AES-128 对称密钥密码。使用 python [关闭]

Question

我试图通过暴力破解剩余的 4 个字符来找到密钥的剩余部分。然后我们使用每个密钥解密，并检查解密后的消息是否在开头有“Salam”。

from Cryptodome.Cipher import AES
def revpad(s):
        """
        This function is to remove padding.

        parameters:
                s:str
                                string to be reverse padded

        """

        k=ord(s[-1])
        temp=0                                          #temporary variable to check padding
        for i in range (1,k):                           #for loop to check padding
                if(s[-i]!=s[-1]):                       #comparision of bytes with the last Byte
                        temp=1

        if(temp==0):
                return (s[:-k])                         #Reverse padded string
        else:
                return ("Wrong padding")



def decrypt(ct,key):
        """
        This function is for decrypting ciphertext in ECB mode

        parameters:
                ct: str
                                ciphertext to be decrypted
                key: str
                                key for ECB mode encryption whose lenght is always a multiple of 16 in this case
        """

        plaintxt=AES.new(key,AES.MODE_ECB)
        pt=plaintxt.decrypt(ct)

        return revpad(pt)                                  #After decrypting padding should be removed

if __name__ == "__main__":
    ciphertext = open("ciphertext2.dat" , "rb").read()
    partial_key = open("partial-key.dat" , "rb").read()
    for i in range(256):
        for j in range(256):
            for k in range(256):
                for l in range(256):
                    remaining_key = chr(i)+chr(j)+chr(k)+chr(l)
                    # print(type(remaining_key))

                    key = partial_key + remaining_key
                    decrypted_text = decrypt(ciphertext , key)
                    if decrypted_text[:5] == "Salam":
                        print(decrypted_text)

我无法从 partial_key 读取我收到此错误：

TypeError: can't concat str to bytes

Answer 1

您似乎错误地使用了range 函数。该函数返回一个生成器，其中包含两个整数之间的值，并带有一个可选参数来更改步长

示例

range(10)  # numbers between 0 and 9
range(1, 10)  # numbers between 1 and 9
range(1, 10, 2) # numbers between 1 and 9, but skipping every second number [1, 3, 5, 7, 9]
range(10, 0, -1) # numbers between 10 and 1, counting backwards

你想要做的是循环一个字符串，为此你不需要 range 函数。要重复一个字符串，只需将其乘以重复次数即可

for i in '0123456789abcdef'*2:
   <insert code here>