diff --git a/Cargo.toml b/Cargo.toml
index 36afc3e..09b40eb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sshcerts"
-version = "0.9.0"
+version = "0.9.1"
 authors = ["Mitchell Grenier <mitchell@confurious.io>"]
 edition = "2018"
 license-file = "LICENSE"
diff --git a/src/ssh/cert.rs b/src/ssh/cert.rs
index f497af4..995a111 100644
--- a/src/ssh/cert.rs
+++ b/src/ssh/cert.rs
@@ -205,17 +205,15 @@ impl Certificate {
         let mut iter = s.split_whitespace();
 
         let kt_name = iter
-            .next()
-            .ok_or_else(|| Error::InvalidFormat)?;
+            .next().ok_or(Error::InvalidFormat)?;
 
-        let key_type = KeyType::from_name(&kt_name)?;
+        let key_type = KeyType::from_name(kt_name)?;
         if !key_type.is_cert {
             return Err(Error::NotCertificate);
         }
 
         let data = iter
-            .next()
-            .ok_or_else(|| Error::InvalidFormat)?;
+            .next().ok_or(Error::InvalidFormat)?;
 
         let comment = iter.next().map(String::from);
         let decoded = base64::decode(&data)?;
@@ -228,7 +226,7 @@ impl Certificate {
         }
 
         let nonce = reader.read_bytes()?;
-        let key = PublicKey::from_reader(&kt_name, &mut reader)?;
+        let key = PublicKey::from_reader(kt_name, &mut reader)?;
         let serial = reader.read_u64()?;
 
         let cert_type = match reader.read_u32()? {
@@ -464,7 +462,7 @@ impl Certificate {
 
         match &self.signature_key.kind {
             PublicKeyKind::Ecdsa(_) => {
-                writer.write_string(&self.signature_key.key_type.name);
+                writer.write_string(self.signature_key.key_type.name);
                 if let Some(signature) = crate::utils::signature_convert_asn1_ecdsa_to_ssh(signature) {
                     writer.write_bytes(&signature);
                 } else {
@@ -473,11 +471,11 @@ impl Certificate {
             },
             PublicKeyKind::Rsa(_) => {
                 writer.write_string("rsa-sha2-512");
-                writer.write_bytes(&signature);
+                writer.write_bytes(signature);
             },
             _ => {
-                writer.write_string(&self.signature_key.key_type.name);
-                writer.write_bytes(&signature);
+                writer.write_string(self.signature_key.key_type.name);
+                writer.write_bytes(signature);
             }
         };
         
@@ -633,7 +631,7 @@ fn verify_signature(signature_buf: &[u8], signed_bytes: &[u8], public_key: &Publ
             let mut sig = r;
             sig.extend(s);
 
-            UnparsedPublicKey::new(alg, &key.key).verify(&signed_bytes, &sig)?;
+            UnparsedPublicKey::new(alg, &key.key).verify(signed_bytes, &sig)?;
             Ok(signature_buf.to_vec())
         },
         PublicKeyKind::Rsa(key) => {
@@ -645,14 +643,14 @@ fn verify_signature(signature_buf: &[u8], signed_bytes: &[u8], public_key: &Publ
             };
             let signature = reader.read_bytes()?;
             let public_key = RsaPublicKeyComponents { n: &key.n, e: &key.e };
-            public_key.verify(alg, &signed_bytes, &signature)?;
+            public_key.verify(alg, signed_bytes, &signature)?;
             Ok(signature_buf.to_vec())
         },
         PublicKeyKind::Ed25519(key) => {
             let alg = &ED25519;
             let signature = reader.read_bytes()?;
             let peer_public_key = UnparsedPublicKey::new(alg, &key.key);
-            peer_public_key.verify(&signed_bytes, &signature)?;
+            peer_public_key.verify(signed_bytes, &signature)?;
             Ok(signature_buf.to_vec())
         },
     }
diff --git a/src/ssh/privkey.rs b/src/ssh/privkey.rs
index c5b7de8..9ceea7e 100644
--- a/src/ssh/privkey.rs
+++ b/src/ssh/privkey.rs
@@ -119,8 +119,8 @@ impl ToASN1 for RsaPrivateKey {
                 vec![ASN1Block::Integer(0, BigInt::from_bytes_be(Sign::Plus, &self.d))],
                 vec![ASN1Block::Integer(0, BigInt::from_bytes_be(Sign::Plus, &self.p))],
                 vec![ASN1Block::Integer(0, BigInt::from_bytes_be(Sign::Plus, &self.q))],
-                vec![ASN1Block::Integer(0, BigInt::from_bytes_be(Sign::Plus, &self.exp.as_ref().unwrap()))],
-                vec![ASN1Block::Integer(0, BigInt::from_bytes_be(Sign::Plus, &self.exq.as_ref().unwrap()))],
+                vec![ASN1Block::Integer(0, BigInt::from_bytes_be(Sign::Plus, self.exp.as_ref().unwrap()))],
+                vec![ASN1Block::Integer(0, BigInt::from_bytes_be(Sign::Plus, self.exq.as_ref().unwrap()))],
                 vec![ASN1Block::Integer(0, BigInt::from_bytes_be(Sign::Plus, &self.coefficient))],
                 Vec::new(),
             ]
@@ -168,8 +168,8 @@ fn read_private_key(reader: &mut Reader<'_>) -> Result<PrivateKey> {
                     coefficient,
                     p,
                     q,
-                    exp: exp,
-                    exq: exq,
+                    exp,
+                    exq,
                 }
             ),
                 PublicKey {
@@ -230,7 +230,7 @@ fn read_private_key(reader: &mut Reader<'_>) -> Result<PrivateKey> {
         key_type: kt,
         kind,
         pubkey,
-        comment: if comment.len() == 0 {None} else {Some(comment)},
+        comment: if comment.is_empty() {None} else {Some(comment)},
     })
 }
 
