1
from typing import List
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# IP置换表
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IP = [58, 50, 42, 34, 26, 18, 10, 2,
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      60, 52, 44, 36, 28, 20, 12, 4,
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      62, 54, 46, 38, 30, 22, 14, 6,
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      64, 56, 48, 40, 32, 24, 16, 8,
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      57, 49, 41, 33, 25, 17, 9, 1,
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      59, 51, 43, 35, 27, 19, 11, 3,
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      61, 53, 45, 37, 29, 21, 13, 5,
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      63, 55, 47, 39, 31, 23, 15, 7]
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# 逆IP置换表
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IP_INV = [40, 8, 48, 16, 56, 24, 64, 32,
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          39, 7, 47, 15, 55, 23, 63, 31,
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          38, 6, 46, 14, 54, 22, 62, 30,
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          37, 5, 45, 13, 53, 21, 61, 29,
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          36, 4, 44, 12, 52, 20, 60, 28,
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          35, 3, 43, 11, 51, 19, 59, 27,
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          34, 2, 42, 10, 50, 18, 58, 26,
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          33, 1, 41, 9, 49, 17, 57, 25]
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# 扩展置换E表
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E = [32, 1, 2, 3, 4, 5,
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     4, 5, 6, 7, 8, 9,
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     8, 9, 10, 11, 12, 13,
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     12, 13, 14, 15, 16, 17,
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     16, 17, 18, 19, 20, 21,
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     20, 21, 22, 23, 24, 25,
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     24, 25, 26, 27, 28, 29,
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     28, 29, 30, 31, 32, 1]
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# P盒置换表
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P = [16, 7, 20, 21, 29, 12, 28, 17,
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     1, 15, 23, 26, 5, 18, 31, 10,
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     2, 8, 24, 14, 32, 27, 3, 9,
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     19, 13, 30, 6, 22, 11, 4, 25]
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# PC-1置换表（密钥初始置换）
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PC1 = [57, 49, 41, 33, 25, 17, 9,
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       1, 58, 50, 42, 34, 26, 18,
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       10, 2, 59, 51, 43, 35, 27,
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       19, 11, 3, 60, 52, 44, 36,
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       63, 55, 47, 39, 31, 23, 15,
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       7, 62, 54, 46, 38, 30, 22,
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       14, 6, 61, 53, 45, 37, 29,
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       21, 13, 5, 28, 20, 12, 4]
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# PC-2置换表（子密钥生成）
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PC2 = [14, 17, 11, 24, 1, 5,
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       3, 28, 15, 6, 21, 10,
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       23, 19, 12, 4, 26, 8,
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       16, 7, 27, 20, 13, 2,
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       41, 52, 31, 37, 47, 55,
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       30, 40, 51, 45, 33, 48,
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       44, 49, 39, 56, 34, 53,
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       46, 42, 50, 36, 29, 32]
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# 左移位数表
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SHIFT_SCHEDULE = [1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1]
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# S盒定义（8个）
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S_BOX = [
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    # S1
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    [[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7],
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     [0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8],
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     [4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0],
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     [15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13]],
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    # S2
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    [[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10],
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     [3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5],
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     [0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15],
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     [13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9]],
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    # S3
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    [[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8],
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     [13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1],
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     [13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7],
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     [1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12]],
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    # S4
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    [[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15],
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     [13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9],
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     [10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4],
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     [3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14]],
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    # S5
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    [[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9],
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     [14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6],
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     [4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14],
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     [11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3]],
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    # S6
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    [[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11],
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     [10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8],
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     [9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6],
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     [4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13]],
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    # S7
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    [[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1],
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     [13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6],
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     [1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2],
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     [6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]],
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    # S8
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    [[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7],
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     [1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2],
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     [7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8],
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     [2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]]
