Refactor code based on clippy suggestions

src/set4.rs

@@ -17,9 +17,7 @@ pub fn challenge25() {
             panic!("challenge25 - edit - out of bounds");
         }
 
-        for i in 0..newtext.len() {
-            plaintext.0[offset + i] = newtext[i];
-        }
+        plaintext.0[offset..(newtext.len() + offset)].copy_from_slice(&newtext[..]);
         ctr::encrypt(key, 0, &plaintext)
     }
 
@@ -64,12 +62,12 @@ pub fn challenge26() {
     // comment1=cooking%20MCs;userdata=aaaaaaaaaaaaaaaa;comment2=%20like%20a%20pound%20of%20bacon
     // comment1=cooking%20MCs;userdata=fobar;admin=true;comment2=%20like%20a%20pound%20of%20bacon
     let input = "aaaaaaaaaaaaaaaa";
-    let cipher = encrypt(&input, &key);
+    let cipher = encrypt(input, &key);
     let keystream = utils::xor(&cipher.0[32..48], &Bytes::from_utf8(input).0);
 
     let input = "fobar;admin=true";
     let mut flipped_cipher = cipher.0[0..32].to_vec();
-    flipped_cipher.append(&mut utils::xor(&keystream, &input.as_bytes()));
+    flipped_cipher.append(&mut utils::xor(&keystream, input.as_bytes()));
     flipped_cipher.append(&mut cipher.0[48..cipher.len()].to_vec());
 
     let cleartext = ctr::decrypt(&key, 0, &Bytes(flipped_cipher));
@@ -84,7 +82,7 @@ pub fn challenge27() {
         // AES-CBC(P_1, P_2, P_3) -> C_1, C_2, C_3
         let mut ct = Bytes::from_utf8("comment1=cooking%20MCs;userdata=secretsaucenouse");
         ct.pad_pkcs7(16);
-        cbc::encrypt(&key, &key, &ct)
+        cbc::encrypt(key, key, &ct)
     }
 
     fn decrypt(key: &Bytes, cipher: &Bytes) -> Result<Bytes, Bytes> {
@@ -93,7 +91,7 @@ pub fn challenge27() {
         // values). Noncompliant messages should raise an exception or return an
         // error that includes the decrypted plaintext (this happens all the
         // time in real systems, for what it's worth).
-        let mut cleartext = cbc::decrypt(&key, &key, &cipher);
+        let mut cleartext = cbc::decrypt(key, key, cipher);
         cleartext.remove_pkcs7(16);
         match std::str::from_utf8(&cleartext.0) {
             Ok(_) => Ok(cleartext),
@@ -191,7 +189,7 @@ pub fn challenge29() {
         // With the registers "fixated", hash the additional data you want to
         // forge.
         s.fix(fixate.try_into().unwrap(), byte_len);
-        s.hash(&bytes)
+        s.hash(bytes)
     }
 
     // use random
@@ -263,7 +261,7 @@ pub fn challenge30() {
             .map(|c| u32::from_le_bytes(c.try_into().unwrap()))
             .collect();
         m.fix(fixate.try_into().unwrap(), byte_len);
-        m.hash(&bytes)
+        m.hash(bytes)
     }
 
     let key = Bytes::random_range(2, 64);