Accept subgroup messages and distinguish own device replicas

src/dm/dm_core.c

@@ -542,7 +542,11 @@ int dm_accept_message(struct UTUN_INSTANCE* inst, const uint8_t* msg, size_t len
         return -1;
     }
     if (dm_verify_message(inst, inst->node_id, msg, len) != 0) return -1;
-    int deleted = dm_history_deleted(inst, msg, len, 0, NULL);
+    struct dm_message_view message;
+    if (dm_message_parse(msg, len, &message)) return -1;
+    int side = message.mode == DM_MODE_GROUPS ? dm_message_target(&message, inst->node_id, NULL, NULL) : 1;
+    int dir = side == 0;
+    int deleted = dm_history_deleted(inst, msg, len, dir, NULL);
     if (deleted < 0) return -1;
     uint64_t conv, seq, author;
     memcpy(&conv, msg, 8);
@@ -558,38 +562,56 @@ int dm_accept_message(struct UTUN_INSTANCE* inst, const uint8_t* msg, size_t len
     if (created) {
         memset(&c, 0, sizeof(c));
         snprintf(c.conv_id, sizeof(c.conv_id), "%s", conv_id);
+        c.mode = message.mode;
         c.peer_node_id = author;
         if (!dm_shared_group_id(dm, author, &c.group_id)) {
             DEBUG_WARN(DEBUG_CATEGORY_DM, "%s: unknown correspondent peer=%llu", DM_ID, (unsigned long long)author);
             return -1;
         }
-        if (dm_node_pubkeys(dm, author, c.peer_x25519, c.peer_ed25519) != 0 ||
+        if (c.mode == DM_MODE_GROUPS) {
+            c.parties[0] = message.parties[side]; c.parties[1] = message.parties[1 - side];
+            if (!side) {
+                c.peer_node_id = 0;
+                for (unsigned i = 0; i < message.target_count; i++) {
+                    struct dm_target target;
+                    if (dm_message_target_at(&message, i, &target)) return -1;
+                    if (target.side == 1) { c.peer_node_id = target.node; break; }
+                }
+            }
+            memcpy(c.peer_x25519, c.parties[1].x, 32); memcpy(c.peer_ed25519, c.parties[1].ed, 32);
+            uint8_t private_key[32];
+            if (dm_party_private(inst, c.parties, private_key)) return -1;
+            int error = dm_derive_content_key(private_key, c.parties[1].x, c.content_key);
+            OPENSSL_cleanse(private_key, sizeof(private_key));
+            if (error) return -1;
+        } else if (dm_node_pubkeys(dm, author, c.peer_x25519, c.peer_ed25519) != 0 ||
             dm_derive_content_key(inst->my_keys.private_key, c.peer_x25519, c.content_key) != 0) return -1;
         char name[128] = {0};
-        chat_core_get_node_name(inst, author, name, sizeof(name));
+        chat_core_get_node_name(inst, c.peer_node_id, name, sizeof(name));
         dm_copy_peer_name(c.peer_name, name, strlen(name), conv_id);
     }
-    if (c.peer_node_id != author) {
+    if (c.mode != message.mode || (c.mode == DM_MODE_DEVICE && c.peer_node_id != author) ||
+        (c.mode == DM_MODE_GROUPS && (!dm_party_equal(c.parties, message.parties + side) ||
+                                    !dm_party_equal(c.parties + 1, message.parties + 1 - side)))) {
         DEBUG_ERROR(DEBUG_CATEGORY_DM, "%s: conversation author mismatch conv=%s", DM_ID, conv_id);
         return -1;
     }
-    uint16_t enc_len;
-    memcpy(&enc_len, msg + 33 + msg[32], 2);
+    if (!dm_conv_active(dm, &c)) return -1;
     uint8_t nonce[DM_NONCE_SIZE], plain[DM_DATA_MAX + 1];
     size_t plain_len = 0;
     dm_build_nonce(conv, author, seq, nonce);
-    if (media_ccm_decrypt(c.content_key, nonce, msg + 35 + msg[32], enc_len, plain, &plain_len) != 0) return -1;
+    if (media_ccm_decrypt(c.content_key, nonce, message.ciphertext, message.ciphertext_size, plain, &plain_len) != 0) return -1;
     if (dm_message_media(msg, len)) {
         struct attachment_info info;
         if (attachment_decode(plain, plain_len, &info)) return -1;
     }
     if (dm_exec(dm, "BEGIN IMMEDIATE") != 0) return -1;
-    int inserted = dm_store_message(dm, conv_id, 0, msg, len);
-    if (seq > c.last_in_seq) c.last_in_seq = seq; /* Только статистика; не курсор dedup. */
+    int inserted = dm_store_message(dm, conv_id, dir, msg, len);
+    if (!dir && seq > c.last_in_seq) c.last_in_seq = seq; /* Только статистика; не курсор dedup. */
     uint64_t ts;
     memcpy(&ts, msg + 16, 8);
     if (ts > c.last_ts) c.last_ts = ts;
-    if (inserted < 0 || dm_conv_save(dm, &c) != 0 || dm_media_track(inst, 0, msg, len) != 0 ||
+    if (inserted < 0 || dm_conv_save(dm, &c) != 0 || dm_media_track(inst, dir, msg, len) != 0 ||
         (inserted && dm_history_show(inst, conv_id)) || dm_exec(dm, "COMMIT") != 0) {
         dm_exec(dm, "ROLLBACK");
         return -1;

src/dm/dm_history.c

@@ -19,7 +19,7 @@ int dm_history_init(struct UTUN_INSTANCE* inst) {
     const char* sql =
         "CREATE TABLE IF NOT EXISTS dm_history(conv_id TEXT PRIMARY KEY,generation INTEGER NOT NULL,hidden INTEGER NOT NULL);"
         "CREATE TABLE IF NOT EXISTS dm_deleted_messages(conv_id TEXT NOT NULL,dir INTEGER NOT NULL,seq INTEGER NOT NULL,"
-        "body_hash BLOB NOT NULL,media_id BLOB,media_receipt BLOB,PRIMARY KEY(conv_id,dir,seq));"
+        "author INTEGER NOT NULL,body_hash BLOB NOT NULL,media_id BLOB,media_receipt BLOB,PRIMARY KEY(conv_id,author,seq));"
         "CREATE TABLE IF NOT EXISTS dm_local_files(path TEXT PRIMARY KEY,conv_id TEXT NOT NULL,generation INTEGER NOT NULL,"
         "busy INTEGER NOT NULL DEFAULT 0,retry_at INTEGER NOT NULL DEFAULT 0);"
         "UPDATE dm_local_files SET busy=0;";