Starknet Keccak

[marioiordanov]

The PR includes:

Implementation of starknet_keccak hash function

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This change is 

[yair-starkware]

Reviewed 3 of 3 files at r1, all commit messages.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @marioiordanov)

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src/hash.rs line 58 at r1 (raw file):

    let mut res_bytes: [u8; 32] = [0; 32];
    masked_number.to_big_endian(&mut res_bytes);
    StarkFelt::new(res_bytes).expect("error when converting to StarkFelt")

Return a Result instead of expecting

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src/hash_test.rs line 75 at r1 (raw file):

#[test]
fn starknet_keccak_mask() {
    let mask: U256 = U256::pow(U256::from(2), U256::from(250)) - U256::from(1);

Is it possible to calculate this in the const itself? (not blocking)

Code quote:

let mask: U256 = U256::pow(U256::from(2), U256::from(250)) - U256::from(1);

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src/hash_test.rs line 86 at r1 (raw file):

    let expected_keccak_felt =
        stark_felt!("0x362398bec32bc0ebb411203221a35a0301193a96f317ebe5e40be9f60d15320");
    let increase_balance_keccak_felt = crate::hash::starknet_keccak("increase_balance".as_bytes());

Replace the full path by importing the function

Code quote:

crate::

[marioiordanov]

Reviewable status: 1 of 3 files reviewed, 2 unresolved discussions (waiting on @yair-starkware)

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src/hash.rs line 58 at r1 (raw file):

Previously, yair-starkware (Yair) wrote…

Return a Result instead of expecting

Done.

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src/hash_test.rs line 75 at r1 (raw file):

Previously, yair-starkware (Yair) wrote…

Is it possible to calculate this in the const itself? (not blocking)

No, because it gives a compilation error: he trait Sub<_> is implemented for U256, but that implementation is not const

[yair-starkware]

Reviewed 1 of 2 files at r2.
Reviewable status: 2 of 3 files reviewed, 1 unresolved discussion (waiting on @marioiordanov)

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src/hash.rs line 24 at r2 (raw file):

const CHOOSER_FULL: u8 = 15;
const CHOOSER_HALF: u8 = 14;
/// the MASK equals to U256::pow(U256::from(2), U256::from(250)) - U256::from(1)

The

Code quote:

the