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__pycache__	[ DIR ]	drwxr-xr-x
agent.py	13.05 KB	-rw-r--r--
auth_handler.py	34.98 KB	-rw-r--r--
ber.py	4.25 KB	-rw-r--r--
buffered_pipe.py	7.29 KB	-rw-r--r--
channel.py	48.18 KB	-rw-r--r--
client.py	31.37 KB	-rw-r--r--
common.py	8.12 KB	-rw-r--r--
compress.py	1.26 KB	-rw-r--r--
config.py	26.66 KB	-rw-r--r--
dsskey.py	8 KB	-rw-r--r--
ecdsakey.py	11.21 KB	-rw-r--r--
ed25519key.py	7.26 KB	-rw-r--r--
file.py	19.13 KB	-rw-r--r--
hostkeys.py	12.98 KB	-rw-r--r--
__init__.py	3.91 KB	-rw-r--r--
kex_curve25519.py	4.46 KB	-rw-r--r--
kex_ecdh_nist.py	4.91 KB	-rw-r--r--
kex_gex.py	10.11 KB	-rw-r--r--
kex_group14.py	1.79 KB	-rw-r--r--
kex_group16.py	2.23 KB	-rw-r--r--
kex_group1.py	5.66 KB	-rw-r--r--
kex_gss.py	24 KB	-rw-r--r--
message.py	8.81 KB	-rw-r--r--
packet.py	22.13 KB	-rw-r--r--
pipe.py	3.83 KB	-rw-r--r--
pkey.py	28.31 KB	-rw-r--r--
primes.py	5 KB	-rw-r--r--
proxy.py	4.54 KB	-rw-r--r--
py3compat.py	4.11 KB	-rw-r--r--
rsakey.py	7.17 KB	-rw-r--r--
server.py	29.7 KB	-rw-r--r--
sftp_attr.py	8.22 KB	-rw-r--r--
sftp_client.py	33.82 KB	-rw-r--r--
sftp_file.py	20.1 KB	-rw-r--r--
sftp_handle.py	7.26 KB	-rw-r--r--
sftp.py	5.89 KB	-rw-r--r--
sftp_server.py	19.14 KB	-rw-r--r--
sftp_si.py	12.28 KB	-rw-r--r--
ssh_exception.py	7.24 KB	-rw-r--r--
ssh_gss.py	28.21 KB	-rw-r--r--
transport.py	122.91 KB	-rw-r--r--
util.py	8.36 KB	-rw-r--r--
_version.py	80 B	-rw-r--r--
_winapi.py	11.09 KB	-rw-r--r--
win_pageant.py	4.17 KB	-rw-r--r--

Code Editor : kex_ecdh_nist.py

"""
Ephemeral Elliptic Curve Diffie-Hellman (ECDH) key exchange
RFC 5656, Section 4
"""

from hashlib import sha256, sha384, sha512
from paramiko.message import Message
from paramiko.py3compat import byte_chr, long
from paramiko.ssh_exception import SSHException
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives import serialization
from binascii import hexlify

_MSG_KEXECDH_INIT, _MSG_KEXECDH_REPLY = range(30, 32)
c_MSG_KEXECDH_INIT, c_MSG_KEXECDH_REPLY = [byte_chr(c) for c in range(30, 32)]

class KexNistp256:

name = "ecdh-sha2-nistp256"
    hash_algo = sha256
    curve = ec.SECP256R1()

def __init__(self, transport):
        self.transport = transport
        # private key, client public and server public keys
        self.P = long(0)
        self.Q_C = None
        self.Q_S = None

def start_kex(self):
        self._generate_key_pair()
        if self.transport.server_mode:
            self.transport._expect_packet(_MSG_KEXECDH_INIT)
            return
        m = Message()
        m.add_byte(c_MSG_KEXECDH_INIT)
        # SEC1: V2.0  2.3.3 Elliptic-Curve-Point-to-Octet-String Conversion
        m.add_string(
            self.Q_C.public_bytes(
                serialization.Encoding.X962,
                serialization.PublicFormat.UncompressedPoint,
            )
        )
        self.transport._send_message(m)
        self.transport._expect_packet(_MSG_KEXECDH_REPLY)

