neo_decompiler/nef/parser/
checksum.rs

1use sha2::{Digest, Sha256};
2
3use super::NefParser;
4
5fn checksum_prefix(bytes: &[u8]) -> u32 {
6    let mut array = [0u8; 4];
7    array.copy_from_slice(&bytes[..4]);
8    u32::from_le_bytes(array)
9}
10
11impl NefParser {
12    /// Calculate the NEF checksum over the payload bytes.
13    ///
14    /// This implements the double-SHA256 checksum used by the NEF container and
15    /// returns the first 4 bytes of the resulting digest as a little-endian
16    /// `u32`.
17    #[must_use]
18    pub fn calculate_checksum(payload: &[u8]) -> u32 {
19        let first = Sha256::digest(payload);
20        let second = Sha256::digest(first.as_slice());
21        checksum_prefix(second.as_slice())
22    }
23}

neo_decompiler/nef/parser/checksum.rs

neo_decompiler/nef/parser/
checksum.rs