@@ -330,13 +330,13 @@ impl PrivateKey {
                 let salt = enc_reader.read_bytes()?;
                 let rounds = enc_reader.read_u32()?;
                 let mut output = [0; 48];
-                if let Err(_) = bcrypt_pbkdf(passphrase.as_str(), &salt, rounds, &mut output) {
+                if bcrypt_pbkdf(passphrase.as_str(), &salt, rounds, &mut output).is_err() {
                     return Err(Error::InvalidFormat);
                 }
 
                 let mut cipher = Aes256Ctr::new(
-                    &GenericArray::from_slice(&output[..32]),
-                    &GenericArray::from_slice(&output[32..]),
+                    GenericArray::from_slice(&output[..32]),
+                    GenericArray::from_slice(&output[32..]),
                 );
 
                 match cipher.try_apply_keystream(&mut remaining_bytes) {
diff --git a/src/ssh/pubkey.rs b/src/ssh/pubkey.rs
index a6eecd5..a0c0f8c 100644
--- a/src/ssh/pubkey.rs
+++ b/src/ssh/pubkey.rs
@@ -143,9 +143,9 @@ impl Fingerprint {
     /// ```
     pub fn compute<T: ?Sized + AsRef<[u8]>>(kind: FingerprintKind, data: &T) -> Fingerprint {
         let digest = match kind {
-            FingerprintKind::Sha256 => digest::digest(&digest::SHA256, &data.as_ref()).as_ref().to_vec(),
-            FingerprintKind::Sha384 => digest::digest(&digest::SHA384, &data.as_ref()).as_ref().to_vec(),
-            FingerprintKind::Sha512 => digest::digest(&digest::SHA512, &data.as_ref()).as_ref().to_vec(),
+            FingerprintKind::Sha256 => digest::digest(&digest::SHA256, data.as_ref()).as_ref().to_vec(),
+            FingerprintKind::Sha384 => digest::digest(&digest::SHA384, data.as_ref()).as_ref().to_vec(),
+            FingerprintKind::Sha512 => digest::digest(&digest::SHA512, data.as_ref()).as_ref().to_vec(),
         };
 
         let mut encoded = base64::encode(&digest);
@@ -194,18 +194,10 @@ impl PublicKey {
     pub fn from_string(contents: &str) -> Result<PublicKey> {
         let mut iter = contents.split_whitespace();
 
-        let kt_name = iter
-            .next()
-            .ok_or_else(|| Error::InvalidFormat)?;
-
-        let data = iter
-            .next()
-            .ok_or_else(|| Error::InvalidFormat)?;
-
+        let kt_name = iter.next().ok_or(Error::InvalidFormat)?;
+        let data = iter.next().ok_or(Error::InvalidFormat)?;
         let comment = iter.next().map(String::from);
-
-        let key_type = KeyType::from_name(&kt_name)?;
-
+        let key_type = KeyType::from_name(kt_name)?;
         let decoded = base64::decode(&data)?;
         let mut reader = Reader::new(&decoded);
 
