Aspia Host

Purpose
Installing
Automation of installation
Settings
Command line
Environment variables
Files
Security log
Logs
Notes
Android

1. Purpose

Accepts incoming connections from Clients to manage the computer on which it is installed.

2. Installing

Windows x86
  Run aspia-host-<version>-x86.msi and follow the instructions on the screen.

Windows x86_64
  Run aspia-host-<version>-x86_64.msi and follow the instructions on the screen.

macOS
  Run aspia-host-<version>-universal.pkg and follow the instructions on the screen.

Ubuntu
  sudo apt install ./aspia-host-<version>-x86_64.deb

RHEL and compatible
  sudo dnf install ./aspia-host-<version>-x86_64.rpm

Android
  Open aspia-host-<version>-arm64.apk on the device and follow the instructions on the screen.

3. Automation of installation

On Windows the parameters of the Host and its users can be applied automatically during the installation. To do this:

Install the Host on one of the computers, configure the parameters and add the users.
Export the configuration with the Export settings button on the General tab of the settings, or with the aspia_host --export <file> command.
Name the file aspia-host.json and place it in the same directory as the MSI package.

During the installation the configuration is imported from this file automatically. The installation must be started from a local location (a local disk or a flash drive); it may not work when installing from network locations or when deploying with AD.

4. Settings

To change Host parameters, the application has a Settings dialog. Below is an overview of the possible options.

4.1. General tab

On the “General” tab, you can configure basic application settings, as well as import and export settings.

Incoming port

TCP port on which the Host accepts incoming connections, 8050 by default.

Preferred video capturer

The method of capturing the screen. With “Default” the Host chooses it itself. Not displayed on Linux.

Allow hardware video encoding

Allows to encode the video with the graphics adapter. Not displayed on Linux.

Updates

The automatic checking and installation of updates with the selected frequency, the update channel and the button to check for updates immediately.

Import/Export

Import and export settings allow you to save the current configuration to an JSON file for later recovery (for backup purposes) or automatic deployment. Import and export of parameters can be done through a graphical user interface and from the command line. To perform import and export via a graphical interface, use the Import settings and Export settings buttons in the Settings group. To perform import and export via the command line, use the following commands (for “silent” import and export without displaying messages or dialogs, add argument --silent):

aspia_host --import <file>
aspia_host --export <file>

4.2. Security tab

On the “Security” tab, you can configure settings for additional protection of the application.

Password Protection of Settings

This option allows you to set a password that will be requested when you try to open the Host Settings dialog. The password is stored in the secure data base of the Host, which only administrators can read and change.

One-time Password

When this option is enabled, the Host interface will display a one-time password, which the user can dictate to the connector for a one-time connection. You can also configure the frequency of automatic change of this password (or disable automatic change, then the password will change only when the service is restarted), specify the characters that the password can contain and the length of the password.

Connection Confirmation

When this option is enabled, a connection confirmation dialog will be displayed to allow the user to accept or reject the incoming connection. You can also configure the time interval after which the incoming connection will be automatically confirmed and the action that will be performed if there is no active user in the computer’s operating system when connecting (the connection can be automatically accepted or rejected).

Other

The Disable Aspia shutdown option blocks the exit command in the window of the Host, so the user cannot close the application.

4.3. Router tab

On the “Router” tab you can specify parameters for connecting to the Aspia Router. Enter the server address and public key and apply the settings.

4.4. Users tab

To manage users, you need to run the Aspia Host Settings and go to the “Users” tab.

To add a user, use the Add button. To edit a user, use the Modify button, and to delete a user, the Delete button. When adding a new user, you need to enter a username and password, as well as select the types of sessions that this user can connect to.

Warning! When you change your username, you also need to re-enter the password.

The dialog for adding or editing a user is as follows:

5. Command Line

Argument	Description
`--install`	Installs the Host service. Administrator rights are required to execute.
`--remove`	Removes the Host service. Administrator rights are required to execute.
`--start`	Starts the Host service. Administrator rights are required to execute.
`--stop`	Stops the Host service. Administrator rights are required to execute.
`--import <file>`	Imports the configuration from a JSON file.
`--export <file>`	Exports the configuration to a JSON file.
`--silent`	Imports or exports the configuration without displaying any messages.
`--config`	Opens the settings of the Host.
`--security-log`	Opens the security log.
`--hidden`	Starts the application without displaying its window.
`--version`	Displays the version of the application.
`--help`	Displays help about command line arguments.

6. Environment variables

ASPIA_NO_OVERFLOW_DETECTION - If the variable exists (with any value), then the automatic network stack overflow detection mechanism is disabled. If the variable does not exist, then Aspia tries to automatically adjust to the change in bandwidth by changing the FPS, scaling the image or other actions.
ASPIA_DEFAULT_FPS - Determines the FPS with which the connection starts. If variable ASPIA_NO_OVERFLOW_DETECTION is not declared, then in the future the FPS can be lowered or increased. If variable ASPIA_NO_OVERFLOW_DETECTION is declared, then this FPS value will be used for the duration of the connection. It can take values from 1 to 60. The default value is 24.
ASPIA_MIN_FPS - Determines the value to which the FPS can be reduced during automatic bandwidth adjustment. If variable ASPIA_NO_OVERFLOW_DETECTION is declared, then this value is ignored. It can take values from 1 to 60. The default value is 10.
ASPIA_MAX_FPS - Determines the maximum value up to which the FPS can be increased during automatic bandwidth control. If variable ASPIA_NO_OVERFLOW_DETECTION is declared, then this value is ignored. It can take values from 1 to 60. For computers with more than 2 logical processors, the default value is 30. Otherwise, the default value is 20.
ASPIA_NO_VERIFY_TLS_PEER - If the variable is declared, then the validity of the TLS certificate is not checked when checking for updates and downloading them. It is not recommended to declare this variable unnecessarily. Declaring this variable can help solve the problem with checking for updates in Windows 7/2008R2, where root certificates are not updated.
ASPIA_SMALL_ICON_SIZE - Sets the size of the small icons of the interface in pixels, from 16 to 48, default 24.

