Vaulted key database fully used

Now all keys are encrypted when they're not in use to thwart cold-boot
attacks. Furthermore, all unlocking messages are sent in bulk to avoid
fragmentation and improve performance.

client.c

@@ -84,11 +84,14 @@ static bool attempt_unlock_luks_volume(struct keyclient_t *keyclient, const stru
 		return false;
 	}
 
-	/* Volume! */
+	/* This is a valid volume which we need to unlock */
 	int volume_index = keydb_get_volume_index(host, volume);
 	if (volume_index != -1) {
 		if (keyclient->opts->no_luks) {
 			keyclient->volume_unlocked[volume_index] = true;
+#ifdef DEBUG
+			dump_hexline(stderr, "Raw key: ", unlock_msg->luks_passphrase_raw, LUKS_PASSPHRASE_RAW_SIZE_BYTES, false);
+#endif
 		} else {
 			if (!keyclient->volume_unlocked[volume_index]) {
 				bool success = unlock_luks_volume(volume, unlock_msg);

server.c

@@ -142,6 +142,11 @@ static int psk_server_callback(SSL *ssl, const unsigned char *identity, size_t i
 	return result;
 }
 
+static void copy_luks_passphrase_callback(void *vctx, unsigned int volume_index, const void *source) {
+	struct msg_t *msgs = (struct msg_t*)vctx;
+	memcpy(msgs[volume_index].luks_passphrase_raw, source, LUKS_PASSPHRASE_RAW_SIZE_BYTES);
+}
+
 static void client_handler_thread(void *vctx) {
 	struct client_thread_ctx_t *client = (struct client_thread_ctx_t*)vctx;
 
@@ -156,19 +161,21 @@ static void client_handler_thread(void *vctx) {
 		} else {
 			if (client->host) {
 				log_msg(LLVL_DEBUG, "Client \"%s\" connected, sending unlock data for %d volumes.", client->host->host_name, client->host->volume_count);
+				/* Initially prepare all messages we're about to send to the
+				 * client by filling the UUID fields */
+				struct msg_t msgs[client->host->volume_count];
 				for (unsigned int i = 0; i < client->host->volume_count; i++) {
 					const struct volume_entry_t *volume = &client->host->volumes[i];
+					memcpy(msgs[i].volume_uuid, volume->volume_uuid, 16);
+				}
 
-					struct msg_t msg = { 0 };
-					memcpy(msg.volume_uuid, volume->volume_uuid, 16);
-					memcpy(msg.luks_passphrase_raw, volume->luks_passphrase_raw, LUKS_PASSPHRASE_RAW_SIZE_BYTES);
+				/* Then also fill the keys */
+				vaulted_keydb_get_volume_luks_passphases_raw(client->vaulted_keydb, copy_luks_passphrase_callback, msgs, client->host);
 
-					int txlen = SSL_write(ssl, &msg, sizeof(msg));
-					OPENSSL_cleanse(&msg, sizeof(msg));
-					if (txlen != sizeof(msg)) {
-						log_msg(LLVL_WARNING, "Tried to send message of %d bytes, but sent %d. Severing connection to client.", sizeof(msg), txlen);
-						break;
-					}
+				int txlen = SSL_write(ssl, &msgs, sizeof(msgs));
+				OPENSSL_cleanse(&msgs, sizeof(msgs));
+				if (txlen != (long)sizeof(msgs)) {
+					log_msg(LLVL_WARNING, "Tried to send message of %d bytes, but sent %d. Severing connection to client.", sizeof(msgs), txlen);
 				}
 			} else {
 				log_msg(LLVL_FATAL, "Client connected, but no host set.");
@@ -316,6 +323,7 @@ bool keyserver_start(const struct pgmopts_server_t *opts) {
 		close(keyserver.tcp_sd);
 	}
 	free_generic_tls_context(&keyserver.gctx);
+	vaulted_keydb_free(keyserver.vaulted_keydb);
 	keydb_free(keyserver.keydb);
 	return success;
 }

vaulted_keydb.c

@@ -83,19 +83,13 @@ bool vaulted_keydb_get_tls_psk(struct vaulted_keydb_t *vaulted_keydb, uint8_t de
 	return true;
 }
 
-bool vaulted_keydb_get_volume_luks_passphase_raw(struct vaulted_keydb_t *vaulted_keydb, uint8_t dest[LUKS_PASSPHRASE_RAW_SIZE_BYTES], const struct host_entry_t *host, const struct volume_entry_t *volume) {
+bool vaulted_keydb_get_volume_luks_passphases_raw(struct vaulted_keydb_t *vaulted_keydb, void (*copy_callback)(void *vctx, unsigned int volume_index, const void *source), void *copy_ctx, const struct host_entry_t *host) {
 	int host_index = keydb_get_host_index(vaulted_keydb->keydb, host);
 	if (host_index < 0) {
 		log_msg(LLVL_FATAL, "Unable to retrieve host index for vaulted key db entry.");
 		return false;
 	}
 
-	int volume_index = keydb_get_volume_index(host, volume);
-	if (volume_index < 0) {
-		log_msg(LLVL_FATAL, "Unable to retrieve volume index for vaulted key db entry.");
-		return false;
-	}
-
 	/* Get a pointer into the vaulted structure */
 	struct luks_passphrase_vault_entry_t *entry = vaulted_keydb_get_luks_passphrase_for_hostindex(vaulted_keydb, host_index);
 
@@ -105,12 +99,13 @@ bool vaulted_keydb_get_volume_luks_passphase_raw(struct vaulted_keydb_t *vaulted
 		return false;
 	}
 
-	/* Copy out the data we need */
-	memcpy(dest, &entry->volumes[volume_index].luks_passphrase_raw, LUKS_PASSPHRASE_RAW_SIZE_BYTES);
+	/* Copy out the data we need by calling back for all volumes */
+	for (unsigned int i = 0; i < host->volume_count; i++) {
+		copy_callback(copy_ctx, i, &entry->volumes[i].luks_passphrase_raw);
+	}
 
 	/* And close it back up */
 	if (!vault_close(vaulted_keydb->luks_passphrase_vault)) {
-		OPENSSL_cleanse(dest, PSK_SIZE_BYTES);
 		log_msg(LLVL_FATAL, "Unable to close LUKS passphrase vault of vaulted key db entry.");
 		return false;
 	}

vaulted_keydb.h

@@ -45,7 +45,7 @@ struct vaulted_keydb_t {
 
 /*************** AUTO GENERATED SECTION FOLLOWS ***************/
 bool vaulted_keydb_get_tls_psk(struct vaulted_keydb_t *vaulted_keydb, uint8_t dest[PSK_SIZE_BYTES], const struct host_entry_t *host);
-bool vaulted_keydb_get_volume_luks_passphase_raw(struct vaulted_keydb_t *vaulted_keydb, uint8_t dest[LUKS_PASSPHRASE_RAW_SIZE_BYTES], const struct host_entry_t *host, const struct volume_entry_t *volume);
+bool vaulted_keydb_get_volume_luks_passphases_raw(struct vaulted_keydb_t *vaulted_keydb, void (*copy_callback)(void *ctx, unsigned int volume_index, const void *source), void *copy_ctx, const struct host_entry_t *host);
 struct vaulted_keydb_t *vaulted_keydb_new(struct keydb_t *keydb);
 void vaulted_keydb_free(struct vaulted_keydb_t *vaulted_keydb);
 /***************  AUTO GENERATED SECTION ENDS   ***************/