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