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|
use tracing::trace;
use crate::nixbase32;
/// The mime type used for NAR files, both compressed and uncompressed
pub const MIME_TYPE_NAR: &str = "application/x-nix-nar";
/// The mime type used for NARInfo files
pub const MIME_TYPE_NARINFO: &str = "text/x-nix-narinfo";
/// The mime type used for the `nix-cache-info` file
pub const MIME_TYPE_CACHE_INFO: &str = "text/x-nix-cache-info";
/// Parses a `14cx20k6z4hq508kqi2lm79qfld5f9mf7kiafpqsjs3zlmycza0k.nar`
/// string and returns the nixbase32-decoded digest, as well as the compression
/// suffix (which might be empty).
pub fn parse_nar_str(s: &str) -> Option<([u8; 32], &str)> {
if !s.is_char_boundary(52) {
trace!("invalid string, no char boundary at 52");
return None;
}
let (hash_str, suffix) = s.split_at(52);
// we know hash_str is 52 bytes, so it's ok to unwrap here.
let hash_str_fixed: [u8; 52] = hash_str.as_bytes().try_into().unwrap();
match suffix.strip_prefix(".nar") {
Some(compression_suffix) => match nixbase32::decode_fixed(hash_str_fixed) {
Err(e) => {
trace!(err=%e, "invalid nixbase32 encoding");
None
}
Ok(digest) => Some((digest, compression_suffix)),
},
None => {
trace!("no .nar suffix");
None
}
}
}
/// Parses a `3mzh8lvgbynm9daj7c82k2sfsfhrsfsy.narinfo` string and returns the
/// nixbase32-decoded digest.
pub fn parse_narinfo_str(s: &str) -> Option<[u8; 20]> {
if !s.is_char_boundary(32) {
trace!("invalid string, no char boundary at 32");
return None;
}
match s.split_at(32) {
(hash_str, ".narinfo") => {
// we know this is 32 bytes, so it's ok to unwrap here.
let hash_str_fixed: [u8; 32] = hash_str.as_bytes().try_into().unwrap();
match nixbase32::decode_fixed(hash_str_fixed) {
Err(e) => {
trace!(err=%e, "invalid nixbase32 encoding");
None
}
Ok(digest) => Some(digest),
}
}
_ => {
trace!("invalid string, no .narinfo suffix");
None
}
}
}
#[cfg(test)]
mod test {
use super::{parse_nar_str, parse_narinfo_str};
use hex_literal::hex;
#[test]
fn parse_nar_str_success() {
assert_eq!(
(
hex!("13a8cf7ca57f68a9f1752acee36a72a55187d3a954443c112818926f26109d91"),
""
),
parse_nar_str("14cx20k6z4hq508kqi2lm79qfld5f9mf7kiafpqsjs3zlmycza0k.nar").unwrap()
);
assert_eq!(
(
hex!("13a8cf7ca57f68a9f1752acee36a72a55187d3a954443c112818926f26109d91"),
".xz"
),
parse_nar_str("14cx20k6z4hq508kqi2lm79qfld5f9mf7kiafpqsjs3zlmycza0k.nar.xz").unwrap()
)
}
#[test]
fn parse_nar_str_failure() {
assert!(parse_nar_str("14cx20k6z4hq508kqi2lm79qfld5f9mf7kiafpqsjs3zlmycza0").is_none());
assert!(
parse_nar_str("14cx20k6z4hq508kqi2lm79qfld5f9mf7kiafpqsjs3zlmycza0🦊.nar").is_none()
)
}
#[test]
fn parse_narinfo_str_success() {
assert_eq!(
hex!("8a12321522fd91efbd60ebb2481af88580f61600"),
parse_narinfo_str("00bgd045z0d4icpbc2yyz4gx48ak44la.narinfo").unwrap()
);
}
#[test]
fn parse_narinfo_str_failure() {
assert!(parse_narinfo_str("00bgd045z0d4icpbc2yyz4gx48ak44la").is_none());
assert!(parse_narinfo_str("/00bgd045z0d4icpbc2yyz4gx48ak44la").is_none());
assert!(parse_narinfo_str("000000").is_none());
assert!(parse_narinfo_str("00bgd045z0d4icpbc2yyz4gx48ak44l🦊.narinfo").is_none());
}
}
|
