Introduce and move new Arduino examples and configuration updates.

[gojimmypi]

Description

This PR introduces a new AES CTR (Counter Mode) Arduino example sketch along with supporting template files and configuration updates. The example demonstrates AES CTR encryption and decryption capabilities of wolfSSL on Arduino platforms.

edit: Moving Arduino examples. See wolfSSL/wolfssl-examples#499

edit (2): Expanded the scope of handling the various combinations of these macros in user_settings.h:

• #define NO_TLS
• #define WOLFCRYPT_ONLY
• #define NO_WOLFSSL_CLIENT
• #define NO_WOLFSSL_SERVER

Some combinations would cause compiler warnings about things declared and note used. Additional gating applied to handle this.

One combination now causes a hard error via settings.h:

//#define NO_TLS
//#define WOLFCRYPT_ONLY
#define NO_WOLFSSL_CLIENT
#define NO_WOLFSSL_SERVER

Key Changes

1. New AES CTR Example:

   • Added IDE/ARDUINO/sketches/wolfssl_AES_CTR/wolfssl_AES_CTR.ino - A complete example demonstrating AES CTR encryption/decryption
   • Added supporting project files (README.md, .adeps, .sln, .vgdbproj) for various Arduino IDE environments
   • Tested on Arduino using Teensy 4.1 (ARM Cortex-M7 at 600 MHz)
   • AES CTR GPLV2 Contributed by Chris Jennings Feb 2025; Thank you!

2. Arduino Template Example:

   • Added IDE/ARDUINO/sketches/template/ directory with reference template files
   • Includes multi-file example structure with helper files and library organization
   • Provides VisualGDB project files for easier development

3. Configuration Updates:

   • Updated examples/configs/user_settings_arduino.h to include AES CTR support
   • Added WOLFSSL_AES and WOLFSSL_AES_COUNTER macros
   • Updated version identifier to v5.7.6
   • Added ECC and RSA hardening options

4. Arduino Integration Improvements:

   • Added wolfssl-arduino.cpp with Arduino-specific Serial.print helper function
   • Updated wolfssl.h to properly declare the helper function
   • Updated wolfssl-arduino.sh script to include the new cpp file in Arduino library builds

5. Documentation Updates:

   • Updated IDE/ARDUINO/README.md with references to new examples
   • Updated IDE/ARDUINO/sketches/README.md to include new examples
   • Added troubleshooting information for common Arduino build issues

6. Code Cleanup:

   • Fixed file locations and directory references
   • Removed stray tabs and improved formatting
   • Fixed spelling errors in documentation and comments

Fixes zd# 19275

Testing

How did you test?

Tested on Arduino using Teensy 4.1

• ARM Cortex-M7 at 600 MHz
• Float point math unit, 64 & 32 bits
• 7936K Flash, 1024K RAM (512K tightly coupled), 4K EEPROM (emulated)
• QSPI memory expansion, locations for 2 extra RAM or Flash chips

See https://www.pjrc.com/store/teensy41.html

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[gojimmypi]

Jenkins retest this please

to retry "Unable to create live FilePath for wolf-linux-cloud-node"

[gojimmypi]

Edit: I added a new updated file: examples/configs/user_settings_arduino.h that includes these macros for the AES_CTR example that would otherwise need to be added manually.

#define WOLFSSL_AES
#define WOLFSSL_AES_COUNTER

This user_settings_arduino.h file will be the new default user_settings.h for the next release of the Arduino-wolfSSL library. In the meantime, the changes can be made manually or with the install script.

I also included some minor changes to avoid warnings in Arduino related to hardening and not using client nor server examples.

[gojimmypi]

Jenkins retest this please.

To retry unrelated DTLS 1.3 group 6 failure 4740 "invalid stream header: 636F7272"

[gojimmypi]

Jenkins retest this please.

For "Unable to create live FilePath for wolf-linux-cloud-node-nnn; wolf-linux-cloud-node-nnn was marked offline: Connection was broken"

@dgarske I've expanded the scope of this PR to include an additional example. See ZD 19275. Updated description and PR title.

In particular note the new additional gating changes to tls.c that otherwise gave compiler warnings depending on client / server settings.

[gojimmypi]

Jenkins retest this please.

multi-test-script 5141 unavailable.

[gojimmypi]

Jenkins retest this please.

no output (or no permissions?) to test 4416.

java.io.StreamCorruptedException: invalid stream header in 7660

[dgarske]

Is it possible to put these example into wolfssl-examples or another public repo?

[gojimmypi]

Yes, it's certainly possible, although that would not have been my first choice. I get it that wolfSSL could contain only the core library, and arguably no examples at all.

It should be possible to modify the Arduino publishing script to pull from multiple repositories (core + examples) and push everything to the Arduino-wolfSSL repo for publishing to Arduino (or a local directory).

Do you prefer that all or only some of the Arduino examples be moved?

[dgarske]

@gojimmypi in my opinion its better to split out library changes like TLSX gating and this Arduino feature to separate PR's. I also think you should not have the Arduino examples in the library proper. They should be in a different repo like wolfssl-examples.

[gojimmypi]

@dgarske I've created wolfSSL/wolfssl-examples#499 to move the Arduino examples.

It will be a multi-step process. I'll next remove the examples from this repo in this PR, leaving only the README.md files that are known to be included in docs, blogs, other PRs, etc.

Once the wolfssl-examples PR is merged, I will create a new PR here to modify the install script to pull the examples from new location when publishing to Arduino-wolfSSL.

Once this PR is merged, I'll create a new PR in the wolfssl-examples to enable more testing in the new arduino.yml workflow file that would otherwise fail without the changes in this PR.

[dgarske]

Retest this please: multiple "Found unhandled org.jenkinsci.plugins.workflow.support.steps.AgentOfflineException exception:".

[dgarske]

Retest this please: "Found unhandled hudson.remoting.RequestAbortedException exception:"

[gojimmypi]

No, just one error and one section that includes !WOLFCRYPT_ONLY && !NO_TLS

Yes, I had that at one point, but when the WOLFCRYPT_ONLY was missing, the error was not very intuitive.

In any case, I've applied your exact change as exactly specified.

[gojimmypi]

Jenkins retest this please

for Unable to create live FilePath for wolf-linux-cloud-node-nnn; marked offline: Connection was broken