2 releases
0.1.1 | Jun 14, 2023 |
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0.1.0 | Jun 14, 2023 |
#1816 in Cryptography
8KB
75 lines
checkpipe
A rust library for computing things about bytes as they flow through pipelines.
The motivating use case is performing a checksum on all bytes passing through a reader or writer.
Example
use checkpipe::{Check, Checker};
use std::io::{Read, Write};
use std::fs::{File, remove_file};
const DATA: [u8; 13] = *b"Hello, world!";
const PATH: &'static str = "foo.txt";
pub fn write_checksummed() -> std::io::Result<()> {
let outfile = File::create(PATH)?;
let mut outpipe = Checker::new_default_hasher(outfile);
outpipe.write_all(DATA.as_slice())?;
let checksum = outpipe.output();
outpipe.write(&mut checksum.to_le_bytes()[..])?;
Ok(())
}
pub fn read_checksummed() -> std::io::Result<()> {
let infile = File::open(PATH)?;
let mut inpipe = Checker::new_default_hasher(infile);
let mut buf = [0u8; DATA.len()];
inpipe.read(&mut buf)?;
let checksum = inpipe.output();
let mut checksum_buf = [0u8; 8];
inpipe.read(&mut checksum_buf)?;
assert_eq!(checksum, u64::from_le_bytes(checksum_buf));
Ok(())
}
pub fn main() -> std::io::Result<()> {
write_checksummed()?;
read_checksummed()?;
remove_file(PATH)
}
Implementing your own checks
Implement the Check
trait on a struct, which provides methods for taking a chunk of bytes,
and eventually returning the result of its computation.
Then wrap that struct and some struct through which bytes pass in a Checker
.
Check
is already implemented for all types implementing Hasher
,
and there are some convenience methods in place if you want to use rust's default hasher.
If the wrapped type in Checker
is Read
or Write
, so too will the Checker
.