Wi-Fi Provisioning

Overview

This component provides APIs that control Wi-Fi provisioning service for receiving and configuring Wi-Fi credentials over SoftAP or BLE transport via secure Protocol Communication (protocomm) sessions. The set of wifi_prov_mgr_ APIs help in quickly implementing a provisioning service having necessary features with minimal amount of code and sufficient flexibility.

Initialization

wifi_prov_mgr_init() is called to configure and initialize the provisioning manager and thus this must be called prior to invoking any other wifi_prov_mgr_ APIs. Note that the manager relies on other components of IDF, namely NVS, TCP/IP, Event Loop and Wi-Fi (and optionally mDNS), hence these must be initialized beforehand. The manager can be de-initialized at any moment by making a call to wifi_prov_mgr_deinit().

wifi_prov_mgr_config_t config = {
    .scheme = wifi_prov_scheme_ble,
    .scheme_event_handler = WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BTDM
};

ESP_ERR_CHECK( wifi_prov_mgr_init(config) );

The configuration structure wifi_prov_mgr_config_t has a few fields to specify the behavior desired of the manager :

• scheme : This is used to specify the provisioning scheme. Each scheme corresponds to one of the modes of transport supported by protocomm. Hence, we have three options :

  • wifi_prov_scheme_ble : BLE transport and GATT Server for handling provisioning commands

  • wifi_prov_scheme_softap : Wi-Fi SoftAP transport and HTTP Server for handling provisioning commands

  • wifi_prov_scheme_console : Serial transport and console for handling provisioning commands

• scheme_event_handler : An event handler defined along with scheme. Choosing appropriate scheme specific event handler allows the manager to take care of certain matters automatically. Presently this is not used for either SoftAP or Console based provisioning, but is very convenient for BLE. To understand how, we must recall that Bluetooth requires quite some amount of memory to function and once provisioning is finished, the main application may want to reclaim back this memory (or part of it, if it needs to use either BLE or classic BT). Also, upon every future reboot of a provisioned device, this reclamation of memory needs to be performed again. To reduce this complication in using wifi_prov_scheme_ble, the scheme specific handlers have been defined, and depending upon the chosen handler, the BLE / classic BT / BTDM memory will be freed automatically when the provisioning manager is de-initialized. The available options are:

  • WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BTDM - Free both classic BT and BLE (BTDM) memory. Used when main application doesn’t require Bluetooth at all.

  • WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BLE - Free only BLE memory. Used when main application requires classic BT.

  • WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BT - Free only classic BT. Used when main application requires BLE. In this case freeing happens right when the manager is initialized.

  • WIFI_PROV_EVENT_HANDLER_NONE - Don’t use any scheme specific handler. Used when provisioning scheme is not BLE (i.e. SoftAP or Console), or when main application wants to handle the memory reclaiming on its own, or needs both BLE and classic BT to function.

• app_event_handler (Deprecated) : It is now recommended to catch WIFI_PROV_EVENT``s that are emitted to the default event loop handler. See definition of ``wifi_prov_cb_event_t for the list of events that are generated by the provisioning service. Here is an excerpt showing some of the provisioning events:

static void event_handler(void* arg, esp_event_base_t event_base,
                          int event_id, void* event_data)
{
    if (event_base == WIFI_PROV_EVENT) {
        switch (event_id) {
            case WIFI_PROV_START:
                ESP_LOGI(TAG, "Provisioning started");
                break;
            case WIFI_PROV_CRED_RECV: {
                wifi_sta_config_t *wifi_sta_cfg = (wifi_sta_config_t *)event_data;
                ESP_LOGI(TAG, "Received Wi-Fi credentials"
                         "\n\tSSID     : %s\n\tPassword : %s",
                         (const char *) wifi_sta_cfg->ssid,
                         (const char *) wifi_sta_cfg->password);
                break;
            }
            case WIFI_PROV_CRED_FAIL: {
                wifi_prov_sta_fail_reason_t *reason = (wifi_prov_sta_fail_reason_t *)event_data;
                ESP_LOGE(TAG, "Provisioning failed!\n\tReason : %s"
                         "\n\tPlease reset to factory and retry provisioning",
                         (*reason == WIFI_PROV_STA_AUTH_ERROR) ?
                         "Wi-Fi station authentication failed" : "Wi-Fi access-point not found");
                break;
            }
            case WIFI_PROV_CRED_SUCCESS:
                ESP_LOGI(TAG, "Provisioning successful");
                break;
            case WIFI_PROV_END:
                /* De-initialize manager once provisioning is finished */
                wifi_prov_mgr_deinit();
                break;
            default:
                break;
        }
    }
}

The manager can be de-initialized at any moment by making a call to wifi_prov_mgr_deinit().

Check Provisioning State

Whether device is provisioned or not can be checked at runtime by calling wifi_prov_mgr_is_provisioned(). This internally checks if the Wi-Fi credentials are stored in NVS.

