Python 脚本之对文件进行哈希校验

需求为对文件进行加密，保留哈希，防止别人篡改文件，代码如下：

import time,re,os

from watchdog.events import *
from watchdog.observers import Observer

def rotation_left(x, num):
    # 循环左移
    num %= 32
    left = (x << num) % (2 ** 32)
    right = (x >> (32 - num)) % (2 ** 32)
    result = left ^ right
    return result

def Int2Bin(x, k):
    x = str(bin(x)[2:])
    result = "0" * (k - len(x)) + x
    return result

class SM3:

    def __init__(self):
        # 常量初始化
        self.IV = [0x7380166F, 0x4914B2B9, 0x172442D7, 0xDA8A0600, 0xA96F30BC, 0x163138AA, 0xE38DEE4D, 0xB0FB0E4E]
        self.T = [0x79cc4519, 0x7a879d8a]
        self.maxu32 = 2 ** 32
        self.w1 = [0] * 68
        self.w2 = [0] * 64

    def ff(self, x, y, z, j):
        # 布尔函数FF
        result = 0
        if j < 16:
            result = x ^ y ^ z
        elif j >= 16:
            result = (x & y) | (x & z) | (y & z)
        return result

    def gg(self, x, y, z, j):
        # 布尔函数GG
        result = 0
        if j < 16:
            result = x ^ y ^ z
        elif j >= 16:
            result = (x & y) | (~x & z)
        return result

    def p(self, x, mode):
        result = 0
        # 置换函数P
        # 输入参数X的长度为32bit(=1个字)
        # 输入参数mode共两种取值：0和1
        if mode == 0:
            result = x ^ rotation_left(x, 9) ^ rotation_left(x, 17)
        elif mode == 1:
            result = x ^ rotation_left(x, 15) ^ rotation_left(x, 23)
        return result

    def sm3_fill(self, msg):
        # 填充消息，使其长度为512bit的整数倍
        # 输入参数msg为bytearray类型
        # 中间参数msg_new_bin为二进制string类型
        # 输出参数msg_new_bytes为bytearray类型
        length = len(msg)  # msg的长度（单位：byte）
        l = length * 8  # msg的长度（单位：bit）

        num = length // 64
        remain_byte = length % 64
        msg_remain_bin = ""
        msg_new_bytes = bytearray((num + 1) * 64)  ##填充后的消息长度，单位：byte

        # 将原数据存储至msg_new_bytes中
        for i in range(length):
            msg_new_bytes[i] = msg[i]

        # remain部分以二进制字符串形式存储
        remain_bit = remain_byte * 8  # 单位：bit
        for i in range(remain_byte):
            msg_remain_bin += "{:08b}".format(msg[num * 64 + i])

        k = (448 - l - 1) % 512
        while k < 0:
            # k为满足 l + k + 1 = 448 % 512 的最小非负整数
            k += 512

        msg_remain_bin += "1" + "0" * k + Int2Bin(l, 64)

        for i in range(0, 64 - remain_byte):
            str = msg_remain_bin[i * 8 + remain_bit: (i + 1) * 8 + remain_bit]
            temp = length + i
            msg_new_bytes[temp] = int(str, 2)  # 将2进制字符串按byte为组转换为整数
        return msg_new_bytes

    def sm3_msg_extend(self, msg):
        # 扩展函数: 将512bit的数据msg扩展为132个字（w1共68个字，w2共64个字）
        # 输入参数msg为bytearray类型,长度为512bit=64byte
        for i in range(0, 16):
            self.w1[i] = int.from_bytes(msg[i * 4:(i + 1) * 4], byteorder="big")

        for i in range(16, 68):
            self.w1[i] = self.p(self.w1[i - 16] ^ self.w1[i - 9] ^ rotation_left(self.w1[i - 3], 15),
                                1) ^ rotation_left(self.w1[i - 13], 7) ^ self.w1[i - 6]

        for i in range(64):
            self.w2[i] = self.w1[i] ^ self.w1[i + 4]