@@ -216,7 +208,7 @@ impl PublicKey {
         }
 
         // Construct a new `PublicKey` value and preserve the `comment` value.
-        let k = PublicKey::from_reader(&kt_name, &mut reader)?;
+        let k = PublicKey::from_reader(kt_name, &mut reader)?;
         let key = PublicKey {
             key_type,
             kind: k.kind,
@@ -256,7 +248,7 @@ impl PublicKey {
     /// we already have a reader for reading an OpenSSH certificate key and
     /// we want to extract the public key information from it.
     pub(crate) fn from_reader(kt_name: &str, reader: &mut Reader<'_>) -> Result<PublicKey> {
-        let kt = KeyType::from_name(&kt_name)?;
+        let kt = KeyType::from_name(kt_name)?;
 
         let kind = match kt.kind {
             KeyTypeKind::Rsa | KeyTypeKind::RsaCert => {
@@ -339,7 +331,7 @@ impl PublicKey {
                 w.write_mpint(&k.n);
             }
             PublicKeyKind::Ecdsa(ref k) => {
-                w.write_string(&k.curve.identifier);
+                w.write_string(k.curve.identifier);
                 w.write_bytes(&k.key);
             }
             PublicKeyKind::Ed25519(ref k) => {
diff --git a/src/ssh/signer.rs b/src/ssh/signer.rs
index bb1798c..7f020c7 100644
--- a/src/ssh/signer.rs
+++ b/src/ssh/signer.rs
@@ -30,11 +30,11 @@ pub fn create_signer(privkey: PrivateKey) -> Box<dyn Fn(&[u8]) -> Option<Vec<u8>
 
 /// This is in this file to prevent a circular dependency between PrivateKey
 /// and the signer module.
-impl Into<Box<dyn Fn(&[u8]) -> Option<Vec<u8>> + Send + Sync>> for PrivateKey {
-    fn into(self) -> Box<dyn Fn(&[u8]) -> Option<Vec<u8>> + Send + Sync> {
+impl From<PrivateKey> for Box<dyn Fn(&[u8]) -> Option<Vec<u8>> + Send + Sync> {
+    fn from(priv_key: PrivateKey) -> Box<dyn Fn(&[u8]) -> Option<Vec<u8>> + Send + Sync> {
         Box::new(move |buf: &[u8]| {
-            ssh_cert_signer(buf, &self)
-        })
+            ssh_cert_signer(buf, &priv_key)
+        }) 
     }
 }
 
@@ -59,9 +59,7 @@ pub fn ssh_cert_signer(buf: &[u8], privkey: &PrivateKey) -> Option<Vec<u8>> {
             let rng = rand::SystemRandom::new();
             let mut signature = vec![0; keypair.public_modulus_len()];
 
-            if let Err(_) = keypair.sign(&signature::RSA_PKCS1_SHA512, &rng, buf, &mut signature) {
-                return None
-            }
+            keypair.sign(&signature::RSA_PKCS1_SHA512, &rng, buf, &mut signature).ok()?;
 
             Some(signature)
         },
@@ -80,12 +78,12 @@ pub fn ssh_cert_signer(buf: &[u8], privkey: &PrivateKey) -> Option<Vec<u8>> {
             };
 
             let key = if key.key[0] == 0x0_u8 {&key.key[1..]} else {&key.key};
-            let key_pair = match signature::EcdsaKeyPair::from_private_key_and_public_key(alg, &key, &pubkey) {
+            let key_pair = match signature::EcdsaKeyPair::from_private_key_and_public_key(alg, key, pubkey) {
                 Ok(kp) => kp,
                 Err(_) => return None,
             };
 
-            match key_pair.sign(&rng, &buf) {
+            match key_pair.sign(&rng, buf) {
                 Ok(sig) => Some(sig.as_ref().to_vec()),
                 Err(_) => None,
             }
@@ -101,7 +99,7 @@ pub fn ssh_cert_signer(buf: &[u8], privkey: &PrivateKey) -> Option<Vec<u8>> {
                 Err(_) => return None,
             };
 
-            Some(key_pair.sign(&buf).as_ref().to_vec())
+            Some(key_pair.sign(buf).as_ref().to_vec())
         },
     }
 }
\ No newline at end of file
diff --git a/src/ssh/writer.rs b/src/ssh/writer.rs
index 8a26426..c214af4 100644
--- a/src/ssh/writer.rs
+++ b/src/ssh/writer.rs
@@ -36,7 +36,7 @@ impl Writer {
         let size = val.len() as u32;
         let mut buf = size.to_be_bytes().to_vec();
         self.inner.append(&mut buf);
-        self.inner.extend_from_slice(&val);
+        self.inner.extend_from_slice(val);
     }
 