Note that presently manager does not have its own NVS namespace for storage of Wi-Fi credentials, instead it relies on the esp_wifi_ APIs to set and get the credentials stored in NVS from the default location.

If provisioning state needs to be reset, any of the following approaches may be taken :

• the associated part of NVS partition has to be erased manually

• main application must implement some logic to call esp_wifi_ APIs for erasing the credentials at runtime

• main application must implement some logic to force start the provisioning irrespective of the provisioning state

bool provisioned = false;
ESP_ERR_CHECK( wifi_prov_mgr_is_provisioned(&provisioned) );

Start Provisioning Service

At the time of starting provisioning we need to specify a service name and the corresponding key. These translate to :

• Wi-Fi SoftAP SSID and passphrase, respectively, when scheme is wifi_prov_scheme_softap

• BLE Device name (service key is ignored) when scheme is wifi_prov_scheme_ble

Also, since internally the manager uses protocomm, we have the option of choosing one of the security features provided by it :

• Security 1 is secure communication which consists of a prior handshake involving X25519 key exchange along with authentication using a proof of possession (pop), followed by AES-CTR for encryption/decryption of subsequent messages

• Security 0 is simply plain text communication. In this case the pop is simply ignored

See Provisioning for details about the security features.

const char *service_name = "my_device";
const char *service_key  = "password";

wifi_prov_security_t security = WIFI_PROV_SECURITY_1;
const char *pop = "abcd1234";

ESP_ERR_CHECK( wifi_prov_mgr_start_provisioning(security, pop, service_name, service_key) );

The provisioning service will automatically finish only if it receives valid Wi-Fi AP credentials followed by successfully connection of device to the AP (IP obtained). Regardless of that, the provisioning service can be stopped at any moment by making a call to wifi_prov_mgr_stop_provisioning().

Note

If the device fails to connect with the provided credentials, it won’t accept new credentials anymore, but the provisioning service will keep on running (only to convey failure to the client), until the device is restarted. Upon restart the provisioning state will turn out to be true this time (as credentials will be found in NVS), but device will again fail to connect with those same credentials (unless an AP with the matching credentials somehow does become available). This situation can be fixed by resetting the credentials in NVS or force starting the provisioning service. This has been explained above in Check Provisioning State.

Waiting For Completion

Typically, the main application will wait for the provisioning to finish, then de-initialize the manager to free up resources and finally start executing its own logic.

There are two ways for making this possible. The simpler way is to use a blocking call to wifi_prov_mgr_wait().

// Start provisioning service
ESP_ERR_CHECK( wifi_prov_mgr_start_provisioning(security, pop, service_name, service_key) );

// Wait for service to complete
wifi_prov_mgr_wait();

// Finally de-initialize the manager
wifi_prov_mgr_deinit();

The other way is to use the default event loop handler to catch WIFI_PROV_EVENT``s and call :cpp:func:`wifi_prov_mgr_deinit()` when event ID is ``WIFI_PROV_END:

static void event_handler(void* arg, esp_event_base_t event_base,
                          int event_id, void* event_data)
{
    if (event_base == WIFI_PROV_EVENT && event_id == WIFI_PROV_END) {
        /* De-initialize manager once provisioning is finished */
        wifi_prov_mgr_deinit();
    }
}

User Side Implementation

When the service is started, the device to be provisioned is identified by the advertised service name which, depending upon the selected transport, is either the BLE device name or the SoftAP SSID.

When using SoftAP transport, for allowing service discovery, mDNS must be initialized before starting provisioning. In this case the hostname set by the main application is used, and the service type is internally set to _esp_wifi_prov.

When using BLE transport, a custom 128 bit UUID should be set using wifi_prov_scheme_ble_set_service_uuid(). This UUID will be included in the BLE advertisement and will correspond to the primary GATT service that provides provisioning endpoints as GATT characteristics. Each GATT characteristic will be formed using the primary service UUID as base, with different auto assigned 12th and 13th bytes (assume counting starts from 0th byte). Since, an endpoint characteristic UUID is auto assigned, it shouldn’t be used to identify the endpoint. Instead, client side applications should identify the endpoints by reading the User Characteristic Description (0x2901) descriptor for each characteristic, which contains the endpoint name of the characteristic. For example, if the service UUID is set to 55cc035e-fb27-4f80-be02-3c60828b7451, each endpoint characteristic will be assigned a UUID like 55cc____-fb27-4f80-be02-3c60828b7451, with unique values at the 12th and 13th bytes.

