Issues while creating TLS connection with x25519 curve set

tlsfreak commented 4 years ago

Brief description

crafting TLS 1.2 packets with x25519 curve set doesn't seems to be implemented, and throw errors

Environment

Scapy version: Version 2.4.4rc2.dev6
Python version: 3.5.3
Operating System: Linux debian 4.9.0-13-amd64

How to reproduce

run this:

    load_layer("tls")
        .....
    ext = TLS_Ext_SupportedEllipticCurves(groups=['x25519', 'secp256r1', 'secp384r1'])
         ...
    ch = TLSClientHello(ciphers=ciphers, ext=ext, comp=compression)
    t = TLSClientAutomaton(client_hello=ch, server=..., data=[...])

Actual result

'_X25519PublicKey' object has no attribute 'public_numbers'
> /usr/local/lib/python3.5/dist-packages/scapy-2.4.4rc2.dev6-py3.5.egg/scapy/layers/tls/crypto/cipher_aead.py(148)auth_encrypt()
-> raise CipherError(P, A)

Expected result

a successful TLS 1.2 handshake

Related resources

gpotter2 commented 4 years ago

Thanks for the report, but I'm having troubles reproducing this.

Could you share a snippet that works and reproduces it ? (if I remove all the unused arguments from your snipped, it works on my end)

tlsfreak commented 4 years ago

by default, scapy client automaton force the signature algorithm to "sha256+rsa" this is per scapy/layers/tls/automaton_cli.py once you comment that out:


    @ATMT.condition(PREPARE_CLIENTFLIGHT1)
    def should_add_ClientHello(self):
        if self.client_hello:
            p = self.client_hello
        else:
            p = TLSClientHello()
     #   ext = []
        # Add TLS_Ext_SignatureAlgorithms for TLS 1.2 ClientHello
      #  if self.cur_session.advertised_tls_version == 0x0303:
       #     ext += [TLS_Ext_SignatureAlgorithms(sig_algs=["sha256+rsa"])]
        # Add TLS_Ext_ServerName
     #   if self.server_name:
      #      ext += TLS_Ext_ServerName(
       #         servernames=[ServerName(servername=self.server_name)]
        #    )
        #p.ext = ext
        self.add_msg(p)
        raise self.ADDED_CLIENTHELLO()

try and use the following code snippet:

    load_layer("tls")

    # TLS Version 
    version = "1.2"

    ciphers = [TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384]
    ciphers += [TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256]

    ciphers += [TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384]
    ciphers += [TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256]

    ciphers += [TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384]
    ciphers += [TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256]

    ciphers += [TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384]
    ciphers += [TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256]

    ciphers += [TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA]
    ciphers += [TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA]

    ciphers += [TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA]
    ciphers += [TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA]

    compression='null'
    ext1 = TLS_Ext_ServerName(servernames=ServerName(servername=target_domain))
    ext2 = TLS_Ext_CSR(stype='ocsp', req=OCSPStatusRequest())
    ext3 = TLS_Ext_SupportedEllipticCurves(groups=['x25519', \
                                                    'secp256r1', \
                                                    'secp384r1'])
    ext4 = TLS_Ext_SupportedPointFormat(ecpl='uncompressed')
    ext5 = TLS_Ext_SignatureAlgorithms(sig_algs=['sha256+rsa', \
                                                'sha384+rsa', \
                                                'sha1+rsa', \
                                                'sha256+ecdsa', \
                                                'sha384+ecdsa',  \
                                                'sha1+ecdsa', \
                                                'sha1+dsa', \
                                                'sha512+rsa', \
                                                'sha512+ecdsa'])

    ext = [ext1, ext2, ext3, ext4, ext5]
    ch = TLSClientHello(gmt_unix_time=get_random_timestamp(1), ciphers=ciphers, ext=ext, comp=compression)
    ch.show()
    t = TLSClientAutomaton(client_hello=ch, server=..., dport=443, data=...)
    t.run()

code crashes here:

> 
> /usr/local/lib/python3.5/dist-packages/scapy-2.4.4rc2.dev20-py3.5.egg/scapy/layers/tls/keyexchange.py(799)fill_missing()
-> x = pubkey.public_numbers().x
(Pdb)

gpotter2 commented 3 years ago

Note to self:

from scapy.all import *
from scapy.layers.tls.all import *

class ModifiedTLSClientAutomaton(TLSClientAutomaton):
    @ATMT.condition(TLSClientAutomaton.PREPARE_CLIENTFLIGHT1)
    def should_add_ClientHello(self):
        if self.client_hello:
            p = self.client_hello
        else:
            p = TLSClientHello()
        self.add_msg(p)
        raise self.ADDED_CLIENTHELLO()

# TLS Version
target_domain = "www.google.com"
version = "1.2"

ciphers = [TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384]
ciphers += [TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256]
ciphers += [TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384]
ciphers += [TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256]
ciphers += [TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384]
ciphers += [TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256]
ciphers += [TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384]
ciphers += [TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256]
ciphers += [TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA]
ciphers += [TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA]
ciphers += [TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA]
ciphers += [TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA]

compression='null'
ext1 = TLS_Ext_ServerName(servernames=ServerName(servername=target_domain))
ext2 = TLS_Ext_CSR(stype='ocsp', req=OCSPStatusRequest())
ext3 = TLS_Ext_SupportedEllipticCurves(groups=['x25519', 'secp256r1', 'secp384r1'])
ext4 = TLS_Ext_SupportedPointFormat(ecpl='uncompressed')
ext5 = TLS_Ext_SignatureAlgorithms(sig_algs=['sha256+rsa', 'sha384+rsa', 'sha1+rsa', 'sha256+ecdsa', 'sha384+ecdsa', 'sha1+ecdsa', 'sha1+dsa', 'sha512+rsa', 'sha512+ecdsa'])

ext = [ext1, ext2, ext3, ext4, ext5]
ch = TLSClientHello(gmt_unix_time=10000, ciphers=ciphers, ext=ext, comp=compression)
ch.show()
t = ModifiedTLSClientAutomaton(client_hello=ch, server="www.google.com", dport=443)
t.run()

gpotter2 commented 3 years ago

Hi @tlsfreak and sorry for the delay. This should be fixed in https://github.com/secdev/scapy/pull/2929 It would be great if you could have a look and try it out. Thanks

secdev / scapy