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.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 _HTTP_REQUEST_
Jan Jongboom 1:3bff14db67c7 2 #define _HTTP_REQUEST_
Jan Jongboom 1:3bff14db67c7 3
Jan Jongboom 1:3bff14db67c7 4 #include <string>
Jan Jongboom 1:3bff14db67c7 5 #include <vector>
Jan Jongboom 1:3bff14db67c7 6 #include <map>
Jan Jongboom 1:3bff14db67c7 7 #include "http_parser.h"
Jan Jongboom 1:3bff14db67c7 8 #include "http_response.h"
Jan Jongboom 1:3bff14db67c7 9 #include "http_request_builder.h"
Jan Jongboom 1:3bff14db67c7 10 #include "http_response_parser.h"
Jan Jongboom 1:3bff14db67c7 11 #include "http_parsed_url.h"
Jan Jongboom 1:3bff14db67c7 12
Jan Jongboom 1:3bff14db67c7 13 /**
Jan Jongboom 1:3bff14db67c7 14 * @todo:
Jan Jongboom 1:3bff14db67c7 15 * - Userinfo parameter is not handled
Jan Jongboom 1:3bff14db67c7 16 * - Allow socket re-use
Jan Jongboom 1:3bff14db67c7 17 */
Jan Jongboom 1:3bff14db67c7 18
Jan Jongboom 1:3bff14db67c7 19
Jan Jongboom 1:3bff14db67c7 20 /**
Jan Jongboom 1:3bff14db67c7 21 * \brief HttpRequest implements the logic for interacting with HTTPS servers.
Jan Jongboom 1:3bff14db67c7 22 */
Jan Jongboom 1:3bff14db67c7 23 class HttpRequest {
Jan Jongboom 1:3bff14db67c7 24 public:
Jan Jongboom 1:3bff14db67c7 25 /**
Jan Jongboom 1:3bff14db67c7 26 * HttpRequest Constructor
Jan Jongboom 1:3bff14db67c7 27 *
Jan Jongboom 1:3bff14db67c7 28 * @param[in] aNetwork The network interface
Jan Jongboom 1:3bff14db67c7 29 * @param[in] aMethod HTTP method to use
Jan Jongboom 1:3bff14db67c7 30 * @param[in] url URL to the resource
Jan Jongboom 1:3bff14db67c7 31 * @param[in] aBodyCallback Callback on which to retrieve chunks of the response body.
Jan Jongboom 1:3bff14db67c7 32 If not set, the complete body will be allocated on the HttpResponse object,
Jan Jongboom 1:3bff14db67c7 33 which might use lots of memory.
Jan Jongboom 1:3bff14db67c7 34 */
Jan Jongboom 1:3bff14db67c7 35 HttpRequest(NetworkInterface* aNetwork, http_method aMethod, const char* url, Callback<void(const char *at, size_t length)> aBodyCallback = 0)
Jan Jongboom 1:3bff14db67c7 36 : network(aNetwork), method(aMethod), body_callback(aBodyCallback)
Jan Jongboom 1:3bff14db67c7 37 {
Jan Jongboom 1:3bff14db67c7 38 error = 0;
Jan Jongboom 1:3bff14db67c7 39 response = NULL;
Jan Jongboom 1:3bff14db67c7 40
Jan Jongboom 1:3bff14db67c7 41 parsed_url = new ParsedUrl(url);
Jan Jongboom 1:3bff14db67c7 42 request_builder = new HttpRequestBuilder(method, parsed_url);
Jan Jongboom 1:3bff14db67c7 43 }
Jan Jongboom 1:3bff14db67c7 44
Jan Jongboom 1:3bff14db67c7 45 /**
Jan Jongboom 1:3bff14db67c7 46 * HttpRequest Constructor
Jan Jongboom 1:3bff14db67c7 47 */
Jan Jongboom 1:3bff14db67c7 48 ~HttpRequest() {
Jan Jongboom 1:3bff14db67c7 49 // should response be owned by us? Or should user free it?
Jan Jongboom 1:3bff14db67c7 50 // maybe implement copy constructor on response...
Jan Jongboom 1:3bff14db67c7 51 if (response) {
Jan Jongboom 1:3bff14db67c7 52 delete response;
Jan Jongboom 1:3bff14db67c7 53 }
Jan Jongboom 1:3bff14db67c7 54
Jan Jongboom 1:3bff14db67c7 55 if (parsed_url) {
Jan Jongboom 1:3bff14db67c7 56 delete parsed_url;
Jan Jongboom 1:3bff14db67c7 57 }
Jan Jongboom 1:3bff14db67c7 58
Jan Jongboom 1:3bff14db67c7 59 if (request_builder) {
Jan Jongboom 1:3bff14db67c7 60 delete request_builder;
Jan Jongboom 1:3bff14db67c7 61 }
Jan Jongboom 1:3bff14db67c7 62 }
Jan Jongboom 1:3bff14db67c7 63
Jan Jongboom 1:3bff14db67c7 64 /**
Jan Jongboom 1:3bff14db67c7 65 * Execute the request and receive the response.
