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  • Committer: Alex Gaynor
  • Date: 2014-03-30 02:22:36 UTC
  • mto: This revision was merged to the branch mainline in revision 746.
  • Revision ID: git-v1:6f211115f49edcea7d23b764d7cf3a84ff12f5f0
Switch from using PyCrypto's Random to using os.urandom.

There's several reasons for this change:

1) It's faster for reads up to 1024 bytes (nearly 10x faster for 16 byte reads)
2) It receives considerably more security review since it's in the kernel.
3) It's yet another step towards running on PyPy.
4) Using userspace CSPRNGs is considered something of an anti-pattern. See:
   http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/
   http://webcache.googleusercontent.com/search?q=cache:2nTvpCgKZXIJ:www.2uo.de/myths-about-urandom/+&cd=3&hl=en&ct=clnk&gl=us

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paramiko/pkey.py
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from Crypto.Cipher import DES3, AES
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from paramiko import util
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from paramiko.common import o600, rng, zero_byte
 
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from paramiko.common import o600, zero_byte
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from paramiko.py3compat import u, encodebytes, decodebytes, b
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from paramiko.ssh_exception import SSHException, PasswordRequiredException
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        """
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        return u(encodebytes(self.asbytes())).replace('\n', '')
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    def sign_ssh_data(self, rng, data):
 
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    def sign_ssh_data(self, data):
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        """
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        Sign a blob of data with this private key, and return a `.Message`
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        representing an SSH signature message.
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        :param .Crypto.Util.rng.RandomPool rng: a secure random number generator.
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        :param str data: the data to sign.
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        :return: an SSH signature `message <.Message>`.
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        """
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            keysize = self._CIPHER_TABLE[cipher_name]['keysize']
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            blocksize = self._CIPHER_TABLE[cipher_name]['blocksize']
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            mode = self._CIPHER_TABLE[cipher_name]['mode']
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            salt = rng.read(16)
 
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            salt = os.urandom(16)
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            key = util.generate_key_bytes(MD5, salt, password, keysize)
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            if len(data) % blocksize != 0:
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                n = blocksize - len(data) % blocksize
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                #data += rng.read(n)
 
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                #data += os.urandom(n)
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                # that would make more sense ^, but it confuses openssh.
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                data += zero_byte * n
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            data = cipher.new(key, mode, salt).encrypt(data)