diff --git a/src/crypto/cipher/aes.rs b/src/crypto/cipher/aes.rs
index c055d1f..16171fe 100644
--- a/src/crypto/cipher/aes.rs
+++ b/src/crypto/cipher/aes.rs
@@ -13,19 +13,19 @@ impl Cipher for AES {
     const KEY_SIZE: usize = 16;
 
     fn encrypt(data: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
-        let cipher = Aes128Cbc::new_from_slices(&key, &iv)?;
+        let cipher = Aes128Cbc::new_from_slices(key, iv)?;
 
-        return Ok(cipher.encrypt_vec(data));
+        Ok(cipher.encrypt_vec(data))
     }
 
     fn decrypt(data: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
-        let cipher = Aes128Cbc::new_from_slices(&key, &iv)?;
+        let cipher = Aes128Cbc::new_from_slices(key, iv)?;
 
         let result = cipher.decrypt_vec(data);
-        return match result {
+        match result {
             Ok(data) => Ok(data),
             Err(err) => Err(Error::BlockModeError(err)),
-        };
+        }
     }
 }
 
diff --git a/src/crypto/cipher/tdes.rs b/src/crypto/cipher/tdes.rs
index e876bb6..1bcea0e 100644
--- a/src/crypto/cipher/tdes.rs
+++ b/src/crypto/cipher/tdes.rs
@@ -14,19 +14,19 @@ impl Cipher for Tdes {
     const KEY_SIZE: usize = 16;
 
     fn encrypt(data: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
-        let cipher = TDesEde2Cbc::new_from_slices(&key, &iv)?;
+        let cipher = TDesEde2Cbc::new_from_slices(key, iv)?;
 
-        return Ok(cipher.encrypt_vec(data));
+        Ok(cipher.encrypt_vec(data))
     }
 
     fn decrypt(data: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
-        let cipher = TDesEde2Cbc::new_from_slices(&key, &iv)?;
+        let cipher = TDesEde2Cbc::new_from_slices(key, iv)?;
 
         let result = cipher.decrypt_vec(data);
-        return match result {
+        match result {
             Ok(data) => Ok(data),
             Err(err) => Err(Error::BlockModeError(err)),
-        };
+        }
     }
 }
 
diff --git a/src/crypto/cipher/tdes_2k.rs b/src/crypto/cipher/tdes_2k.rs
index 8f57b00..a249ef7 100644
--- a/src/crypto/cipher/tdes_2k.rs
+++ b/src/crypto/cipher/tdes_2k.rs
@@ -14,19 +14,19 @@ impl Cipher for Tdes2k {
     const KEY_SIZE: usize = 16;
 
     fn encrypt(data: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
-        let cipher = TDesEde2Cbc::new_from_slices(&key, &iv)?;
+        let cipher = TDesEde2Cbc::new_from_slices(key, iv)?;
 
-        return Ok(cipher.encrypt_vec(data));
+        Ok(cipher.encrypt_vec(data))
     }
 
     fn decrypt(data: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
-        let cipher = TDesEde2Cbc::new_from_slices(&key, &iv)?;
+        let cipher = TDesEde2Cbc::new_from_slices(key, iv)?;
 
         let result = cipher.decrypt_vec(data);
-        return match result {
+        match result {
             Ok(data) => Ok(data),
             Err(err) => Err(Error::BlockModeError(err)),
-        };
+        }
     }
 }
 
diff --git a/src/crypto/cipher/tdes_3k.rs b/src/crypto/cipher/tdes_3k.rs
index 3ba5626..9a20b9c 100644
--- a/src/crypto/cipher/tdes_3k.rs
+++ b/src/crypto/cipher/tdes_3k.rs
@@ -14,19 +14,19 @@ impl Cipher for Tdes3k {
     const KEY_SIZE: usize = 24;
 
     fn encrypt(data: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
-        let cipher = TDesEde3Cbc::new_from_slices(&key, &iv)?;
+        let cipher = TDesEde3Cbc::new_from_slices(key, iv)?;
 
