Module sha

Available on crate feature unstable only.

Secure Hash Algorithm (SHA) Accelerator

Overview

This SHA accelerator is a hardware device that speeds up the SHA algorithm significantly, compared to a SHA algorithm implemented solely in software

Configuration

This driver allows you to perform cryptographic hash operations using various hash algorithms supported by the SHA peripheral, such as:

• SHA-1
• SHA-224
• SHA-256
• SHA-384
• SHA-512

The driver supports two working modes:

• Typical SHA
• DMA-SHA

It provides functions to update the hash calculation with input data, finish the hash calculation and retrieve the resulting hash value. The SHA peripheral on ESP chips can handle large data streams efficiently, making it suitable for cryptographic applications that require secure hashing.

To use the SHA Peripheral Driver, you need to initialize it with the desired SHA mode and the corresponding SHA peripheral. Once initialized, you can update the hash calculation by providing input data, finish the calculation to retrieve the hash value and repeat the process for a new hash calculation if needed.

Examples

let mut source_data = "HELLO, ESPRESSIF!".as_bytes();
let mut sha = Sha::new(peripherals.SHA);
let mut hasher = sha.start::<Sha256>();
// Short hashes can be created by decreasing the output buffer to the
// desired length
let mut output = [0u8; 32];

while !source_data.is_empty() {
    // All the HW Sha functions are infallible so unwrap is fine to use if
    // you use block!
    source_data = block!(hasher.update(source_data)).unwrap();
}

// Finish can be called as many times as desired to get multiple copies of
// the output.
block!(hasher.finish(output.as_mut_slice())).unwrap();

Implementation State

• DMA-SHA Mode is not supported.

Structs

• Sha
  The SHA Accelerator driver instance
• Sha1
  A SHA implementation struct.
• Sha256
  A SHA implementation struct.
• Sha384
  A SHA implementation struct.
• Sha512
  A SHA implementation struct.
• ShaDigest
  An active digest

Traits

• ShaAlgorithm
  This trait encapsulates the configuration for a specific SHA algorithm.