Question

我试图用两个Python文件加密和解密5-14 MB文本文件，一个包含加密/解密方法，另一个包含这些方法的运行器。

这是类文件：

from Crypto.Cipher import AES
from Crypto import Random
import sys
import codecs
reload(sys)
sys.setdefaultencoding('utf8')
sys.stdout = codecs.getwriter('utf8')(sys.stdout)

class Crypt:
    def __init__(self, encrypted, key):
        self.message = encrypted
        self.key = key

    def encrypt(self):
        iv = Random.new().read(AES.block_size)
        if len(self.message) % AES.block_size != 0:
            self.message += " " * (AES.block_size - (len(self.message) % AES.block_size))

        lenKey = len(self.key)
        if lenKey > 32:
            self.key = self.key[:32]

        cipher = AES.new(self.key, AES.MODE_CFB, iv)
        return iv + cipher.encrypt(self.message)

    def decrypt(self):
        iv, message = (self.message[:AES.block_size], self.message[AES.block_size:])
        if len(message) % AES.block_size != 0:
            message += " " * (AES.block_size - (len(message) % AES.block_size))

        lenKey = len(self.key)
        if lenKey > 32:
            self.key = self.key[:32]

        cipher = AES.new(self.key, AES.MODE_CFB, iv)
        return cipher.decrypt(message).strip()

这是跑步者：

import crypt_classes
from Crypto.Hash import SHA256
import sys
reload(sys)
sys.setdefaultencoding('utf8')

h = SHA256.new()
while True:
    choice = raw_input("Encrypt [1] or decrypt [2]? ").strip()
    if choice != "1" and choice != "2":
        print "Invalid choice, please try again."
        continue
    key = ""
    first = ""
    confirm = ""
    while True:
        first = raw_input("Enter passphrase (>= 32 chars): ").strip()
        # confirm = raw_input("Confirm passphrase: ").strip()
        confirm = first
        if first == confirm and len(confirm) >= 32:
            h.update(first)
            key = h.hexdigest()
            break
        else:
            print "Passphrases did not match or were shorter than 32 characters. Try again."
            continue
    if choice == "1":
        f = open("encrypted.txt", "w")
        h = open("source.txt", "r")
        message = h.read()
        h.close()
        encrypter = crypt_classes.Crypt(message, key)
        e = encrypter.encrypt()
        f.write(e)
        f.close()
        break
    elif choice == "2":
        f = open("encrypted.txt", "r")
        encrypted = f.read()
        f.close()
        decrypter = crypt_classes.Crypt(encrypted, key)
        w = open("decrypted.txt", "w")
        o = decrypter.decrypt()
        w.write(o)
        w.close()
        break

加密工作正常，但是当文件被解密并且程序表面上完成时，文件中只显示几行以及一些杂项字符，如：

# This data file generated by 23andMe at: Thu May 22 15:47:06 2008
#
# Below is a text version of your data. Fields are TAB-separated
# Each line corresponds to a single SNP.  For each SNP, we provide its identifier 
# (an rsid or an internal id), its lU�

如果需要进一步详细说明，请发表评论。

谢谢！

Answer 1

只需使用简单的功能。我觉得这里不需要上课了。

取十六进制摘要然后截断使有效密钥长度为128 而你似乎想要256。

不要将加密数据写为UTF8。不要使用填充进行CFB模式。

我的尝试（适用于我的系统）;如果您愿意，可以将加密和解密函数及其导入放在单独的文件（模块）中。

from Crypto.Hash import SHA256
from Crypto.Cipher import AES
from Crypto import Random
import sys

def encrypt_data(data, key):
    iv=Random.new().read(AES.block_size)
    aes=AES.new(key, AES.MODE_CFB, iv)
    return iv+aes.encrypt(data)

def decrypt_data(data, key):
    iv = data[:16]
    data = data[16:]
    aes=AES.new(key, AES.MODE_CFB, iv)
    return aes.decrypt(data)

h = SHA256.new()
while True:
    choice = raw_input("Encrypt [1] or decrypt [2]? ").strip()
    if choice != "1" and choice != "2":
        print "Invalid choice, please try again."
        continue
    key = ""
    first = ""
    confirm = ""
    while True:
        first = raw_input("Enter passphrase (>= 32 chars): ").strip()
        # confirm = raw_input("Confirm passphrase: ").strip()
        confirm = first
        if first == confirm and len(confirm) >= 32:
            h.update(first)
            key = h.digest()
            break
        else:
            print "Passphrases did not match or were shorter than 32 characters. Try again."
            continue
    if choice == "1":
        f = open("encryptedDNA.txt", "w")
        h = open("genome_Mikolaj_Habryn_20080522154706.txt", "r")
        message = h.read()
       h.close()
       encmessage = encrypt_data(message, key)
       f.write(encmessage)
       f.close()
       break
    elif choice == "2":
        f = open("encryptedDNA.txt", "r")
        encrypted = f.read()
        f.close()
        decrypted = decrypt_data(encrypted,key)
        w = open("decryptedDNA.txt", "w")
        w.write(decrypted)
        w.close()
        break

〜

经过几行处理输入后，PyCrypto AES突然停止解密

1 个答案: