Format

src/crypto/aes.rs

@@ -13,10 +13,13 @@
 
 #![allow(dead_code)]
 
-use aes::Aes256;
-use ctr::{Ctr128BE, cipher::{KeyIvInit, StreamCipher}};
-use zeroize::Zeroize;
 use crate::error::{ProxyError, Result};
+use aes::Aes256;
+use ctr::{
+    Ctr128BE,
+    cipher::{KeyIvInit, StreamCipher},
+};
+use zeroize::Zeroize;
 
 type Aes256Ctr = Ctr128BE<Aes256>;
 
@@ -42,33 +45,39 @@ impl AesCtr {
             cipher: Aes256Ctr::new(key.into(), (&iv_bytes).into()),
         }
     }
-    
+
     /// Create from key and IV slices
     pub fn from_key_iv(key: &[u8], iv: &[u8]) -> Result<Self> {
         if key.len() != 32 {
-            return Err(ProxyError::InvalidKeyLength { expected: 32, got: key.len() });
+            return Err(ProxyError::InvalidKeyLength {
+                expected: 32,
+                got: key.len(),
+            });
         }
         if iv.len() != 16 {
-            return Err(ProxyError::InvalidKeyLength { expected: 16, got: iv.len() });
+            return Err(ProxyError::InvalidKeyLength {
+                expected: 16,
+                got: iv.len(),
+            });
         }
-        
+
         let key: [u8; 32] = key.try_into().unwrap();
         let iv = u128::from_be_bytes(iv.try_into().unwrap());
         Ok(Self::new(&key, iv))
     }
-    
+
     /// Encrypt/decrypt data in-place (CTR mode is symmetric)
     pub fn apply(&mut self, data: &mut [u8]) {
         self.cipher.apply_keystream(data);
     }
-    
+
     /// Encrypt data, returning new buffer
     pub fn encrypt(&mut self, data: &[u8]) -> Vec<u8> {
         let mut output = data.to_vec();
         self.apply(&mut output);
         output
     }
-    
+
     /// Decrypt data (for CTR, identical to encrypt)
     pub fn decrypt(&mut self, data: &[u8]) -> Vec<u8> {
         self.encrypt(data)
@@ -99,27 +108,33 @@ impl Drop for AesCbc {
 impl AesCbc {
     /// AES block size
     const BLOCK_SIZE: usize = 16;
-    
+
     /// Create new AES-CBC cipher with key and IV
     pub fn new(key: [u8; 32], iv: [u8; 16]) -> Self {
         Self { key, iv }
     }
-    
+
     /// Create from slices
     pub fn from_slices(key: &[u8], iv: &[u8]) -> Result<Self> {
         if key.len() != 32 {
-            return Err(ProxyError::InvalidKeyLength { expected: 32, got: key.len() });
+            return Err(ProxyError::InvalidKeyLength {
+                expected: 32,
+                got: key.len(),
+            });
         }
         if iv.len() != 16 {
-            return Err(ProxyError::InvalidKeyLength { expected: 16, got: iv.len() });
+            return Err(ProxyError::InvalidKeyLength {
+                expected: 16,
+                got: iv.len(),
+            });
         }
-        
+
         Ok(Self {
             key: key.try_into().unwrap(),
             iv: iv.try_into().unwrap(),
         })
     }
-    
+
     /// Encrypt a single block using raw AES (no chaining)
     fn encrypt_block(&self, block: &[u8; 16], key_schedule: &aes::Aes256) -> [u8; 16] {
         use aes::cipher::BlockEncrypt;
@@ -127,7 +142,7 @@ impl AesCbc {
         key_schedule.encrypt_block((&mut output).into());
         output
     }
-    
+
     /// Decrypt a single block using raw AES (no chaining)
     fn decrypt_block(&self, block: &[u8; 16], key_schedule: &aes::Aes256) -> [u8; 16] {
         use aes::cipher::BlockDecrypt;
@@ -135,7 +150,7 @@ impl AesCbc {
         key_schedule.decrypt_block((&mut output).into());
         output
     }
-    
+
     /// XOR two 16-byte blocks
     fn xor_blocks(a: &[u8; 16], b: &[u8; 16]) -> [u8; 16] {
         let mut result = [0u8; 16];
@@ -144,27 +159,28 @@ impl AesCbc {
         }
         result
     }
-    
+
     /// Encrypt data using CBC mode with proper chaining
     ///
     /// CBC Encryption: C[i] = AES_Encrypt(P[i] XOR C[i-1]), where C[-1] = IV
     pub fn encrypt(&self, data: &[u8]) -> Result<Vec<u8>> {
         if !data.len().is_multiple_of(Self::BLOCK_SIZE) {