Once connected to the device, the provisioning related protocomm endpoints can be identified as follows :

Endpoints provided by Provisioning Service

Endpoint Name (BLE + GATT Server)	URI (SoftAP + HTTP Server + mDNS)	Description
prov-session	http://<mdns-hostname>.local/prov-session	Security endpoint used for session establishment
prov-scan	http://wifi-prov.local/prov-scan	Endpoint used for starting Wi-Fi scan and receiving scan results
prov-config	http://<mdns-hostname>.local/prov-config	Endpoint used for configuring Wi-Fi credentials on device
proto-ver	http://<mdns-hostname>.local/proto-ver	Endpoint for retrieving version info

Immediately after connecting, the client application may fetch the version / capabilities information from the proto-ver endpoint. All communications to this endpoint are un-encrypted, hence necessary information (that may be relevant for deciding compatibility) can be retrieved before establishing a secure session. The response is in JSON format and looks like : prov: { ver:  v1.1, cap:  [no_pop] }, my_app: { ver:  1.345, cap:  [cloud, local_ctrl] },..... Here label prov provides provisioning service version (ver) and capabilities (cap). For now, only no_pop capability is supported, which indicates that the service doesn’t require proof of possession for authentication. Any application related version / capabilities will be given by other labels (like my_app in this example). These additional fields are set using wifi_prov_mgr_set_app_info().

User side applications need to implement the signature handshaking required for establishing and authenticating secure protocomm sessions as per the security scheme configured for use (this is not needed when manager is configured to use protocomm security 0).

See Unified Provisioning for more details about the secure handshake and encryption used. Applications must use the .proto files found under protocomm/proto, which define the Protobuf message structures supported by prov-session endpoint.

Once a session is established, Wi-Fi credentials are configured using the following set of wifi_config commands, serialized as Protobuf messages (the corresponding .proto files can be found under wifi_provisioning/proto) :

• get_status - For querying the Wi-Fi connection status. The device will respond with a status which will be one of connecting / connected / disconnected. If status is disconnected, a disconnection reason will also be included in the status response.

• set_config - For setting the Wi-Fi connection credentials

• apply_config - For applying the credentials saved during set_config and start the Wi-Fi station

After session establishment, client can also request Wi-Fi scan results from the device. The results returned is a list of AP SSIDs, sorted in descending order of signal strength. This allows client applications to display APs nearby to the device at the time of provisioning, and users can select one of the SSIDs and provide the password which is then sent using the wifi_config commands described above. The wifi_scan endpoint supports the following protobuf commands :

• scan_start - For starting Wi-Fi scan with various options :

  • blocking (input) - If true, the command returns only when the scanning is finished

  • passive (input) - If true scan is started in passive mode (this may be slower) instead of active mode

  • group_channels (input) - This specifies whether to scan all channels in one go (when zero) or perform scanning of channels in groups, with 120ms delay between scanning of consecutive groups, and the value of this parameter sets the number of channels in each group. This is useful when transport mode is SoftAP, where scanning all channels in one go may not give the Wi-Fi driver enough time to send out beacons, and hence may cause disconnection with any connected stations. When scanning in groups, the manager will wait for atleast 120ms after completing scan on a group of channels, and thus allow the driver to send out the beacons. For example, given that the total number of Wi-Fi channels is 14, then setting group_channels to 4, will create 5 groups, with each group having 3 channels, except the last one which will have 14 % 3 = 2 channels. So, when scan is started, the first 3 channels will be scanned, followed by a 120ms delay, and then the next 3 channels, and so on, until all the 14 channels have been scanned. One may need to adjust this parameter as having only few channels in a group may slow down the overall scan time, while having too many may again cause disconnection. Usually a value of 4 should work for most cases. Note that for any other mode of transport, e.g. BLE, this can be safely set to 0, and hence achieve the fastest overall scanning time.

  • period_ms (input) - Scan parameter specifying how long to wait on each channel

• scan_status - Gives the status of scanning process :

  • scan_finished (output) - When scan has finished this returns true

  • result_count (output) - This gives the total number of results obtained till now. If scan is yet happening this number will keep on updating

• scan_result - For fetching scan results. This can be called even if scan is still on going

  • start_index (input) - Starting index from where to fetch the entries from the results list

  • count (input) - Number of entries to fetch from the starting index

  • entries (output) - List of entries returned. Each entry consists of ssid, channel and rssi information

Additional Endpoints

In case users want to have some additional protocomm endpoints customized to their requirements, this is done in two steps. First is creation of an endpoint with a specific name, and the second step is the registration of a handler for this endpoint. See protocomm for the function signature of an endpoint handler. A custom endpoint must be created after initialization and before starting the provisioning service. Whereas, the protocomm handler is registered for this endpoint only after starting the provisioning service.

wifi_prov_mgr_init(config);
wifi_prov_mgr_endpoint_create("custom-endpoint");
wifi_prov_mgr_start_provisioning(security, pop, service_name, service_key);
wifi_prov_mgr_endpoint_register("custom-endpoint", custom_ep_handler, custom_ep_data);

When the provisioning service stops, the endpoint is unregistered automatically.

One can also choose to call wifi_prov_mgr_endpoint_unregister() to manually deactivate an endpoint at runtime. This can also be used to deactivate the internal endpoints used by the provisioning service.

When / How To Stop Provisioning Service?

The default behavior is that once the device successfully connects using the Wi-Fi credentials set by the apply_config command, the provisioning service will be stopped (and BLE / SoftAP turned off) automatically after responding to the next get_status command. If get_status command is not received by the device, the service will be stopped after a 30s timeout.