7. Files

Data base host.db3 contains all the important data of the Host: the users, the connection to the Router and the key of the computer. Only administrators can read and change it.

Windows
  C:\ProgramData\aspia\secure\host.db3

Linux
  /etc/aspia/secure/host.db3

macOS
  /Library/Application Support/aspia/secure/host.db3

Android
  /data/data/org.aspia.host/files/settings/aspia/secure/host.db3

Parameters files host.ini and host_storage.ini contain the parameters of the service and its state, for example the last received Host ID.

Windows
  C:\ProgramData\aspia\host.ini
  C:\ProgramData\aspia\host_storage.ini

Linux
  /etc/xdg/aspia/host.ini
  /etc/xdg/aspia/host_storage.ini

macOS
  /Library/Preferences/Qt/aspia/host.ini
  /Library/Preferences/Qt/aspia/host_storage.ini

Android
  /data/data/org.aspia.host/files/settings/aspia/host.ini
  /data/data/org.aspia.host/files/settings/aspia/host_storage.ini

The parameters of the appearance of the window of the Host are stored in the profile of the user: %APPDATA%\aspia\host.ini on Windows and ~/.config/aspia/host.ini on Linux and macOS.

8. Security log

The security log records the connections to the Host: the time, the type of the session, the user, the address and the name of the computer of the connecting side and the version of its application, as well as the disconnections and the failed attempts to connect. The log is opened with the Security Log… command of the Aspia menu of the window of the Host or with the aspia_host --security-log command. Administrator rights are required to view it.

A new file is created every week, and the files older than 180 days are deleted automatically. The files are located in the following paths:

Windows
  C:\ProgramData\aspia\secure\logs\

Linux
  /var/log/aspia/security/

macOS
  /Library/Logs/aspia/security/

9. Logs

By default the Host writes the log to files. To configure the logging parameters, use the following recommendations:

To set the log level, declare an environment variable ASPIA_LOG_LEVEL with a value from 0 to 4 (0 - trace, 1 - info, 2 - warning, 3 - error, 4 - fatal). Decreasing the value increases the number of messages in the log.
To enable logging to a file (if it is not enabled by default for platform), declare environment variable ASPIA_LOG_TO_FILE with a value other than 0. If the environment variable is declared with a value of 0, then logging to file will be disabled.
To enable logging to stdout (if it is not enabled by default for platform), declare environment variable ASPIA_LOG_TO_STDOUT with a value other than 0. If the environment variable is declared with a value of 0, then logging to stdout will be disabled.
By default, log files older than 14 days are automatically deleted. If you want to change this value, then declare environment variable ASPIA_MAX_LOG_FILE_AGE with a numeric value in days. The variable can take a value from 0 to 366. If the variable is set to 0, then the log files will not be automatically deleted.

The log files are located in the following paths:

Windows
  %TEMP%\aspia\aspia_host-*.log (the window of the Host)
  C:\Windows\SystemTemp\aspia\aspia_host-*.log (the service; C:\Windows\Temp\aspia on older versions)

Linux
  ~/.local/state/aspia/logs/aspia_host-*.log (the window of the Host)
  /var/log/aspia/host/aspia_host-*.log (the service)

macOS
  $TMPDIR/aspia/aspia_host-*.log

Android
  /sdcard/Android/data/org.aspia.host/files/log/

10. Notes

The ID of the computer is linked to the key stored in the data base of the Host, C:\ProgramData\aspia\secure\host.db3. The key does not contain the ID, but it allows to obtain the ID when connecting to the Router; the ID is assigned at the first connection. The data base also holds the users and the settings of the Host. To keep the ID after reinstalling the operating system, make a backup copy of this file and restore it after the installation of the Host.
Important! If you are cloning an operating system to other computers, make sure that the data base of the Host is removed from the image. Otherwise the computers with the same key will receive the same ID one by one, pushing each other out of the Router. The users and the settings can then be applied with the automatic import.
The configuration of the Host is stored in its data base and in the file C:\ProgramData\aspia\host.ini. To transfer the configuration, use the import and the export. Do not copy these files as they are.
It is recommended to disable HDR mode for correct color rendering.

11. Android

The Host for Android allows to connect to a phone or a tablet; the Desktop and File Transfer sessions are available. At the first start the application asks for the permissions it needs: the accessibility service, the display over other apps, the access to all files and the notifications. The application does not work until all of them are granted.

The Connection section displays the ID of the device and the one-time password, and they can be sent to the connecting side with any application of the device. At every connection Android asks for the consent to capture the screen.

During a desktop session a floating button is displayed on the screen of the device. It opens a menu with the synchronization of the clipboard and the Back, Home and Recents buttons.

The users, the password protection of the settings, the connection to a Router and the updates are configured in the Settings section. The settings can also be imported from a file exported by the Host.

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