-            return Err(ProxyError::Crypto(
-                format!("CBC data must be aligned to 16 bytes, got {}", data.len())
-            ));
+            return Err(ProxyError::Crypto(format!(
+                "CBC data must be aligned to 16 bytes, got {}",
+                data.len()
+            )));
         }
-        
+
         if data.is_empty() {
             return Ok(Vec::new());
         }
-        
+
         use aes::cipher::KeyInit;
         let key_schedule = aes::Aes256::new((&self.key).into());
-        
+
         let mut result = Vec::with_capacity(data.len());
         let mut prev_ciphertext = self.iv;
-        
+
         for chunk in data.chunks(Self::BLOCK_SIZE) {
             let plaintext: [u8; 16] = chunk.try_into().unwrap();
             let xored = Self::xor_blocks(&plaintext, &prev_ciphertext);
@@ -172,30 +188,31 @@ impl AesCbc {
             prev_ciphertext = ciphertext;
             result.extend_from_slice(&ciphertext);
         }
-        
+
         Ok(result)
     }
-    
+
     /// Decrypt data using CBC mode with proper chaining
     ///
     /// CBC Decryption: P[i] = AES_Decrypt(C[i]) XOR C[i-1], where C[-1] = IV
     pub fn decrypt(&self, data: &[u8]) -> Result<Vec<u8>> {
         if !data.len().is_multiple_of(Self::BLOCK_SIZE) {
-            return Err(ProxyError::Crypto(
-                format!("CBC data must be aligned to 16 bytes, got {}", data.len())
-            ));
+            return Err(ProxyError::Crypto(format!(
+                "CBC data must be aligned to 16 bytes, got {}",
+                data.len()
+            )));
         }
-        
+
         if data.is_empty() {
             return Ok(Vec::new());
         }
-        
+
         use aes::cipher::KeyInit;
         let key_schedule = aes::Aes256::new((&self.key).into());
-        
+
         let mut result = Vec::with_capacity(data.len());
         let mut prev_ciphertext = self.iv;
-        
+
         for chunk in data.chunks(Self::BLOCK_SIZE) {
             let ciphertext: [u8; 16] = chunk.try_into().unwrap();
             let decrypted = self.decrypt_block(&ciphertext, &key_schedule);
@@ -203,75 +220,77 @@ impl AesCbc {
             prev_ciphertext = ciphertext;
             result.extend_from_slice(&plaintext);
         }
-        
+
         Ok(result)
     }
-    
+
     /// Encrypt data in-place
     pub fn encrypt_in_place(&self, data: &mut [u8]) -> Result<()> {
         if !data.len().is_multiple_of(Self::BLOCK_SIZE) {
-            return Err(ProxyError::Crypto(
-                format!("CBC data must be aligned to 16 bytes, got {}", data.len())
-            ));
+            return Err(ProxyError::Crypto(format!(
+                "CBC data must be aligned to 16 bytes, got {}",
+                data.len()
+            )));
         }
-        
+
         if data.is_empty() {
             return Ok(());
         }
-        
+
         use aes::cipher::KeyInit;
         let key_schedule = aes::Aes256::new((&self.key).into());
-        
+
         let mut prev_ciphertext = self.iv;
-        
+
         for i in (0..data.len()).step_by(Self::BLOCK_SIZE) {
             let block = &mut data[i..i + Self::BLOCK_SIZE];
-            
+
             for j in 0..Self::BLOCK_SIZE {
                 block[j] ^= prev_ciphertext[j];
             }
-            
+
             let block_array: &mut [u8; 16] = block.try_into().unwrap();
             *block_array = self.encrypt_block(block_array, &key_schedule);
-            
+
             prev_ciphertext = *block_array;
         }
-        
+
         Ok(())
     }
-    
+
     /// Decrypt data in-place
     pub fn decrypt_in_place(&self, data: &mut [u8]) -> Result<()> {
         if !data.len().is_multiple_of(Self::BLOCK_SIZE) {
-            return Err(ProxyError::Crypto(
-                format!("CBC data must be aligned to 16 bytes, got {}", data.len())
-            ));
+            return Err(ProxyError::Crypto(format!(