On the other hand, if device was not able to connect using the provided Wi-Fi credentials, due to incorrect SSID / passphrase, the service will keep running, and get_status will keep responding with disconnected status and reason for disconnection. Any further attempts to provide another set of Wi-Fi credentials, will be rejected. These credentials will be preserved, unless the provisioning service is force started, or NVS erased.

If this default behavior is not desired, it can be disabled by calling wifi_prov_mgr_disable_auto_stop(). Now the provisioning service will only be stopped after an explicit call to wifi_prov_mgr_stop_provisioning(), which returns immediately after scheduling a task for stopping the service. The service stops after a certain delay and WIFI_PROV_END event gets emitted. This delay is specified by the argument to wifi_prov_mgr_disable_auto_stop().

The customized behavior is useful for applications which want the provisioning service to be stopped some time after the Wi-Fi connection is successfully established. For example, if the application requires the device to connect to some cloud service and obtain another set of credentials, and exchange this credentials over a custom protocomm endpoint, then after successfully doing so stop the provisioning service by calling wifi_prov_mgr_stop_provisioning() inside the protocomm handler itself. The right amount of delay ensures that the transport resources are freed only after the response from the protocomm handler reaches the client side application.

Application Examples

For complete example implementation see provisioning/wifi_prov_mgr

Provisioning Tools

Provisioning applications are available for various platforms, along with source code:

• Android:

  • BLE Provisioning app on Play Store.

  • SoftAP Provisioning app on Play Store.

  • Source code on GitHub: esp-idf-provisioning-android.

• iOS:

  • BLE Provisioning app on app store.

  • SoftAP Provisioning app on app Store.

  • Source code on GitHub: esp-idf-provisioning-ios.

• Linux/MacOS/Windows : tools/esp_prov (a python based command line tool for provisioning)

The phone applications offer simple UI and thus more user centric, while the command line application is useful as a debugging tool for developers.

API Reference

Header File

• wifi_provisioning/include/wifi_provisioning/manager.h

Functions

esp_err_t wifi_prov_mgr_init(wifi_prov_mgr_config_t config)

Initialize provisioning manager instance.

Configures the manager and allocates internal resources

Configuration specifies the provisioning scheme (transport) and event handlers

Event WIFI_PROV_INIT is emitted right after initialization is complete

Return

• ESP_OK : Success

• ESP_FAIL : Fail

Parameters

• [in] config: Configuration structure

void wifi_prov_mgr_deinit(void)

Stop provisioning (if running) and release resource used by the manager.

Event WIFI_PROV_DEINIT is emitted right after de-initialization is finished

If provisioning service is still active when this API is called, it first stops the service, hence emitting WIFI_PROV_END, and then performs the de-initialization

esp_err_t wifi_prov_mgr_is_provisioned(bool *provisioned)

Checks if device is provisioned.

This checks if Wi-Fi credentials are present on the NVS

The Wi-Fi credentials are assumed to be kept in the same NVS namespace as used by esp_wifi component

If one were to call esp_wifi_set_config() directly instead of going through the provisioning process, this function will still yield true (i.e. device will be found to be provisioned)

Note

Calling wifi_prov_mgr_start_provisioning() automatically resets the provision state, irrespective of what the state was prior to making the call.

Return

• ESP_OK : Retrieved provision state successfully

• ESP_FAIL : Wi-Fi not initialized

• ESP_ERR_INVALID_ARG : Null argument supplied

• ESP_ERR_INVALID_STATE : Manager not initialized

Parameters

• [out] provisioned: True if provisioned, else false

esp_err_t wifi_prov_mgr_start_provisioning(wifi_prov_security_t security, const char *pop, const char *service_name, const char *service_key)

Start provisioning service.

This starts the provisioning service according to the scheme configured at the time of initialization. For scheme :

• wifi_prov_scheme_ble : This starts protocomm_ble, which internally initializes BLE transport and starts GATT server for handling provisioning requests

• wifi_prov_scheme_softap : This activates SoftAP mode of Wi-Fi and starts protocomm_httpd, which internally starts an HTTP server for handling provisioning requests (If mDNS is active it also starts advertising service with type _esp_wifi_prov._tcp)

Event WIFI_PROV_START is emitted right after provisioning starts without failure

Note

This API will start provisioning service even if device is found to be already provisioned, i.e. wifi_prov_mgr_is_provisioned() yields true

Return

• ESP_OK : Provisioning started successfully

• ESP_FAIL : Failed to start provisioning service

• ESP_ERR_INVALID_STATE : Provisioning manager not initialized or already started

Parameters

• [in] security: Specify which protocomm security scheme to use :

  • WIFI_PROV_SECURITY_0 : For no security

  • WIFI_PROV_SECURITY_1 : x25519 secure handshake for session establishment followed by AES-CTR encryption of provisioning messages

• [in] pop: Pointer to proof of possession string (NULL if not needed). This is relevant only for protocomm security 1, in which case it is used for authenticating secure session

• [in] service_name: Unique name of the service. This translates to:

  • Wi-Fi SSID when provisioning mode is softAP

  • Device name when provisioning mode is BLE

• [in] service_key: Key required by client to access the service (NULL if not needed). This translates to:

  • Wi-Fi password when provisioning mode is softAP

  • ignored when provisioning mode is BLE

void wifi_prov_mgr_stop_provisioning(void)

Stop provisioning service.

