matrix++

Signed-off-by: Nico Schottelius <nico@nico-notebook.schottelius.org>

matrix/matrix-client.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+
+import sys
+import urllib
+from mautrix.client import ClientAPI
+
+matrix_server="ungleich.matrix.ungleich.cloud"
+matrix_user="@nico:ungleich.ch"
+matrix_password=sys.argv[1]
+
+client = ClientAPI(matrixuser,
+                   base_url=f"https://{matrix_server}"
+                   token="syt_123_456")
+
+
+await print(client.whoami())

matrix/matrix-client.sh

@@ -0,0 +1,45 @@
+#!/bin/sh
+
+matrix_server=$1; shift
+# matrix_user=$1; shift
+# matrix_user=$(echo $matrix_user | sed 's/^@/\@/')
+# matrix_password=$1; shift
+
+
+# Login
+# http -j -p "HBhb" \
+#      https://${matrix_server}/_matrix/client/v3/login \
+#      identifier:="{ \"type\":\"m.id.user\", \"user\":\"$matrix_user\" }" \
+#      device_id=nicoshell initial_device_display_name="matrixclientsh" \
+#      type=m.login.password \
+#      password=$matrix_password
+
+# {
+#     "access_token": "..",
+#     "device_id": "nicoshell",
+#     "home_server": "ungleich.ch",
+#     "user_id": "@nico:ungleich.ch",
+#     "well_known": {
+#         "m.homeserver": {
+#             "base_url": "https://ungleich.matrix.ungleich.cloud/"
+#         }
+#     }
+# }
+
+key_url=https://${matrix_server}/_matrix/client/v3/room_keys/keys
+token=$1; shift
+http -j -p "HBhb" $key_url \
+     identifier:="{ \"type\":\"m.id.user\", \"user\":\"$matrix_user\" }" \
+     device_id=nicoshell initial_device_display_name="matrixclientsh" \
+     type=m.login.password \
+     password=$matrix_password
+
+
+# get device keys + master_keys of Nico
+http https://ungleich.matrix.ungleich.cloud/_matrix/client/v3/keys/query access_token=="$token" device_keys:='{ "@nico:ungleich.ch": [] }'
+
+# Get messages
+room_id="!..:..."
+http 'https://ungleich.matrix.ungleich.cloud/_matrix/client/v3/rooms/!pkPjzozYKUNEbcZKKA:unchat.cat/messages' access_token=="$token"
+
+# Get room keys

matrix/matrix-get-messages-from-encrypted-room-via-backup.py

@@ -63,6 +63,10 @@ class UngleichMatrixClient:
             self.access_token = self.login_response.json()['access_token']
 
     def get_room_keys(self):
+        """
+        We assume version == 1 is correct because that's what's seen in reality
+        In theory we need to query the current version on the server first.
+        """
         self._ensure_logged_in()
 
         params = {
@@ -139,6 +143,8 @@ class UngleichMatrixClient:
         # use + b'==') to expand padding https://stackoverflow.com/questions/2941995/python-ignore-incorrect-padding-error-when-base64-decoding
         ephemeral_key_bytes = base64.b64decode(ephemeral_key + '==')
         ephemeral_public_key = X25519PublicKey.from_public_bytes(ephemeral_key_bytes)
+
+        # This is effectively ECDH provided by cryptography library
         shared_key = self.security_private_key.exchange(ephemeral_public_key)
 
         # when we have shared secret, use HDKF to get the AES part
@@ -152,6 +158,7 @@ class UngleichMatrixClient:
         # The first 32 bytes are used as the AES key,
         # the next 32 bytes are used as the MAC key,
         # and the last 16 bytes are used as the AES initialization vector."
+        # Using a key derivation function
         derived_key = HKDF(
             algorithm=hashes.SHA256(),
             length=80,
@@ -171,6 +178,8 @@ class UngleichMatrixClient:
 
         # Pass an empty string through HMAC-SHA-256 using the MAC key generated above. The first 8 bytes of the resulting MAC are base64-encoded, and become the mac property of the session_data.
 
+        # hashed message authentication code = HMAC
+        # This basically allows us to check if we derived the correct key
         mac = HMAC(mac_key, hashes.SHA256())
         mac.update(b'')
 
@@ -195,6 +204,7 @@ class UngleichMatrixClient:
         session_key_bytes = decryptor.update(encrypted_session_key_bytes) + decryptor.finalize()
 
         # Remove PKCS7 padding - block size 128 was guessed / tested to be correct
+        # Needs to be verified - it should in theory be 256
         unpadder = padding.PKCS7(128).unpadder()
         data = unpadder.update(session_key_bytes)
         data += unpadder.finalize()