Jan Jongboom 1:3bff14db67c7 66 */
Jan Jongboom 1:3bff14db67c7 67 HttpResponse* send(const void* body = NULL, nsapi_size_t body_size = 0) {
Jan Jongboom 1:3bff14db67c7 68 if (response != NULL) {
Jan Jongboom 1:3bff14db67c7 69 // already executed this response
Jan Jongboom 1:3bff14db67c7 70 error = -2100; // @todo, make a lookup table with errors
Jan Jongboom 1:3bff14db67c7 71 return NULL;
Jan Jongboom 1:3bff14db67c7 72 }
Jan Jongboom 1:3bff14db67c7 73
Jan Jongboom 1:3bff14db67c7 74 error = 0;
Jan Jongboom 1:3bff14db67c7 75
Jan Jongboom 1:3bff14db67c7 76 TCPSocket socket;
Jan Jongboom 1:3bff14db67c7 77
Jan Jongboom 1:3bff14db67c7 78 nsapi_error_t open_result = socket.open(network);
Jan Jongboom 1:3bff14db67c7 79 if (open_result != 0) {
Jan Jongboom 1:3bff14db67c7 80 error = open_result;
Jan Jongboom 1:3bff14db67c7 81 return NULL;
Jan Jongboom 1:3bff14db67c7 82 }
Jan Jongboom 1:3bff14db67c7 83
Jan Jongboom 1:3bff14db67c7 84 nsapi_error_t connection_result = socket.connect(parsed_url->host(), parsed_url->port());
Jan Jongboom 1:3bff14db67c7 85 if (connection_result != 0) {
Jan Jongboom 1:3bff14db67c7 86 error = connection_result;
Jan Jongboom 1:3bff14db67c7 87 return NULL;
Jan Jongboom 1:3bff14db67c7 88 }
Jan Jongboom 1:3bff14db67c7 89
Jan Jongboom 1:3bff14db67c7 90 char* request = request_builder->build(body, body_size);
Jan Jongboom 1:3bff14db67c7 91 size_t request_size = strlen(request);
Jan Jongboom 1:3bff14db67c7 92
Jan Jongboom 1:3bff14db67c7 93 nsapi_size_or_error_t send_result = socket.send(request, request_size);
Jan Jongboom 1:3bff14db67c7 94
Jan Jongboom 1:3bff14db67c7 95 free(request);
Jan Jongboom 1:3bff14db67c7 96
Jan Jongboom 1:3bff14db67c7 97 if (send_result != request_size) {
Jan Jongboom 1:3bff14db67c7 98 error = send_result;
Jan Jongboom 1:3bff14db67c7 99 return NULL;
Jan Jongboom 1:3bff14db67c7 100 }
Jan Jongboom 1:3bff14db67c7 101
Jan Jongboom 1:3bff14db67c7 102 // Create a response object
Jan Jongboom 1:3bff14db67c7 103 response = new HttpResponse();
Jan Jongboom 1:3bff14db67c7 104 // And a response parser
Jan Jongboom 1:3bff14db67c7 105 HttpResponseParser parser(response, body_callback);
Jan Jongboom 1:3bff14db67c7 106
Jan Jongboom 1:3bff14db67c7 107 // Set up a receive buffer (on the heap)
Jan Jongboom 1:3bff14db67c7 108 uint8_t* recv_buffer = (uint8_t*)malloc(HTTP_RECEIVE_BUFFER_SIZE);
Jan Jongboom 1:3bff14db67c7 109
Jan Jongboom 1:3bff14db67c7 110 // TCPSocket::recv is called until we don't have any data anymore
Jan Jongboom 1:3bff14db67c7 111 nsapi_size_or_error_t recv_ret;
Jan Jongboom 1:3bff14db67c7 112 while ((recv_ret = socket.recv(recv_buffer, HTTP_RECEIVE_BUFFER_SIZE)) > 0) {
Jan Jongboom 1:3bff14db67c7 113 // Pass the chunk into the http_parser
Jan Jongboom 1:3bff14db67c7 114 size_t nparsed = parser.execute((const char*)recv_buffer, recv_ret);
Jan Jongboom 1:3bff14db67c7 115 if (nparsed != recv_ret) {
Jan Jongboom 1:3bff14db67c7 116 // printf("Parsing failed... parsed %d bytes, received %d bytes\n", nparsed, recv_ret);
Jan Jongboom 1:3bff14db67c7 117 error = -2101;
Jan Jongboom 1:3bff14db67c7 118 free(recv_buffer);
Jan Jongboom 1:3bff14db67c7 119 return NULL;
Jan Jongboom 1:3bff14db67c7 120 }
Jan Jongboom 1:3bff14db67c7 121 // No more chunks? break out of this loop
Jan Jongboom 1:3bff14db67c7 122 if (recv_ret < HTTP_RECEIVE_BUFFER_SIZE) {
Jan Jongboom 1:3bff14db67c7 123 break;
Jan Jongboom 1:3bff14db67c7 124 }
Jan Jongboom 1:3bff14db67c7 125 }
Jan Jongboom 1:3bff14db67c7 126 // error?
