Module esp32c3_hal::rsa

Expand description

The RSA driver provides a set of functions to accelerate RSA (Rivest–Shamir–Adleman) cryptographic operations on ESP chips. RSA is a widely used public-key cryptographic algorithm that involves complex mathematical computations, and the RSA accelerator on ESP chips is designed to optimize these computations for faster performance.

Implementation details;

The driver uses low-level peripheral access to read and write data from/to the RSA peripheral.
The driver contains unsafe code blocks as it directly manipulates memory addresses for data transfer.
The driver supports different sizes of operands based on the generic types provided during instantiation.
The nb crate is used to handle non-blocking operations.
The driver provides a set of high-level abstractions to simplify RSA cryptographic operations on ESP chips, allowing developers to leverage the RSA accelerator for improved performance.

Examples

Initialization

let peripherals = Peripherals::take();
let mut system = peripherals.SYSTEM.split();

let mut rsa = Rsa::new(peripherals.RSA);

Async (modular exponentiation)

#[embassy_executor::task]
async fn mod_exp_example(mut rsa: Rsa<'static>) {
    let mut outbuf = [0_u8; U512::BYTES];
    let mut mod_exp = RsaModularExponentiation::<operand_sizes::Op512>::new(
        &mut rsa,
        &BIGNUM_2.to_le_bytes(),
        &BIGNUM_3.to_le_bytes(),
        compute_mprime(&BIGNUM_3),
    );
    let r = compute_r(&BIGNUM_3).to_le_bytes();
    let base = &BIGNUM_1.to_le_bytes();
    mod_exp.exponentiation(&base, &r, &mut outbuf).await;
    let residue_params = DynResidueParams::new(&BIGNUM_3);
    let residue = DynResidue::new(&BIGNUM_1, residue_params);
    let sw_out = residue.pow(&BIGNUM_2);
    assert_eq!(U512::from_le_bytes(outbuf), sw_out.retrieve());
    println!("modular exponentiation done");
}

This peripheral supports async on every available chip except of esp32 (to be solved).

⚠️: The examples for RSA peripheral are quite extensive, so for a more detailed study of how to use this driver please visit the repository with corresponding example.

Modules

operand_sizes
Marker types for the operand sizes

Structs

Rsa
RSA peripheral container
RsaModularExponentiation
Support for RSA peripheral’s modular exponentiation feature that could be used to find the (base ^ exponent) mod modulus.
RsaModularMultiplication
Support for RSA peripheral’s modular multiplication feature that could be used to find the (operand a * operand b) mod modulus.
RsaMultiplication
Support for RSA peripheral’s large number multiplication feature that could be used to find the operand a * operand b.