If provisioning service is active, this API will initiate a process to stop the service and return. Once the service actually stops, the event WIFI_PROV_END will be emitted.

If wifi_prov_mgr_deinit() is called without calling this API first, it will automatically stop the provisioning service and emit the WIFI_PROV_END, followed by WIFI_PROV_DEINIT, before returning.

This API will generally be used along with wifi_prov_mgr_disable_auto_stop() in the scenario when the main application has registered its own endpoints, and wishes that the provisioning service is stopped only when some protocomm command from the client side application is received.

Calling this API inside an endpoint handler, with sufficient cleanup_delay, will allow the response / acknowledgment to be sent successfully before the underlying protocomm service is stopped.

Cleaup_delay is set when calling wifi_prov_mgr_disable_auto_stop(). If not specified, it defaults to 1000ms.

For straightforward cases, using this API is usually not necessary as provisioning is stopped automatically once WIFI_PROV_CRED_SUCCESS is emitted. Stopping is delayed (maximum 30 seconds) thus allowing the client side application to query for Wi-Fi state, i.e. after receiving the first query and sending Wi-Fi state connected response the service is stopped immediately.

void wifi_prov_mgr_wait(void)

Wait for provisioning service to finish.

Calling this API will block until provisioning service is stopped i.e. till event WIFI_PROV_END is emitted.

This will not block if provisioning is not started or not initialized.

esp_err_t wifi_prov_mgr_disable_auto_stop(uint32_t cleanup_delay)

Disable auto stopping of provisioning service upon completion.

By default, once provisioning is complete, the provisioning service is automatically stopped, and all endpoints (along with those registered by main application) are deactivated.

This API is useful in the case when main application wishes to close provisioning service only after it receives some protocomm command from the client side app. For example, after connecting to Wi-Fi, the device may want to connect to the cloud, and only once that is successfully, the device is said to be fully configured. But, then it is upto the main application to explicitly call wifi_prov_mgr_stop_provisioning() later when the device is fully configured and the provisioning service is no longer required.

Note

This must be called before executing wifi_prov_mgr_start_provisioning()

Return

• ESP_OK : Success

• ESP_ERR_INVALID_STATE : Manager not initialized or provisioning service already started

Parameters

• [in] cleanup_delay: Sets the delay after which the actual cleanup of transport related resources is done after a call to wifi_prov_mgr_stop_provisioning() returns. Minimum allowed value is 100ms. If not specified, this will default to 1000ms.

esp_err_t wifi_prov_mgr_set_app_info(const char *label, const char *version, const char **capabilities, size_t total_capabilities)

Set application version and capabilities in the JSON data returned by proto-ver endpoint.

This function can be called multiple times, to specify information about the various application specific services running on the device, identified by unique labels.

The provisioning service itself registers an entry in the JSON data, by the label “prov”, containing only provisioning service version and capabilities. Application services should use a label other than “prov” so as not to overwrite this.

Note

This must be called before executing wifi_prov_mgr_start_provisioning()

Return

• ESP_OK : Success

• ESP_ERR_INVALID_STATE : Manager not initialized or provisioning service already started

• ESP_ERR_NO_MEM : Failed to allocate memory for version string

• ESP_ERR_INVALID_ARG : Null argument

Parameters

• [in] label: String indicating the application name.

• [in] version: String indicating the application version. There is no constraint on format.

• [in] capabilities: Array of strings with capabilities. These could be used by the client side app to know the application registered endpoint capabilities

• [in] total_capabilities: Size of capabilities array

esp_err_t wifi_prov_mgr_endpoint_create(const char *ep_name)

Create an additional endpoint and allocate internal resources for it.

This API is to be called by the application if it wants to create an additional endpoint. All additional endpoints will be assigned UUIDs starting from 0xFF54 and so on in the order of execution.

protocomm handler for the created endpoint is to be registered later using wifi_prov_mgr_endpoint_register() after provisioning has started.

Note

This API can only be called BEFORE provisioning is started

Note

Additional endpoints can be used for configuring client provided parameters other than Wi-Fi credentials, that are necessary for the main application and hence must be set prior to starting the application

Note

After session establishment, the additional endpoints must be targeted first by the client side application before sending Wi-Fi configuration, because once Wi-Fi configuration finishes the provisioning service is stopped and hence all endpoints are unregistered

Return

• ESP_OK : Success

• ESP_FAIL : Failure

Parameters

• [in] ep_name: unique name of the endpoint

esp_err_t wifi_prov_mgr_endpoint_register(const char *ep_name, protocomm_req_handler_t handler, void *user_ctx)

Register a handler for the previously created endpoint.

