sandbox
HTTP and HTTPS library for Mbed OS 5
Dependents: MQTTGateway2 MQTTGatewayK64 http-example-wnc GuardRoom ... more
For the example program, see: sandbox/http-example.
This library is used to make HTTP and HTTPS calls from Mbed OS 5 applications.
HTTP Request API
NetworkInterface* network = /* obtain a NetworkInterface object */
const char body[] = "{\"hello\":\"world\"}";
HttpRequest* request = new HttpRequest(network, HTTP_POST, "http://httpbin.org/post");
request->set_header("Content-Type", "application/json");
HttpResponse* response = request->send(body, strlen(body));
// if response is NULL, check response->get_error()
printf("status is %d - %s\n", response->get_status_code(), response->get_status_message());
printf("body is:\n%s\n", response->get_body_as_string().c_str());
delete request; // also clears out the response
HTTPS Request API
// pass in the root certificates that you trust, there is no central CA registry in Mbed OS
const char SSL_CA_PEM[] = "-----BEGIN CERTIFICATE-----\n"
/* rest of the CA root certificates */;
NetworkInterface* network = /* obtain a NetworkInterface object */
const char body[] = "{\"hello\":\"world\"}";
HttpsRequest* request = new HttpsRequest(network, SSL_CA_PEM, HTTP_GET "https://httpbin.org/status/418");
HttpResponse* response = request->send();
// if response is NULL, check response->get_error()
printf("status is %d - %s\n", response->get_status_code(), response->get_status_message());
printf("body is:\n%s\n", response->get_body().c_str());
delete request;
Note: You can get the root CA for a domain easily from Firefox. Click on the green padlock, click More information > Security > View certificate > Details. Select the top entry in the 'Certificate Hierarchy' and click Export.... This gives you a PEM file. Add the content of the PEM file to your root CA list (here's an image).
Mbed TLS Entropy configuration
If your target does not have a built-in TRNG, or other entropy sources, add the following macros to your mbed_app.json file to disable entropy:
{
"macros": [
"MBEDTLS_TEST_NULL_ENTROPY",
"MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES"
]
}
Note that this is not secure, and you should not deploy this device into production with this configuration.
Memory usage
Small requests where the body of the response is cached by the library (like the one found in main-http.cpp), require 4K of RAM. When the request is finished they require 1.5K of RAM, depending on the size of the response. This applies both to HTTP and HTTPS. If you need to handle requests that return a large response body, see 'Dealing with large body'.
HTTPS requires additional memory: on FRDM-K64F about 50K of heap space (at its peak). This means that you cannot use HTTPS on devices with less than 128K of memory, asyou also need to reserve memory for the stack and network interface.
Dealing with large response body
By default the library will store the full request body on the heap. This works well for small responses, but you'll run out of memory when receiving a large response body. To mitigate this you can pass in a callback as the last argument to the request constructor. This callback will be called whenever a chunk of the body is received. You can set the request chunk size in the HTTP_RECEIVE_BUFFER_SIZE macro (see mbed_lib.json for the definition) although it also depends on the buffer size ofthe underlying network connection.
void body_callback(const char* data, uint32_t data_len) {
// do something with the data
}
HttpRequest* req = new HttpRequest(network, HTTP_GET, "http://pathtolargefile.com", &body_callback);
req->send(NULL, 0);
Dealing with a large request body
If you cannot load the full request into memory, you can pass a callback into the send function. Through this callback you can feed in chunks of the request body. This is very useful if you want to send files from a file system.
