AES加密
关于AES
AES属于分组加密算法，明文长度固定为128位，密钥长度可以为128、192、256位。
本文以明文长度128位，密钥长度128位的AES进行实现。
AES加密解密python实现
# S-Box的预定义值，用于替代输入字节。256
s_box = (
0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16,
)
# 轮常数
rcon = (0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36)
# 轮常数
round_constants = (
0x02, 0x00, 0x00, 0x00,
0x04, 0x00, 0x00, 0x00,
0x08, 0x00, 0x00, 0x00,
0x10, 0x00, 0x00, 0x00,
0x20, 0x00, 0x00, 0x00,
0x40, 0x00, 0x00, 0x00,
0x80, 0x00, 0x00, 0x00,
0x1B, 0x00, 0x00, 0x00,
0x36, 0x00, 0x00, 0x00,
)
# 列混淆矩阵
mix_matrix = [
[0x02, 0x03, 0x01, 0x01],
[0x01, 0x02, 0x03, 0x01],
[0x01, 0x01, 0x02, 0x03],
[0x03, 0x01, 0x01, 0x02]
]
# 逆列混淆矩阵
inv_mix_matrix = [
[0x0E, 0x0B, 0x0D, 0x09],
[0x09, 0x0E, 0x0B, 0x0D],
[0x0D, 0x09, 0x0E, 0x0B],
[0x0B, 0x0D, 0x09, 0x0E]
]
# 逆字节替代盒
inv_s_box = [
0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D
]
# ////////////////////////////////////////////////数据处理
def string_to_hex_array(input_string):
hex_array = []
# 将输入字符串转换为十六进制
hex_string = ''.join([format(ord(char), '02X') for char in input_string])
# 在不足十六的倍数时补0
if len(hex_string) % 32 != 0:
hex_string += '0' * (32 - len(hex_string) % 32)
# 将十六进制字符串分割成十六个字符一组
for i in range(0, len(hex_string), 32):
hex_group = hex_string[i:i + 32]
hex_values = [int(hex_group[i:i+2], 16) for i in range(0, len(hex_group), 2)]
hex_array.append(hex_values)
return hex_array
def hex_array_to_string(hex_array):
hex_string = ""
for hex_values in hex_array:
hex_group = ''.join([format(hex_value, '02X') for hex_value in hex_values])
hex_string += hex_group
# 去掉末尾的零填充
hex_string = hex_string.rstrip('0')
# 将十六进制字符串转换为原始字符串
output_string = bytes.fromhex(hex_string).decode('utf-8')
return output_string
# ////////////////////////////////////////////////加密函数
# 轮密钥加法：将轮密钥与状态矩阵相加。
def add_round_key(state, round_key):
return [[state[i][j] ^ round_key[i * 4 + j] for j in range(4)] for i in range(4)]
# 字节替代：将S-Box替代表应用于状态矩阵的每个字节。
def sub_bytes(state):
return [[s_box[state[i][j]] for j in range(4)] for i in range(4)]
# 行位移：对状态矩阵的行进行位移操作。 （按列操作，第0列不移动，第一列向前移动1位，依此类推）
def shift_rows(s):
return [[s[0][0], s[1][1], s[2][2], s[3][3]],
[s[1][0], s[2][1], s[3][2], s[0][3]],
[s[2][0], s[3][1], s[0][2], s[1][3]],
[s[3][0], s[0][1], s[1][2], s[2][3]]]
# 有限域上的乘法（GF(2^8)）256
def galois_multiply(a, b):
result = 0
while b:
if b & 1:
result ^= a
a <<= 1
if a & 0x100:
a ^= 0x11B # GF(2^8)多项式加法
b >>= 1
return result
# 列混淆：对状态矩阵的列进行混淆操作。（易错）
def mix_columns(state):
new_state = [0] * 16
for row in range(4):
for col in range(4): # 矩阵mix_matrix的一行乘以state的每一列
result = 0
for Round in range(4):
result ^= galois_multiply(mix_matrix[row][Round], state[col][Round]) # 矩阵相乘加号变异或，GF(2^8)有限域乘
new_state[row + col*4] = result
new_state = [[new_state[i * 4 + j] for j in range(4)] for i in range(4)]
return new_state
# 密钥扩展：生成轮密钥。
'''
初始密钥是一个4个字（16字节的序列，128比特）。输入密钥直接被复制到扩展密钥的前四个字中，得到w[1]，w[2]，w[3]，w[4]；
然后每次用4个字填充扩展余下的部分，AES128总共需要44个字(44*4=176位)。在扩展密钥数组中，w[i]的值依赖于w[i-1]和w[i-4](i>=4)。
对w数组中下标不为4的倍数的元素，只是简单地异或，其逻辑关系为：
w[i]=w[i-1] ⊕ w[i-4] （i不为4的倍数）
对w数组下标为4的倍数的元素，采用如下计算方法：
（1）将输入的4个字节循环左移一个字节。
（2）基于S盒对输入字中的每个字节进行S代替。
（3）将步骤2的结果再和轮常量Rcon[i//4]相异或。
（4）将步骤3的结果与w[i-4]异或。
'''
def key_expansion(key):
word_size = 4 # AES-128每个字的字节数
nk = 4 # AES-128密钥中的字数
nr = 10 # AES-128的轮数
expanded_key_size = (nr + 1) * 4 * word_size # 扩展密钥的总大小
expanded_key = [0] * expanded_key_size
# 复制原始密钥到扩展密钥的开头
for i in range(nk):
expanded_key[i * 4:i * 4 + 4] = key[i * 4:i * 4 + 4]
for i in range(nk, (nr + 1) * 4):
temp = list(expanded_key[(i - 1) * 4:i * 4])
