168 lines
6.5 KiB
Python
168 lines
6.5 KiB
Python
#-*-coding:utf-8-*-
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import copy
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from .func import xor, rotl, get_uint32_be, put_uint32_be, \
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bytes_to_list, list_to_bytes, padding, unpadding
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#Expanded SM4 box table
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SM4_BOXES_TABLE = [
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0xd6,0x90,0xe9,0xfe,0xcc,0xe1,0x3d,0xb7,0x16,0xb6,0x14,0xc2,0x28,0xfb,0x2c,
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0x05,0x2b,0x67,0x9a,0x76,0x2a,0xbe,0x04,0xc3,0xaa,0x44,0x13,0x26,0x49,0x86,
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0x06,0x99,0x9c,0x42,0x50,0xf4,0x91,0xef,0x98,0x7a,0x33,0x54,0x0b,0x43,0xed,
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0xcf,0xac,0x62,0xe4,0xb3,0x1c,0xa9,0xc9,0x08,0xe8,0x95,0x80,0xdf,0x94,0xfa,
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0x75,0x8f,0x3f,0xa6,0x47,0x07,0xa7,0xfc,0xf3,0x73,0x17,0xba,0x83,0x59,0x3c,
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0x19,0xe6,0x85,0x4f,0xa8,0x68,0x6b,0x81,0xb2,0x71,0x64,0xda,0x8b,0xf8,0xeb,
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0x0f,0x4b,0x70,0x56,0x9d,0x35,0x1e,0x24,0x0e,0x5e,0x63,0x58,0xd1,0xa2,0x25,
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0x22,0x7c,0x3b,0x01,0x21,0x78,0x87,0xd4,0x00,0x46,0x57,0x9f,0xd3,0x27,0x52,
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0x4c,0x36,0x02,0xe7,0xa0,0xc4,0xc8,0x9e,0xea,0xbf,0x8a,0xd2,0x40,0xc7,0x38,
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0xb5,0xa3,0xf7,0xf2,0xce,0xf9,0x61,0x15,0xa1,0xe0,0xae,0x5d,0xa4,0x9b,0x34,
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0x1a,0x55,0xad,0x93,0x32,0x30,0xf5,0x8c,0xb1,0xe3,0x1d,0xf6,0xe2,0x2e,0x82,
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0x66,0xca,0x60,0xc0,0x29,0x23,0xab,0x0d,0x53,0x4e,0x6f,0xd5,0xdb,0x37,0x45,
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0xde,0xfd,0x8e,0x2f,0x03,0xff,0x6a,0x72,0x6d,0x6c,0x5b,0x51,0x8d,0x1b,0xaf,
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0x92,0xbb,0xdd,0xbc,0x7f,0x11,0xd9,0x5c,0x41,0x1f,0x10,0x5a,0xd8,0x0a,0xc1,
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0x31,0x88,0xa5,0xcd,0x7b,0xbd,0x2d,0x74,0xd0,0x12,0xb8,0xe5,0xb4,0xb0,0x89,
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0x69,0x97,0x4a,0x0c,0x96,0x77,0x7e,0x65,0xb9,0xf1,0x09,0xc5,0x6e,0xc6,0x84,
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0x18,0xf0,0x7d,0xec,0x3a,0xdc,0x4d,0x20,0x79,0xee,0x5f,0x3e,0xd7,0xcb,0x39,
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0x48,
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]
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# System parameter
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SM4_FK = [0xa3b1bac6,0x56aa3350,0x677d9197,0xb27022dc]
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# fixed parameter
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SM4_CK = [
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0x00070e15,0x1c232a31,0x383f464d,0x545b6269,
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0x70777e85,0x8c939aa1,0xa8afb6bd,0xc4cbd2d9,
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0xe0e7eef5,0xfc030a11,0x181f262d,0x343b4249,
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0x50575e65,0x6c737a81,0x888f969d,0xa4abb2b9,
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0xc0c7ced5,0xdce3eaf1,0xf8ff060d,0x141b2229,
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0x30373e45,0x4c535a61,0x686f767d,0x848b9299,
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0xa0a7aeb5,0xbcc3cad1,0xd8dfe6ed,0xf4fb0209,
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0x10171e25,0x2c333a41,0x484f565d,0x646b7279
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]
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SM4_ENCRYPT = 0
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SM4_DECRYPT = 1
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class CryptSM4(object):
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def __init__(self, mode=SM4_ENCRYPT):
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self.sk = [0]*32
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self.mode = mode
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# Calculating round encryption key.
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# args: [in] a: a is a 32 bits unsigned value;
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# return: sk[i]: i{0,1,2,3,...31}.