const void * get_chunk(uint32_t* out_size) {
// set the value of out_size (via *out_size = 10) to the size of the buffer
// return the buffer
// if you don't have any more data, set *out_size to 0
}
HttpRequest* req = new HttpRequest(network, HTTP_POST, "http://my_api.com/upload");
req->send(callback(&get_chunk));
Socket re-use
By default the library opens a new socket per request. This is wasteful, especially when dealing with TLS requests. You can re-use sockets like this:
HTTP
TCPSocket* socket = new TCPSocket();
nsapi_error_t open_result = socket->open(network);
// check open_result
nsapi_error_t connect_result = socket->connect("httpbin.org", 80);
// check connect_result
// Pass in `socket`, instead of `network` as first argument
HttpRequest* req = new HttpRequest(socket, HTTP_GET, "http://httpbin.org/status/418");
HTTPS
TLSSocket* socket = new TLSSocket();
nsapi_error_t r;
// make sure to check the return values for the calls below (should return NSAPI_ERROR_OK)
r = socket->open(network);
r = socket->set_root_ca_cert(SSL_CA_PEM);
r = socket->connect("httpbin.org", 443);
// Pass in `socket`, instead of `network` as first argument, and omit the `SSL_CA_PEM` argument
HttpsRequest* get_req = new HttpsRequest(socket, HTTP_GET, "https://httpbin.org/status/418");
Request logging
To make debugging easier you can log the raw request body that goes over the line. This also works with chunked encoding.
uint8_t *request_buffer = (uint8_t*)calloc(2048, 1);
req->set_request_log_buffer(request_buffer, 2048);
// after the request is done:
printf("\n----- Request buffer -----\n");
for (size_t ix = 0; ix < req->get_request_log_buffer_length(); ix++) {
printf("%02x ", request_buffer[ix]);
}
printf("\n");
Integration tests
Integration tests are located in the TESTS folder and are ran through Greentea. Instructions on how to run the tests are in http-example.
Mbed OS 5.10 or lower
If you want to use this library on Mbed OS 5.10 or lower, you need to add the TLSSocket library to your project. This library is included in Mbed OS 5.11 and up.
Tested on
- K64F with Ethernet.
- NUCLEO_F411RE with ESP8266.
- ODIN-W2 with WiFi.
- K64F with Atmel 6LoWPAN shield.
- DISCO-L475VG-IOT01A with WiFi.
- Mbed Simulator.
LICENSE
- Committer:
- Jan Jongboom
- Date:
- 2019-08-12
- Revision:
- 39:a8d157986ad8
- Parent:
- 0:910f5949759f
File content as of revision 39:a8d157986ad8:
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction, and
distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by the copyright
owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all other entities
that control, are controlled by, or are under common control with that entity.
For the purposes of this definition, "control" means (i) the power, direct or
indirect, to cause the direction or management of such entity, whether by
contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity exercising
permissions granted by this License.
"Source" form shall mean the preferred form for making modifications, including
but not limited to software source code, documentation source, and configuration
files.
"Object" form shall mean any form resulting from mechanical transformation or
translation of a Source form, including but not limited to compiled object code,
generated documentation, and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or Object form, made
available under the License, as indicated by a copyright notice that is included
in or attached to the work (an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object form, that
is based on (or derived from) the Work and for which the editorial revisions,
annotations, elaborations, or other modifications represent, as a whole, an
original work of authorship. For the purposes of this License, Derivative Works
shall not include works that remain separable from, or merely link (or bind by
name) to the interfaces of, the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including the original version
of the Work and any modifications or additions to that Work or Derivative Works
thereof, that is intentionally submitted to Licensor for inclusion in the Work
by the copyright owner or by an individual or Legal Entity authorized to submit
on behalf of the copyright owner. For the purposes of this definition,
"submitted" means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems, and
issue tracking systems that are managed by, or on behalf of, the Licensor for
the purpose of discussing and improving the Work, but excluding communication
that is conspicuously marked or otherwise designated in writing by the copyright
owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity on behalf
of whom a Contribution has been received by Licensor and subsequently
incorporated within the Work.
2. Grant of Copyright License.
Subject to the terms and conditions of this License, each Contributor hereby
grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
irrevocable copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the Work and such
Derivative Works in Source or Object form.