-        return Ok(cipher.encrypt_vec(data));
+        Ok(cipher.encrypt_vec(data))
     }
 
     fn decrypt(data: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
-        let cipher = TDesEde3Cbc::new_from_slices(&key, &iv)?;
+        let cipher = TDesEde3Cbc::new_from_slices(key, iv)?;
 
         let result = cipher.decrypt_vec(data);
-        return match result {
+        match result {
             Ok(data) => Ok(data),
             Err(err) => Err(Error::BlockModeError(err)),
-        };
+        }
     }
 }
 
diff --git a/src/crypto/cipher_key.rs b/src/crypto/cipher_key.rs
index f4cc387..a805f08 100644
--- a/src/crypto/cipher_key.rs
+++ b/src/crypto/cipher_key.rs
@@ -74,11 +74,7 @@ pub fn get_key_size(cipher: CipherType) -> usize {
 
 /// Check Key Slice
 pub fn check_key(key: &[u8], cipher: CipherType) -> bool {
-    if key.len() != get_key_size(cipher) {
-        false
-    } else {
-        true
-    }
+    key.len() == get_key_size(cipher)
 }
 
 /// Set Key Version for DES/TDES Keys
diff --git a/src/crypto/util.rs b/src/crypto/util.rs
index dba855b..b00fe77 100644
--- a/src/crypto/util.rs
+++ b/src/crypto/util.rs
@@ -20,9 +20,9 @@ pub fn expand_to_blocksize(data: &mut [u8], blocksize: usize) -> Result<Vec<u8>>
     let diff = data.len() % blocksize;
 
     if diff == 0 {
-        return Ok(data.to_vec());
+        Ok(data.to_vec())
     } else {
-        let mut buf = vec![0 as u8; data.len() + blocksize - diff];
+        let mut buf = vec![0_u8; data.len() + blocksize - diff];
         buf[..data.len()].copy_from_slice(data);
         Ok(buf)
     }
diff --git a/src/desfire/desfire.rs b/src/desfire/desfire.rs
index 8da1c51..499615c 100644
--- a/src/desfire/desfire.rs
+++ b/src/desfire/desfire.rs
@@ -93,7 +93,7 @@ impl Desfire {
         let rnd_b_enc = rnd_b_response_body.as_slice();
         // println!("RND_B_ENC: {:x?}", rnd_b_enc);
 
-        let rnd_b = Tdes::decrypt(rnd_b_enc, key, vec![0 as u8; 8].as_slice()).unwrap();
+        let rnd_b = Tdes::decrypt(rnd_b_enc, key, vec![0_u8; 8].as_slice()).unwrap();
         // println!("RND_B: {:x?}", rnd_b);
 
         let mut rnd_b_rl = rnd_b.clone();
@@ -153,7 +153,7 @@ impl Desfire {
         self.session_key = Some(generate_session_key_des(&rnd_a, rnd_b.as_slice()).unwrap());
         // println!("SESSION_KEY: {:x?}", self.session_key.as_ref().unwrap());
 
-        self.cbc_iv = Some(vec![0 as u8; 8]);
+        self.cbc_iv = Some(vec![0_u8; 8]);
         // println!("CBC_IV: {:x?}", self.cbc_iv.as_ref().unwrap());
         Ok(())
     }
@@ -184,7 +184,7 @@ impl Desfire {
     ) -> Result<(APDUCommand, Vec<u8>, Vec<u8>)> {
         // println!("RND_B_ENC: {:x?}", challenge);
 
-        let rnd_b = AES::decrypt(challenge, key, vec![0 as u8; 16].as_slice()).unwrap();
+        let rnd_b = AES::decrypt(challenge, key, vec![0_u8; 16].as_slice()).unwrap();
         // println!("RND_B: {:x?}", rnd_b);
 
         // auth_iv = rnd_b.clone();
@@ -192,7 +192,7 @@ impl Desfire {
         rnd_b_rl.rotate_left(1);
         // println!("RND_B_RL: {:x?}", rnd_b_rl);
 
