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| import random
import string
def compute_crc16(data: bytes) -> int:
"""
在 Python 中复现 PHP 的 CRC-16/MODBUS 算法。
"""
checksum = 0xFFFF
for byte in data:
checksum ^= byte
for _ in range(8):
if checksum & 1:
checksum = (checksum >> 1) ^ 0xA001
else:
checksum >>= 1
return checksum
def calculate_crc8(data: bytes) -> int:
"""
在 Python 中复现 PHP 的查表法 CRC8 算法。
"""
crc8_table = [
0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15, 0x38, 0x3F, 0x36, 0x31,
0x24, 0x23, 0x2A, 0x2D, 0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,
0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D, 0xE0, 0xE7, 0xEE, 0xE9,
0xFC, 0xFB, 0xF2, 0xF5, 0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85, 0xA8, 0xAF, 0xA6, 0xA1,
0xB4, 0xB3, 0xBA, 0xBD, 0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,
0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA, 0xB7, 0xB0, 0xB9, 0xBE,
0xAB, 0xAC, 0xA5, 0xA2, 0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32, 0x1F, 0x18, 0x11, 0x16,
0x03, 0x04, 0x0D, 0x0A, 0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,
0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A, 0x89, 0x8E, 0x87, 0x80,
0x95, 0x92, 0x9B, 0x9C, 0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC, 0xC1, 0xC6, 0xCF, 0xC8,
0xDD, 0xDA, 0xD3, 0xD4, 0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,
0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44, 0x19, 0x1E, 0x17, 0x10,
0x05, 0x02, 0x0B, 0x0C, 0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B, 0x76, 0x71, 0x78, 0x7F,
0x6A, 0x6D, 0x64, 0x63, 0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,
0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13, 0xAE, 0xA9, 0xA0, 0xA7,
0xB2, 0xB5, 0xBC, 0xBB, 0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB, 0xE6, 0xE1, 0xE8, 0xEF,
0xFA, 0xFD, 0xF4, 0xF3
]
crc = 0
for byte in data:
crc = crc8_table[(crc ^ byte) & 0xff]
return crc & 0xff
def find_collision():
"""
寻找符合条件的密码碰撞。
"""
secret_pass = "Enj0yNSSCTF4th!"
secret_pass_bytes = secret_pass.encode('utf-8')
pass_len = len(secret_pass_bytes)
target_crc16 = compute_crc16(secret_pass_bytes)
target_crc8 = calculate_crc8(secret_pass_bytes)
print(f"原始密码: {secret_pass}")
print(f"目标 CRC16: {hex(target_crc16)}")
print(f"目标 CRC8: {hex(target_crc8)}")
print("-" * 30)
print("正在尝试寻找碰撞...")
charset = string.ascii_letters + string.digits + string.punctuation
attempts = 0
while True:
attempts += 1
user_input = ''.join(random.choice(charset) for _ in range(pass_len))
user_input_bytes = user_input.encode('utf-8')
if user_input == secret_pass:
continue
user_crc16 = compute_crc16(user_input_bytes)
user_crc8 = calculate_crc8(user_input_bytes)
if user_crc16 == target_crc16 and user_crc8 == target_crc8:
print(f"\n成功找到碰撞!")
print(f"尝试次数: {attempts}")
print(f"找到的密码: {user_input}")
print(f"它的 CRC16: {hex(user_crc16)}")
print(f"它的 CRC8: {hex(user_crc8)}")
break
if attempts % 1000000 == 0:
print(f"已尝试 {attempts} 次，当前尝试: {user_input}")
if __name__ == "__main__":
find_collision()
|
