From 846ab858a6dd2e962d3e110147f4274416026f5a Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Thu, 19 May 2016 12:01:15 +0100
Subject: Python wrapper: support for inbound group sessions
---
python/olm/__init__.py | 1 +
python/olm/__main__.py | 76 +++++++++++++++++++++++++++++---
python/olm/inbound_group_session.py | 86 +++++++++++++++++++++++++++++++++++++
3 files changed, 158 insertions(+), 5 deletions(-)
create mode 100644 python/olm/inbound_group_session.py
(limited to 'python/olm')
diff --git a/python/olm/__init__.py b/python/olm/__init__.py
index 8681d12..31b29b9 100644
--- a/python/olm/__init__.py
+++ b/python/olm/__init__.py
@@ -1,3 +1,4 @@
from .account import Account
from .session import Session
from .outbound_group_session import OutboundGroupSession
+from .inbound_group_session import InboundGroupSession
diff --git a/python/olm/__main__.py b/python/olm/__main__.py
index 8bb2419..3fcf24d 100755
--- a/python/olm/__main__.py
+++ b/python/olm/__main__.py
@@ -210,14 +210,43 @@ def build_arg_parser():
outbound_group.add_argument("session_file", help="Local group session file")
outbound_group.set_defaults(func=do_outbound_group)
+ group_credentials = commands.add_parser("group_credentials", help="Export the current outbound group session credentials")
+ group_credentials.add_argument("session_file", help="Local outbound group session file")
+ group_credentials.add_argument("credentials_file", help="File to write credentials to (default stdout)",
+ type=argparse.FileType('w'), nargs='?',
+ default=sys.stdout)
+ group_credentials.set_defaults(func=do_group_credentials)
+
group_encrypt = commands.add_parser("group_encrypt", help="Encrypt a group message")
- group_encrypt.add_argument("session_file", help="Local group session file")
- group_encrypt.add_argument("plaintext_file", help="Plaintext",
- type=argparse.FileType('rb'), default=sys.stdin)
- group_encrypt.add_argument("message_file", help="Message",
- type=argparse.FileType('wb'), default=sys.stdout)
+ group_encrypt.add_argument("session_file", help="Local outbound group session file")
+ group_encrypt.add_argument("plaintext_file", help="Plaintext file (default stdin)",
+ type=argparse.FileType('rb'), nargs='?',
+ default=sys.stdin)
+ group_encrypt.add_argument("message_file", help="Message file (default stdout)",
+ type=argparse.FileType('w'), nargs='?',
+ default=sys.stdout)
group_encrypt.set_defaults(func=do_group_encrypt)
+ inbound_group = commands.add_parser(
+ "inbound_group",
+ help=("Create an inbound group session based on credentials from an "+
+ "outbound group session"))
+ inbound_group.add_argument("session_file", help="Local inbound group session file")
+ inbound_group.add_argument("credentials_file",
+ help="File to read credentials from (default stdin)",
+ type=argparse.FileType('r'), nargs='?',
+ default=sys.stdin)
+ inbound_group.set_defaults(func=do_inbound_group)
+
+ group_decrypt = commands.add_parser("group_decrypt", help="Decrypt a group message")
+ group_decrypt.add_argument("session_file", help="Local inbound group session file")
+ group_decrypt.add_argument("message_file", help="Message file (default stdin)",
+ type=argparse.FileType('r'), nargs='?',
+ default=sys.stdin)
+ group_decrypt.add_argument("plaintext_file", help="Plaintext file (default stdout)",
+ type=argparse.FileType('wb'), nargs='?',
+ default=sys.stdout)
+ group_decrypt.set_defaults(func=do_group_decrypt)
return parser
def do_outbound_group(args):
@@ -240,6 +269,43 @@ def do_group_encrypt(args):
f.write(session.pickle(args.key))
args.message_file.write(message)
+def do_group_credentials(args):
+ session = OutboundGroupSession()
+ with open(args.session_file, "rb") as f:
+ session.unpickle(args.key, f.read())
+ result = {
+ 'message_index': session.message_index(),
+ 'session_key': session.session_key(),
+ }