This API can be called by the application to register a protocomm handler to any endpoint that was created using wifi_prov_mgr_endpoint_create().

Note

This API can only be called AFTER provisioning has started

Note

Additional endpoints can be used for configuring client provided parameters other than Wi-Fi credentials, that are necessary for the main application and hence must be set prior to starting the application

Note

After session establishment, the additional endpoints must be targeted first by the client side application before sending Wi-Fi configuration, because once Wi-Fi configuration finishes the provisioning service is stopped and hence all endpoints are unregistered

Return

• ESP_OK : Success

• ESP_FAIL : Failure

Parameters

• [in] ep_name: Name of the endpoint

• [in] handler: Endpoint handler function

• [in] user_ctx: User data

void wifi_prov_mgr_endpoint_unregister(const char *ep_name)

Unregister the handler for an endpoint.

This API can be called if the application wants to selectively unregister the handler of an endpoint while the provisioning is still in progress.

All the endpoint handlers are unregistered automatically when the provisioning stops.

Parameters

• [in] ep_name: Name of the endpoint

esp_err_t wifi_prov_mgr_event_handler(void *ctx, system_event_t *event)

Event handler for provisioning manager.

This is called from the main event handler and controls the provisioning manager’s internal state machine depending on incoming Wi-Fi events

Note

: This function is DEPRECATED, because events are now handled internally using the event loop library, esp_event. Calling this will do nothing and simply return ESP_OK.

Return

• ESP_OK : Event handled successfully

Parameters

• [in] ctx: Event context data

• [in] event: Event info

esp_err_t wifi_prov_mgr_get_wifi_state(wifi_prov_sta_state_t *state)

Get state of Wi-Fi Station during provisioning.

Return

• ESP_OK : Successfully retrieved Wi-Fi state

• ESP_FAIL : Provisioning app not running

Parameters

• [out] state: Pointer to wifi_prov_sta_state_t variable to be filled

esp_err_t wifi_prov_mgr_get_wifi_disconnect_reason(wifi_prov_sta_fail_reason_t *reason)

Get reason code in case of Wi-Fi station disconnection during provisioning.

Return

• ESP_OK : Successfully retrieved Wi-Fi disconnect reason

• ESP_FAIL : Provisioning app not running

Parameters

• [out] reason: Pointer to wifi_prov_sta_fail_reason_t variable to be filled

esp_err_t wifi_prov_mgr_configure_sta(wifi_config_t *wifi_cfg)

Runs Wi-Fi as Station with the supplied configuration.

Configures the Wi-Fi station mode to connect to the AP with SSID and password specified in config structure and sets Wi-Fi to run as station.

This is automatically called by provisioning service upon receiving new credentials.

If credentials are to be supplied to the manager via a different mode other than through protocomm, then this API needs to be called.

Event WIFI_PROV_CRED_RECV is emitted after credentials have been applied and Wi-Fi station started

Return

• ESP_OK : Wi-Fi configured and started successfully

• ESP_FAIL : Failed to set configuration

Parameters

• [in] wifi_cfg: Pointer to Wi-Fi configuration structure

esp_err_t wifi_prov_mgr_reset_sm_state_on_failure(void)

Reset internal state machine and clear provisioned credentials.

This API can be used to restart provisioning in case invalid credentials are entered.

Return

• ESP_OK : Reset provisioning state machine successfully

• ESP_FAIL : Failed to reset provisioning state machine

• ESP_ERR_INVALID_STATE : Manager not initialized

Structures

struct wifi_prov_event_handler_t

Event handler that is used by the manager while provisioning service is active.

Public Members

wifi_prov_cb_func_t event_cb

Callback function to be executed on provisioning events

void *user_data

User context data to pass as parameter to callback function

struct wifi_prov_scheme

Structure for specifying the provisioning scheme to be followed by the manager.

Note

Ready to use schemes are available:

• wifi_prov_scheme_ble : for provisioning over BLE transport + GATT server

• wifi_prov_scheme_softap : for provisioning over SoftAP transport + HTTP server

• wifi_prov_scheme_console : for provisioning over Serial UART transport + Console (for debugging)

Public Members

esp_err_t (*prov_start)(protocomm_t *pc, void *config)

Function which is to be called by the manager when it is to start the provisioning service associated with a protocomm instance and a scheme specific configuration

esp_err_t (*prov_stop)(protocomm_t *pc)

Function which is to be called by the manager to stop the provisioning service previously associated with a protocomm instance

void *(*new_config)(void)

Function which is to be called by the manager to generate a new configuration for the provisioning service, that is to be passed to prov_start()

void (*delete_config)(void *config)

Function which is to be called by the manager to delete a configuration generated using new_config()

esp_err_t (*set_config_service)(void *config, const char *service_name, const char *service_key)

Function which is to be called by the manager to set the service name and key values in the configuration structure

esp_err_t (*set_config_endpoint)(void *config, const char *endpoint_name, uint16_t uuid)

Function which is to be called by the manager to set a protocomm endpoint with an identifying name and UUID in the configuration structure

wifi_mode_t wifi_mode

Sets mode of operation of Wi-Fi during provisioning This is set to :

• WIFI_MODE_APSTA for SoftAP transport

• WIFI_MODE_STA for BLE transport

struct wifi_prov_mgr_config_t

Structure for specifying the manager configuration.

