refactor(proto): consolidate tests

crates/irtt-proto/src/hmac.rs

@@ -96,76 +96,3 @@ pub fn verify_packet_hmac(key: &[u8], packet: &[u8]) -> Result<()> {
 pub(crate) fn hmac_offset() -> usize {
     HEADER_SIZE
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::{
-        flags::{FLAG_HMAC, FLAG_OPEN},
-        MAGIC,
-    };
-
-    fn reference_copy_zero_hmac(
-        key: &[u8],
-        packet: &[u8],
-        hmac_offset: usize,
-    ) -> Result<[u8; HMAC_SIZE]> {
-        if packet.len().saturating_sub(hmac_offset) < HMAC_SIZE {
-            return Err(ProtoError::InvalidHmacOffset);
-        }
-        let mut copy = packet.to_vec();
-        copy[hmac_offset..hmac_offset + HMAC_SIZE].fill(0);
-        let mut mac = HmacMd5::new_from_slice(key).expect("HMAC accepts keys of any size");
-        mac.update(&copy);
-        let bytes = mac.finalize().into_bytes();
-        let mut out = [0u8; HMAC_SIZE];
-        out.copy_from_slice(&bytes);
-        Ok(out)
-    }
-
-    fn packet_with_hmac_field(hmac_bytes: [u8; HMAC_SIZE]) -> Vec<u8> {
-        let mut packet = Vec::new();
-        packet.extend_from_slice(&MAGIC);
-        packet.push(FLAG_OPEN | FLAG_HMAC);
-        packet.extend_from_slice(&hmac_bytes);
-        packet.extend_from_slice(&[1, 2, 3, 4]);
-        packet
-    }
-
-    #[test]
-    fn compute_and_verify_hmac() {
-        let mut packet = packet_with_hmac_field([0; HMAC_SIZE]);
-
-        compute_hmac_in_place(b"testkey", &mut packet, hmac_offset()).unwrap();
-        verify_hmac(b"testkey", &packet, hmac_offset()).unwrap();
-        assert_eq!(
-            verify_hmac(b"wrong", &packet, hmac_offset()),
-            Err(ProtoError::BadHmac)
-        );
-    }
-
-    #[test]
-    fn compute_hmac_matches_copy_and_zero_semantics() {
-        let mut packet = packet_with_hmac_field([0xa5; HMAC_SIZE]);
-        packet.extend_from_slice(&[5, 6, 7, 8, 9]);
-
-        let digest = compute_hmac(b"testkey", &packet, hmac_offset()).unwrap();
-        let reference = reference_copy_zero_hmac(b"testkey", &packet, hmac_offset()).unwrap();
-
-        assert_eq!(digest, reference);
-    }
-
-    #[test]
-    fn verify_hmac_rejects_modified_authenticated_byte() {
-        let mut packet = packet_with_hmac_field([0; HMAC_SIZE]);
-        compute_hmac_in_place(b"testkey", &mut packet, hmac_offset()).unwrap();
-
-        verify_hmac(b"testkey", &packet, hmac_offset()).unwrap();
-        packet[hmac_offset() + HMAC_SIZE + 1] ^= 0x01;
-
-        assert_eq!(
-            verify_hmac(b"testkey", &packet, hmac_offset()),
-            Err(ProtoError::BadHmac)
-        );
-    }
-}