if i % nk == 0: # 是4的倍数，比非倍数多几步运算
# 执行密钥调度核心操作（循环、替代和Rcon）
temp = temp[1:] + temp[:1] # 字循环，左移一个字节
for j in range(4):
temp[j] = s_box[temp[j]] # 查S盒，字节代换
temp[0] ^= rcon[i // nk - 1] # 轮常量异或，给定的表格，一共有10个
for j in range(4):
expanded_key[i * 4 + j] = expanded_key[(i - nk) * 4 + j] ^ temp[j]
expanded_key = [expanded_key[i:i+16] for i in range(0, len(expanded_key), 16)]
return expanded_key
# 主AES加密函数
def aes_encrypt(plaintext, key):
# 划分成4乘4的小块
state = [[plaintext[i * 4 + j] for j in range(4)] for i in range(4)]
round_keys = key_expansion(key) # 包含原始密钥，0为原始密钥
# 初始变换
state = add_round_key(state, round_keys[0])
# 9次循环
for round in range(1, 10):
# 字节替代：将S-Box替代表应用于状态矩阵的每个字节。
state = sub_bytes(state)
# 行位移：对状态矩阵的行进行位移操作。
state = shift_rows(state)
# 列混淆：对状态矩阵的列进行混淆操作。
state = mix_columns(state) # 错误
# 轮密钥加法：将轮密钥与状态矩阵相加。
state = add_round_key(state, round_keys[round])
# 最终循环，没有列混合
state = sub_bytes(state)
state = shift_rows(state)
state = add_round_key(state, round_keys[10])
cipher_text = [state[j][i] for j in range(4) for i in range(4)] # i和j写反了 （需要转置）
return cipher_text
# //////////////////////////////////////////////解密函数
# 逆列混淆：对状态矩阵的列进行逆混淆操作。
def inv_mix_columns(state):
new_state = [0] * 16
for col in range(4):
for row in range(4):
result = 0
for i in range(4):
result ^= galois_multiply(inv_mix_matrix[row][i], state[col][i])
new_state[col + row * 4] = result
new_state = [[new_state[i + j * 4] for j in range(4)] for i in range(4)] # 按列放置（将new_state转置）
return new_state
# 逆字节替代：将逆S-Box替代表应用于状态矩阵的每个字节。
def inv_sub_bytes(state):
return [[inv_s_box[state[i][j]] for j in range(4)] for i in range(4)]
# 逆行位移：对状态矩阵的行进行逆位移操作。（按列操作，第0列不移动，第一列向后移动1位，依此类推）
def inv_shift_rows(s):
return [[s[0][0], s[3][1], s[2][2], s[1][3]],
[s[1][0], s[0][1], s[3][2], s[2][3]],
[s[2][0], s[1][1], s[0][2], s[3][3]],
[s[3][0], s[2][1], s[1][2], s[0][3]]]
# 逆AES解密函数
def aes_decrypt(cipher_text, key):
state = [[cipher_text[i * 4 + j] for j in range(4)] for i in range(4)]
round_keys = key_expansion(key)
state = add_round_key(state, round_keys[10])
for round in range(9, 0, -1):
state = inv_shift_rows(state)
state = inv_sub_bytes(state)
state = add_round_key(state, round_keys[round])
state = inv_mix_columns(state)
state = inv_shift_rows(state)
state = inv_sub_bytes(state)
state = add_round_key(state, round_keys[0])
plain_text = [state[j][i] for j in range(4) for i in range(4)]
return plain_text
# ////////////////////////////////////////////////////开始运行
# text = input("请输入要加密的字符: ")
input_str = "Hello, World!fdgfjhvbbbnvgfkuy***"
key_string = "rdghubcxdoknghjt"
# 调用函数进行转换
hex_data = string_to_hex_array(input_str)
key_string = string_to_hex_array(key_string)
key = key_string[0] # 取前十六个字符（十六位密钥）
print("明文十六进制:")
for k in range(len(hex_data)):
for i in range(4):
for j in range(4):
print(format(hex_data[k][i * 4 + j], '02x'), end=" ")
cipher_texts = []
for i in range(len(hex_data)):
cipher_text = aes_encrypt(hex_data[i], key) # 加密
cipher_texts.append(cipher_text)
print("\n密文十六进制:")
for k in range(len(cipher_texts)):
for i in range(4):
for j in range(4):
print(format(cipher_texts[k][i * 4 + j], '02x'), end=" ")
decrypted_texts = []
for i in range(len(hex_data)):
decrypted_text = aes_decrypt(cipher_texts[i], key) # 解密
decrypted_texts.append(decrypted_text)
print("\n解密后的明文十六进制:")
for k in range(len(decrypted_texts)):
for i in range(4):
for j in range(4):
print(format(decrypted_texts[k][i * 4 + j], '02x'), end=" ")
print("\n")
de_text = hex_array_to_string(decrypted_texts)
print("解密明文：")
print(de_text)
图片来源于网络