Public Members

wifi_prov_scheme_t scheme

Provisioning scheme to use. Following schemes are already available:

• wifi_prov_scheme_ble : for provisioning over BLE transport + GATT server

• wifi_prov_scheme_softap : for provisioning over SoftAP transport + HTTP server + mDNS (optional)

• wifi_prov_scheme_console : for provisioning over Serial UART transport + Console (for debugging)

wifi_prov_event_handler_t scheme_event_handler

Event handler required by the scheme for incorporating scheme specific behavior while provisioning manager is running. Various options may be provided by the scheme for setting this field. Use WIFI_PROV_EVENT_HANDLER_NONE when not used. When using scheme wifi_prov_scheme_ble, the following options are available:

• WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BTDM

• WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BLE

• WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BT

wifi_prov_event_handler_t app_event_handler

Event handler that can be set for the purpose of incorporating application specific behavior. Use WIFI_PROV_EVENT_HANDLER_NONE when not used.

Macros

WIFI_PROV_EVENT_HANDLER_NONE

Event handler can be set to none if not used.

Type Definitions

typedef void (*wifi_prov_cb_func_t)(void *user_data, wifi_prov_cb_event_t event, void *event_data)

typedef struct wifi_prov_scheme wifi_prov_scheme_t

Structure for specifying the provisioning scheme to be followed by the manager.

Note

Ready to use schemes are available:

• wifi_prov_scheme_ble : for provisioning over BLE transport + GATT server

• wifi_prov_scheme_softap : for provisioning over SoftAP transport + HTTP server

• wifi_prov_scheme_console : for provisioning over Serial UART transport + Console (for debugging)

typedef enum wifi_prov_security wifi_prov_security_t

Security modes supported by the Provisioning Manager.

These are same as the security modes provided by protocomm

Enumerations

enum wifi_prov_cb_event_t

Events generated by manager.

These events are generated in order of declaration and, for the stretch of time between initialization and de-initialization of the manager, each event is signaled only once

Values:

WIFI_PROV_INIT

Emitted when the manager is initialized

WIFI_PROV_START

Indicates that provisioning has started

WIFI_PROV_CRED_RECV

Emitted when Wi-Fi AP credentials are received via protocomm endpoint wifi_config. The event data in this case is a pointer to the corresponding wifi_sta_config_t structure

WIFI_PROV_CRED_FAIL

Emitted when device fails to connect to the AP of which the credentials were received earlier on event WIFI_PROV_CRED_RECV. The event data in this case is a pointer to the disconnection reason code with type wifi_prov_sta_fail_reason_t

WIFI_PROV_CRED_SUCCESS

Emitted when device successfully connects to the AP of which the credentials were received earlier on event WIFI_PROV_CRED_RECV

WIFI_PROV_END

Signals that provisioning service has stopped

WIFI_PROV_DEINIT

Signals that manager has been de-initialized

enum wifi_prov_security

Security modes supported by the Provisioning Manager.

These are same as the security modes provided by protocomm

Values:

WIFI_PROV_SECURITY_0 = 0

No security (plain-text communication)

WIFI_PROV_SECURITY_1

This secure communication mode consists of X25519 key exchange

• proof of possession (pop) based authentication

• AES-CTR encryption

Header File

• wifi_provisioning/include/wifi_provisioning/scheme_ble.h

Functions

void wifi_prov_scheme_ble_event_cb_free_btdm(void *user_data, wifi_prov_cb_event_t event, void *event_data)

void wifi_prov_scheme_ble_event_cb_free_ble(void *user_data, wifi_prov_cb_event_t event, void *event_data)

void wifi_prov_scheme_ble_event_cb_free_bt(void *user_data, wifi_prov_cb_event_t event, void *event_data)

esp_err_t wifi_prov_scheme_ble_set_service_uuid(uint8_t *uuid128)

Set the 128 bit GATT service UUID used for provisioning.

This API is used to override the default 128 bit provisioning service UUID, which is 0000ffff-0000-1000-8000-00805f9b34fb.

This must be called before starting provisioning, i.e. before making a call to wifi_prov_mgr_start_provisioning(), otherwise the default UUID will be used.

Note

The data being pointed to by the argument must be valid atleast till provisioning is started. Upon start, the manager will store an internal copy of this UUID, and this data can be freed or invalidated afterwords.

Return

• ESP_OK : Success

• ESP_ERR_INVALID_ARG : Null argument

Parameters

• [in] uuid128: A custom 128 bit UUID

esp_err_t wifi_prov_scheme_ble_set_mfg_data(uint8_t *mfg_data, ssize_t mfg_data_len)

Set manufacturer specific data in scan response.

