mirror of
https://github.com/OPSnet/xld_logchecker.py.git
synced 2026-01-16 15:04:17 -05:00
Simplified scrambling function
This commit is contained in:
puddly
119
xld.py
119
xld.py
@@ -1,7 +1,7 @@
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#!/usr/bin/env python3
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import sys
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import copy
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import base64
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import struct
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import argparse
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@@ -15,21 +15,24 @@ DIGEST_LENGTH = 64 + len('\nVersion=0001')
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def bit_concat32(high, low):
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return ((high & 0xFFFFFFFF) << 32) | (low & 0xFFFFFFFF)
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def byte_swap(bits, n):
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n = n & (1 << bits) - 1
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return int.from_bytes(n.to_bytes(bits // 8, 'little')[::-1], 'little')
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def reverse_bytes32(n):
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as_bytes = n.to_bytes(4, 'little')[::-1]
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return int.from_bytes(as_bytes, 'little')
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def LODWORD(n):
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def concat_reverse_bytes32(high, low):
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return bit_concat32(reverse_bytes32(high), reverse_bytes32(low))
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def LOW32(n):
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return n & 0x00000000FFFFFFFF
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def HIDWORD(n):
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def HIGH32(n):
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return (n & 0xFFFFFFFF00000000) >> 32
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def set_LODWORD(n, v):
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def set_LOW32(n, v):
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return (n & 0xFFFFFFFF00000000) | (v & 0xFFFFFFFF)
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def set_HIDWORD(n, v):
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return (n & 0x00000000FFFFFFFF) | ((v & 0xFFFFFFFF) << 32)
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def set_HIGH32(n, v):
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return ((v & 0xFFFFFFFF) << 32) | (n & 0x00000000FFFFFFFF)
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def rotate_left(n, k):
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return ((n << k) & 0xFFFFFFFF) | (n >> (32 - k))
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@@ -38,9 +41,8 @@ def rotate_right(n, k):
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return ((n >> k) | (n << (32 - k))) & 0xFFFFFFFF
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def almost_sha256(data):
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# Non-standard initial state
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state = (0x1D95E3A4, 0x06520EF5, 0x3A9CFB75, 0x6104BCAE, 0x09CEDA82, 0xBA55E60B, 0xEAEC16C6, 0xEB19AF15)
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def sha256(data, initial_state):
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state = initial_state
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# Standard round constants
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round_constants = (0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, 0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5, 0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3, 0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174, 0xE49B69C1, 0xEFBE4786, 0x0FC19DC6, 0x240CA1CC, 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA, 0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, 0xC6E00BF3, 0xD5A79147, 0x06CA6351, 0x14292967, 0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13, 0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85, 0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3, 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070, 0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, 0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3, 0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208, 0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2)
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@@ -52,11 +54,13 @@ def almost_sha256(data):
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data += b'\x80' + (b'\x00' * ((K - 7) // 8)) + L.to_bytes(8, 'big')
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for start in range(0, len(data), 64):
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# Process chunks of 64 bytes
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chunk = data[start:start + 64]
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round_state = [0] * 64
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round_state[0:16] = struct.unpack('!16L', chunk)
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for i in range(0, len(chunk), 4):
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round_state[i // 4] = int.from_bytes(chunk[i:i + 4], 'big')
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for i in range(16, 64):
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s0 = rotate_right(round_state[i - 15], 7) ^ rotate_right(round_state[i - 15], 18) ^ (round_state[i - 15] >> 3)
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s1 = rotate_right(round_state[i - 2], 17) ^ rotate_right(round_state[i - 2], 19) ^ (round_state[i - 2] >> 10)
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@@ -89,80 +93,57 @@ def almost_sha256(data):
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def scramble(data):
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previous = MAGIC_INITIAL_STATE
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mod_current = 0
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X = LOW32(MAGIC_INITIAL_STATE)
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Y = HIGH32(MAGIC_INITIAL_STATE)
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output = b''
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output = []
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for size in range(DIGEST_LENGTH, 0, -8):
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current = 0
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for offset in range(0, len(data), 8):
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size = len(data) - offset
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needs_padding = (size < 8) # We will always need padding in the end
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# If we can read off two 32-bit integers, do it. Otherwise, reuse the last state
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if size >= 8:
