Print Wi-Fi connection details saved in NetworkManager as a QR code

qifi.py

"""
Print Wi-Fi connection details saved in NetworkManager as a QR code supported
on Android (with Barcode Scanner or NeoReader) and iOS 11+.

Usage:
    python3 qifi.py [SSID]
    # (by default, currently active network will be used)
"""

import dbus  # sudo apt install python3-dbus
from qrcode import QRCode  # pip install qrcode


def get_all_props(obj, type):
    props = dbus.Interface(obj, "org.freedesktop.DBus.Properties")
    return props.GetAll(type)


def get_connection_info(ssid=None):
    bus = dbus.SystemBus()

    if ssid is None:
        nm_obj = bus.get_object(
            "org.freedesktop.NetworkManager", "/org/freedesktop/NetworkManager"
        )
        nm_props = get_all_props(nm_obj, "org.freedesktop.NetworkManager")

        for act_conn_path in nm_props["ActiveConnections"]:
            act_conn_obj = bus.get_object(
                "org.freedesktop.NetworkManager", act_conn_path
            )
            act_conn_props = get_all_props(
                act_conn_obj, "org.freedesktop.NetworkManager.Connection.Active"
            )
            if act_conn_props["Type"] == "802-11-wireless":
                break

        conn_obj = bus.get_object(
            "org.freedesktop.NetworkManager", act_conn_props["Connection"]
        )
        conn = dbus.Interface(
            conn_obj, "org.freedesktop.NetworkManager.Settings.Connection"
        )
        settings = conn.GetSettings()

    else:
        settings_obj = bus.get_object(
            "org.freedesktop.NetworkManager", "/org/freedesktop/NetworkManager/Settings"
        )
        settings_props = get_all_props(
            settings_obj, "org.freedesktop.NetworkManager.Settings"
        )
        for conn_path in settings_props["Connections"]:
            conn_obj = bus.get_object("org.freedesktop.NetworkManager", conn_path)
            conn = dbus.Interface(
                conn_obj, "org.freedesktop.NetworkManager.Settings.Connection"
            )
            try:
                settings = conn.GetSettings()
            except:
                continue
            if settings["connection"]["type"] != "802-11-wireless":
                continue
            conn_ssid = "".join(chr(i) for i in settings["802-11-wireless"]["ssid"])
            if conn_ssid == ssid:
                break
        else:
            raise KeyError("No network with SSID " + ssid)

    secrets = conn.GetSecrets("802-11-wireless-security")

    return {
        "ssid": "".join(chr(i) for i in settings["802-11-wireless"]["ssid"]),
        "algo": (
            "WEP"
            if settings["802-11-wireless-security"]["key-mgmt"].startswith("wep")
            else "WPA"
        ),
        "psk": secrets["802-11-wireless-security"]["psk"],
    }


if __name__ == "__main__":
    import sys
    ssid = sys.argv[1] if len(sys.argv) > 1 else None
    conn_info = get_connection_info(ssid)

    qr = QRCode()
    qr.add_data(
        f"WIFI:S:{conn_info['ssid']};T:{conn_info['algo']};P:{conn_info['psk']};;"
    )
    qr.print_ascii(tty=True)

    print("")
    print(f"  Network name: {conn_info['ssid']}")
    print(f"      Password: {conn_info['psk']}")
    print("")

Named after https://www.qifi.org/, a wifi QR generator by @evgeni that I've been using regularly before.