This must be called before starting provisioning, i.e. before making a call to wifi_prov_mgr_start_provisioning().

Note

It is important to understand that length of custom manufacturer data should be within limits. The manufacturer data goes into scan response along with BLE device name. By default, BLE device name length is of 11 Bytes, however it can vary as per application use case. So, one has to honour the scan response data size limits i.e. (mfg_data_len + 2) < 31 - (device_name_length + 2 ). If the mfg_data length exceeds this limit, the length will be truncated.

Return

• ESP_OK : Success

• ESP_ERR_INVALID_ARG : Null argument

Parameters

• [in] mfg_data: Custom manufacturer data

• [in] mfg_data_len: Manufacturer data length

Macros

WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BTDM

WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BLE

WIFI_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BT

Header File

• wifi_provisioning/include/wifi_provisioning/scheme_softap.h

Functions

void wifi_prov_scheme_softap_set_httpd_handle(void *handle)

Provide HTTPD Server handle externally.

Useful in cases wherein applications need the webserver for some different operations, and do not want the wifi provisioning component to start/stop a new instance.

Note

This API should be called before wifi_prov_mgr_start_provisioning()

Parameters

• [in] handle: Handle to HTTPD server instance

Header File

• wifi_provisioning/include/wifi_provisioning/scheme_console.h

Header File

• wifi_provisioning/include/wifi_provisioning/wifi_config.h

Functions

esp_err_t wifi_prov_config_data_handler(uint32_t session_id, const uint8_t *inbuf, ssize_t inlen, uint8_t **outbuf, ssize_t *outlen, void *priv_data)

Handler for receiving and responding to requests from master.

This is to be registered as the wifi_config endpoint handler (protocomm protocomm_req_handler_t) using protocomm_add_endpoint()

Structures

struct wifi_prov_sta_conn_info_t

WiFi STA connected status information.

Public Members

char ip_addr[IP4ADDR_STRLEN_MAX]

IP Address received by station

char bssid[6]

BSSID of the AP to which connection was estalished

char ssid[33]

SSID of the to which connection was estalished

uint8_t channel

Channel of the AP

uint8_t auth_mode

Authorization mode of the AP

struct wifi_prov_config_get_data_t

WiFi status data to be sent in response to get_status request from master.

Public Members

wifi_prov_sta_state_t wifi_state

WiFi state of the station

wifi_prov_sta_fail_reason_t fail_reason

Reason for disconnection (valid only when wifi_state is WIFI_STATION_DISCONNECTED)

wifi_prov_sta_conn_info_t conn_info

Connection information (valid only when wifi_state is WIFI_STATION_CONNECTED)

struct wifi_prov_config_set_data_t

WiFi config data received by slave during set_config request from master.

Public Members

char ssid[33]

SSID of the AP to which the slave is to be connected

char password[64]

Password of the AP

char bssid[6]

BSSID of the AP

uint8_t channel

Channel of the AP

struct wifi_prov_config_handlers

Internal handlers for receiving and responding to protocomm requests from master.

This is to be passed as priv_data for protocomm request handler (refer to wifi_prov_config_data_handler()) when calling protocomm_add_endpoint().

Public Members

esp_err_t (*get_status_handler)(wifi_prov_config_get_data_t *resp_data, wifi_prov_ctx_t **ctx)

Handler function called when connection status of the slave (in WiFi station mode) is requested

esp_err_t (*set_config_handler)(const wifi_prov_config_set_data_t *req_data, wifi_prov_ctx_t **ctx)

Handler function called when WiFi connection configuration (eg. AP SSID, password, etc.) of the slave (in WiFi station mode) is to be set to user provided values

esp_err_t (*apply_config_handler)(wifi_prov_ctx_t **ctx)

Handler function for applying the configuration that was set in set_config_handler. After applying the station may get connected to the AP or may fail to connect. The slave must be ready to convey the updated connection status information when get_status_handler is invoked again by the master.

wifi_prov_ctx_t *ctx

Context pointer to be passed to above handler functions upon invocation

Type Definitions

typedef struct wifi_prov_ctx wifi_prov_ctx_t

Type of context data passed to each get/set/apply handler function set in wifi_prov_config_handlers structure.

This is passed as an opaque pointer, thereby allowing it be defined later in application code as per requirements.

typedef struct wifi_prov_config_handlers wifi_prov_config_handlers_t

Internal handlers for receiving and responding to protocomm requests from master.

This is to be passed as priv_data for protocomm request handler (refer to wifi_prov_config_data_handler()) when calling protocomm_add_endpoint().

Enumerations

enum wifi_prov_sta_state_t

WiFi STA status for conveying back to the provisioning master.

Values:

WIFI_PROV_STA_CONNECTING

WIFI_PROV_STA_CONNECTED

WIFI_PROV_STA_DISCONNECTED

enum wifi_prov_sta_fail_reason_t

WiFi STA connection fail reason.

Values:

WIFI_PROV_STA_AUTH_ERROR

WIFI_PROV_STA_AP_NOT_FOUND

Provide feedback about this document