3 releases (breaking)
0.3.0 | Jun 1, 2024 |
---|---|
0.2.0 | Apr 28, 2024 |
0.1.0 | Apr 28, 2024 |
#47 in #ed25519
2,422 downloads per month
Used in 21 crates
(6 directly)
44KB
709 lines
const-crypto
A #[no_std]
library for const
sha2/sha3 hashing, ed25519 off-curve point evaluation, and bs58 decoding/encoding with minimal dependencies.
Features
- We write a
const
implementation of Edwards point decompression and use it to provide aconst
implementation of on/off curve evaluation. This is then used to build aconst
implementation of Solana'sPubkey::find_program_address
. NOTE: this point decompression implementation is not cryptographically safe; it does not use constant time implementations for the internal math operations, as it is not intended to be used with secrets. Do not reuse. - Base58 encoding of 32 byte arrays into strings (and vice versa, i.e. decoding). The encoding is taken from
fd_bs58
, and adapted forconst
/`#[no_std] with some bug fixes. - Full sha2/sha3 hash suites. Re-exports of
sha2-const-stable
(authored by yours truly) andkeccak-const
(authored by OffChainLabs)
Usage
The file examples/pda.rs
concisely demonstrates all functionality:
use const_crypto::{bs58, ed25519, sha2, sha3};
/// Uses const bs58 to roundtrip (decode + encode) system_program ID
pub const PROGRAM_KEY: [u8; 32] = bs58::decode_pubkey("11111111111111111111111111111111");
pub const PROGRAM_KEY_STR: &'static str = bs58::encode_pubkey(&PROGRAM_KEY).str();
const _: () = assert!(ascii_str_eq(
PROGRAM_KEY_STR,
"11111111111111111111111111111111"
));
/// Uses const ed25519 (and thus const sha2 internally)
pub const PROGRAM_DERIVED_ADDRESS: [u8; 32] =
ed25519::derive_program_address(&[b"seed"], &PROGRAM_KEY).0;
// the address is off curve
const _: () = assert!(!ed25519::crypto_unsafe_is_on_curve(
&PROGRAM_DERIVED_ADDRESS
));
pub fn main() {
pub const KECCAK_DEMO: [u8; 32] = sha3::Keccak256::new().update(b"const-keccak").finalize();
pub const SHA3_256_DEMO: [u8; 32] = sha3::Sha3_256::new().update(b"const-sha3").finalize();
pub const SHA256_DEMO: [u8; 32] = sha2::Sha256::new().update(b"const-sha2").finalize();
println!("pda = {PROGRAM_DERIVED_ADDRESS:?}\n");
println!("keccak = {KECCAK_DEMO:?}\n");
println!("sha3_256 = {SHA3_256_DEMO:?}\n");
println!("sha256 = {SHA256_DEMO:?}\n");
}
/// A utility function used to show round trip is correct
pub const fn ascii_str_eq(a: &str, b: &str) -> bool {
assert!(a.len() == b.len());
assert!(a.is_ascii());
assert!(b.is_ascii());
let mut i = 0;
while i < a.len() {
assert!(a.as_bytes()[i] == b.as_bytes()[i]);
i += 1
}
true
}
Dependencies
~4.5MB