def parse_next(self, ptype, m):
        if self.transport.server_mode and (ptype == _MSG_KEXECDH_INIT):
            return self._parse_kexecdh_init(m)
        elif not self.transport.server_mode and (ptype == _MSG_KEXECDH_REPLY):
            return self._parse_kexecdh_reply(m)
        raise SSHException(
            "KexECDH asked to handle packet type {:d}".format(ptype)
        )

def _generate_key_pair(self):
        self.P = ec.generate_private_key(self.curve, default_backend())
        if self.transport.server_mode:
            self.Q_S = self.P.public_key()
            return
        self.Q_C = self.P.public_key()

def _parse_kexecdh_init(self, m):
        Q_C_bytes = m.get_string()
        self.Q_C = ec.EllipticCurvePublicKey.from_encoded_point(
            self.curve, Q_C_bytes
        )
        K_S = self.transport.get_server_key().asbytes()
        K = self.P.exchange(ec.ECDH(), self.Q_C)
        K = long(hexlify(K), 16)
        # compute exchange hash
        hm = Message()
        hm.add(
            self.transport.remote_version,
            self.transport.local_version,
            self.transport.remote_kex_init,
            self.transport.local_kex_init,
        )
        hm.add_string(K_S)
        hm.add_string(Q_C_bytes)
        # SEC1: V2.0  2.3.3 Elliptic-Curve-Point-to-Octet-String Conversion
        hm.add_string(
            self.Q_S.public_bytes(
                serialization.Encoding.X962,
                serialization.PublicFormat.UncompressedPoint,
            )
        )
        hm.add_mpint(long(K))
        H = self.hash_algo(hm.asbytes()).digest()
        self.transport._set_K_H(K, H)
        sig = self.transport.get_server_key().sign_ssh_data(
            H, self.transport.host_key_type
        )
        # construct reply
        m = Message()
        m.add_byte(c_MSG_KEXECDH_REPLY)
        m.add_string(K_S)
        m.add_string(
            self.Q_S.public_bytes(
                serialization.Encoding.X962,
                serialization.PublicFormat.UncompressedPoint,
            )
        )
        m.add_string(sig)
        self.transport._send_message(m)
        self.transport._activate_outbound()

def _parse_kexecdh_reply(self, m):
        K_S = m.get_string()
        Q_S_bytes = m.get_string()
        self.Q_S = ec.EllipticCurvePublicKey.from_encoded_point(
            self.curve, Q_S_bytes
        )
        sig = m.get_binary()
        K = self.P.exchange(ec.ECDH(), self.Q_S)
        K = long(hexlify(K), 16)
        # compute exchange hash and verify signature
        hm = Message()
        hm.add(
            self.transport.local_version,
            self.transport.remote_version,
            self.transport.local_kex_init,
            self.transport.remote_kex_init,
        )
        hm.add_string(K_S)
        # SEC1: V2.0  2.3.3 Elliptic-Curve-Point-to-Octet-String Conversion
        hm.add_string(
            self.Q_C.public_bytes(
                serialization.Encoding.X962,
                serialization.PublicFormat.UncompressedPoint,
            )
        )
        hm.add_string(Q_S_bytes)
        hm.add_mpint(K)
        self.transport._set_K_H(K, self.hash_algo(hm.asbytes()).digest())
        self.transport._verify_key(K_S, sig)
        self.transport._activate_outbound()

class KexNistp384(KexNistp256):
    name = "ecdh-sha2-nistp384"
    hash_algo = sha384
    curve = ec.SECP384R1()

class KexNistp521(KexNistp256):
    name = "ecdh-sha2-nistp521"
    hash_algo = sha512
    curve = ec.SECP521R1()

${this.title}

Code Editor : kex_ecdh_nist.py