diff --git a/quicktap/src/drivers/linux.rs b/quicktap/src/drivers/linux.rs
index b99aa62..dd7971e 100644
--- a/quicktap/src/drivers/linux.rs
+++ b/quicktap/src/drivers/linux.rs
@@ -57,12 +57,7 @@ impl GenericDriver for TunDevice {
     }
 
     fn write(&mut self, packet: TunPacket) -> Result<(), Box<dyn Error>> {
-        loop {
-            let written = self.device.write(&packet.packet)?;
-            if written == 0 {
-                break;
-            }
-        }
+        let _ = self.device.write(&packet.packet)?;
         Ok(())
     }
 }
\ No newline at end of file
diff --git a/quicktap/src/qcrypto/aead.rs b/quicktap/src/qcrypto/aead.rs
index 9ce3cf8..5077517 100644
--- a/quicktap/src/qcrypto/aead.rs
+++ b/quicktap/src/qcrypto/aead.rs
@@ -1,4 +1,4 @@
-use chacha20poly1305::{ChaCha20Poly1305, Error, Key, KeyInit, XChaCha20Poly1305};
+use chacha20poly1305::{ChaCha20Poly1305, Error, KeyInit, XChaCha20Poly1305};
 use chacha20poly1305::aead::{Aead, Payload, Nonce};
 
 pub fn qcrypto_aead(key: &[u8; 32], counter: u64, plaintext: &[u8], authtext: &[u8]) -> Result<Vec<u8>, Error> {
diff --git a/quicktap/src/qcrypto/hkdf.rs b/quicktap/src/qcrypto/hkdf.rs
index b8af21d..83f7681 100644
--- a/quicktap/src/qcrypto/hkdf.rs
+++ b/quicktap/src/qcrypto/hkdf.rs
@@ -9,8 +9,8 @@ pub fn qcrypto_hkdf<const N: usize>(key: &[u8], input: &[u8]) -> Result<[[u8; 32
 
     result_array[0] = t1;
 
-    for n in 0..N {
-        result_array[n-1] = qcrypto_hmac_twice(&t0, &result_array[n-2], &[n as u8]);
+    for n in 1..N {
+        result_array[n] = qcrypto_hmac_twice(&t0, &result_array[n-1], &[n as u8]);
     }
 
     Ok(result_array)
diff --git a/quicktap/src/qcrypto/tests.rs b/quicktap/src/qcrypto/tests.rs
index 51c9f43..1246e32 100644
--- a/quicktap/src/qcrypto/tests.rs
+++ b/quicktap/src/qcrypto/tests.rs
@@ -2,6 +2,7 @@ use hex_lit::hex;
 use x25519_dalek::PublicKey;
 use crate::qcrypto::aead::{qcrypto_aead, qcrypto_aead_decrypt, qcrypto_xaead, qcrypto_xaead_decrypt};
 use crate::qcrypto::hashes::{qcrypto_hash, qcrypto_hmac, qcrypto_mac};
+use crate::qcrypto::hkdf::qcrypto_hkdf;
 use crate::qcrypto::pki::{qcrypto_dh, qcrypto_dh_generate};
 
 #[test]
@@ -41,4 +42,9 @@ fn qcrypto_aead_test() {
 fn qcrypto_xaead_test() {
     let ciphertext = qcrypto_xaead(&[0u8; 32], &[0u8; 24], &[0u8; 32], &[0u8; 32]).unwrap();
     assert_eq!(qcrypto_xaead_decrypt(&[0u8; 32], &[0u8; 24], &ciphertext, &[0u8; 32]).unwrap(), [0u8; 32].to_vec())
+}
+#[test]
+fn qcrypto_hkdf_test() {
+    let derived = qcrypto_hkdf::<1>(&[0u8; 32], &[0u8; 32]).unwrap();
+    assert_eq!(derived, [hex!("1090894613df8aef670b0b867e222daebc0d3e436cdddbc16c65855ab93cc91a")])
 }
\ No newline at end of file