+                "CBC data must be aligned to 16 bytes, got {}",
+                data.len()
+            )));
         }
-        
+
         if data.is_empty() {
             return Ok(());
         }
-        
+
         use aes::cipher::KeyInit;
         let key_schedule = aes::Aes256::new((&self.key).into());
-        
+
         let mut prev_ciphertext = self.iv;
-        
+
         for i in (0..data.len()).step_by(Self::BLOCK_SIZE) {
             let block = &mut data[i..i + Self::BLOCK_SIZE];
-            
+
             let current_ciphertext: [u8; 16] = block.try_into().unwrap();
-            
+
             let block_array: &mut [u8; 16] = block.try_into().unwrap();
             *block_array = self.decrypt_block(block_array, &key_schedule);
-            
+
             for j in 0..Self::BLOCK_SIZE {
                 block[j] ^= prev_ciphertext[j];
             }
-            
+
             prev_ciphertext = current_ciphertext;
         }
-        
+
         Ok(())
     }
 }
@@ -318,227 +337,227 @@ impl Decryptor for PassthroughEncryptor {
 #[cfg(test)]
 mod tests {
     use super::*;
-    
+
     // ============= AES-CTR Tests =============
-    
+
     #[test]
     fn test_aes_ctr_roundtrip() {
         let key = [0u8; 32];
         let iv = 12345u128;
-        
+
         let original = b"Hello, MTProto!";
-        
+
         let mut enc = AesCtr::new(&key, iv);
         let encrypted = enc.encrypt(original);
-        
+
         let mut dec = AesCtr::new(&key, iv);
         let decrypted = dec.decrypt(&encrypted);
-        
+
         assert_eq!(original.as_slice(), decrypted.as_slice());
     }
-    
+
     #[test]
     fn test_aes_ctr_in_place() {
         let key = [0x42u8; 32];
         let iv = 999u128;
-        
+
         let original = b"Test data for in-place encryption";
         let mut data = original.to_vec();
-        
+
         let mut cipher = AesCtr::new(&key, iv);
         cipher.apply(&mut data);
-        
+
         assert_ne!(&data[..], original);
-        
+
         let mut cipher = AesCtr::new(&key, iv);
         cipher.apply(&mut data);
-        
+
         assert_eq!(&data[..], original);
     }
-    
+
     // ============= AES-CBC Tests =============
-    
+
     #[test]
     fn test_aes_cbc_roundtrip() {
         let key = [0u8; 32];
         let iv = [0u8; 16];
-        
+
         let original = [0u8; 32];
-        
+
         let cipher = AesCbc::new(key, iv);
         let encrypted = cipher.encrypt(&original).unwrap();
         let decrypted = cipher.decrypt(&encrypted).unwrap();
-        
+
         assert_eq!(original.as_slice(), decrypted.as_slice());
     }
-    
+
     #[test]
     fn test_aes_cbc_chaining_works() {
         let key = [0x42u8; 32];
         let iv = [0x00u8; 16];
-        
+
         let plaintext = [0xAAu8; 32];
-        
+
         let cipher = AesCbc::new(key, iv);
         let ciphertext = cipher.encrypt(&plaintext).unwrap();
-        
+
         let block1 = &ciphertext[0..16];
         let block2 = &ciphertext[16..32];
-        
+
         assert_ne!(
             block1, block2,
             "CBC chaining broken: identical plaintext blocks produced identical ciphertext"
         );
     }
-    
+
     #[test]
     fn test_aes_cbc_known_vector() {
         let key = [0u8; 32];
         let iv = [0u8; 16];
         let plaintext = [0u8; 16];
-        
+
         let cipher = AesCbc::new(key, iv);
         let ciphertext = cipher.encrypt(&plaintext).unwrap();
-        
+
         let decrypted = cipher.decrypt(&ciphertext).unwrap();
         assert_eq!(plaintext.as_slice(), decrypted.as_slice());
-        
+
         assert_ne!(ciphertext.as_slice(), plaintext.as_slice());
     }
-    
+
     #[test]
     fn test_aes_cbc_multi_block() {
         let key = [0x12u8; 32];
         let iv = [0x34u8; 16];
-        
+
         let plaintext: Vec<u8> = (0..80).collect();
-        
+
         let cipher = AesCbc::new(key, iv);