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]
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def str_to_bits(text: str, size: int) -> List[int]:
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    """将字符串转换为位列表"""
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    bits = []
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    for i in range(size):
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        byte = i // 8
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        bit = 7 - (i % 8)
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        if byte < len(text):
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            bits.append((ord(text[byte]) >> bit) & 1)
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        else:
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            bits.append(0)
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    return bits
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def hex_to_bits(hex_str: str, size: int) -> List[int]:
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    """将十六进制字符串转换为位列表"""
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    bits = []
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    hex_str = hex_str.replace(" ", "").replace("0x", "").zfill(size//4)
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    for char in hex_str:
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        val = int(char, 16)
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        for i in range(3, -1, -1):
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            bits.append((val >> i) & 1)
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    return bits[:size]
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def bits_to_hex(bits: List[int]) -> str:
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    """将位列表转换为十六进制字符串"""
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    hex_str = ""
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    for i in range(0, len(bits), 8):
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        byte = 0
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        for j in range(8):
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            if i+j < len(bits):
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                byte = (byte << 1) | bits[i+j]
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        hex_str += f"{byte:02X}"
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    return hex_str.lower()
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def permute(bits: List[int], table: List[int]) -> List[int]:
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    """按置换表进行置换"""
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    return [bits[table[i]-1] for i in range(len(table))]
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def left_shift(bits: List[int], n: int) -> List[int]:
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    """循环左移"""
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    return bits[n:] + bits[:n]
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def generate_subkeys(key_bits: List[int]) -> List[List[int]]:
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    """生成16个子密钥"""
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    # PC-1置换
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    key_pc1 = permute(key_bits, PC1)
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    # 分成左右两部分
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    C = key_pc1[:28]
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    D = key_pc1[28:]
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    subkeys = []
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    for round_num in range(16):
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        # 循环左移
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        shift = SHIFT_SCHEDULE[round_num]
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        C = left_shift(C, shift)
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        D = left_shift(D, shift)
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        # PC-2置换生成子密钥
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        combined = C + D
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        subkey = permute(combined, PC2)
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        subkeys.append(subkey)
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    return subkeys
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def f_function(R: List[int], K: List[int]) -> List[int]:
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    """f函数"""
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    # 扩展置换E
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    R_expanded = permute(R, E)
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    # 与子密钥异或
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    xor_result = [R_expanded[i] ^ K[i] for i in range(48)]
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    # S盒替换
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    sbox_output = []
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    for i in range(8):
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        # 取6位
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        block = xor_result[i*6:(i+1)*6]
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        row = (block[0] << 1) | block[5]
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        col = (block[1] << 3) | (block[2] << 2) | (block[3] << 1) | block[4]
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        val = S_BOX[i][row][col]
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        # 转换为4位
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        sbox_output.extend([(val >> 3) & 1, (val >> 2) & 1, (val >> 1) & 1, val & 1])
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    # P盒置换
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    return permute(sbox_output, P)
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def des_encrypt(plaintext_bits: List[int], key_bits: List[int]) -> List[int]:
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    """DES加密"""
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    # 初始置换IP
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    bits = permute(plaintext_bits, IP)
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    # 生成子密钥
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    subkeys = generate_subkeys(key_bits)
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    # 分成左右两部分
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    L = bits[:32]
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    R = bits[32:]
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    # 16轮迭代
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    for i in range(16):
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        L_next = R[:]
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        f_result = f_function(R, subkeys[i])
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        R_next = [L[j] ^ f_result[j] for j in range(32)]
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        L, R = L_next, R_next
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    # 最后交换（算法中先交换再末置换）
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    combined = R + L
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    # 末置换IP^-1
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    ciphertext = permute(combined, IP_INV)
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    return ciphertext
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# 测试
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if __name__ == "__main__":
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    plaintext_hex = "0123456789ABCDEF"
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    key_hex = "133457799BBCDFF1"
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    # 转换为位列表
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    plaintext_bits = hex_to_bits(plaintext_hex, 64)
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    key_bits = hex_to_bits(key_hex, 64)
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    print(f"明文: {plaintext_hex}")
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    print(f"密钥: {key_hex}")
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    # 加密
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    ciphertext_bits = des_encrypt(plaintext_bits, key_bits)
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    ciphertext_hex = bits_to_hex(ciphertext_bits)
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    print(f"密文: {ciphertext_hex}")