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a = int.from_bytes(data[offset:offset + 4], 'little')
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b = int.from_bytes(data[offset + 4:offset + 8], 'little')
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if not needs_padding:
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offset = DIGEST_LENGTH - size
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chunk1 = int.from_bytes(data[offset:offset + 4], 'little')
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chunk2 = int.from_bytes(data[offset + 4:offset + 8], 'little')
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current = previous ^ bit_concat32(byte_swap(32, chunk2), byte_swap(32, chunk1))
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else:
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current = byte_swap(64, bit_concat32(mod_current, HIDWORD(mod_current)))
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X ^= reverse_bytes32(a)
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Y ^= reverse_bytes32(b)
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# Do some kind of 8-round scramble on the state four times
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for i in range(4):
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for j in range(2):
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current = set_HIDWORD(current, HIDWORD(current) ^ current)
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Y ^= X
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a = (MAGIC_CONSTANTS[4*j + 0] + HIDWORD(current)) & 0xFFFFFFFF
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b = a
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a = rotate_left(a, 1)
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c = (b - 1 + a) & 0xFFFFFFFF
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d = c
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c = rotate_left(c, 4)
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current = set_LODWORD(current, d ^ c ^ current)
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a = (MAGIC_CONSTANTS[4*j + 0] + Y) & 0xFFFFFFFF
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b = (a - 1 + rotate_left(a, 1)) & 0xFFFFFFFF
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e = (MAGIC_CONSTANTS[4*j + 1] + current) & 0xFFFFFFFF
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f = e
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e = rotate_left(e, 2)
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g = (f + 1 + e) & 0xFFFFFFFF
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h = g
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g = rotate_left(g, 8)
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i = (MAGIC_CONSTANTS[4*j + 2] + (h ^ g)) & 0xFFFFFFFF
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p = i
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i = rotate_left(i, 1)
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k = (i - p) & 0xFFFFFFFF
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l = k
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k = rotate_left(k, 16)
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X ^= b ^ rotate_left(b, 4)
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current = set_HIDWORD(current, HIDWORD(current) ^ (current | l) ^ k)
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m = (MAGIC_CONSTANTS[4*j + 3] + HIDWORD(current)) & 0xFFFFFFFF
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n = m
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m = rotate_left(m, 2)
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c = (MAGIC_CONSTANTS[4*j + 1] + X) & 0xFFFFFFFF
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d = (c + 1 + rotate_left(c, 2)) & 0xFFFFFFFF
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current = set_LODWORD(current, ((n + 1 + m) ^ current) & 0xFFFFFFFF)
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e = (MAGIC_CONSTANTS[4*j + 2] + (d ^ rotate_left(d, 8))) & 0xFFFFFFFF
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f = (rotate_left(e, 1) - e) & 0xFFFFFFFF
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previous = current
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mod_current = byte_swap(64, (current << 32) | HIDWORD(current))
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if needs_padding:
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remaining = bytearray(data[len(output):])
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Y ^= (X | f) ^ rotate_left(f, 16)
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for i in range(size):
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remaining[i] ^= mod_current & 0xFF
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mod_current >>= 8
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output += remaining
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break
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g = (MAGIC_CONSTANTS[4*j + 3] + Y) & 0xFFFFFFFF
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X ^= (g + 1 + rotate_left(g, 2)) & 0xFFFFFFFF
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output += mod_current.to_bytes(8, 'little')
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output.append(concat_reverse_bytes32(Y, X).to_bytes(8, 'little'))
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return output
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if size > 0:
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last_chunk = output.pop()
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output.append(bytearray(data[8 * len(output) + i] ^ last_chunk[i] for i in range(size)))
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return b''.join(output)
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def encode(data):
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import base64
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# Non-standard base64 alphabet
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mapping = str.maketrans(
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'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
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@@ -193,7 +174,9 @@ def extract_info(data):
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def xld_verify(data):
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data, version, old_signature = extract_info(data)
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hashed_data = (almost_sha256(data.encode('utf-8')) + '\nVersion=0001').encode('ascii')
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initial_state = (0x1D95E3A4, 0x06520EF5, 0x3A9CFB75, 0x6104BCAE, 0x09CEDA82, 0xBA55E60B, 0xEAEC16C6, 0xEB19AF15)
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hashed_data = (sha256(data.encode('utf-8'), initial_state) + '\nVersion=0001').encode('ascii')
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scrambled_data = scramble(hashed_data)
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signature = encode(scrambled_data)
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