         let ciphertext = cipher.encrypt(&plaintext).unwrap();
         let decrypted = cipher.decrypt(&ciphertext).unwrap();
-        
+
         assert_eq!(plaintext, decrypted);
     }
-    
+
     #[test]
     fn test_aes_cbc_in_place() {
         let key = [0x12u8; 32];
         let iv = [0x34u8; 16];
-        
+
         let original = [0x56u8; 48];
         let mut buffer = original;
-        
+
         let cipher = AesCbc::new(key, iv);
-        
+
         cipher.encrypt_in_place(&mut buffer).unwrap();
         assert_ne!(&buffer[..], &original[..]);
-        
+
         cipher.decrypt_in_place(&mut buffer).unwrap();
         assert_eq!(&buffer[..], &original[..]);
     }
-    
+
     #[test]
     fn test_aes_cbc_empty_data() {
         let cipher = AesCbc::new([0u8; 32], [0u8; 16]);
-        
+
         let encrypted = cipher.encrypt(&[]).unwrap();
         assert!(encrypted.is_empty());
-        
+
         let decrypted = cipher.decrypt(&[]).unwrap();
         assert!(decrypted.is_empty());
     }
-    
+
     #[test]
     fn test_aes_cbc_unaligned_error() {
         let cipher = AesCbc::new([0u8; 32], [0u8; 16]);
-        
+
         let result = cipher.encrypt(&[0u8; 15]);
         assert!(result.is_err());
-        
+
         let result = cipher.encrypt(&[0u8; 17]);
         assert!(result.is_err());
     }
-    
+
     #[test]
     fn test_aes_cbc_avalanche_effect() {
         let key = [0xAB; 32];
         let iv = [0xCD; 16];
-        
+
         let plaintext1 = [0u8; 32];
         let mut plaintext2 = [0u8; 32];
         plaintext2[0] = 0x01;
-        
+
         let cipher = AesCbc::new(key, iv);
-        
+
         let ciphertext1 = cipher.encrypt(&plaintext1).unwrap();
         let ciphertext2 = cipher.encrypt(&plaintext2).unwrap();
-        
+
         assert_ne!(&ciphertext1[0..16], &ciphertext2[0..16]);
         assert_ne!(&ciphertext1[16..32], &ciphertext2[16..32]);
     }
-    
+
     #[test]
     fn test_aes_cbc_iv_matters() {
         let key = [0x55; 32];
         let plaintext = [0x77u8; 16];
-        
+
         let cipher1 = AesCbc::new(key, [0u8; 16]);
         let cipher2 = AesCbc::new(key, [1u8; 16]);
-        
+
         let ciphertext1 = cipher1.encrypt(&plaintext).unwrap();
         let ciphertext2 = cipher2.encrypt(&plaintext).unwrap();
-        
+
         assert_ne!(ciphertext1, ciphertext2);
     }
-    
+
     #[test]
     fn test_aes_cbc_deterministic() {
         let key = [0x99; 32];
         let iv = [0x88; 16];
         let plaintext = [0x77u8; 32];
-        
+
         let cipher = AesCbc::new(key, iv);
-        
+
         let ciphertext1 = cipher.encrypt(&plaintext).unwrap();
         let ciphertext2 = cipher.encrypt(&plaintext).unwrap();
-        
+
         assert_eq!(ciphertext1, ciphertext2);
     }
-    
+
     // ============= Zeroize Tests =============
-    
+
     #[test]
     fn test_aes_cbc_zeroize_on_drop() {
         let key = [0xAA; 32];
         let iv = [0xBB; 16];
-        
+
         let cipher = AesCbc::new(key, iv);
         // Verify key/iv are set
         assert_eq!(cipher.key, [0xAA; 32]);
         assert_eq!(cipher.iv, [0xBB; 16]);
-        
+
         drop(cipher);
         // After drop, key/iv are zeroized (can't observe directly,
         // but the Drop impl runs without panic)
     }
-    
+
     // ============= Error Handling Tests =============
-    
+
     #[test]
     fn test_invalid_key_length() {
         let result = AesCtr::from_key_iv(&[0u8; 16], &[0u8; 16]);
         assert!(result.is_err());
-        
+
         let result = AesCbc::from_slices(&[0u8; 16], &[0u8; 16]);
         assert!(result.is_err());
     }
-    
+
     #[test]
     fn test_invalid_iv_length() {
         let result = AesCtr::from_key_iv(&[0u8; 32], &[0u8; 8]);
         assert!(result.is_err());
-        
+
         let result = AesCbc::from_slices(&[0u8; 32], &[0u8; 8]);
         assert!(result.is_err());
     }
-}
+}

