)
if prefix:
_hex.write(prefix)
remaining_hex_width -= len(prefix)
color = byte_color(b)
if color != current_color:
_hex.write(color)
_asc.write(color)
current_color = color
_hex.write(F'{b:02X}')
remaining_hex_width -= 2
_asc.write(chr(b) if b in printable else '.')
_hex.write(S.RESET_ALL)
_hex.write(' ' * remaining_hex_width)
_asc.write(S.RESET_ALL)
line = F'{_hex.getvalue()}{metrics.txt_separator}{_asc.getvalue():<{columns}}'
if addr_width:
line = F'{lno*columns:0{addr_width}X}: {line}'
yield line
if not metrics.expand:
previous = chunk
def _unpack(self, data):
if len(data) % 4:
raise ValueError(
'The input data is not aligned to a multiple of 4 bytes.')
return chunks.unpack(data, 4)
