Commit 499f680f authored by Mark Haines's avatar Mark Haines
Browse files

Add python ctypes bindings and a command line script using them

parent 76f49cf1
#! /usr/bin/python
from ctypes import *
import json
lib = cdll.LoadLibrary("build/libaxolotl.so")
lib.axolotl_error.argtypes = []
lib.axolotl_error.restypes = c_size_t
ERR = lib.axolotl_error()
class AxolotlError(Exception):
pass
lib.axolotl_account_size.argtypes = []
lib.axolotl_account_size.restype = c_size_t
lib.axolotl_account.argtypes = [c_void_p]
lib.axolotl_account.restype = c_void_p
lib.axolotl_account_last_error.argtypes = [c_void_p]
lib.axolotl_account_last_error.restype = c_char_p
def account_errcheck(res, func, args):
if res == ERR:
raise AxolotlError("%s: %s" % (
func.__name__, lib.axolotl_account_last_error(args[0])
))
return res
def account_function(func, *types):
func.argtypes = (c_void_p,) + types
func.restypes = c_size_t
func.errcheck = account_errcheck
account_function(
lib.axolotl_pickle_account, c_void_p, c_size_t, c_void_p, c_size_t
)
account_function(
lib.axolotl_unpickle_account, c_void_p, c_size_t, c_void_p, c_size_t
)
account_function(lib.axolotl_create_account_random_length)
account_function(lib.axolotl_create_account, c_void_p, c_size_t)
account_function(lib.axolotl_account_identity_keys_length)
account_function(lib.axolotl_account_identity_keys, c_void_p, c_size_t)
account_function(lib.axolotl_account_one_time_keys_length)
account_function(lib.axolotl_account_one_time_keys, c_void_p, c_size_t)
def read_random(n):
with open("/dev/urandom", "rb") as f:
return f.read(n)
class Account(object):
def __init__(self):
self.buf = create_string_buffer(lib.axolotl_account_size())
self.ptr = lib.axolotl_account(self.buf)
def create(self):
random_length = lib.axolotl_create_account_random_length(self.ptr)
random = read_random(random_length)
random_buffer = create_string_buffer(random)
lib.axolotl_create_account(self.ptr, random_buffer, random_length)
def pickle(self, key):
key_buffer = create_string_buffer(key)
pickle_length = lib.axolotl_pickle_account_length(self.ptr)
pickle_buffer = create_string_buffer(pickle_length)
lib.axolotl_pickle_account(
self.ptr, key_buffer, len(key), pickle_buffer, pickle_length
)
return pickle_buffer.raw
def unpickle(self, key, pickle):
key_buffer = create_string_buffer(key)
pickle_buffer = create_string_buffer(pickle)
lib.axolotl_unpickle_account(
self.ptr, key_buffer, len(key), pickle_buffer, len(pickle)
)
def identity_keys(self):
out_length = lib.axolotl_account_identity_keys_length(self.ptr)
out_buffer = create_string_buffer(out_length)
lib.axolotl_account_identity_keys(self.ptr, out_buffer, out_length)
return json.loads(out_buffer.raw)
def one_time_keys(self):
out_length = lib.axolotl_account_one_time_keys_length(self.ptr)
out_buffer = create_string_buffer(out_length)
lib.axolotl_account_one_time_keys(self.ptr, out_buffer, out_length)
return json.loads(out_buffer.raw)
def clear(self):
pass
lib.axolotl_session_size.argtypes = []
lib.axolotl_session_size.restype = c_size_t
lib.axolotl_session.argtypes = [c_void_p]
lib.axolotl_session.restype = c_void_p
lib.axolotl_session_last_error.argtypes = [c_void_p]
lib.axolotl_session_last_error.restype = c_char_p
def session_errcheck(res, func, args):
if res == ERR:
raise AxolotlError("%s: %s" % (
func.__name__, lib.axolotl_session_last_error(args[0])
))
return res
def session_function(func, *types):
func.argtypes = (c_void_p,) + types
func.restypes = c_size_t
func.errcheck = session_errcheck
session_function(lib.axolotl_session_last_error)
session_function(
lib.axolotl_pickle_session, c_void_p, c_size_t, c_void_p, c_size_t
)
session_function(
lib.axolotl_unpickle_session, c_void_p, c_size_t, c_void_p, c_size_t
)
session_function(lib.axolotl_create_outbound_session_random_length)
session_function(
lib.axolotl_create_outbound_session,
c_void_p, # Account
c_void_p, c_size_t, # Identity Key
c_uint, # One Time Key Id
c_void_p, c_size_t, # One Time Key
c_void_p, c_size_t, # Random
)
session_function(
lib.axolotl_create_inbound_session,
c_void_p, # Account
c_void_p, c_size_t, # Pre Key Message
)
session_function(lib.axolotl_matches_inbound_session, c_void_p, c_size_t)
session_function(lib.axolotl_encrypt_message_type)
session_function(lib.axolotl_encrypt_random_length)
