From 9cdd0d55f2e1acc9d84dd36409f87a7a633a32f3 Mon Sep 17 00:00:00 2001 From: Irit Arkin Date: Fri, 28 Aug 2015 09:27:57 +0100 Subject: [PATCH] Small edit --- yotta/data/example-tls-client/README.md | 36 +++++++++++++++---------- 1 file changed, 22 insertions(+), 14 deletions(-) diff --git a/yotta/data/example-tls-client/README.md b/yotta/data/example-tls-client/README.md index f245ea173..c181933a1 100644 --- a/yotta/data/example-tls-client/README.md +++ b/yotta/data/example-tls-client/README.md @@ -1,4 +1,4 @@ -# HTTPS File Download Example/ TLS Client +# HTTPS File Download Example for TLS Client This application downloads a file from an HTTPS server (developer.mbed.org) and looks for a specific string in that file. @@ -6,25 +6,25 @@ This example is implemented as a logic class (HelloHTTPS) wrapping a TCP socket ## Pre-requisites -To build and run this example the following requirements are necessary: +To build and run this example you must have: * A computer with the following software installed: * [CMake](http://www.cmake.org/download/). * [yotta](https://github.com/ARMmbed/yotta). Please note that **yotta has its own set of dependencies**, listed in the [installation instructions](http://armmbed.github.io/yotta/#installing-on-windows). * [Python](https://www.python.org/downloads/). - * [ARM GCC toolchain](https://launchpad.net/gcc-arm-embedded). - * A serial terminal emulator (e.g. screen, pySerial, cu). -* An [FRDM-K64F](http://developer.mbed.org/platforms/FRDM-K64F/) development board, or another board that has an ethernet port and is supported by mbed OS (in which case you'll have to substitute frdm-k64f-gcc with the appropriate target in the instructions below). -* An ethernet connection to the internet. -* An ethernet cable. + * [The ARM GCC toolchain](https://launchpad.net/gcc-arm-embedded). + * A serial terminal emulator (Like screen, pySerial and cu). +* An [FRDM-K64F](http://developer.mbed.org/platforms/FRDM-K64F/) development board, or another board supported by mbed OS (in which case you'll have to substitute frdm-k64f-gcc with the appropriate target in the instructions below). * A micro-USB cable. +* An Ethernet connection to the internet. +* An Ethernet cable. * If your OS is Windows, please follow the installation instructions [for the serial port driver](https://developer.mbed.org/handbook/Windows-serial-configuration). ## Getting started -1. Connect the FRDM-K64F to the internet using the ethernet cable. +1. Connect the FRDM-K64F to the internet using the Ethernet cable. -2. Connect the FRDM-K64F to the computer with the micro-USB cable, being careful to use the "OpenSDA" connector on the target board. +2. Connect the FRDM-K64F to the computer with the micro-USB cable, being careful to use the "OpenSDA" connector on the target board. 3. Navigate to the mbedtls directory supplied with your release and open a terminal. @@ -42,9 +42,15 @@ To build and run this example the following requirements are necessary: 6. Copy `build/frdm-k64f-gcc/test/mbedtls-test-example-tls-client.bin` to your mbed board and wait until the LED next to the USB port stops blinking. -7. Start the serial terminal emulator and connect to the virtual serial port presented by FRDM-K64F. For settings, use 115200 baud, 8N1, no flow control. **Warning:** for this example, the baud rate is not the default 9600, it is 115200. +7. Start the serial terminal emulator and connect to the virtual serial port presented by FRDM-K64F. -8. Press the reset button on the board. + Use the following settings: + + * 115200 baud (not 9600). + * 8N1. + * No flow control. + +8. Press the Reset button on the board. 9. The output in the terminal window should look similar to this: @@ -105,9 +111,9 @@ To build and run this example the following requirements are necessary: ## Debugging the TLS connection -If you are experiencing problems with this example, you should first rule out network issues by making sure the [simple HTTP file downloader example](https://github.com/ARMmbed/mbed-example-network-private/tree/maste r/test/helloworld-tcpclient) for the TCP module works as expected. If not, please follow the debug instructions for this example. +If you are experiencing problems with this example, you should first rule out network issues by making sure the [simple HTTP file downloader example](https://github.com/ARMmbed/mbed-example-network-private/tree/master/test/helloworld-tcpclient) for the TCP module works as expected. If not, please follow the debug instructions below. -To print out more debug information about the TLS connection, edit the file `source/main.cpp` and change the definition of `DEBUG_LEVEL` near the top of the file from 0 to a positive number: +To print out more debug information about the TLS connection, edit the file `source/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. @@ -125,4 +131,6 @@ If the TLS connection is failing with an error similar to: Failed to fetch /media/uploads/mbed_official/hello.txt from developer.mbed.org:443 ``` -it 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 reason for this error may be a proxy providing a different certificate. Proxys 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 attacker, therefore use at your own risk, or for debugging only! +it 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 reason for this error may be 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 attacker, therefore use at your own risk, or for debugging only!