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Fixes #325 -- add support for Ed25519 keys
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Original file line number | Diff line number | Diff line change |
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@@ -0,0 +1,136 @@ | ||
# This file is part of paramiko. | ||
# | ||
# Paramiko is free software; you can redistribute it and/or modify it under the | ||
# terms of the GNU Lesser General Public License as published by the Free | ||
# Software Foundation; either version 2.1 of the License, or (at your option) | ||
# any later version. | ||
# | ||
# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY | ||
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR | ||
# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more | ||
# details. | ||
# | ||
# You should have received a copy of the GNU Lesser General Public License | ||
# along with Paramiko; if not, write to the Free Software Foundation, Inc., | ||
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | ||
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import nacl.signing | ||
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import six | ||
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from paramiko.message import Message | ||
from paramiko.pkey import PKey | ||
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OPENSSH_AUTH_MAGIC = "openssh-key-v1\x00" | ||
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def unpad(data): | ||
padding_length = six.indexbytes(data, -1) | ||
if padding_length > 16: | ||
raise SSHException('Invalid key') | ||
for i in range(1, padding_length + 1): | ||
if six.indexbytes(data, -i) != (padding_length - i + 1): | ||
raise SSHException('Invalid key') | ||
return data[:-padding_length] | ||
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class Ed25519Key(PKey): | ||
def __init__(self, msg=None, data=None, filename=None, password=None): | ||
verifying_key = signing_key = None | ||
if msg is None and data is not None: | ||
msg = Message(data) | ||
if msg is not None: | ||
if msg.get_text() != "ssh-ed25519": | ||
raise SSHException('Invalid key') | ||
verifying_key = nacl.signing.VerifyKey(msg.get_bytes(32)) | ||
elif filename is not None: | ||
with open(filename, "rb") as f: | ||
data = self._read_private_key("OPENSSH", f) | ||
signing_key = self._parse_signing_key_data(data) | ||
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if signing_key is None and verifying_key is None: | ||
import pdb; pdb.set_trace() | ||
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self._signing_key = signing_key | ||
self._verifying_key = verifying_key | ||
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def _parse_signing_key_data(self, data): | ||
# We may eventually want this to be usable for other key types, as | ||
# OpenSSH moves to it, but for now this is just for Ed25519 keys. | ||
message = Message(data) | ||
if message.get_bytes(len(OPENSSH_AUTH_MAGIC)) != OPENSSH_AUTH_MAGIC: | ||
raise SSHException('Invalid key') | ||
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ciphername = message.get_string() | ||
kdfname = message.get_string() | ||
kdfoptions = message.get_string() | ||
num_keys = message.get_int() | ||
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if ciphername != "none" or kdfname != "none" or kdfoptions: | ||
raise NotImplementedError("Encrypted keys are not implemented") | ||
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public_keys = [] | ||
for _ in range(num_keys): | ||
# We don't need the public keys, fast-forward through them. | ||
pubkey = Message(message.get_binary()) | ||
if pubkey.get_string() != 'ssh-ed25519': | ||
raise SSHException('Invalid key') | ||
public_keys.append(pubkey.get_binary()) | ||
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message = Message(unpad(message.get_binary())) | ||
if message.get_int() != message.get_int(): | ||
raise SSHException('Invalid key') | ||
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signing_keys = [] | ||
for i in range(num_keys): | ||
if message.get_string() != 'ssh-ed25519': | ||
raise SSHException('Invalid key') | ||
# A copy of the public key, again, ignore. | ||
public = message.get_binary() | ||
key_data = message.get_binary() | ||
# The second half of the key data is yet another copy of the public | ||
# key... | ||
signing_key = nacl.signing.SigningKey(key_data[:32]) | ||
assert ( | ||
signing_key.verify_key.encode() == public == public_keys[i] == key_data[32:] | ||
) | ||
signing_keys.append(signing_key) | ||
# Comment, ignore. | ||
message.get_string() | ||
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if len(signing_keys) != 1: | ||
raise SSHException('Invalid key') | ||
return signing_keys[0] | ||
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def asbytes(self): | ||
m = Message() | ||
m.add_string('ssh-ed25519') | ||
m.add_bytes(self._signing_key.verify_key.encode()) | ||
return m.asbytes() | ||
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def get_name(self): | ||
return "ssh-ed25519" | ||
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def get_bits(self): | ||
return 256 | ||
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def can_sign(self): | ||
return self._signing_key is not None | ||
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def sign_ssh_data(self, data): | ||
m = Message() | ||
m.add_string('ssh-ed25519') | ||
m.add_string(self._signing_key.sign(data).signature) | ||
return m | ||
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def verify_ssh_sig(self, data, msg): | ||
if msg.get_text() != 'ssh-ed25519': | ||
return False | ||
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try: | ||
self._verifying_key.verify(data, msg.get_binary()) | ||
except nacl.exceptions.BadSignatureError: | ||
return False | ||
else: | ||
return True |
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Original file line number | Diff line number | Diff line change |
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@@ -75,6 +75,7 @@ | |
], | ||
install_requires=[ | ||
'cryptography>=1.1', | ||
'pynacl', | ||
'pyasn1>=0.1.7', | ||
], | ||
) |