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pythonencryptionputtypycrypto

Reading a private key generated with Putty in ezPyCrypto

I used Putty Key Generator to create a private key, called Putty-Private.ppk. I can use this private key with Pageant and Putty to connect to the servers of my hosting provider.

Now, I want to connect to the server with xmlrpc based remote API. To do this I installed ezPyCrypto which is advised by many as an easy to use python encryption library. To test the encryption I wrote the following code:

mypass = "xxx"
fd = open("Putty-Private.ppk")
pubprivkey = fd.read()
fd.close()
k = ezPyCrypto.key(pubprivkey, passphrase = mypass)
dec = k.decString(enc)

But the system gives the following error in ezPyCrypto.key(...) invocation:

CryptoKeyError: Attempted to import invalid key, or passphrase is bad

I am sure that passphrase is correct. So, I guess I cannot use the private key generator by Putty in ezPyCrypto. Is that right? What is the explanation for the reason of this error?

Solution

  • The .ppk extension makes me guess the private key comes from "Save private key" in puttygen. This file format is not supported by pretty much anything except PuTTY itself. I can't find what private key format ezPyCrypto expects, but you might have better luck with a private key file made from "Conversions -> Export OpenSSH key" in puttygen.