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/mbed-http/http_request_builder.h@1:3bff14db67c7, 2017-02-16 (annotated)

Committer:
Jan Jongboom
Date:
Thu Feb 16 11:13:40 2017 +0100
Revision:
1:3bff14db67c7
Add mbed-http

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jan Jongboom 1:3bff14db67c7 1 #ifndef _MBED_HTTP_REQUEST_BUILDER_H_
Jan Jongboom 1:3bff14db67c7 2 #define _MBED_HTTP_REQUEST_BUILDER_H_
Jan Jongboom 1:3bff14db67c7 3
Jan Jongboom 1:3bff14db67c7 4 #include <string>
Jan Jongboom 1:3bff14db67c7 5 #include <map>
Jan Jongboom 1:3bff14db67c7 6 #include "http_parser.h"
Jan Jongboom 1:3bff14db67c7 7 #include "http_parsed_url.h"
Jan Jongboom 1:3bff14db67c7 8
Jan Jongboom 1:3bff14db67c7 9 class HttpRequestBuilder {
Jan Jongboom 1:3bff14db67c7 10 public:
Jan Jongboom 1:3bff14db67c7 11 HttpRequestBuilder(http_method a_method, ParsedUrl* a_parsed_url)
Jan Jongboom 1:3bff14db67c7 12 : method(a_method), parsed_url(a_parsed_url)
Jan Jongboom 1:3bff14db67c7 13 {
Jan Jongboom 1:3bff14db67c7 14 set_header("Host", string(parsed_url->host()));
Jan Jongboom 1:3bff14db67c7 15 }
Jan Jongboom 1:3bff14db67c7 16
Jan Jongboom 1:3bff14db67c7 17 /**
Jan Jongboom 1:3bff14db67c7 18 * Set a header for the request
Jan Jongboom 1:3bff14db67c7 19 * If the key already exists, it will be overwritten...
Jan Jongboom 1:3bff14db67c7 20 */
Jan Jongboom 1:3bff14db67c7 21 void set_header(string key, string value) {
Jan Jongboom 1:3bff14db67c7 22 map<string, string>::iterator it = headers.find(key);
Jan Jongboom 1:3bff14db67c7 23
Jan Jongboom 1:3bff14db67c7 24 if (it != headers.end()) {
Jan Jongboom 1:3bff14db67c7 25 it->second = value;
Jan Jongboom 1:3bff14db67c7 26 }
Jan Jongboom 1:3bff14db67c7 27 else {
Jan Jongboom 1:3bff14db67c7 28 headers.insert(headers.end(), pair<string, string>(key, value));
Jan Jongboom 1:3bff14db67c7 29 }
Jan Jongboom 1:3bff14db67c7 30 }
Jan Jongboom 1:3bff14db67c7 31
Jan Jongboom 1:3bff14db67c7 32 char* build(const void* body, size_t body_size) {
Jan Jongboom 1:3bff14db67c7 33 const char* method_str = http_method_str(method);
Jan Jongboom 1:3bff14db67c7 34
Jan Jongboom 1:3bff14db67c7 35 if (body_size > 0) {
Jan Jongboom 1:3bff14db67c7 36 char buffer[10];
Jan Jongboom 1:3bff14db67c7 37 snprintf(buffer, 10, "%d", body_size);
Jan Jongboom 1:3bff14db67c7 38 set_header("Content-Length", string(buffer));
Jan Jongboom 1:3bff14db67c7 39 }
Jan Jongboom 1:3bff14db67c7 40
Jan Jongboom 1:3bff14db67c7 41 size_t size = 0;
Jan Jongboom 1:3bff14db67c7 42
Jan Jongboom 1:3bff14db67c7 43 // first line is METHOD PATH+QUERY HTTP/1.1\r\n
Jan Jongboom 1:3bff14db67c7 44 size += strlen(method_str) + 1 + strlen(parsed_url->path()) + strlen(parsed_url->query()) + 1 + 8 + 2;
Jan Jongboom 1:3bff14db67c7 45
Jan Jongboom 1:3bff14db67c7 46 // after that we'll do the headers
Jan Jongboom 1:3bff14db67c7 47 typedef map<string, string>::iterator it_type;
