我正在尝试制作一个处理RSA加密和解密的程序,以便使用rsa库发送消息。目前我正在实现它只使用1个密钥对,但稍后会进行更改。我在检查存储密钥的文件是否存在的逻辑上遇到了一些麻烦。这些函数的逻辑如下:
import rsa
################################################
keySize = 256
################################################
def genKeys():
pubkey, privkey = rsa.newkeys(keySize)
with open("public.pem", "w") as pub:
pub.write(str(pubkey))
with open("private.pem", "w") as priv:
priv.write(str(privkey))
return pubkey, privkey
def readKeys():
with open("private.pem", "r") as priv:
keydata = priv.read()
privkey = rsa.PrivateKey.load_pkcs1(keydata)
print(privkey)
with open("public.pem", "r") as pub:
keydata = pub.read()
pubkey = rsa.PublicKey.load_pkcs1(keydata)
print(pubkey)
return pubkey, privkey
def send(message, pubkey):
message = message.encode('utf-8')
crypto = rsa.encrypt(message, pubkey)
return crypto
def recv(crypto, privkey):
message = rsa.decrypt(crypto, privkey)
message = message.decode('utf-8')
return message
def main():
global pubkey, privkey
try:
if (open("private.pem", "r") and open("public.pem", "r")) == True:
pubkey, privkey = readKeys()
except:
(pubkey, privkey) = genKeys()
cryptMessage = send('hello world', pubkey)
print(cryptMessage)
print(recv(cryptMessage, privkey))
if __name__ == "__main__":
main()
main()
函数,特别是try: except:
语句是我的问题所在。我得到的错误是builtins.NameError: name 'pubkey' is not defined
。我已经尝试将变量声明为全局变量,这是其他答案建议的,但这对我不起作用,或者我做错了。
感谢您的帮助。抱歉,这个菜鸟问题。
编辑:
所以,这解决了我的第一个问题。但是,现在当我使用try/except
语句时,它会尝试调用值为None
的变量,即使我使用函数为它们赋值。堆栈跟踪是
File "", line 61, in <module>
main()
File "", line 56, in main
cryptMessage = send('hello world', pubkey)
File "", line 37, in send
crypto = rsa.encrypt(message, pubkey)
File "/usr/local/lib/python3.6/dist-packages/rsa/pkcs1.py", line 169, in encrypt
keylength = common.byte_size(pub_key.n)
builtins.AttributeError: 'NoneType' object has no attribute 'n'
答案 0 :(得分:1)
即使您在函数内部声明变量为全局变量,您仍需要初始化它,或者在全局范围内或在声明它们时。
import rsa
################################################
keySize = 256
################################################
# DECLARATION IN GLOBAL SCOPE
pubkey = None
privkey = None
def genKeys():
pubkey, privkey = rsa.newkeys(keySize)
with open("public.pem", "w") as pub:
pub.write(str(pubkey))
with open("private.pem", "w") as priv:
priv.write(str(privkey))
return pubkey, privkey
def readKeys():
with open("private.pem", "r") as priv:
keydata = priv.read()
privkey = rsa.PrivateKey.load_pkcs1(keydata)
print(privkey)
with open("public.pem", "r") as pub:
keydata = pub.read()
pubkey = rsa.PublicKey.load_pkcs1(keydata)
print(pubkey)
return pubkey, privkey
def send(message, pubkey):
message = message.encode('utf-8')
crypto = rsa.encrypt(message, pubkey)
return crypto
def recv(crypto, privkey):
message = rsa.decrypt(crypto, privkey)
message = message.decode('utf-8')
return message
def main():
# DECLARATION INSIDE THE FUNCTION
global pubkey, privkey; pubkey = privkey = None
try:
if (open("private.pem", "r") and open("public.pem", "r")) == True:
pubkey, privkey = readKeys()
except:
(pubkey, privkey) = genKeys()
cryptMessage = send('hello world', pubkey)
print(cryptMessage)
print(recv(cryptMessage, privkey))
if __name__ == "__main__":
main()
答案 1 :(得分:0)
您应该在函数genKeys()
之外声明变量pubkey和privkey,然后错误应该消失。
这是我的第一篇文章,希望对你有所帮助。
问候。
答案 2 :(得分:0)
你的问题在这里:
if (open("private.pem", "r") and open("public.pem", "r")) == True:
Python逻辑运算符返回上次检查的值,而不是True或False。该值是open命令的file
对象不等于True。您可以使用os.path.isfile
检查文件是否存在,并完全跳过try / except块。或者你可以尝试在try块中实际读取,就像这样
(为了演示而精简)
# dummys for test...
def readKeys():
print('try read')
return open('public.pem').read(), open('private.pem').read()
def genKeys():
print('try write')
open('public.pem','w').write('foo')
open('private.pem','w').write('bar')
return 'foo', 'bar'
def main():
global pubkey, privkey
try:
pubkey, privkey = readKeys()
except:
(pubkey, privkey) = genKeys()
if __name__ == "__main__":
main()