     /// Writes a `string` value to the underlying byte sequence.
diff --git a/src/utils.rs b/src/utils.rs
index edb2e47..c681fc5 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -29,7 +29,7 @@ pub fn asn_der_to_r_s(buf: &[u8]) -> Option<(&[u8], &[u8])> {
 /// This function will take an ASN1 encoded ECDSA signature and return
 /// an SSH Signature blob
 pub fn signature_convert_asn1_ecdsa_to_ssh(signature: &[u8]) -> Option<Vec<u8>> {
-    let (r,s) = match asn_der_to_r_s(&signature) {
+    let (r,s) = match asn_der_to_r_s(signature) {
         Some((r,s)) => (r, s),
         None => return None,
     };
diff --git a/src/x509/mod.rs b/src/x509/mod.rs
index 58d1558..dcc22fc 100644
--- a/src/x509/mod.rs
+++ b/src/x509/mod.rs
@@ -83,7 +83,7 @@ pub fn der_encoding_to_ssh_public_key(key: &[u8]) -> Result<PublicKey, Error> {
 /// This function is used to extract an SSH public key from an x509
 /// certificate
 pub fn extract_ssh_pubkey_from_x509_certificate(cert: &[u8]) -> Result<PublicKey, Error> {
-    let parsed_cert = match x509_parser::parse_x509_certificate(&cert) {
+    let parsed_cert = match x509_parser::parse_x509_certificate(cert) {
         Ok((_, c)) => c,
         Err(_) => return Err(Error::ParsingError)
     };
@@ -94,7 +94,7 @@ pub fn extract_ssh_pubkey_from_x509_certificate(cert: &[u8]) -> Result<PublicKey
 /// This function is used to extract an SSH public key from an x509
 /// certificate signing request
 pub fn extract_ssh_pubkey_from_x509_csr(csr: &[u8]) -> Result<PublicKey, Error> {
-    let parsed_csr = match x509_parser::certification_request::X509CertificationRequest::from_der(&csr) {
+    let parsed_csr = match x509_parser::certification_request::X509CertificationRequest::from_der(csr) {
         Ok((_, csr)) => csr,
         Err(_) => return Err(Error::ParsingError)
     };
diff --git a/src/yubikey/mod.rs b/src/yubikey/mod.rs
index 149a3c8..c1e8343 100644
--- a/src/yubikey/mod.rs
+++ b/src/yubikey/mod.rs
@@ -14,7 +14,7 @@ pub enum Error {
 impl std::fmt::Display for Error {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match *self {
-            Error::PivError(ref e) => write!(f, "{}", e.to_string()),
+            Error::PivError(ref e) => write!(f, "{}", e),
         }
     }
 }
diff --git a/src/yubikey/piv/management.rs b/src/yubikey/piv/management.rs
index fc1b34d..9eee196 100644
--- a/src/yubikey/piv/management.rs
+++ b/src/yubikey/piv/management.rs
@@ -133,14 +133,14 @@ impl super::Yubikey {
     /// Generate CSR for slot
     pub fn generate_csr(&mut self, slot: &SlotId, common_name: &str,) -> Result<Vec<u8>> {
         let mut params = rcgen::CertificateParams::new(vec![]);
-        params.alg = match self.configured(&slot)? {
+        params.alg = match self.configured(slot)? {
             PublicKeyInfo::EcP256(_) => &rcgen::PKCS_ECDSA_P256_SHA256,
             PublicKeyInfo::EcP384(_) => &rcgen::PKCS_ECDSA_P384_SHA384,
             _ => return Err(Error::Unsupported),
         };
         params.distinguished_name.push(rcgen::DnType::CommonName, common_name.to_string());
 
-        let csr_signer = CSRSigner::new(self.yk.serial().into(), slot.clone());
+        let csr_signer = CSRSigner::new(self.yk.serial().into(), *slot);
         params.key_pair = Some(rcgen::KeyPair::from_remote(Box::new(csr_signer)).unwrap());
 
         let csr = rcgen::Certificate::from_params(params).unwrap();
diff --git a/src/yubikey/piv/mod.rs b/src/yubikey/piv/mod.rs
index caf0d51..9d8e384 100644
--- a/src/yubikey/piv/mod.rs
+++ b/src/yubikey/piv/mod.rs
@@ -48,7 +48,7 @@ pub struct Yubikey {
 
 impl std::fmt::Debug for Yubikey {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        writeln!(f, "YubiKey: {}", self.yk.serial().to_string())
+        writeln!(f, "YubiKey: {}", self.yk.serial())
     }
 }
 
diff --git a/src/yubikey/piv/ssh.rs b/src/yubikey/piv/ssh.rs
index 5b183a3..73c52ae 100644
--- a/src/yubikey/piv/ssh.rs
+++ b/src/yubikey/piv/ssh.rs
@@ -48,7 +48,7 @@ impl super::Yubikey {
             _ => return Err(Error::Unsupported),
         };
 
-        self.sign_data(&buf, alg, slot)
+        self.sign_data(buf, alg, slot)
     }
 
 }
\ No newline at end of file