3. Grant of Patent License.
Subject to the terms and conditions of this License, each Contributor hereby
grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
irrevocable (except as stated in this section) patent license to make, have
made, use, offer to sell, sell, import, and otherwise transfer the Work, where
such license applies only to those patent claims licensable by such Contributor
that are necessarily infringed by their Contribution(s) alone or by combination
of their Contribution(s) with the Work to which such Contribution(s) was
submitted. If You institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work or a
Contribution incorporated within the Work constitutes direct or contributory
patent infringement, then any patent licenses granted to You under this License
for that Work shall terminate as of the date such litigation is filed.
4. Redistribution.
You may reproduce and distribute copies of the Work or Derivative Works thereof
in any medium, with or without modifications, and in Source or Object form,
provided that You meet the following conditions:
You must give any other recipients of the Work or Derivative Works a copy of
this License; and
You must cause any modified files to carry prominent notices stating that You
changed the files; and
You must retain, in the Source form of any Derivative Works that You distribute,
all copyright, patent, trademark, and attribution notices from the Source form
of the Work, excluding those notices that do not pertain to any part of the
Derivative Works; and
If the Work includes a "NOTICE" text file as part of its distribution, then any
Derivative Works that You distribute must include a readable copy of the
attribution notices contained within such NOTICE file, excluding those notices
that do not pertain to any part of the Derivative Works, in at least one of the
following places: within a NOTICE text file distributed as part of the
Derivative Works; within the Source form or documentation, if provided along
with the Derivative Works; or, within a display generated by the Derivative
Works, if and wherever such third-party notices normally appear. The contents of
the NOTICE file are for informational purposes only and do not modify the
License. You may add Your own attribution notices within Derivative Works that
You distribute, alongside or as an addendum to the NOTICE text from the Work,
provided that such additional attribution notices cannot be construed as
modifying the License.
You may add Your own copyright statement to Your modifications and may provide
additional or different license terms and conditions for use, reproduction, or
distribution of Your modifications, or for any such Derivative Works as a whole,
provided Your use, reproduction, and distribution of the Work otherwise complies
with the conditions stated in this License.
5. Submission of Contributions.
Unless You explicitly state otherwise, any Contribution intentionally submitted
for inclusion in the Work by You to the Licensor shall be under the terms and
conditions of this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify the terms of
any separate license agreement you may have executed with Licensor regarding
such Contributions.
6. Trademarks.
This License does not grant permission to use the trade names, trademarks,
service marks, or product names of the Licensor, except as required for
reasonable and customary use in describing the origin of the Work and
reproducing the content of the NOTICE file.
7. Disclaimer of Warranty.
Unless required by applicable law or agreed to in writing, Licensor provides the
Work (and each Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
including, without limitation, any warranties or conditions of TITLE,
NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
solely responsible for determining the appropriateness of using or
redistributing the Work and assume any risks associated with Your exercise of
permissions under this License.
8. Limitation of Liability.
In no event and under no legal theory, whether in tort (including negligence),
contract, or otherwise, unless required by applicable law (such as deliberate
and grossly negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special, incidental,
or consequential damages of any character arising as a result of this License or
out of the use or inability to use the Work (including but not limited to
damages for loss of goodwill, work stoppage, computer failure or malfunction, or
any and all other commercial damages or losses), even if such Contributor has
been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability.
While redistributing the Work or Derivative Works thereof, You may choose to
offer, and charge a fee for, acceptance of support, warranty, indemnity, or
other liability obligations and/or rights consistent with this License. However,
in accepting such obligations, You may act only on Your own behalf and on Your
sole responsibility, not on behalf of any other Contributor, and only if You
agree to indemnify, defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason of your
accepting any such warranty or additional liability.
---
http_parser.c is based on src/http/ngx_http_parse.c from NGINX copyright
Igor Sysoev.
Additional changes are licensed under the same terms as NGINX and
copyright Joyent, Inc. and other Node contributors. All rights reserved.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.