Merge remote-tracking branch 'matrix/master'

include/olm/message.h

@@ -35,7 +35,6 @@ extern "C" {
  * The length of the buffer needed to hold a group message.
  */
 size_t _olm_encode_group_message_length(
-    size_t group_session_id_length,
     uint32_t chain_index,
     size_t ciphertext_length,
     size_t mac_length
@@ -45,8 +44,6 @@ size_t _olm_encode_group_message_length(
  * Writes the message headers into the output buffer.
  *
  * version:            version number of the olm protocol
- * session_id:         group session identifier
- * session_id_length:  length of session_id
  * message_index:      message index
  * ciphertext_length:  length of the ciphertext
  * output:             where to write the output. Should be at least
@@ -58,8 +55,6 @@ size_t _olm_encode_group_message_length(
  */
 size_t _olm_encode_group_message(
     uint8_t version,
-    const uint8_t *session_id,
-    size_t session_id_length,
     uint32_t message_index,
     size_t ciphertext_length,
     uint8_t *output,
@@ -69,8 +64,6 @@ size_t _olm_encode_group_message(
 
 struct _OlmDecodeGroupMessageResults {
     uint8_t version;
-    const uint8_t *session_id;
-    size_t session_id_length;
     uint32_t message_index;
     int has_message_index;
     const uint8_t *ciphertext;

src/inbound_group_session.c

@@ -231,9 +231,7 @@ static size_t _decrypt(
         return (size_t)-1;
     }
 
-    if (!decoded_results.has_message_index || !decoded_results.session_id
-        || !decoded_results.ciphertext
-    ) {
+    if (!decoded_results.has_message_index || !decoded_results.ciphertext ) {
         session->last_error = OLM_BAD_MESSAGE_FORMAT;
         return (size_t)-1;
     }

src/message.cpp

@@ -328,18 +328,15 @@ void olm::decode_one_time_key_message(
 
 
 
-static const std::uint8_t GROUP_SESSION_ID_TAG = 012;
-static const std::uint8_t GROUP_MESSAGE_INDEX_TAG = 020;
-static const std::uint8_t GROUP_CIPHERTEXT_TAG = 032;
+static const std::uint8_t GROUP_MESSAGE_INDEX_TAG = 010;
+static const std::uint8_t GROUP_CIPHERTEXT_TAG = 022;
 
 size_t _olm_encode_group_message_length(
-    size_t group_session_id_length,
     uint32_t message_index,
     size_t ciphertext_length,
     size_t mac_length
 ) {
     size_t length = VERSION_LENGTH;
-    length += 1 + varstring_length(group_session_id_length);
     length += 1 + varint_length(message_index);
     length += 1 + varstring_length(ciphertext_length);
     length += mac_length;
@@ -349,19 +346,14 @@ size_t _olm_encode_group_message_length(
 
 size_t _olm_encode_group_message(
     uint8_t version,
-    const uint8_t *session_id,
-    size_t session_id_length,
     uint32_t message_index,
     size_t ciphertext_length,
     uint8_t *output,
     uint8_t **ciphertext_ptr
 ) {
     std::uint8_t * pos = output;
-    std::uint8_t * session_id_pos;
 
     *(pos++) = version;
-    pos = encode(pos, GROUP_SESSION_ID_TAG, session_id_pos, session_id_length);
-    std::memcpy(session_id_pos, session_id, session_id_length);
     pos = encode(pos, GROUP_MESSAGE_INDEX_TAG, message_index);
     pos = encode(pos, GROUP_CIPHERTEXT_TAG, *ciphertext_ptr, ciphertext_length);
     return pos-output;
@@ -376,8 +368,6 @@ void _olm_decode_group_message(
     std::uint8_t const * end = input + input_length - mac_length;
     std::uint8_t const * unknown = nullptr;
 
-    results->session_id = nullptr;
-    results->session_id_length = 0;
     bool has_message_index = false;
     results->message_index = 0;
     results->ciphertext = nullptr;
@@ -388,10 +378,6 @@ void _olm_decode_group_message(
     results->version = *(pos++);
 
     while (pos != end) {
-        pos = decode(
-            pos, end, GROUP_SESSION_ID_TAG,
-            results->session_id, results->session_id_length
-        );
         pos = decode(
             pos, end, GROUP_MESSAGE_INDEX_TAG,
             results->message_index, has_message_index

src/outbound_group_session.c

@@ -187,7 +187,7 @@ static size_t raw_message_length(
     mac_length = megolm_cipher->ops->mac_length(megolm_cipher);
 
     return _olm_encode_group_message_length(
-        GROUP_SESSION_ID_LENGTH, session->ratchet.counter,
+        session->ratchet.counter,
         ciphertext_length, mac_length);
 }
 
@@ -220,7 +220,6 @@ static size_t _encrypt(
      */
     message_length = _olm_encode_group_message(
         OLM_PROTOCOL_VERSION,
-        session->session_id, GROUP_SESSION_ID_LENGTH,
         session->ratchet.counter,
         ciphertext_length,
         buffer,

tests/test_message.cpp

@@ -67,12 +67,8 @@ assert_equals(message2, output, 35);
 
     TestCase test_case("Group message encode test");
 
-    const uint8_t session_id[] = "sessionid";
-    size_t session_id_len = 9;
-
-    size_t length = _olm_encode_group_message_length(
-        session_id_len, 200, 10, 8);
-    size_t expected_length = 1 + (2+session_id_len) + (1+2) + (2+10) + 8;
+    size_t length = _olm_encode_group_message_length(200, 10, 8);
+    size_t expected_length = 1 + (1+2) + (2+10) + 8;
     assert_equals(expected_length, length);
 
     uint8_t output[50];
@@ -80,7 +76,6 @@ assert_equals(message2, output, 35);
 
     _olm_encode_group_message(
         3,
-        session_id, session_id_len,
         200, // counter
         10,  // ciphertext length
         output,
@@ -89,9 +84,8 @@ assert_equals(message2, output, 35);
 
     uint8_t expected[] =
         "\x03"
-        "\x0A\x09sessionid"
-        "\x10\xC8\x01"
-        "\x1A\x0A";
+        "\x08\xC8\x01"
+        "\x12\x0A";
 
     assert_equals(expected, output, sizeof(expected)-1);
     assert_equals(output+sizeof(expected)-1, ciphertext_ptr);
@@ -103,17 +97,12 @@ assert_equals(message2, output, 35);
     struct _OlmDecodeGroupMessageResults results;
     std::uint8_t message[] =
         "\x03"
-        "\x0A\x09sessionid"
-        "\x10\xC8\x01"
-        "\x1A\x0A" "ciphertext"
+        "\x08\xC8\x01"
+        "\x12\x0A" "ciphertext"
         "hmacsha2";
 
-    const uint8_t expected_session_id[] = "sessionid";
-
     _olm_decode_group_message(message, sizeof(message)-1, 8, &results);
     assert_equals(std::uint8_t(3), results.version);
-    assert_equals(std::size_t(9), results.session_id_length);
-    assert_equals(expected_session_id, results.session_id, 9);
     assert_equals(1, results.has_message_index);
     assert_equals(std::uint32_t(200), results.message_index);
     assert_equals(std::size_t(10), results.ciphertext_length);