+ json.dump(result, args.credentials_file, indent=4)
+
+def do_inbound_group(args):
+ if os.path.exists(args.session_file):
+ sys.stderr.write("Session %r file already exists\n" % (
+ args.session_file,
+ ))
+ sys.exit(1)
+ credentials = json.load(args.credentials_file)
+ for k in ('message_index', 'session_key'):
+ if not k in credentials:
+ sys.stderr.write("Credentials file is missing %s\n" % k)
+ sys.exit(1);
+
+ session = InboundGroupSession()
+ session.init(credentials['message_index'], credentials['session_key'])
+ with open(args.session_file, "wb") as f:
+ f.write(session.pickle(args.key))
+
+def do_group_decrypt(args):
+ session = InboundGroupSession()
+ with open(args.session_file, "rb") as f:
+ session.unpickle(args.key, f.read())
+ message = args.message_file.read()
+ plaintext = session.decrypt(message)
+ with open(args.session_file, "wb") as f:
+ f.write(session.pickle(args.key))
+ args.plaintext_file.write(plaintext)
+
if __name__ == '__main__':
parser = build_arg_parser()
args = parser.parse_args()
diff --git a/python/olm/inbound_group_session.py b/python/olm/inbound_group_session.py
new file mode 100644
index 0000000..6c01095
--- /dev/null
+++ b/python/olm/inbound_group_session.py
@@ -0,0 +1,86 @@
+import json
+
+from ._base import *
+
+lib.olm_inbound_group_session_size.argtypes = []
+lib.olm_inbound_group_session_size.restype = c_size_t
+
+lib.olm_inbound_group_session.argtypes = [c_void_p]
+lib.olm_inbound_group_session.restype = c_void_p
+
+lib.olm_inbound_group_session_last_error.argtypes = [c_void_p]
+lib.olm_inbound_group_session_last_error.restype = c_char_p
+
+def inbound_group_session_errcheck(res, func, args):
+ if res == ERR:
+ raise OlmError("%s: %s" % (
+ func.__name__, lib.olm_inbound_group_session_last_error(args[0])
+ ))
+ return res
+
+
+def inbound_group_session_function(func, *types):
+ func.argtypes = (c_void_p,) + types
+ func.restypes = c_size_t
+ func.errcheck = inbound_group_session_errcheck
+
+
+inbound_group_session_function(
+ lib.olm_pickle_inbound_group_session, c_void_p, c_size_t, c_void_p, c_size_t
+)
+inbound_group_session_function(
+ lib.olm_unpickle_inbound_group_session, c_void_p, c_size_t, c_void_p, c_size_t
+)
+
+inbound_group_session_function(
+ lib.olm_init_inbound_group_session, c_uint32, c_void_p, c_size_t
+)
+
+inbound_group_session_function(
+ lib.olm_group_decrypt_max_plaintext_length, c_void_p, c_size_t
+)
+inbound_group_session_function(
+ lib.olm_group_decrypt,
+ c_void_p, c_size_t, # message
+ c_void_p, c_size_t, # plaintext
+)
+
+class InboundGroupSession(object):
+ def __init__(self):
+ self.buf = create_string_buffer(lib.olm_inbound_group_session_size())
+ self.ptr = lib.olm_inbound_group_session(self.buf)
+
+ def pickle(self, key):
+ key_buffer = create_string_buffer(key)
+ pickle_length = lib.olm_pickle_inbound_group_session_length(self.ptr)
+ pickle_buffer = create_string_buffer(pickle_length)
+ lib.olm_pickle_inbound_group_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.olm_unpickle_inbound_group_session(
+ self.ptr, key_buffer, len(key), pickle_buffer, len(pickle)
+ )
+
+ def init(self, message_index, session_key):
+ key_buffer = create_string_buffer(session_key)
+ lib.olm_init_inbound_group_session(
+ self.ptr, message_index, key_buffer, len(session_key)
+ )
+
+ def decrypt(self, message):
+ message_buffer = create_string_buffer(message)
+ max_plaintext_length = lib.olm_group_decrypt_max_plaintext_length(
+ self.ptr, message_buffer, len(message)
+ )
+ plaintext_buffer = create_string_buffer(max_plaintext_length)
+ message_buffer = create_string_buffer(message)
+ plaintext_length = lib.olm_group_decrypt(
+ self.ptr, message_buffer, len(message),
+ plaintext_buffer, max_plaintext_length
+ )
+ return plaintext_buffer.raw[:plaintext_length]
--
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