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/main-http.cpp@29:5ad8f931e4ff, 2018-03-27 (annotated)

Committer:
Jan Jongboom
Date:
Tue Mar 27 11:57:33 2018 +0200
Revision:
29:5ad8f931e4ff
Parent:
28:9bccd981a393
Child:
30:4825e4f38844
Move serial baud rate config into mbed_app.json

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jan Jongboom 0:85fdc69bc10c 1 #include "select-demo.h"
Jan Jongboom 0:85fdc69bc10c 2
Jan Jongboom 0:85fdc69bc10c 3 #if DEMO == DEMO_HTTP
Jan Jongboom 0:85fdc69bc10c 4
Jan Jongboom 0:85fdc69bc10c 5 #include "mbed.h"
Jan Jongboom 0:85fdc69bc10c 6 #include "easy-connect.h"
Jan Jongboom 0:85fdc69bc10c 7 #include "http_request.h"
Jan Jongboom 0:85fdc69bc10c 8
Jan Jongboom 0:85fdc69bc10c 9 void dump_response(HttpResponse* res) {
Jan Jongboom 0:85fdc69bc10c 10 printf("Status: %d - %s\n", res->get_status_code(), res->get_status_message().c_str());
Jan Jongboom 0:85fdc69bc10c 11
Jan Jongboom 0:85fdc69bc10c 12 printf("Headers:\n");
Jan Jongboom 0:85fdc69bc10c 13 for (size_t ix = 0; ix < res->get_headers_length(); ix++) {
Jan Jongboom 7:5d32909f77de 14 printf("\t%s: %s\n", res->get_headers_fields()[ix]->c_str(), res->get_headers_values()[ix]->c_str());
Jan Jongboom 0:85fdc69bc10c 15 }
Jan Jongboom 5:42f713b19337 16 printf("\nBody (%d bytes):\n\n%s\n", res->get_body_length(), res->get_body_as_string().c_str());
Jan Jongboom 0:85fdc69bc10c 17 }
Jan Jongboom 0:85fdc69bc10c 18
Jan Jongboom 0:85fdc69bc10c 19 int main() {
Jan Jongboom 0:85fdc69bc10c 20 // Connect to the network (see mbed_app.json for the connectivity method used)
Jan Jongboom 15:65a49b573ba5 21 NetworkInterface* network = easy_connect(true);
Jan Jongboom 0:85fdc69bc10c 22 if (!network) {
Jan Jongboom 0:85fdc69bc10c 23 printf("Cannot connect to the network, see serial output");
Jan Jongboom 0:85fdc69bc10c 24 return 1;
Jan Jongboom 0:85fdc69bc10c 25 }
Jan Jongboom 0:85fdc69bc10c 26
Jan Jongboom 0:85fdc69bc10c 27 // Do a GET request to httpbin.org
Jan Jongboom 5:42f713b19337 28 {
Jan Jongboom 14:3c173847e681 29 // By default the body is automatically parsed and stored in a buffer, this is memory heavy.
Jan Jongboom 14:3c173847e681 30 // To receive chunked response, pass in a callback as last parameter to the constructor.
Jan Jongboom 5:42f713b19337 31 HttpRequest* get_req = new HttpRequest(network, HTTP_GET, "http://httpbin.org/status/418");
Jan Jongboom 0:85fdc69bc10c 32
Jan Jongboom 5:42f713b19337 33 HttpResponse* get_res = get_req->send();
Jan Jongboom 5:42f713b19337 34 if (!get_res) {
Jan Jongboom 5:42f713b19337 35 printf("HttpRequest failed (error code %d)\n", get_req->get_error());
Jan Jongboom 5:42f713b19337 36 return 1;
Jan Jongboom 5:42f713b19337 37 }
Jan Jongboom 5:42f713b19337 38
Jan Jongboom 5:42f713b19337 39 printf("\n----- HTTP GET response -----\n");
Jan Jongboom 5:42f713b19337 40 dump_response(get_res);
Jan Jongboom 5:42f713b19337 41
Jan Jongboom 5:42f713b19337 42 delete get_req;
Jan Jongboom 0:85fdc69bc10c 43 }
Jan Jongboom 0:85fdc69bc10c 44
Jan Jongboom 0:85fdc69bc10c 45 // POST request to httpbin.org
Jan Jongboom 5:42f713b19337 46 {
Jan Jongboom 5:42f713b19337 47 HttpRequest* post_req = new HttpRequest(network, HTTP_POST, "http://httpbin.org/post");
Jan Jongboom 5:42f713b19337 48 post_req->set_header("Content-Type", "application/json");
Jan Jongboom 0:85fdc69bc10c 49
Jan Jongboom 5:42f713b19337 50 const char body[] = "{\"hello\":\"world\"}";
Jan Jongboom 0:85fdc69bc10c 51
Jan Jongboom 5:42f713b19337 52 HttpResponse* post_res = post_req->send(body, strlen(body));
Jan Jongboom 5:42f713b19337 53 if (!post_res) {
Jan Jongboom 5:42f713b19337 54 printf("HttpRequest failed (error code %d)\n", post_req->get_error());
Jan Jongboom 5:42f713b19337 55 return 1;
Jan Jongboom 5:42f713b19337 56 }
Jan Jongboom 5:42f713b19337 57
Jan Jongboom 5:42f713b19337 58 printf("\n----- HTTP POST response -----\n");
Jan Jongboom 5:42f713b19337 59 dump_response(post_res);
Jan Jongboom 5:42f713b19337 60
Jan Jongboom 5:42f713b19337 61 delete post_req;
Jan Jongboom 0:85fdc69bc10c 62 }
Jan Jongboom 0:85fdc69bc10c 63
Jan Jongboom 28:9bccd981a393 64 wait(osWaitForever);
Jan Jongboom 0:85fdc69bc10c 65 }
Jan Jongboom 0:85fdc69bc10c 66
Jan Jongboom 0:85fdc69bc10c 67 #endif