-        let rnd_ab = [&rnd_a, rnd_b_rl.as_slice()].concat();
+        let rnd_ab = [rnd_a, rnd_b_rl.as_slice()].concat();
         // println!("RND_AB: {:x?}", rnd_ab);
 
         let rnd_ab_enc = AES::encrypt(rnd_ab.as_slice(), key, challenge).unwrap();
@@ -233,8 +233,8 @@ impl Desfire {
         self.session_key = Some(generate_session_key_aes(expected_response, challenge).unwrap());
         // println!("SESSION_KEY: {:x?}", self.session_key.as_ref().unwrap());
 
-        self.cbc_iv = Some(vec![0 as u8; 16]); //FIXME: this should be a random value
-                                               // println!("CBC_IV: {:x?}", self.cbc_iv.as_ref().unwrap());
+        self.cbc_iv = Some(vec![0_u8; 16]); //FIXME: this should be a random value
+                                            // println!("CBC_IV: {:x?}", self.cbc_iv.as_ref().unwrap());
 
         Ok(())
     }
@@ -619,7 +619,7 @@ impl Desfire {
             ret = response.check();
         }
 
-        return ret;
+        ret
     }
 
     pub fn read_data_chunk_cmd(
@@ -648,7 +648,7 @@ impl Desfire {
             ..Default::default()
         };
 
-        return Ok(cmd_read_data_chunk);
+        Ok(cmd_read_data_chunk)
     }
 
     /// Read data from a file
@@ -685,13 +685,13 @@ impl Desfire {
             let response = self.card.as_ref().unwrap().transmit(cmd_read_data).unwrap();
             // println!("RESPONSE: {}", response);
 
-            response.check().or_else(|e| return Err(e))?;
+            response.check()?;
             // // println!("RESPONSE_DATA: {:x?}, WITHOUT_CMAC: {:x?}", response.body.as_ref().unwrap(), response.body.as_ref().unwrap()[..bytes_toread].to_vec());
 
             read_buffer.append(&mut response.body.unwrap()[..bytes_toread].to_vec());
         }
 
-        return Ok(read_buffer);
+        Ok(read_buffer)
     }
 }
 
@@ -726,7 +726,7 @@ pub fn generate_keysetting1(
     file_directory_access: FileDirectoryAccess,
     change_master_key: ChangeMasterKey,
 ) -> Result<u8> {
-    return match FromPrimitive::from_u8(change_key) {
+    match FromPrimitive::from_u8(change_key) {
         Some(ChangeApplicationKey::MASTERKEY)
         | Some(ChangeApplicationKey::SAMEKEY)
         | Some(ChangeApplicationKey::ALLKEYS) => Ok((change_key << 4)
@@ -735,7 +735,7 @@ pub fn generate_keysetting1(
             | file_directory_access as u8
             | change_master_key as u8),
         None => {
-            if change_key < 0x01 || change_key >= 0x08 {
+            if !(0x01..0x08).contains(&change_key) {
                 Err(InvalidKeyID)
             } else {
                 Ok((change_key << 4)
@@ -745,7 +745,7 @@ pub fn generate_keysetting1(
                     | change_master_key as u8)
             }
         }
-    };
+    }
 }
 
 /// Generate KeySetting2 for Application Creation
@@ -759,11 +759,11 @@ pub fn generate_keysetting2(
     file_identifier: FileIdentifiers,
     num_keys: u8,
 ) -> Result<u8> {
-    return if num_keys < 0x01 || num_keys >= 0x0D {
+    if !(0x01..0x0D).contains(&num_keys) {
         Err(NumKeys)
     } else {
         Ok(crypto_operations as u8 | file_identifier as u8 | num_keys)
-    };
+    }
 }
 
