2.7 KiB
Authenticated encryption example
This application performs authenticated encryption and authenticated decryption of a buffer. It serves as a tutorial for the basic authenticated encryption functions of mbed TLS.
Pre-requisites
To build and run this example the requirements below are necessary:
- A computer with the following software installed:
- CMake.
- yotta. Please note that yotta has its own set of dependencies, listed in the installation instructions.
- Python.
- ARM GCC toolchain.
- A serial terminal emulator (e.g. screen, pySerial, cu).
- An FRDM-K64F development board, or another board supported by mbed OS (in that case you'll have to substitute frdm-k64f-gcc with the appropriate target below).
- A micro-USB cable.
- If your OS is Windows, please follow the installation instructions for the serial port driver.
Getting started
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Connect the FRDM-K64F to the computer with the micro-USB cable, being careful to use the micro-usb port labeled "OpenSDA".
-
Navigate to the mbedtls directory supplied with your release and open a terminal.
-
Set the yotta target:
yotta target frdm-k64f-gcc
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Build mbedtls and the examples. This will take a long time if it is the first time:
$ yt build
-
Copy
build/frdm-k64f-gcc/test/mbedtls-test-example-authcrypt.bin
to your mbed board and wait until the LED next to the USB port stops blinking. -
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.
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Press the reset button on the board.
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The output in the terminal window should look like:
{{timeout;10}} {{host_test_name;default}} {{description;mbed TLS example authcrypt}} {{test_id;MBEDTLS_EX_AUTHCRYPT}} {{start}} plaintext message: 536f6d65207468696e67732061726520626574746572206c65667420756e7265616400 ciphertext: c57f7afb94f14c7977d785d08682a2596bd62ee9dcf216b8cccd997afee9b402f5de1739e8e6467aa363749ef39392e5c66622b01c7203ec0a3d14 decrypted: 536f6d65207468696e67732061726520626574746572206c65667420756e7265616400 DONE {{success}} {{end}}
The actual output for the ciphertext line will vary on each run due to the use of a random nonce in the encryption process.