src/crypto/hash.rs

@@ -12,10 +12,10 @@
 //! usages are intentional and protocol-mandated.
 
 use hmac::{Hmac, Mac};
-use sha2::Sha256;
 use md5::Md5;
 use sha1::Sha1;
 use sha2::Digest;
+use sha2::Sha256;
 
 type HmacSha256 = Hmac<Sha256>;
 
@@ -28,8 +28,7 @@ pub fn sha256(data: &[u8]) -> [u8; 32] {
 
 /// SHA-256 HMAC
 pub fn sha256_hmac(key: &[u8], data: &[u8]) -> [u8; 32] {
-    let mut mac = HmacSha256::new_from_slice(key)
-        .expect("HMAC accepts any key length");
+    let mut mac = HmacSha256::new_from_slice(key).expect("HMAC accepts any key length");
     mac.update(data);
     mac.finalize().into_bytes().into()
 }
@@ -124,27 +123,18 @@ pub fn derive_middleproxy_keys(
     srv_ipv6: Option<&[u8; 16]>,
 ) -> ([u8; 32], [u8; 16]) {
     let s = build_middleproxy_prekey(
-        nonce_srv,
-        nonce_clt,
-        clt_ts,
-        srv_ip,
-        clt_port,
-        purpose,
-        clt_ip,
-        srv_port,
-        secret,
-        clt_ipv6,
-        srv_ipv6,
+        nonce_srv, nonce_clt, clt_ts, srv_ip, clt_port, purpose, clt_ip, srv_port, secret,
+        clt_ipv6, srv_ipv6,
     );
 
     let md5_1 = md5(&s[1..]);
     let sha1_sum = sha1(&s);
     let md5_2 = md5(&s[2..]);
-    
+
     let mut key = [0u8; 32];
     key[..12].copy_from_slice(&md5_1[..12]);
     key[12..].copy_from_slice(&sha1_sum);
-    
+
     (key, md5_2)
 }
 
@@ -164,17 +154,8 @@ mod tests {
         let secret = vec![0x55u8; 128];
 
         let prekey = build_middleproxy_prekey(
-            &nonce_srv,
-            &nonce_clt,
-            &clt_ts,
-            srv_ip,
-            &clt_port,
-            b"CLIENT",
-            clt_ip,
-            &srv_port,
-            &secret,
-            None,
-            None,
+            &nonce_srv, &nonce_clt, &clt_ts, srv_ip, &clt_port, b"CLIENT", clt_ip, &srv_port,
+            &secret, None, None,
         );
         let digest = sha256(&prekey);
         assert_eq!(

src/crypto/mod.rs

@@ -4,7 +4,7 @@ pub mod aes;
 pub mod hash;
 pub mod random;
 
-pub use aes::{AesCtr, AesCbc};
+pub use aes::{AesCbc, AesCtr};
 pub use hash::{
     build_middleproxy_prekey, crc32, crc32c, derive_middleproxy_keys, sha256, sha256_hmac,
 };

src/crypto/random.rs

@@ -3,11 +3,11 @@
 #![allow(deprecated)]
 #![allow(dead_code)]
 
-use rand::{Rng, RngExt, SeedableRng};
-use rand::rngs::StdRng;
-use parking_lot::Mutex;
-use zeroize::Zeroize;
 use crate::crypto::AesCtr;
+use parking_lot::Mutex;
+use rand::rngs::StdRng;
+use rand::{Rng, RngExt, SeedableRng};
+use zeroize::Zeroize;
 