session_function(lib.axolotl_encrypt_message_length, c_size_t)
session_function(
lib.axolotl_encrypt,
c_void_p, c_size_t, # Plaintext
c_void_p, c_size_t, # Random
c_void_p, c_size_t, # Message
);
session_function(
lib.axolotl_decrypt_max_plaintext_length,
c_size_t, # Message Type
c_void_p, c_size_t, # Message
)
session_function(
lib.axolotl_decrypt,
c_size_t, # Message Type
c_void_p, c_size_t, # Message
c_void_p, c_size_t, # Plaintext
)
class Session(object):
def __init__(self):
self.buf = create_string_buffer(lib.axolotl_session_size())
self.ptr = lib.axolotl_session(self.buf)
def pickle(self, key):
key_buffer = create_string_buffer(key)
pickle_length = lib.axolotl_pickle_session_length(self.ptr)
pickle_buffer = create_string_buffer(pickle_length)
lib.axolotl_pickle_session(
self.ptr, key_buffer, len(key), pickle_buffer, pickle_length
)
return pickle_buffer.raw
def unpickle(self, key, pickle):
key_buffer = create_string_buffer(key)
pickle_buffer = create_string_buffer(pickle)
lib.axolotl_unpickle_session(
self.ptr, key_buffer, len(key), pickle_buffer, len(pickle)
)
def create_outbound(self, account, identity_key, one_time_key_id,
one_time_key):
r_length = lib.axolotl_create_outbound_session_random_length(self.ptr)
random = read_random(r_length)
random_buffer = create_string_buffer(random)
identity_key_buffer = create_string_buffer(identity_key)
one_time_key_buffer = create_string_buffer(one_time_key)
lib.axolotl_create_outbound_session(
self.ptr,
account.ptr,
identity_key_buffer, len(identity_key),
one_time_key_id,
one_time_key_buffer, len(one_time_key),
random_buffer, r_length
)
def create_inbound(self, account, one_time_key_message):
one_time_key_message_buffer = create_string_buffer(one_time_key_message)
lib.axolotl_create_inbound_session(
self.ptr,
account.ptr,
one_time_key_message_buffer, len(one_time_key_message)
)
def matches_inbound(self, one_time_key_message):
one_time_key_message_buffer = create_string_buffer(one_time_key_message)
return bool(lib.axolotl_create_inbound_session(
self.ptr,
one_time_key_message_buffer, len(one_time_key_message)
))
def encrypt(self, plaintext):
r_length = lib.axolotl_encrypt_random_length(self.ptr)
random = read_random(r_length)
random_buffer = create_string_buffer(random)
message_type = lib.axolotl_encrypt_message_type(self.ptr)
message_length = lib.axolotl_encrypt_message_length(
self.ptr, len(plaintext)
)
message_buffer = create_string_buffer(message_length)
plaintext_buffer = create_string_buffer(plaintext)
lib.axolotl_encrypt(
self.ptr,
plaintext_buffer, len(plaintext),
random_buffer, r_length,
message_buffer, message_length,
)
return message_type, message_buffer.raw
def decrypt(self, message_type, message):
message_buffer = create_string_buffer(message)
max_plaintext_length = lib.axolotl_decrypt_max_plaintext_length(
self.ptr, message_type, message_buffer, len(message)
)
plaintext_buffer = create_string_buffer(max_plaintext_length)
message_buffer = create_string_buffer(message)
plaintext_length = lib.axolotl_decrypt(
self.ptr, message_type, message_buffer, len(message),
plaintext_buffer, max_plaintext_length
)
return plaintext_buffer.raw[:plaintext_length]
def clear(self):
pass
if __name__ == '__main__':
import argparse
import sys
import os
import yaml
parser = argparse.ArgumentParser()
parser.add_argument("--key", help="Account encryption key", default="")
commands = parser.add_subparsers()
create_account = commands.add_parser("create_account", help="Create a new account")
create_account.add_argument("account_file", help="Local account file")
def do_create_account(args):
if os.path.exists(args.account_file):
sys.stderr.write("Account %r file already exists" % (
args.account_file,
))
sys.exit(1)
account = Account()
account.create()
with open(args.account_file, "wb") as f:
f.write(account.pickle(args.key))
create_account.set_defaults(func=do_create_account)
keys = commands.add_parser("keys", help="List public keys for an account")
keys.add_argument("account_file", help="Local account_file")
def do_keys(args):
account = Account()
with open(args.account_file, "rb") as f:
account.unpickle(args.key, f.read())
(r_id, id_key), (signed_id, signed_key) = account.identity_keys()
ot_keys = account.one_time_keys()
result1 = {
"identityKey": str(id_key),
"signedKey": {
"keyId": signed_id,
"publicKey": str(signed_key),
