#-*-coding:utf-8-*- import copy from .func import xor, rotl, get_uint32_be, put_uint32_be, \ bytes_to_list, list_to_bytes, padding, unpadding #Expanded SM4 box table SM4_BOXES_TABLE = [ 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, ] # System parameter SM4_FK = [0xa3b1bac6,0x56aa3350,0x677d9197,0xb27022dc] # fixed parameter SM4_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 ] SM4_ENCRYPT = 0 SM4_DECRYPT = 1 class CryptSM4(object): def __init__(self, mode=SM4_ENCRYPT): self.sk = [0]*32 self.mode = mode # Calculating round encryption key. # args: [in] a: a is a 32 bits unsigned value; # return: sk[i]: i{0,1,2,3,...31}. @classmethod def _round_key(cls, ka): b = [0, 0, 0, 0] a = put_uint32_be(ka) b[0] = SM4_BOXES_TABLE[a[0]] b[1] = SM4_BOXES_TABLE[a[1]] b[2] = SM4_BOXES_TABLE[a[2]] b[3] = SM4_BOXES_TABLE[a[3]] bb = get_uint32_be(b[0:4]) rk = bb ^ (rotl(bb, 13)) ^ (rotl(bb, 23)) return rk # Calculating and getting encryption/decryption contents. # args: [in] x0: original contents; # args: [in] x1: original contents; # args: [in] x2: original contents; # args: [in] x3: original contents; # args: [in] rk: encryption/decryption key; # return the contents of encryption/decryption contents. @classmethod def _f(cls, x0, x1, x2, x3, rk): # "T algorithm" == "L algorithm" + "t algorithm". # args: [in] a: a is a 32 bits unsigned value; # return: c: c is calculated with line algorithm "L" and nonline algorithm "t" def _sm4_l_t(ka): b = [0, 0, 0, 0] a = put_uint32_be(ka) b[0] = SM4_BOXES_TABLE[a[0]] b[1] = SM4_BOXES_TABLE[a[1]] b[2] = SM4_BOXES_TABLE[a[2]] b[3] = SM4_BOXES_TABLE[a[3]] bb = get_uint32_be(b[0:4]) c = bb ^ (rotl(bb, 2)) ^ (rotl(bb, 10)) ^ (rotl(bb, 18)) ^ (rotl(bb, 24)) return c return (x0 ^ _sm4_l_t(x1 ^ x2 ^ x3 ^ rk)) def set_key(self, key, mode): key = bytes_to_list(key) MK = [0, 0, 0, 0] k = [0]*36 MK[0] = get_uint32_be(key[0:4]) MK[1] = get_uint32_be(key[4:8]) MK[2] = get_uint32_be(key[8:12]) MK[3] = get_uint32_be(key[12:16]) k[0:4] = xor(MK[0:4], SM4_FK[0:4]) for i in range(32): k[i + 4] = k[i] ^ ( self._round_key(k[i + 1] ^ k[i + 2] ^ k[i + 3] ^ SM4_CK[i])) self.sk[i] = k[i + 4] self.mode = mode if mode == SM4_DECRYPT: for idx in range(16): t = self.sk[idx] self.sk[idx] = self.sk[31 - idx] self.sk[31 - idx] = t def one_round(self, sk, in_put): out_put = [] ulbuf = [0]*36 ulbuf[0] = get_uint32_be(in_put[0:4]) ulbuf[1] = get_uint32_be(in_put[4:8]) ulbuf[2] = get_uint32_be(in_put[8:12]) ulbuf[3] = get_uint32_be(in_put[12:16]) for idx in range(32): ulbuf[idx + 4] = self._f(ulbuf[idx], ulbuf[idx + 1], ulbuf[idx + 2], ulbuf[idx + 3], sk[idx]) out_put += put_uint32_be(ulbuf[35]) out_put += put_uint32_be(ulbuf[34]) out_put += put_uint32_be(ulbuf[33]) out_put += put_uint32_be(ulbuf[32]) return out_put def crypt_ecb(self, input_data): # SM4-ECB block encryption/decryption input_data = bytes_to_list(input_data) if self.mode == SM4_ENCRYPT: input_data = padding(input_data) length = len(input_data) i = 0 output_data = [] while length > 0: output_data += self.one_round(self.sk, input_data[i:i+16]) i += 16 length -= 16 if self.mode == SM4_DECRYPT: return list_to_bytes(unpadding(output_data)) return list_to_bytes(output_data) def crypt_cbc(self, iv, input_data): #SM4-CBC buffer encryption/decryption i = 0 output_data = [] tmp_input = [0]*16 iv = bytes_to_list(iv) if self.mode == SM4_ENCRYPT: input_data = padding(bytes_to_list(input_data)) length = len(input_data) while length > 0: tmp_input[0:16] = xor(input_data[i:i+16], iv[0:16]) output_data += self.one_round(self.sk, tmp_input[0:16]) iv = copy.deepcopy(output_data[i:i+16]) i += 16 length -= 16 return list_to_bytes(output_data) else: length = len(input_data) while length > 0: output_data += self.one_round(self.sk, input_data[i:i+16]) output_data[i:i+16] = xor(output_data[i:i+16], iv[0:16]) iv = copy.deepcopy(input_data[i:i + 16]) i += 16 length -= 16 return list_to_bytes(unpadding(output_data))