Function checksum_to_digits

bitvm/src/signatures/utils.rs:21–38

Converts the given `checksum` into a vector of digits. ## Output format - sequence of `n_digits` many digits - each digit a `u32` value in range `0..base` - checksum converted into BE bytes, in turn converted into digits

(mut checksum: u32, base: u32, n_digits: u32)

/// - each digit a `u32` value in range `0..base`
/// - checksum converted into BE bytes, in turn converted into digits
pub(super) fn checksum_to_digits(mut checksum: u32, base: u32, n_digits: u32) -> Vec<u32> {
    debug_assert!((16..=256).contains(&base));
    debug_assert!(
        base.checked_pow(n_digits)
            .map(|upper_limit| checksum < upper_limit)
            .unwrap_or(true),
        "Checksum is too large to fit into the given number of digits"
    );

    let mut digits = vec![0; n_digits as usize]; // cast safety: 32-bit machine or higher

    for digit in digits.iter_mut().rev() {
        *digit = checksum % base;
        checksum = (checksum - *digit) / base;
    }

    digits
}

/// Converts the given `message` into a vector of digits.
///