Jan Jongboom 1:3bff14db67c7 48 for(it_type it = headers.begin(); it != headers.end(); it++) {
Jan Jongboom 1:3bff14db67c7 49 // line is KEY: VALUE\r\n
Jan Jongboom 1:3bff14db67c7 50 size += it->first.length() + 1 + 1 + it->second.length() + 2;
Jan Jongboom 1:3bff14db67c7 51 }
Jan Jongboom 1:3bff14db67c7 52
Jan Jongboom 1:3bff14db67c7 53 // then the body, first an extra newline
Jan Jongboom 1:3bff14db67c7 54 size += 2;
Jan Jongboom 1:3bff14db67c7 55
Jan Jongboom 1:3bff14db67c7 56 // body
Jan Jongboom 1:3bff14db67c7 57 size += body_size;
Jan Jongboom 1:3bff14db67c7 58
Jan Jongboom 1:3bff14db67c7 59 // extra newline
Jan Jongboom 1:3bff14db67c7 60 size += 2;
Jan Jongboom 1:3bff14db67c7 61
Jan Jongboom 1:3bff14db67c7 62 // Now let's print it
Jan Jongboom 1:3bff14db67c7 63 char* req = (char*)calloc(size + 1, 1);
Jan Jongboom 1:3bff14db67c7 64 char* originalReq = req;
Jan Jongboom 1:3bff14db67c7 65
Jan Jongboom 1:3bff14db67c7 66 sprintf(req, "%s %s%s HTTP/1.1\r\n", method_str, parsed_url->path(), parsed_url->query());
Jan Jongboom 1:3bff14db67c7 67 req += strlen(method_str) + 1 + strlen(parsed_url->path()) + strlen(parsed_url->query()) + 1 + 8 + 2;
Jan Jongboom 1:3bff14db67c7 68
Jan Jongboom 1:3bff14db67c7 69 typedef map<string, string>::iterator it_type;
Jan Jongboom 1:3bff14db67c7 70 for(it_type it = headers.begin(); it != headers.end(); it++) {
Jan Jongboom 1:3bff14db67c7 71 // line is KEY: VALUE\r\n
Jan Jongboom 1:3bff14db67c7 72 sprintf(req, "%s: %s\r\n", it->first.c_str(), it->second.c_str());
Jan Jongboom 1:3bff14db67c7 73 req += it->first.length() + 1 + 1 + it->second.length() + 2;
Jan Jongboom 1:3bff14db67c7 74 }
Jan Jongboom 1:3bff14db67c7 75
Jan Jongboom 1:3bff14db67c7 76 sprintf(req, "\r\n");
Jan Jongboom 1:3bff14db67c7 77 req += 2;
Jan Jongboom 1:3bff14db67c7 78
Jan Jongboom 1:3bff14db67c7 79 if (body_size > 0) {
Jan Jongboom 1:3bff14db67c7 80 sprintf(req, "%s", (char*)body);
Jan Jongboom 1:3bff14db67c7 81 }
Jan Jongboom 1:3bff14db67c7 82 req += body_size;
Jan Jongboom 1:3bff14db67c7 83
Jan Jongboom 1:3bff14db67c7 84 sprintf(req, "\r\n");
Jan Jongboom 1:3bff14db67c7 85 req += 2;
Jan Jongboom 1:3bff14db67c7 86
Jan Jongboom 1:3bff14db67c7 87 // Uncomment to debug...
Jan Jongboom 1:3bff14db67c7 88 // printf("----- BEGIN REQUEST -----\n");
Jan Jongboom 1:3bff14db67c7 89 // printf("%s", originalReq);
Jan Jongboom 1:3bff14db67c7 90 // printf("----- END REQUEST -----\n");
Jan Jongboom 1:3bff14db67c7 91
Jan Jongboom 1:3bff14db67c7 92 return originalReq;
Jan Jongboom 1:3bff14db67c7 93 }
Jan Jongboom 1:3bff14db67c7 94
Jan Jongboom 1:3bff14db67c7 95 private:
Jan Jongboom 1:3bff14db67c7 96 http_method method;
Jan Jongboom 1:3bff14db67c7 97 ParsedUrl* parsed_url;
Jan Jongboom 1:3bff14db67c7 98 map<string, string> headers;
Jan Jongboom 1:3bff14db67c7 99 };
Jan Jongboom 1:3bff14db67c7 100
Jan Jongboom 1:3bff14db67c7 101 #endif // _MBED_HTTP_REQUEST_BUILDER_H_