Jan Jongboom 1:3bff14db67c7 127 if (recv_ret < 0) {
Jan Jongboom 1:3bff14db67c7 128 error = recv_ret;
Jan Jongboom 1:3bff14db67c7 129 free(recv_buffer);
Jan Jongboom 1:3bff14db67c7 130 return NULL;
Jan Jongboom 1:3bff14db67c7 131 }
Jan Jongboom 1:3bff14db67c7 132
Jan Jongboom 1:3bff14db67c7 133 // When done, call parser.finish()
Jan Jongboom 1:3bff14db67c7 134 parser.finish();
Jan Jongboom 1:3bff14db67c7 135
Jan Jongboom 1:3bff14db67c7 136 // Free the receive buffer
Jan Jongboom 1:3bff14db67c7 137 free(recv_buffer);
Jan Jongboom 1:3bff14db67c7 138
Jan Jongboom 1:3bff14db67c7 139 // Close the socket
Jan Jongboom 1:3bff14db67c7 140 socket.close();
Jan Jongboom 1:3bff14db67c7 141
Jan Jongboom 1:3bff14db67c7 142 return response;
Jan Jongboom 1:3bff14db67c7 143 }
Jan Jongboom 1:3bff14db67c7 144
Jan Jongboom 1:3bff14db67c7 145 /**
Jan Jongboom 1:3bff14db67c7 146 * Set a header for the request.
Jan Jongboom 1:3bff14db67c7 147 *
Jan Jongboom 1:3bff14db67c7 148 * The 'Host' and 'Content-Length' headers are set automatically.
Jan Jongboom 1:3bff14db67c7 149 * Setting the same header twice will overwrite the previous entry.
Jan Jongboom 1:3bff14db67c7 150 *
Jan Jongboom 1:3bff14db67c7 151 * @param[in] key Header key
Jan Jongboom 1:3bff14db67c7 152 * @param[in] value Header value
Jan Jongboom 1:3bff14db67c7 153 */
Jan Jongboom 1:3bff14db67c7 154 void set_header(string key, string value) {
Jan Jongboom 1:3bff14db67c7 155 request_builder->set_header(key, value);
Jan Jongboom 1:3bff14db67c7 156 }
Jan Jongboom 1:3bff14db67c7 157
Jan Jongboom 1:3bff14db67c7 158 /**
Jan Jongboom 1:3bff14db67c7 159 * Get the error code.
Jan Jongboom 1:3bff14db67c7 160 *
Jan Jongboom 1:3bff14db67c7 161 * When send() fails, this error is set.
Jan Jongboom 1:3bff14db67c7 162 */
Jan Jongboom 1:3bff14db67c7 163 nsapi_error_t get_error() {
Jan Jongboom 1:3bff14db67c7 164 return error;
Jan Jongboom 1:3bff14db67c7 165 }
Jan Jongboom 1:3bff14db67c7 166
Jan Jongboom 1:3bff14db67c7 167 private:
Jan Jongboom 1:3bff14db67c7 168 NetworkInterface* network;
Jan Jongboom 1:3bff14db67c7 169 http_method method;
Jan Jongboom 1:3bff14db67c7 170 Callback<void(const char *at, size_t length)> body_callback;
Jan Jongboom 1:3bff14db67c7 171
Jan Jongboom 1:3bff14db67c7 172 ParsedUrl* parsed_url;
Jan Jongboom 1:3bff14db67c7 173
Jan Jongboom 1:3bff14db67c7 174 HttpRequestBuilder* request_builder;
Jan Jongboom 1:3bff14db67c7 175 HttpResponse* response;
Jan Jongboom 1:3bff14db67c7 176
Jan Jongboom 1:3bff14db67c7 177 nsapi_error_t error;
Jan Jongboom 1:3bff14db67c7 178 };
Jan Jongboom 1:3bff14db67c7 179
Jan Jongboom 1:3bff14db67c7 180 #endif // _HTTP_REQUEST_