},
"lastResortKey": {
"keyId": ot_keys[0][0],
"publicKey": str(ot_keys[0][1]),
},
}
result2 = {
"oneTimeKeys": [{
"keyId": k[0],
"publicKey": str(k[1]),
} for k in ot_keys[1:]]
}
try:
yaml.dump(result1, sys.stdout, default_flow_style=False)
yaml.dump(result2, sys.stdout, default_flow_style=False)
except:
pass
keys.set_defaults(func=do_keys)
outbound = commands.add_parser("outbound", help="Create an outbound session")
outbound.add_argument("account_file", help="Local account file")
outbound.add_argument("session_file", help="Local session file")
outbound.add_argument("identity_key", help="Remote identity key")
outbound.add_argument("signed_key_id", help="Remote signed key id",
type=int)
outbound.add_argument("signed_key", help="Remote signed key")
outbound.add_argument("one_time_key_id", help="Remote one time key id",
type=int)
outbound.add_argument("one_time_key", help="Remote one time key")
def do_outbound(args):
if os.path.exists(args.session_file):
sys.stderr.write("Session %r file already exists" % (
args.account_file,
))
sys.exit(1)
account = Account()
with open(args.account_file, "rb") as f:
account.unpickle(args.key, f.read())
session = Session()
session.create_outbound(
account, args.identity_key, args.signed_key_id, args.signed_key,
args.one_time_key_id, args.one_time_key
)
with open(args.session_file, "wb") as f:
f.write(session.pickle(args.key))
outbound.set_defaults(func=do_outbound)
def open_in(path):
if path == "-":
return sys.stdin
else:
return open(path, "rb")
def open_out(path):
if path == "-":
return sys.stdout
else:
return open(path, "wb")
inbound = commands.add_parser("inbound", help="Create an inbound session")
inbound.add_argument("account_file", help="Local account file")
inbound.add_argument("session_file", help="Local session file")
inbound.add_argument("message_file", help="Message", default="-")
inbound.add_argument("plaintext_file", help="Plaintext", default="-")
def do_inbound(args):
if os.path.exists(args.session_file):
sys.stderr.write("Session %r file already exists" % (
args.account_file,
))
sys.exit(1)
account = Account()
with open(args.account_file, "rb") as f:
account.unpickle(args.key, f.read())
with open_in(args.message_file) as f:
message_type = f.read(8)
message = f.read()
if message_type != "PRE_KEY ":
sys.stderr.write("Expecting a PRE_KEY message")
sys.exit(1)
session = Session()
session.create_inbound(account, message)
plaintext = session.decrypt(0, message)
with open(args.session_file, "wb") as f:
f.write(session.pickle(args.key))
with open_out(args.plaintext_file) as f:
f.write(plaintext)
inbound.set_defaults(func=do_inbound)
encrypt = commands.add_parser("encrypt", help="Encrypt a message")
encrypt.add_argument("session_file", help="Local session file")
encrypt.add_argument("plaintext_file", help="Plaintext", default="-")
encrypt.add_argument("message_file", help="Message", default="-")
def do_encrypt(args):
session = Session()
with open(args.session_file, "rb") as f:
session.unpickle(args.key, f.read())
with open_in(args.plaintext_file) as f:
plaintext = f.read()
message_type, message = session.encrypt(plaintext)
with open(args.session_file, "wb") as f:
f.write(session.pickle(args.key))
with open_out(args.message_file) as f:
f.write(["PRE_KEY ", "MESSAGE "][message_type])
f.write(message)
encrypt.set_defaults(func=do_encrypt)
decrypt = commands.add_parser("decrypt", help="Decrypt a message")
decrypt.add_argument("session_file", help="Local session file")
decrypt.add_argument("plaintext_file", help="Plaintext", default="-")
decrypt.add_argument("message_file", help="Message", default="-")
def do_decrypt(args):
session = Session()
with open(args.session_file, "rb") as f:
session.unpickle(args.key, f.read())
with open_in(args.message_file) as f:
message_type = f.read(8)
message = f.read()
if message_type not in {"PRE_KEY ", "MESSAGE "}:
sys.stderr.write("Expecting a PRE_KEY or MESSAGE message")
sys.exit(1)
message_type = 1 if message_type == "MESSAGE " else 0
plaintext = session.decrypt(message_type, message)
with open(args.session_file, "wb") as f:
f.write(session.pickle(args.key))
with open_out(args.plaintext_file) as f:
f.write(plaintext)
decrypt.set_defaults(func=do_decrypt)
args = parser.parse_args()
args.func(args)
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