Alloy Book

Example: hashing_functions

Example

To run this example:

• Clone the examples repository: git clone git@github.com:alloy-rs/examples.git
• Run: cargo run --example hashing_functions

//! Example of basic usage of hashing functions.

use alloy::primitives::{eip191_hash_message, keccak256};
use eyre::Result;

fn main() -> Result<()> {
    // [`Keccak-256`]: https://en.wikipedia.org/wiki/SHA-3
    let hash = keccak256(b"hello world");
    assert_eq!(
        hash.to_string(),
        "0x47173285a8d7341e5e972fc677286384f802f8ef42a5ec5f03bbfa254cb01fad"
    );
    assert_eq!(hash.len(), 32);

    // Hash a message according to [EIP-191] (version `0x01`).
    //
    // The final message is a UTF-8 string, encoded as follows:
    // `"\x19Ethereum Signed Message:\n" + message.length + message`
    //
    // This message is then hashed using [`Keccak-256`]: https://en.wikipedia.org/wiki/SHA-3.
    //
    // [EIP-191]: https://eips.ethereum.org/EIPS/eip-191
    let eip191_hash = eip191_hash_message(b"hello_world");
    assert_eq!(
        eip191_hash.to_string(),
        "0xd52de6e039c023a7c77752126e4d9d99e2a7dacea3d19e97e9c2ebcb3ecf1c00"
    );
    assert_eq!(eip191_hash.len(), 32);

    Ok(())
}

Find the source code on Github here.