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| import struct
import sys
a=[0x99,0xDD,0x56,0xFF,0x6D,0xD9,0x55,0x54,0x42,0x4D,0x79,0x1A,0x34,0xB7,0x81,0x2F]
UNK_10170 = b''
for i in a:
UNK_10170+=i.to_bytes(1)
b=[0x87,0xC1,0x56,0xC0,0x4C,0xF4,0x63,0x4F]
UNK_10180 = b''
for i in b:
UNK_10180+=i.to_bytes(1)
enc=[0xA9,0xB,0x5C,0x1C,0xA3,0x41,0x88,0xCA,0x66,0xD9,0x77,0x1D,0x78,0x3,0x8E,0x7A,0xBA,0x7B,0xD4,0x90,0xCD,0x50,0x7,0x83,0x41,0x4A,0x82,0x9C,0x79,0x1D,0xCC,0x6F,0x9D,0x2F,0x39,0x2D,0xA2,0xDA,0x83,0x1B]
TARGET_CIPHERTEXT = b''
for i in enc:
TARGET_CIPHERTEXT+=i.to_bytes(1)
def rc4_ksa(key):
"""RC4 Key-Scheduling Algorithm (based on sub_2C740)"""S = list(range(256))
j = 0
key_bytes = key
key_len = len(key_bytes)
for i in range(256):
j = (j + S[i] + key_bytes[i % key_len]) % 256
S[i], S[j] = S[j], S[i]
return S
def rc4_prga_sub_293E0(initial_S, input_data):
"""RC4 Pseudo-Random Generation Algorithm (based on sub_293E0 loop)"""S = list(initial_S)
output_data = bytearray(len(input_data))
v8 = 0
v7 = 0
for k in range(len(input_data)):
v8 = (v8 + 1) % 256
v7 = (v7 + S[v8]) % 256
S[v8], S[v7] = S[v7], S[v8]
keystream_index = (S[v7] + S[v8]) % 256
keystream_byte = S[keystream_index]
output_data[k] = keystream_byte ^ input_data[k]
return bytes(output_data)
XTEA_DELTA_CONSTANT = 1640531527 # 0x61C88647
def calculate_encryption_v4_sequence(key_bytes):
"""计算加密轮次中 v4 值的序列。"""v4_sequence = [0]
v4_current = 0
k = [
struct.unpack('<I', key_bytes[i*4 : i*4+4])[0]
for i in range(4)
]
for round_index in range(32):
k2_index = round_index & 3
k2 = k[k2_index]
v4_update_term = (round_index ^ k2) - XTEA_DELTA_CONSTANT
v4_current = (v4_current + v4_update_term) & 0xFFFFFFFF
v4_sequence.append(v4_current)
return v4_sequence
def decrypt_block_round(v6_end, v5_end, v4_start_of_round, v4_end_of_round, round_index, key_bytes):
"""解密定制 XTEA 变种的一轮。"""v6_end = v6_end & 0xFFFFFFFF
v5_end = v5_end & 0xFFFFFFFF
v4_start_of_round = v4_start_of_round & 0xFFFFFFFF
v4_end_of_round = v4_end_of_round & 0xFFFFFFFF
k = [
struct.unpack('<I', key_bytes[i*4 : i*4+4])[0]
for i in range(4)
]
k3_index = (v4_end_of_round >> 11) & 3
k3 = k[k3_index]
intermediate_term2 = v6_end + ((v6_end >> 5) ^ (v6_end << 4))
term2 = (k3 + v4_end_of_round) ^ intermediate_term2
v5_start = (v5_end - term2) & 0xFFFFFFFF
k1_index = v4_start_of_round & 3
k1 = k[k1_index]
intermediate_term1 = v5_start + ((v5_start >> 5) ^ (v5_start << 4))
term1 = (k1 + v4_start_of_round) ^ intermediate_term1
v6_start = (v6_end - term1) & 0xFFFFFFFF
return (v6_start, v5_start)
def cbc_decrypt(ciphertext, key, iv):
"""使用定制 XTEA 变种以 CBC 模式解密密文。"""block_size = 8 # 字节
if len(ciphertext) % block_size != 0:
print(f"错误：密文长度 ({len(ciphertext)}) 不是分组大小 ({block_size}) 的倍数。无法执行 CBC 解密。")
sys.exit(1)
v4_sequence = calculate_encryption_v4_sequence(key)
plaintext_bytes = bytearray()
previous_ciphertext_block = iv
for i in range(0, len(ciphertext), block_size):
current_ciphertext_block = ciphertext[i : i + block_size]
c0, c1 = struct.unpack('<II', current_ciphertext_block)
decrypted_block_state = (c0, c1)
for reverse_round_index in range(31, -1, -1):
v4_start = v4_sequence[reverse_round_index]
v4_end = v4_sequence[reverse_round_index + 1]
decrypted_block_state = decrypt_block_round(
decrypted_block_state[0], decrypted_block_state[1],
v4_start, v4_end,
reverse_round_index,
key
)
p_prime_bytes = struct.pack('<II', decrypted_block_state[0], decrypted_block_state[1])
plaintext_block = bytes([
p_prime_bytes[j] ^ previous_ciphertext_block[j] for j in range(block_size)
])
plaintext_bytes.extend(plaintext_block)
previous_ciphertext_block = current_ciphertext_block
return bytes(plaintext_bytes)
if not UNK_10170 or len(UNK_10170) != 16:
print("错误：请提供 UNK_10170 的 16 字节数据，需从 SO 文件中提取。")
elif not UNK_10180 or len(UNK_10180) != 8:
print("错误：请提供 UNK_10180 的 8 字节数据，需从 SO 文件中提取。")
elif not TARGET_CIPHERTEXT or len(TARGET_CIPHERTEXT) != 40: # <-- 检查长度为 40 字节
print(f"错误：请提供 TARGET_CIPHERTEXT 的 **完整的 40 字节** 数据，需从 SO 文件中提取。")
print(f"(当前提供的长度为 {len(TARGET_CIPHERTEXT)})")
else:
print("占位符数据似乎已提供。尝试解密...")
rc4_key_material = b"DoNotHackMe"
S_box_for_73040 = rc4_ksa(rc4_key_material)
KEY_QWORD_73040 = rc4_prga_sub_293E0(list(S_box_for_73040), UNK_10170)
S_box_for_73050 = rc4_ksa(rc4_key_material)
KEY_QWORD_73050 = rc4_prga_sub_293E0(list(S_box_for_73050), UNK_10180)
print(f"派生出的加密密钥 (qword_73040): {KEY_QWORD_73040.hex()}")
print(f"派生出的 IV (qword_73050): {KEY_QWORD_73050.hex()}")
print(f"目标密文 (40字节): {TARGET_CIPHERTEXT.hex()}")
decrypted_padded_plaintext = cbc_decrypt(TARGET_CIPHERTEXT, KEY_QWORD_73040, KEY_QWORD_73050)
plaintext = decrypted_padded_plaintext.rstrip(b'\x00')
print(f"\n解密后的填充明文 (40 字节): {decrypted_padded_plaintext.hex()}") # <-- 输出提示长度为 40
try:
flag = plaintext.decode('utf-8')
print(f"恢复的 Flag (解码为 UTF-8): {flag}")
except UnicodeDecodeError:
print(f"无法将恢复的明文解码为 UTF-8。")
print(f"恢复的明文字节 (十六进制): {plaintext.hex()}")
except Exception as e:
print(f"在最终处理过程中发生未知错误: {e}")
# palu{thiS_T1Me_it_seeM5_tO_8e_ReAl_te@}
|
