mbed-os-examples
Hello world example of a TLS client: fetch an HTTPS page. The canonical source for this example lives at https://github.com/ARMmbed/mbed-os-example-tls
HTTPS File Download Example for TLS Client on mbed OS
This application downloads a file from an HTTPS server (developer.mbed.org) and looks for a specific string in that file.
Getting started
Building with mbed CLI
If you'd like to use mbed CLI to build this, then you should set up your environment if you have not done so already. For instructions, refer to the main readme. The instructions here relate to using the developer.mbed.org Online Compiler
Import the program in to the Online Compiler, select your board from the drop down in the top right hand corner and then compile the application. Once it has built, you can drag and drop the binary onto your device.
Required hardware
This example also requires an Ethernet cable an connection to the internet additional to the hardware requirements in the main readme.
Monitoring the application
NOTE: Make sure that the Ethernet cable is plugged in correctly before running the application.
The output in the terminal window should be similar to this:
terminal output
Using Ethernet LWIP
Client IP Address is 10.2.203.43
Connecting with developer.mbed.org
Starting the TLS handshake...
TLS connection to developer.mbed.org established
Server certificate:
cert. version : 3
serial number : 11:21:B8:47:9B:21:6C:B1:C6:AF:BC:5D:0C:19:52:DC:D7:C3
issuer name : C=BE, O=GlobalSign nv-sa, CN=GlobalSign Organization Validation CA - SHA256 - G2
subject name : C=GB, ST=Cambridgeshire, L=Cambridge, O=ARM Ltd, CN=*.mbed.com
issued on : 2016-03-03 12:26:08
expires on : 2017-04-05 10:31:02
signed using : RSA with SHA-256
RSA key size : 2048 bits
basic constraints : CA=false
subject alt name : *.mbed.com, mbed.org, *.mbed.org, mbed.com
key usage : Digital Signature, Key Encipherment
ext key usage : TLS Web Server Authentication, TLS Web Client Authentication
Certificate verification passed
HTTPS: Received 439 chars from server
HTTPS: Received 200 OK status ... [OK]
HTTPS: Received 'Hello world!' status ... [OK]
HTTPS: Received message:
HTTP/1.1 200 OK
Server: nginx/1.7.10
Date: Wed, 20 Jul 2016 10:00:35 GMT
Content-Type: text/plain
Content-Length: 14
Connection: keep-alive
Last-Modified: Fri, 27 Jul 2012 13:30:34 GMT
Accept-Ranges: bytes
Cache-Control: max-age=36000
Expires: Wed, 20 Jul 2016 20:00:35 GMT
X-Upstream-L3: 172.17.0.3:80
X-Upstream-L2: developer-sjc-indigo-1-nginx
Strict-Transport-Security: max-age=31536000; includeSubdomains
Hello world!
Debugging the TLS connection
To print out more debug information about the TLS connection, edit the file `main.cpp` and change the definition of `DEBUG_LEVEL` (near the top of the file) from 0 to a positive number:
- Level 1 only prints non-zero return codes from SSL functions and information about the full certificate chain being verified.
- Level 2 prints more information about internal state updates.
- Level 3 is intermediate.
- Level 4 (the maximum) includes full binary dumps of the packets.
The TLS connection can fail with an error similar to:
error message
mbedtls_ssl_write() failed: -0x2700 (-9984): X509 - Certificate verification failed, e.g. CRL, CA or signature check failed
Failed to fetch /media/uploads/mbed_official/hello.txt from developer.mbed.org:443
This probably means you need to update the contents of the SSL_CA_PEM constant (this can happen if you modify HTTPS_SERVER_NAME, or when developer.mbed.org switches to a new CA when updating its certificate).
Another possible reason for this error is a proxy providing a different certificate. Proxies can be used in some network configurations or for performing man-in-the-middle attacks. If you choose to ignore this error and proceed with the connection anyway, you can change the definition of UNSAFE near the top of the file from 0 to 1.
Warning: this removes all security against a possible active attacker, so use at your own risk or for debugging only!
History
Merge pull request #264 from dgreen-arm/point-master-at-mbed-os-master
2019-11-18, by mbed_official [Mon, 18 Nov 2019 14:00:49 +0000] rev 98
Merge pull request #264 from dgreen-arm/point-master-at-mbed-os-master
Point master branch at Mbed OS master
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #235 from adbridge/master
2019-02-25, by mbed_official [Mon, 25 Feb 2019 16:42:26 +0000] rev 97
Merge pull request #235 from adbridge/master
All the CI tests have passed.
Updating mbed-os to mbed-os-5.11.5
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #234 from adbridge/master
2019-02-13, by mbed_official [Wed, 13 Feb 2019 18:32:23 +0000] rev 96
Merge pull request #234 from adbridge/master
All the CI tests pass.
Updating mbed-os to mbed-os-5.11.4
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #232 from ARMmbed/tls-client_psa
2019-01-28, by mbed_official [Mon, 28 Jan 2019 16:15:09 +0000] rev 95
Merge pull request #232 from ARMmbed/tls-client_psa
Allow the use of PSA Crypto in TLS client example
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #231 from cmonr/master
2019-01-17, by mbed_official [Thu, 17 Jan 2019 14:30:19 +0000] rev 94
Merge pull request #231 from cmonr/master
All the CI tests passed.
Updating mbed-os to mbed-os-5.11.2
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #220 from RonEld/undefine_mpi_max_size
2019-01-08, by mbed_official [Tue, 08 Jan 2019 12:45:12 +0000] rev 93
Merge pull request #220 from RonEld/undefine_mpi_max_size
Undefine MBEDTLS_MPI_MAX_SIZE
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #222 from dgreen-arm/tls-client-ublox-fix
2019-01-07, by mbed_official [Mon, 07 Jan 2019 13:30:08 +0000] rev 92
Merge pull request #222 from dgreen-arm/tls-client-ublox-fix
Set default network driver on Ublox target to ethernet
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #225 from adbridge/master
2019-01-04, by mbed_official [Fri, 04 Jan 2019 18:00:17 +0000] rev 91
Merge pull request #225 from adbridge/master
Updating mbed-os to mbed-os-5.11.1
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #224 from ARMmbed/mbed-os-5.11.0-oob
2018-12-28, by mbed_official [Fri, 28 Dec 2018 09:00:22 +0000] rev 90
Merge pull request #224 from ARMmbed/mbed-os-5.11.0-oob
Updating mbed-os to mbed-os-5.11.0
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls
Merge pull request #215 from cmonr/master
2018-11-21, by mbed_official [Wed, 21 Nov 2018 09:45:17 +0000] rev 89
Merge pull request #215 from cmonr/master
Updating mbed-os to mbed-os-5.10.4
The failing tests are tracked as known issues
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Commit copied from https://github.com/ARMmbed/mbed-os-example-tls