 /// Generate FileAccess Rights for File Settings
@@ -784,14 +784,14 @@ pub fn generate_file_access_rights(
     read_write: u8,
     configure: u8,
 ) -> Result<u16> {
-    return if read > 0x0F || write >= 0x0F || read_write >= 0x0F || configure >= 0x0F {
+    if read > 0x0F || write >= 0x0F || read_write >= 0x0F || configure >= 0x0F {
         Err(InvalidKeyID)
     } else {
         Ok((((read as u16) << 12)
             | ((write as u16) << 8)
             | ((read_write as u16) << 4)
             | configure as u16) as u16)
-    };
+    }
 }
 
 #[cfg(test)]
@@ -876,12 +876,12 @@ mod tests {
 
     #[test]
     fn generate_sessionkey_des() {
-        let rndA = hex!("a541a9dc9138df07");
-        let rndB = hex!("cbe55aa893b2da25");
+        let rnd_a = hex!("a541a9dc9138df07");
+        let rnd_b = hex!("cbe55aa893b2da25");
 
         let expected_sessionkey = hex!("a541a9dccbe55aa8a541a9dccbe55aa8");
 
-        let sessionkey = generate_session_key_des(&rndA, &rndB).unwrap();
+        let sessionkey = generate_session_key_des(&rnd_a, &rnd_b).unwrap();
 
         // println!("expected sessionkey: {:X?}", expected_sessionkey);
         // println!("actual sessionkey:   {:X?}", sessionkey.as_slice());
@@ -891,12 +891,12 @@ mod tests {
 
     #[test]
     fn generate_sessionkey_aes() {
-        let rndA = hex!("bc14dfde20074617e45a8822f06fdd91");
-        let rndB = hex!("482ddc54426e6dee560413b8d95471f5");
+        let rnd_a = hex!("bc14dfde20074617e45a8822f06fdd91");
+        let rnd_b = hex!("482ddc54426e6dee560413b8d95471f5");
 
         let expected_sessionkey = hex!("bc14dfde482ddc54f06fdd91d95471f5");
 
-        let sessionkey = generate_session_key_aes(&rndA, &rndB).unwrap();
+        let sessionkey = generate_session_key_aes(&rnd_a, &rnd_b).unwrap();
 
         // println!("expected sessionkey: {:X?}", expected_sessionkey);
         // println!("actual sessionkey:   {:X?}", sessionkey.as_slice());
@@ -1092,7 +1092,7 @@ mod tests {
                 })
             });
 
-        let rndA = hex!("5f7d1dd12d979173");
+        let rnd_a = hex!("5f7d1dd12d979173");
         let key = CipherKey::new_empty(CipherType::TDES).unwrap();
         // println!("{:x?}", key.key.deref());
 
@@ -1103,7 +1103,7 @@ mod tests {
         };
 
         desfire
-            .authenticate_iso_des(0x00, key.key.as_ref(), Some(rndA))
+            .authenticate_iso_des(0x00, key.key.as_ref(), Some(rnd_a))
             .unwrap();
 
         let sessionkey_expected = hex!("5f7d1dd1f449db5c5f7d1dd1f449db5c");
@@ -1207,7 +1207,7 @@ mod tests {
             body: Some(hex!("8fdc476f6bac44fe9150e285abd68d48").to_vec())
         }));
 
-        let rndA = hex!("2176770e7a6eb4bef00d5e4b201d1e57");
+        let rnd_a = hex!("2176770e7a6eb4bef00d5e4b201d1e57");
         let key = CipherKey::new_empty(CipherType::AES).unwrap();
         // println!("{:x?}", key.key.deref());
 
@@ -1218,7 +1218,7 @@ mod tests {
         };
 
         desfire
-            .authenticate_iso_aes(0x00, key.key.as_ref(), Some(rndA))
+            .authenticate_iso_aes(0x00, key.key.as_ref(), Some(rnd_a))
             .unwrap();
 
         let sessionkey_expected = hex!("2176770e11c512ca201d1e57fde6e15a");
diff --git a/src/desfire/mod.rs b/src/desfire/mod.rs
index 1812fd8..85fc914 100644
--- a/src/desfire/mod.rs
+++ b/src/desfire/mod.rs
@@ -116,5 +116,6 @@ pub enum FileTypes {
 
