我一直在尝试用Python实现AES CBC解密。由于加密文本不是16字节的倍数,因此填充是必要的。没有填充,此错误浮出水面
“TypeError:Odd-length string”
但我找不到在PyCrypto Python中实现PKCS5的正确参考。 有没有命令来实现这个? 感谢
在调查马库斯的建议后,我做了这个。
我的目标实际上是使用此代码解密十六进制消息(128字节)。但是,输出是“?:”,它非常小,unpad命令正在删除这些字节。这是代码。
from Crypto.Cipher import AES
BS = 16
pad = lambda s: s + (BS - len(s) % BS) * chr(BS - len(s) % BS)
unpad = lambda s : s[0:-ord(s[-1])]
class AESCipher:
def __init__( self, key ):
self.key = key
def encrypt( self, raw ):
raw = pad(raw)
iv = raw[:16]
raw=raw[16:]
#iv = Random.new().read( AES.block_size )
cipher = AES.new( self.key, AES.MODE_CBC, iv )
return ( iv + cipher.encrypt( raw ) ).encode("hex")
def decrypt( self, enc ):
iv = enc[:16]
enc= enc[16:]
cipher = AES.new(self.key, AES.MODE_CBC, iv )
return unpad(cipher.decrypt( enc))
mode = AES.MODE_CBC
key = "140b41b22a29beb4061bda66b6747e14"
ciphertext = "4ca00ff4c898d61e1edbf1800618fb2828a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81";
key=key[:32]
decryptor = AESCipher(key)
decryptor.__init__(key)
plaintext = decryptor.decrypt(ciphertext)
print plaintext
答案 0 :(得分:20)
您需要在解密之前解码十六进制编码值。如果您想使用十六进制编码密钥,也可以对其进行解码。
在这里,这应该有用。
from Crypto.Cipher import AES
from Crypto import Random
BS = 16
pad = lambda s: s + (BS - len(s) % BS) * chr(BS - len(s) % BS)
unpad = lambda s : s[0:-ord(s[-1])]
class AESCipher:
def __init__( self, key ):
"""
Requires hex encoded param as a key
"""
self.key = key.decode("hex")
def encrypt( self, raw ):
"""
Returns hex encoded encrypted value!
"""
raw = pad(raw)
iv = Random.new().read(AES.block_size);
cipher = AES.new( self.key, AES.MODE_CBC, iv )
return ( iv + cipher.encrypt( raw ) ).encode("hex")
def decrypt( self, enc ):
"""
Requires hex encoded param to decrypt
"""
enc = enc.decode("hex")
iv = enc[:16]
enc= enc[16:]
cipher = AES.new(self.key, AES.MODE_CBC, iv )
return unpad(cipher.decrypt( enc))
if __name__== "__main__":
key = "140b41b22a29beb4061bda66b6747e14"
ciphertext = "4ca00ff4c898d61e1edbf1800618fb2828a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81"
key=key[:32]
decryptor = AESCipher(key)
plaintext = decryptor.decrypt(ciphertext)
print "%s" % plaintext