sglass520 / cc3220-provisioning-https-client

CC3220 provisioning and HTTPS client if provisioned

Summary

Allows AP provisioning on CC3220 device. If device is provisioned, adds task to task scheduler to enable HTTPS client and POST to a web server.

Peripherals Exercised

• Board_LED0 - Blinking led Indicates disconnected. Led on indicates connection established
• Board_LED1 - Led on indicates error occurred
• Board_LED2 - Led on indicates error occurred and while blinking, indicates that the board is trying to connect to AP.

Usage

• Build the project and flash from the debugger or by using the SimpleLink Uniflash

• In order to use HTTP, use the SimpleLink Uniflash under Advanced->Network Applications->HTTP Server

  • enable the secured check box
  • set Port Number to 443
  • Make sure Rom Pages are enabled
  • Enable secondary port and set to 80

• Open a serial session (e.g. HyperTerminal,puTTY,Tera Term, etc.) to the appropriate COM port.

The COM port can be determined via Device Manager in Windows or via ls /dev/tty* in Linux.

The connection should have the following settings

    Baud-rate:    115200
    Data bits:       8
    Stop bits:       1
    Parity:       None
    Flow Control: None

• The program starts by showing on the terminal the application name and tries to establish connection with existing profiles. If connection is not establish during preconfigured time out, provisioning will start, wait for connection to be established and IP acquire. After connection is establish Ping is continuously sent to default gateway to verify the connection.

Application Design Details

The SimpleLink Wi-Fi provisioning process is divided into the Configuration stage and the Confirmation stage. The process begins with the configuration stage. During this stage, the SimpleLink Wi-Fi device waits for the end user to provide (using an external device such as a smartphone or tablet running a dedicated provisioning application) the information needed to connect to the wireless network as follows:

• Network name (SSID)
• Password
• Device name (optional)
• UUID (optional)

The device internally saves the provided network information into its serial flash memory as a new profile. Once a profile is successfully configured, the device moves to the confirmation stage. The confirmation stage tests the profile that was configured during the configuration stage. During the confirmation stage, the device tries to connect to the wireless network found in the new configured profile. If the connection is successful, the device also tries to provide feedback about the successful connection to the user’s smart phone provisioning application, which configured the profile. A connection is defined as successful if the WLAN connection is established, and an IP address is acquired. If the connection is successful, and the feedback is delivered to the user, the confirmation stage is successful, and the provisioning process successfully ends. If the connection attempt fails, or if it is successful but the feedback is not delivered to the user, the confirmation stage fails, and the device moves back to the configuration stage. At this point, the user’s smart phone provisioning app can ask the device to send the fail reason of the previous confirmation attempt, and configure a new profile.

HTTPS Client

The HTTPS Client is managed in the http_push.c source file. The definitions of HOST_NAME,HOST_URI,POST_DATA,SSL_CA_CERT should correspond with the users desired configuration. The HTTP clint task is initiated from the HandleUserApplication() function in the provisioning.c source file. This function should be used to initiate any additional user tasks. The HTTPS client negotiates SSL protocol with the web server - for information on setting up secure SSL read the SSL/Certificates section.

SSL/Certificates

If attempting secure HTTPS connection, only few items must be modified and implemented:

• Set device time
• Flash Root CA on CC3220 using UniFlash
• Specify Root CA in http_push.c source file

The device time must be set in order to validate the Root CA. The function setDeviceTime() in provisioning.c should be modified accordingly. The Root CA for the server attempting to negotiate with must be flashed onto the device. The Root CA may be found using some tools such as ssltools.com or OpenSSL. The Root CA can be exported as DER format (must be DER) using OpenSSL or Firefox (Chrome does not export DER). Using UniFlash, you can flash the certificate as a user file. The flashed file path should be specified in the http_push.c source file.

External Configuration

When the provisioning process is started in APSC + external configuration mode , the device is ready to serve stations trying to connect to it (for AP provisioning), ready to handle SmartConfig transmissions (SC provisioning), and can allow the host to execute an additional external provisioning method that is not implemented inside the networking subsystem (for example: WAC).

Using the external configuration requires to implement and uncomment the following functions (search for [External configuration] in the example code): • StartExternalProvisioning() - start the external provisioning process. once SL_WLAN_PROVISIONING_EXTERNAL_CONFIGURATION_READY arrives, call this function in order to start the external provisioning process (i.e open socket and receive the profile credentials). • StopExternalProvisioning() - stop the external provisioning process (i.e in case of AP provisioning or AP SC success, external provisioning is no longer needed). • IsActiveExternalConfirmation() - Implement a function which check the current status of the external provisioning run.

In order to start the provisioning in SL_WLAN_PROVISIONING_CMD_START_MODE_APSC_EXTERNAL_CONFIGURATION call sl_WlanProvisioning API with provisioningCmd = SL_WLAN_PROVISIONING_CMD_START_MODE_APSC_EXTERNAL_CONFIGURATION;

Please install the latest CC32xx Service Pack in order to get the most optimization and lowest current consumption.

References

• For more detailed information please refer to the programmer's user guide and review the Provisioning chapter 15.
• For more detailed information regarding the provisioning feature, please refer to the provisioning application report
• For further information please refer to the user programmers guide: CC3X20 Programmer's Guide