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@classmethod
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def _round_key(cls, ka):
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b = [0, 0, 0, 0]
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a = put_uint32_be(ka)
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b[0] = SM4_BOXES_TABLE[a[0]]
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b[1] = SM4_BOXES_TABLE[a[1]]
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b[2] = SM4_BOXES_TABLE[a[2]]
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b[3] = SM4_BOXES_TABLE[a[3]]
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bb = get_uint32_be(b[0:4])
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rk = bb ^ (rotl(bb, 13)) ^ (rotl(bb, 23))
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return rk
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# Calculating and getting encryption/decryption contents.
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# args: [in] x0: original contents;
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# args: [in] x1: original contents;
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# args: [in] x2: original contents;
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# args: [in] x3: original contents;
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# args: [in] rk: encryption/decryption key;
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# return the contents of encryption/decryption contents.
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@classmethod
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def _f(cls, x0, x1, x2, x3, rk):
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# "T algorithm" == "L algorithm" + "t algorithm".
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# args: [in] a: a is a 32 bits unsigned value;
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# return: c: c is calculated with line algorithm "L" and nonline algorithm "t"
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def _sm4_l_t(ka):
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b = [0, 0, 0, 0]
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a = put_uint32_be(ka)
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b[0] = SM4_BOXES_TABLE[a[0]]
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b[1] = SM4_BOXES_TABLE[a[1]]
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b[2] = SM4_BOXES_TABLE[a[2]]
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b[3] = SM4_BOXES_TABLE[a[3]]
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bb = get_uint32_be(b[0:4])
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c = bb ^ (rotl(bb, 2)) ^ (rotl(bb, 10)) ^ (rotl(bb, 18)) ^ (rotl(bb, 24))
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return c
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return (x0 ^ _sm4_l_t(x1 ^ x2 ^ x3 ^ rk))
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def set_key(self, key, mode):
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key = bytes_to_list(key)
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MK = [0, 0, 0, 0]
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k = [0]*36
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MK[0] = get_uint32_be(key[0:4])
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MK[1] = get_uint32_be(key[4:8])
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MK[2] = get_uint32_be(key[8:12])
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MK[3] = get_uint32_be(key[12:16])
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k[0:4] = xor(MK[0:4], SM4_FK[0:4])
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for i in range(32):
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k[i + 4] = k[i] ^ (
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self._round_key(k[i + 1] ^ k[i + 2] ^ k[i + 3] ^ SM4_CK[i]))
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self.sk[i] = k[i + 4]
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self.mode = mode
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if mode == SM4_DECRYPT:
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for idx in range(16):
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t = self.sk[idx]
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self.sk[idx] = self.sk[31 - idx]
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self.sk[31 - idx] = t
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def one_round(self, sk, in_put):
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out_put = []
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ulbuf = [0]*36
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ulbuf[0] = get_uint32_be(in_put[0:4])
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ulbuf[1] = get_uint32_be(in_put[4:8])
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ulbuf[2] = get_uint32_be(in_put[8:12])
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ulbuf[3] = get_uint32_be(in_put[12:16])
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for idx in range(32):
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ulbuf[idx + 4] = self._f(ulbuf[idx], ulbuf[idx + 1], ulbuf[idx + 2], ulbuf[idx + 3], sk[idx])
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out_put += put_uint32_be(ulbuf[35])
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out_put += put_uint32_be(ulbuf[34])
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out_put += put_uint32_be(ulbuf[33])
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out_put += put_uint32_be(ulbuf[32])
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return out_put
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def crypt_ecb(self, input_data):
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# SM4-ECB block encryption/decryption
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input_data = bytes_to_list(input_data)
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if self.mode == SM4_ENCRYPT:
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input_data = padding(input_data)
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length = len(input_data)
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i = 0
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output_data = []
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while length > 0:
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output_data += self.one_round(self.sk, input_data[i:i+16])
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i += 16
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length -= 16
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if self.mode == SM4_DECRYPT:
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return list_to_bytes(unpadding(output_data))
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return list_to_bytes(output_data)
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def crypt_cbc(self, iv, input_data):
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#SM4-CBC buffer encryption/decryption
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i = 0
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output_data = []
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tmp_input = [0]*16
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iv = bytes_to_list(iv)
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if self.mode == SM4_ENCRYPT:
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input_data = padding(bytes_to_list(input_data))
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length = len(input_data)
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while length > 0:
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tmp_input[0:16] = xor(input_data[i:i+16], iv[0:16])
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output_data += self.one_round(self.sk, tmp_input[0:16])
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iv = copy.deepcopy(output_data[i:i+16])
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i += 16
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length -= 16
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return list_to_bytes(output_data)
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else:
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length = len(input_data)
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while length > 0:
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output_data += self.one_round(self.sk, input_data[i:i+16])
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output_data[i:i+16] = xor(output_data[i:i+16], iv[0:16])
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iv = copy.deepcopy(input_data[i:i + 16])
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i += 16
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length -= 16
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return list_to_bytes(unpadding(output_data))
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