SHA-2

The OpenVM SHA-2 guest library provides access to a set of accelerated SHA-2 family hash functions. Currently, it supports the following:

• SHA-256

SHA-256

Refer here for more details on SHA-256.

For SHA-256, the SHA2 guest library provides two functions for use in your guest code:

• sha256(input: &[u8]) -> [u8; 32]: Computes the SHA-256 hash of the input data and returns it as an array of 32 bytes.
• set_sha256(input: &[u8], output: &mut [u8; 32]): Sets the output to the SHA-256 hash of the input data into the provided output buffer.

See the full example here.

Example

use core::hint::black_box;

use hex::FromHex;
use openvm_sha2::sha256;
openvm::entry!(main);

pub fn main() {
    let test_vectors = [(
        "",
        "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
    )];
    for (input, expected_output) in test_vectors.iter() {
        let input = Vec::from_hex(input).unwrap();
        let expected_output = Vec::from_hex(expected_output).unwrap();
        let output = sha256(&black_box(input));
        if output != *expected_output {
            panic!();
        }
    }
}

To be able to import the sha256 function, add the following to your Cargo.toml file:

openvm-sha2 = { git = "https://github.com/openvm-org/openvm.git" }
hex = { version = "0.4.3" }

Config parameters

For the guest program to build successfully add the following to your .toml file:

[app_vm_config.sha256]