sandbox / Mbed OS http-example

HTTP and HTTPS example application for Mbed OS 5

Dependencies:   mbed-http

This application demonstrates how to make HTTP and HTTPS requests and parse the response from Mbed OS 5.

It consists of six example applications, which you can select in source/select-demo.h:

Response parsing is done through nodejs/http-parser.

Note: HTTPS requests do not work on targets with less than 128K of RAM due to the size of the TLS handshake. For more background see mbed-http.

To build

  1. If you're using WiFi, specify the credentials in mbed_app.json.
  2. Build the project in the online compiler or using Mbed CLI.
  3. Flash the project to your development board.
  4. Attach a serial monitor to your board to see the debug messages.

Defining the network interface

This application uses the on-board network interface for your board. If you use an external network interface (f.e. a WiFi module) you need to add the driver to this project. Then, open network-helper.h and specify which network driver to use.

More information is in the Mbed OS documentation under IP Networking.

Entropy (or lack thereof)

On all platforms that do not have the TRNG feature, the application is compiled without TLS entropy sources. This means that your code is inherently unsafe and should not be deployed to any production systems. To enable entropy, remove the MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES and MBEDTLS_TEST_NULL_ENTROPY macros from mbed_app.json.

Flash size

Default flash size for HTTPS is very large, as the application is loading the default Mbed TLS configuration. To use a more optimized version, you can disable unused cypher suites and other Mbed TLS features with a custom configuration file. Create a new configuration file, then add in mbed_app.json:

"MBEDTLS_CONFIG_FILE=\"mbedtls_config.h\""

to the macros array.

Running tests

You can run the integration tests from this project via Mbed CLI.

  1. In select-demo.h set the DEMO macro to DEMO_TESTS.
  2. Set your WiFi credentials in mbed_app.json.
  3. Then run the tests via: 

$ mbed test -v -n mbed-http-tests-tests-*

Tested on

  • K64F with Ethernet.
  • NUCLEO_F411RE with ESP8266 (not working on Mbed OS 5.12+)
  • ODIN-W2 with WiFi.
  • K64F with Atmel 6LoWPAN shield.
  • DISCO-L475VG-IOT01A with WiFi (requires the wifi-ism43362 driver).

source/network-helper.h@35:4b847971db1b, 2019-01-04 (annotated)

Committer:
Jan Jongboom
Date:
Fri Jan 04 13:32:26 2019 +0100
Revision:
35:4b847971db1b
Parent:
31:66704f6f17c5 
Update to Mbed OS 5.11

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jan Jongboom 30:4825e4f38844 1 #ifndef _MBED_HTTP_EXAMPLE_H_
Jan Jongboom 30:4825e4f38844 2 #define _MBED_HTTP_EXAMPLE_H_
Jan Jongboom 30:4825e4f38844 3
Jan Jongboom 30:4825e4f38844 4 #include "mbed.h"
Jan Jongboom 35:4b847971db1b 5 #include "NetworkInterface.h"
Jan Jongboom 30:4825e4f38844 6
Jan Jongboom 30:4825e4f38844 7 /**
Jan Jongboom 30:4825e4f38844 8 * Connect to the network using the default networking interface,
Jan Jongboom 30:4825e4f38844 9 * you can also swap this out with a driver for a different networking interface
Jan Jongboom 30:4825e4f38844 10 * if you use WiFi: see mbed_app.json for the credentials
Jan Jongboom 30:4825e4f38844 11 */
Jan Jongboom 30:4825e4f38844 12 NetworkInterface *connect_to_default_network_interface() {
Jan Jongboom 30:4825e4f38844 13 printf("[NWKH] Connecting to network...\n");
Jan Jongboom 30:4825e4f38844 14
Jan Jongboom 30:4825e4f38844 15 NetworkInterface* network = NetworkInterface::get_default_instance();
Jan Jongboom 35:4b847971db1b 16
Jan Jongboom 35:4b847971db1b 17 if (!network) {
Jan Jongboom 35:4b847971db1b 18 printf("[NWKH] No network interface found, select an interface in 'network-helper.h'\n");
Jan Jongboom 35:4b847971db1b 19 return NULL;
Jan Jongboom 35:4b847971db1b 20 }
Jan Jongboom 30:4825e4f38844 21
Jan Jongboom 30:4825e4f38844 22 nsapi_error_t connect_status = network->connect();
Jan Jongboom 30:4825e4f38844 23
Jan Jongboom 30:4825e4f38844 24 if (connect_status != NSAPI_ERROR_OK) {
Jan Jongboom 30:4825e4f38844 25 printf("[NWKH] Failed to connect to network (%d)\n", connect_status);
Jan Jongboom 30:4825e4f38844 26 return NULL;
Jan Jongboom 30:4825e4f38844 27 }
Jan Jongboom 30:4825e4f38844 28
Jan Jongboom 30:4825e4f38844 29 printf("[NWKH] Connected to the network\n");
Jan Jongboom 30:4825e4f38844 30 printf("[NWKH] IP address: %s\n", network->get_ip_address());
Jan Jongboom 30:4825e4f38844 31 return network;
Jan Jongboom 30:4825e4f38844 32 }
Jan Jongboom 30:4825e4f38844 33
Jan Jongboom 30:4825e4f38844 34 #endif // _MBED_HTTP_EXAMPLE_H_