 mod apduinstructions;
 mod apdustatuscodes;
+#[allow(clippy::module_inception)]
 pub mod desfire;
 pub use crate::desfire::desfire::Desfire;
diff --git a/src/iso7816_4/apducommand.rs b/src/iso7816_4/apducommand.rs
index 2e9fe5e..3046351 100644
--- a/src/iso7816_4/apducommand.rs
+++ b/src/iso7816_4/apducommand.rs
@@ -113,12 +113,7 @@ impl TryFrom<APDUCommand> for Vec<u8> {
     type Error = Error;
 
     fn try_from(cmd: APDUCommand) -> Result<Self> {
-        let mut v: Vec<u8> = vec![];
-        //build header
-        v.push(cmd.cla);
-        v.push(cmd.ins);
-        v.push(cmd.p1);
-        v.push(cmd.p2);
+        let mut v = vec![cmd.cla, cmd.ins, cmd.p1, cmd.p2];
 
         //build body according to case
         match cmd.case {
diff --git a/src/iso7816_4/apduresponse.rs b/src/iso7816_4/apduresponse.rs
index 393832e..0fde581 100644
--- a/src/iso7816_4/apduresponse.rs
+++ b/src/iso7816_4/apduresponse.rs
@@ -56,7 +56,8 @@ impl APDUResponse {
     pub fn new(raw: &[u8]) -> Self {
         if raw.len() < 2 {
             panic!("APDU response must be at least 2 bytes long");
-        } else if raw.len() == 2 {
+        }
+        if raw.len() == 2 {
             APDUResponse {
                 body: None,
                 sw1: raw[0],
@@ -104,7 +105,7 @@ impl APDUResponse {
 
     pub fn check(&self) -> Result<()> {
         if self.sw1 == 0x91 {
-            return match FromPrimitive::from_u8(self.sw2) {
+            match FromPrimitive::from_u8(self.sw2) {
                 Some(APDUStatusWord2::OperationOk) => Ok(()),
                 Some(APDUStatusWord2::NoChanges) => Ok(()),
                 Some(APDUStatusWord2::IllegalCommandCode) => Err(IllegalCommandCode),
@@ -122,7 +123,7 @@ impl APDUResponse {
                 Some(APDUStatusWord2::FileNotFound) => Err(FileNotFound),
                 Some(APDUStatusWord2::ApplicationNotFound) => Err(ApplicationNotFound),
                 None => Err(InvalidStatusWord),
-            };
+            }
         } else {
             Err(InvalidStatusWord)
         }
diff --git a/src/iso7816_4/apdustatuswords.rs b/src/iso7816_4/apdustatuswords.rs
index a32d4c4..af97ca4 100644
--- a/src/iso7816_4/apdustatuswords.rs
+++ b/src/iso7816_4/apdustatuswords.rs
@@ -3,7 +3,7 @@ use num_derive::FromPrimitive;
 #[derive(FromPrimitive)]
 #[repr(u16)]
 pub enum APDUStatusWord {
-    /// Kommando erfolgreich ausgefhrt. xx Datenbytes knnen mit dem GET RESPONSE-Kommando abgeholt werden.	Statuswort zur Steuerung des T=0-Protokolls
+    /// Kommando erfolgreich ausgefhrt. xx Datenbytes knnen mit dem GET RESPONSE-Kommando abgeholt werden. Statuswort zur Steuerung des T=0-Protokolls
     DataReady = 0x6100,
 
     /// Die zurckgegebenen Daten knnen fehlerhaft sein.
@@ -108,7 +108,7 @@ pub enum APDUStatusWord {
     /// Parameter P1/P2 falsch
     WrongParameters2 = 0x6B00,
 
-    /// Falsche Lnge Le; xx gibt die korrekte Lnge an	Statuswort zur Steuerung des T=0-Protokolls
+    /// Falsche Lnge Le; xx gibt die korrekte Lnge an Statuswort zur Steuerung des T=0-Protokolls
     InvalidLe = 0x6C00,
 
     /// Das Kommando (INS) wird nicht untersttzt