esp-mbedtls

This is mbedtls for ESP32 / bare-metal Rust.

It comes with mbedtls precompiled to avoid the need for a complete C toolchain. See build_mbedtls for how it was built.

Status

This should work together with esp-wifi. It currently won't work without. However it's not well tested yet besides the included examples.

See the examples for how to use it. A key thing is to enable the feature big-heap in esp-wifi since more heap memory is needed to get this working.

In general this is heavy in terms of heap memory used and code size. If you can, you should prefer using something like embedded-tls.

For now it's missing advanced configuration options which will be added step-by-step.

Currently this won't work on ESP32-S2 - getting it to work will require tweaking the memory usage a lot!

The examples use one hard-coded address of www.google.com which might not always work.

Certificates

These examples use certificates that expire after a given time.

The script genssl.sh is there to renew expired certificates, without having to manually update them within the code.

Running Examples

Examples are available for:

esp32
esp32c3
esp32s3

Limited support is also available for esp32s2 but it won't compile for async.

To run examples, you need to specify the architecture as a feature, the example name, the target and the toolchain.

You also need to set SSID and PASSWORD as your environment variables

Examples

Xtensa:

SSID=<your_ssid> PASSWORD=<your_password> cargo +esp run --release --example sync_client -F esp32s3 --target xtensa-esp32s3-none-elf

RISC-V:

SSID=<your_ssid> PASSWORD=<your_password> cargo +nightly-2023-03-09 run --release --example async_client -F esp32c3,async --target riscv32imc-unknown-none-elf

Here's a table of the architectures with their corresponding target for quick reference:

Architecture	Target	Toolchain
esp32	xtensa-esp32-none-elf	esp
esp32c3	riscv32imc-unknown-none-elf	nightly-2023-03-09
esp32s3	xtensa-esp32s3-none-elf	esp

Heres's a list of all the examples with their description:

Example	Description
async_client	Example of a HTTPS connection using the async client.
async_client_mTLS	Example of a HTTPS connection using the async client, with certificate authentication. This sends client certificates to a server, and the response indicates informations about the certificates.
sync_client	Example of a HTTPS connection using the sync client.
sync_client_mTLS	Example of a HTTPS connection using the sync client, with certificate authentication. This sends client certificates to a server, and the response indicates informations about the certificates.
async_server	Example of a simple async server with HTTPS support. This uses self-signed certificates, so you will need to enable an exception in your browser.
async_server_mTLS	Example of a simple async server with HTTPS support, with client authentication. You will need to pass client certificates in your request in order to have a successful connection. Refer to the documentation inside the example.
sync_server	Example of a simple sync server with HTTPS support. This uses self-signed certificates, so you will need to enable an exception in your browser.
sync_server_mTLS	Example of a simple sync server with HTTPS support, with client authentication. You will need to pass client certificates in your request in order to have a successful connection. Refer to the documentation inside the example.

This needs espflash version 2.x. If you are using version 1.x you need to remove the flash command from the runner in .cargo/config.toml

License

Licensed under either of:

Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

bugadani / esp-mbedtls