 /// Cryptographically secure PRNG with AES-CTR
 pub struct SecureRandom {
@@ -34,16 +34,16 @@ impl SecureRandom {
     pub fn new() -> Self {
         let mut seed_source = rand::rng();
         let mut rng = StdRng::from_rng(&mut seed_source);
-        
+
         let mut key = [0u8; 32];
         rng.fill_bytes(&mut key);
         let iv: u128 = rng.random();
-        
+
         let cipher = AesCtr::new(&key, iv);
-        
+
         // Zeroize local key copy — cipher already consumed it
         key.zeroize();
-        
+
         Self {
             inner: Mutex::new(SecureRandomInner {
                 rng,
@@ -53,7 +53,7 @@ impl SecureRandom {
             }),
         }
     }
-    
+
     /// Fill a caller-provided buffer with random bytes.
     pub fn fill(&self, out: &mut [u8]) {
         let mut inner = self.inner.lock();
@@ -94,7 +94,7 @@ impl SecureRandom {
         self.fill(&mut out);
         out
     }
-    
+
     /// Generate random number in range [0, max)
     pub fn range(&self, max: usize) -> usize {
         if max == 0 {
@@ -103,16 +103,16 @@ impl SecureRandom {
         let mut inner = self.inner.lock();
         inner.rng.random_range(0..max)
     }
-    
+
     /// Generate random bits
     pub fn bits(&self, k: usize) -> u64 {
         if k == 0 {
             return 0;
         }
-        
+
         let bytes_needed = k.div_ceil(8);
         let bytes = self.bytes(bytes_needed.min(8));
-        
+
         let mut result = 0u64;
         for (i, &b) in bytes.iter().enumerate() {
             if i >= 8 {
@@ -120,14 +120,14 @@ impl SecureRandom {
             }
             result |= (b as u64) << (i * 8);
         }
-        
+
         if k < 64 {
             result &= (1u64 << k) - 1;
         }
-        
+
         result
     }
-    
+
     /// Choose random element from slice
     pub fn choose<'a, T>(&self, slice: &'a [T]) -> Option<&'a T> {
         if slice.is_empty() {
@@ -136,7 +136,7 @@ impl SecureRandom {
             Some(&slice[self.range(slice.len())])
         }
     }
-    
+
     /// Shuffle slice in place
     pub fn shuffle<T>(&self, slice: &mut [T]) {
         let mut inner = self.inner.lock();
@@ -145,13 +145,13 @@ impl SecureRandom {
             slice.swap(i, j);
         }
     }
-    
+
     /// Generate random u32
     pub fn u32(&self) -> u32 {
         let mut inner = self.inner.lock();
         inner.rng.random()
     }
-    
+
     /// Generate random u64
     pub fn u64(&self) -> u64 {
         let mut inner = self.inner.lock();
@@ -169,7 +169,7 @@ impl Default for SecureRandom {
 mod tests {
     use super::*;
     use std::collections::HashSet;
-    
+
     #[test]
     fn test_bytes_uniqueness() {
         let rng = SecureRandom::new();
@@ -177,7 +177,7 @@ mod tests {
         let b = rng.bytes(32);
         assert_ne!(a, b);
     }
-    
+
     #[test]
     fn test_bytes_length() {
         let rng = SecureRandom::new();
@@ -186,63 +186,63 @@ mod tests {
         assert_eq!(rng.bytes(100).len(), 100);
         assert_eq!(rng.bytes(1000).len(), 1000);
     }
-    
+
     #[test]
     fn test_range() {
         let rng = SecureRandom::new();
-        
+
         for _ in 0..1000 {
             let n = rng.range(10);
             assert!(n < 10);
         }
-        
+
         assert_eq!(rng.range(1), 0);
         assert_eq!(rng.range(0), 0);
     }
-    
+
     #[test]
     fn test_bits() {
         let rng = SecureRandom::new();
-        
+
         for _ in 0..100 {
             assert!(rng.bits(1) <= 1);
         }
-        
+
         for _ in 0..100 {
             assert!(rng.bits(8) <= 255);
         }
     }
-    
+
     #[test]
     fn test_choose() {
         let rng = SecureRandom::new();
         let items = vec![1, 2, 3, 4, 5];
-        
+
         let mut seen = HashSet::new();
         for _ in 0..1000 {
             if let Some(&item) = rng.choose(&items) {
                 seen.insert(item);
             }
         }
-        
+
         assert_eq!(seen.len(), 5);
-        
+
         let empty: Vec<i32> = vec![];
         assert!(rng.choose(&empty).is_none());
     }
-    
+
     #[test]
     fn test_shuffle() {
         let rng = SecureRandom::new();
         let original = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
-        
+
         let mut shuffled = original.clone();
         rng.shuffle(&mut shuffled);
-        
+
         let mut sorted = shuffled.clone();
         sorted.sort();
         assert_eq!(sorted, original);
-        
+
         assert_ne!(shuffled, original);
     }
 }