        # 测试扩展数据w1和w2
        # print("w1:")
        # for i in range(0, len(self.w1), 8):
        #     print(hex(self.w1[i]))
        # print("w2:")
        # for i in range(0, len(self.w2), 8):
        #     print(hex(self.w2[i]))

    def sm3_compress(self, msg):
        # 压缩函数
        # 输入参数v为初始化参数，类型为bytes/bytearray，大小为256bit
        # 输入参数msg为512bit的待压缩数据

        self.sm3_msg_extend(msg)
        ss1 = 0

        A = self.IV[0]
        B = self.IV[1]
        C = self.IV[2]
        D = self.IV[3]
        E = self.IV[4]
        F = self.IV[5]
        G = self.IV[6]
        H = self.IV[7]

        for j in range(64):
            if j < 16:
                ss1 = rotation_left((rotation_left(A, 12) + E + rotation_left(self.T[0], j)) % self.maxu32, 7)
            elif j >= 16:
                ss1 = rotation_left((rotation_left(A, 12) + E + rotation_left(self.T[1], j)) % self.maxu32, 7)
            ss2 = ss1 ^ rotation_left(A, 12)
            tt1 = (self.ff(A, B, C, j) + D + ss2 + self.w2[j]) % self.maxu32
            tt2 = (self.gg(E, F, G, j) + H + ss1 + self.w1[j]) % self.maxu32
            D = C
            C = rotation_left(B, 9)
            B = A
            A = tt1
            H = G
            G = rotation_left(F, 19)
            F = E
            E = self.p(tt2, 0)

            # 测试IV的压缩中间值
            # print("j= %d：" % j, hex(A)[2:], hex(B)[2:], hex(C)[2:], hex(D)[2:], hex(E)[2:], hex(F)[2:], hex(G)[2:], hex(H)[2:])

        self.IV[0] ^= A
        self.IV[1] ^= B
        self.IV[2] ^= C
        self.IV[3] ^= D
        self.IV[4] ^= E
        self.IV[5] ^= F
        self.IV[6] ^= G
        self.IV[7] ^= H

    def sm3_update(self, msg):
        # 迭代函数
        # 输入参数msg为bytearray类型
        # msg_new为bytearray类型
        msg_new = self.sm3_fill(msg)  # msg_new经过填充后一定是512的整数倍
        n = len(msg_new) // 64  # n是整数，n>=1

        for i in range(0, n):
            self.sm3_compress(msg_new[i * 64:(i + 1) * 64])

    def sm3_final(self):
        digest_str = ""
        for i in range(len(self.IV)):
            digest_str += hex(self.IV[i])[2:]

        return digest_str.upper()

    def hashFile(self, filename):
        with open(filename, 'rb') as fp:
            contents = fp.read()
            self.sm3_update(bytearray(contents))
        return self.sm3_final()

def getFileName(path):
    ''' 获取指定目录下的所有指定后缀的文件名 '''
    f_list = os.listdir(path)
    # print f_list
    list = []
    for i in f_list:
        # os.path.splitext():分离文件名与扩展名
        if os.path.splitext(i)[1] == '.tsidx':
            list.append(i)
    return list

class FileEventHandler(FileSystemEventHandler):
    def __init__(self):
        FileSystemEventHandler.__init__(self)

    def on_created(self, event):
        if event.is_directory:
            print(event.src_path)
            time.sleep(15)
            if re.compile("db_\d+_\d+_\d+").findall(event.src_path.split("/")[-1]):
                list = getFileName(event.src_path)
                for i in range(len(list)):
                    file_digest = SM3().hashFile(event.src_path + "/" + list[i])
                    file = open(event.src_path + "/sm3(" + str(i) + ").txt", "a")
                    file.write(file_digest+ " " + list[i] + "\n")
                    file.close()

if __name__ == "__main__":
    observer = Observer()
    event_handler = FileEventHandler()
    observer.schedule(event_handler, "/tmp", True)
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()

代码中借鉴了https://blog.csdn.net/weixin_43936250/article/details/105543266的sm3加密，和https://blog.csdn.net/jerry_liufeng/article/details/109603462的目录实时监控