我得到了一个用rc4密钥加密的文件。
我获得了该密钥,并希望使用python脚本对其进行解密。
我怎样才能做到这一点?
python大神给出的解决方案
3秒钟的Google搜索后发现以下内容:http://www.emoticode.net/python/python-implementation-of-rc4-algorithm.html
因此对其进行了修改:
import base64
data = base64.b64decode("<encrypted file contents>")
key = "<rc4 key>"
S = range(256)
j = 0
out = []
#KSA Phase
for i in range(256):
j = (j + S[i] + ord( key[i % len(key)] )) % 256
S[i] , S[j] = S[j] , S[i]
#PRGA Phase
i = j = 0
for char in data:
i = ( i + 1 ) % 256
j = ( j + S[i] ) % 256
S[i] , S[j] = S[j] , S[i]
out.append(chr(ord(char) ^ S[(S[i] + S[j]) % 256]))
print ''.join(out)
不知道这是否行得通,因为您没有提供给我们任何数据。.下次,请发布数据示例,您已经尝试过的代码以及遇到的错误。
编辑-使用文件
import base64
with open("/path/to/file.txt", "r") as encrypted_file:
data = base64.b64decode(encrypted_file.read())
key = "<rc4 key>"
S = range(256)
j = 0
out = []
#KSA Phase
for i in range(256):
j = (j + S[i] + ord( key[i % len(key)] )) % 256
S[i] , S[j] = S[j] , S[i]
#PRGA Phase
i = j = 0
for char in data:
i = ( i + 1 ) % 256
j = ( j + S[i] ) % 256
S[i] , S[j] = S[j] , S[i]
out.append(chr(ord(char) ^ S[(S[i] + S[j]) % 256]))
decrypted_text = ''.join(out)
with open('decrypted.txt', 'w') as decrypted_file:
decrypted_file.write(decrypted_text)