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Hashing and Cryptography

Icon LinkHashing and Cryptography

The Sway standard library provides easy access to a selection of cryptographic hash functions (sha256 and EVM-compatible keccak256), and EVM-compatible secp256k1-based signature recovery operations.

Icon LinkHashing

script;
 
use std::hash::*;
 
impl Hash for Location {
	fn hash(self, ref mut state: Hasher) {
		match self {
			Location::Earth => {
				0_u8.hash(state);
			}
			Location::Mars => {
				1_u8.hash(state);
			}
		}
	}
}
 
impl Hash for Stats {
	fn hash(self, ref mut state: Hasher) {
		self.strength.hash(state);
		self.agility.hash(state);
	}
}
 
impl Hash for Person {
	fn hash(self, ref mut state: Hasher) {
		self.name.hash(state);
		self.age.hash(state);
		self.alive.hash(state);
		self.location.hash(state);
		self.stats.hash(state);
		self.some_tuple.hash(state);
		self.some_array.hash(state);
		self.some_b256.hash(state);
	}
}
 
const VALUE_A = 0x9280359a3b96819889d30614068715d634ad0cf9bba70c0f430a8c201138f79f;
 
enum Location {
	Earth: (),
	Mars: (),
}
 
struct Person {
	name: str,
	age: u64,
	alive: bool,
	location: Location,
	stats: Stats,
	some_tuple: (bool, u64),
	some_array: [u64; 2],
	some_b256: b256,
}
 
struct Stats {
	strength: u64,
	agility: u64,
}
 
fn main() {
	let zero = b256::min();
	// Use the generic sha256 to hash some integers
	let sha_hashed_u8 = sha256(u8::max());
	let sha_hashed_u16 = sha256(u16::max());
	let sha_hashed_u32 = sha256(u32::max());
	let sha_hashed_u64 = sha256(u64::max());
 
	// Or hash a b256
	let sha_hashed_b256 = sha256(VALUE_A);
 
	// You can hash booleans too
	let sha_hashed_bool = sha256(true);
 
	// Strings are not a problem either
	let sha_hashed_str = sha256("Fastest Modular Execution Layer!");
 
	// Tuples of any size work too
	let sha_hashed_tuple = sha256((true, 7));
 
	// As do arrays
	let sha_hashed_array = sha256([4, 5, 6]);
 
	// Enums work too
	let sha_hashed_enum = sha256(Location::Earth);
 
	// Complex structs are not a problem
	let sha_hashed_struct = sha256(Person {
		name: "John",
		age: 9000,
		alive: true,
		location: Location::Mars,
		stats: Stats {
			strength: 10,
			agility: 9,
		},
		some_tuple: (true, 8),
		some_array: [17, 76],
		some_b256: zero,
	});
 
	log(sha_hashed_u8);
	log(sha_hashed_u16);
	log(sha_hashed_u32);
	log(sha_hashed_u64);
	log(sha_hashed_b256);
	log(sha_hashed_bool);
	log(sha_hashed_str);
	log(sha_hashed_tuple);
	log(sha_hashed_array);
	log(sha_hashed_enum);
	log(sha_hashed_struct);
 
	// Use the generic keccak256 to hash some integers
	let keccak_hashed_u8 = keccak256(u8::max());
	let keccak_hashed_u16 = keccak256(u16::max());
	let keccak_hashed_u32 = keccak256(u32::max());
	let keccak_hashed_u64 = keccak256(u64::max());
 
	// Or hash a b256
	let keccak_hashed_b256 = keccak256(VALUE_A);
 
	// You can hash booleans too
	let keccak_hashed_bool = keccak256(true);
 
	// Strings are not a problem either
	let keccak_hashed_str = keccak256("Fastest Modular Execution Layer!");
 
	// Tuples of any size work too
	let keccak_hashed_tuple = keccak256((true, 7));
 
	// As do arrays
	let keccak_hashed_array = keccak256([4, 5, 6]);
 
	// Enums work too
	let keccak_hashed_enum = keccak256(Location::Earth);
 
	// Complex structs are not a problem
	let keccak_hashed_struct = keccak256(Person {
		name: "John",
		age: 9000,
		alive: true,
		location: Location::Mars,
		stats: Stats {
			strength: 10,
			agility: 9,
		},
		some_tuple: (true, 8),
		some_array: [17, 76],
		some_b256: zero,
	});
 
	log(keccak_hashed_u8);
	log(keccak_hashed_u16);
	log(keccak_hashed_u32);
	log(keccak_hashed_u64);
	log(keccak_hashed_b256);
	log(keccak_hashed_bool);
	log(keccak_hashed_str);
	log(keccak_hashed_tuple);
	log(keccak_hashed_array);
	log(keccak_hashed_enum);
	log(keccak_hashed_struct);
}
 

Icon LinkSignature Recovery

script;
 
use std::{b512::B512, ecr::{ec_recover, ec_recover_address, EcRecoverError}};
 
const MSG_HASH = 0xee45573606c96c98ba970ff7cf9511f1b8b25e6bcd52ced30b89df1e4a9c4323;
 
fn main() {
	let hi = 0xbd0c9b8792876713afa8bff383eebf31c43437823ed761cc3600d0016de5110c;
	let lo = 0x44ac566bd156b4fc71a4a4cb2655d3dd360c695edb17dc3b64d611e122fea23d;
	let signature: B512 = B512::from((hi, lo));
 
	// A recovered public key pair.
	let public_key = ec_recover(signature, MSG_HASH);
 
	// A recovered Fuel address.
	let result_address: Result<Address, EcRecoverError> = ec_recover_address(signature, MSG_HASH);
	if let Ok(address) = result_address {
		log(address.value);
	} else {
		revert(0);
	}
}
 

Note: Recovery of EVM addresses is also supported via std::vm::evm.