# S盒
SboxTable = \
[
0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7, 0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05,
0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3, 0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99,
0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62,
0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95, 0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6,
0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba, 0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8,
0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b, 0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35,
0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2, 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87,
0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52, 0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e,
0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5, 0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1,
0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55, 0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3,
0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60, 0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f,
0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f, 0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,
0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f, 0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8,
0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd, 0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0,
0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e, 0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,
0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20, 0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48,
]
# 常数FK
FK = [0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc] ; ENCRYPT = 0 ;DECRYPT = 1
# 固定参数CK
CK = \
[
0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
]
def padding(data): #填充
print ("plaintext:\t", bytes (data))
file_data_list = list(data)
lenth = len (file_data_list)
#print ("data lenth:", lenth)
remainder = lenth % 16
if remainder != 0:
i=16-remainder #i为需要填充的位数
#print ("padding numbers = ", i)
for j in range(i):
file_data_list.append(i) #填充 char 0-(i-1)
if remainder == 0:
for k in range(16):
file_data_list.append (0x08) #刚好的话 填充0x08
print("after PKCS5 padding:",file_data_list)
return file_data_list
def list_4_8_to_int32(key_data): # 列表4个8位，组成32位
return int ((key_data[0] << 24) | (key_data[1] << 16) | (key_data[2] << 8) | (key_data[3]))
def n32_to_list4_8(n): #把n分别取32位的每8位放入列表
return [int ((n >> 24) & 0xff), int ((n >> 16) & 0xff), int ((n >> 8) & 0xff), int ((n) & 0xff)]
#循环左移
def shift_left_n(x, n):
return int (int (x << n) & 0xffffffff)
def shift_logical_left(x, n):
return shift_left_n (x, n) | int ((x >> (32 - n)) & 0xffffffff) #两步合在一起实现了循环左移n位
def XOR(a, b):
return list (map (lambda x, y: x ^ y, a, b))
#s盒查找
def sbox(idx):
return SboxTable[idx]
def extended_key_LB(ka): #拓展密钥算法LB
a = n32_to_list4_8 (ka) #a是ka的每8位组成的列表
b = [sbox (i) for i in a] #在s盒中每8位查找后，放入列表b，再组合成int bb
bb = list_4_8_to_int32 (b)
rk = bb ^ (shift_logical_left (bb, 13)) ^ (shift_logical_left (bb, 23))
return rk
def linear_transform_L(ka): #线性变换L
a = n32_to_list4_8 (ka)
b = [sbox (i) for i in a]
bb = list_4_8_to_int32 (b) #bb是经过s盒变换的32位数
return bb ^ (shift_logical_left (bb, 2)) ^ (shift_logical_left (bb, 10)) ^ (shift_logical_left (bb, 18)) ^ (shift_logical_left (bb, 24)) #书上公式
def sm4_round_function(x0, x1, x2, x3, rk): #轮函数
return (x0 ^ linear_transform_L (x1 ^ x2 ^ x3 ^ rk))
class Sm4 (object):
def __init__(self):
self.sk = [0] * 32
self.mode = ENCRYPT
def sm4_set_key(self, key_data, mode): #先算出拓展密钥
self.extended_key_last (key_data, mode)
def extended_key_last(self, key, mode): #密钥扩展算法
MK = [0, 0, 0, 0]
k = [0] * 36
MK[0] = list_4_8_to_int32 (key[0:4])
MK[1] = list_4_8_to_int32 (key[4:8])
MK[2] = list_4_8_to_int32 (key[8:12])
MK[3] = list_4_8_to_int32 (key[12:16])
k[0:4] = XOR (MK, FK)
for i in range (32):
k[i + 4] = k[i] ^ (extended_key_LB (k[i + 1] ^ k[i + 2] ^ k[i + 3] ^ CK[i]))
self.sk = k[4:] #生成的32轮子密钥放到sk中
self.mode = mode
if mode == DECRYPT: #解密时rki逆序
self.sk.reverse ()
def sm4_one_round(self, sk, in_put): #一轮算法 ，4个32位的字=128bit=16个字节（8*16）
item = [list_4_8_to_int32 (in_put[0:4]), list_4_8_to_int32 (in_put[4:8]), list_4_8_to_int32 (in_put[8:12]),
list_4_8_to_int32 (in_put[12:16])] #4字节一个字，把每4个字节变成32位的int
x=item
for i in range (32):
temp=x[3]
x[3] = sm4_round_function (x[0], x[1], x[2], x[3], sk[i]) #x[3]成为x[4]
x[0]=x[1]
x[1]=x[2]
x[2]=temp
print("%dround----->"%(i+1),"key:%-12d\n"%sk[i],"result：",x)
res=x
# res = reduce (lambda x, y: [x[1], x[2], x[3], sm4_round_function (x[0], x[1], x[2], x[3], y)],sk, item) #32轮循环加密
res.reverse ()
rev = map (n32_to_list4_8, res)
out_put = []
[out_put.extend (_) for _ in rev]
return out_put
def encrypt(self, input_data):
# 块加密
output_data = []
tmp = [input_data[i:i + 16] for i in range (0, len (input_data), 16)] #输入数据分块
[output_data.extend (each) for each in map (lambda x: self.sm4_one_round (self.sk, x), tmp)]
return output_data
def encrypt(mode, key, data):
sm4_d = Sm4 ()
sm4_d.sm4_set_key (key, mode)
en_data = sm4_d.encrypt (data)
return en_data
def sm4_crypt_cbc(mode, key, iv, data):
sm4_d = Sm4 ()
sm4_d.sm4_set_key (key, mode)
en_data = sm4_d.sm4_crypt_cbc (iv, data)
return en_data
if __name__ == "__main__":
data=input("plaintext:")
data=bytes(data,'ascii')
key_data=[]
print("16 bytes key:")
key_data=input().split()
for i in range(16):
key_data[i]=int(key_data[i])
print(key_data)
sm4_d = Sm4 () #创建一个Sm4对象
sm4_d.sm4_set_key (key_data, ENCRYPT) #加密模式
padding_data = padding (data) #明文填充
en_data = sm4_d.encrypt (padding_data) #加密
print("ciphertext:\t",en_data)
sm4_d.sm4_set_key (key_data, DECRYPT) #解密模式
print("\ndecode:")
de_data = sm4_d.encrypt (en_data) #解密
# print(file_data)
print("plaintext：",de_data)
i = de_data[-1]
for j in range (i):
de_data.pop ()
print ("after decode：", bytes (de_data))
