Format

src/protocol/obfuscation.rs

@@ -2,9 +2,9 @@
 
 #![allow(dead_code)]
 
-use zeroize::Zeroize;
-use crate::crypto::{sha256, AesCtr};
 use super::constants::*;
+use crate::crypto::{AesCtr, sha256};
+use zeroize::Zeroize;
 
 /// Obfuscation parameters from handshake
 ///
@@ -44,41 +44,40 @@ impl ObfuscationParams {
         let dec_prekey_iv = &handshake[SKIP_LEN..SKIP_LEN + PREKEY_LEN + IV_LEN];
         let dec_prekey = &dec_prekey_iv[..PREKEY_LEN];
         let dec_iv_bytes = &dec_prekey_iv[PREKEY_LEN..];
-        
+
         let enc_prekey_iv: Vec<u8> = dec_prekey_iv.iter().rev().copied().collect();
         let enc_prekey = &enc_prekey_iv[..PREKEY_LEN];
         let enc_iv_bytes = &enc_prekey_iv[PREKEY_LEN..];
-        
+
         for (username, secret) in secrets {
             let mut dec_key_input = Vec::with_capacity(PREKEY_LEN + secret.len());
             dec_key_input.extend_from_slice(dec_prekey);
             dec_key_input.extend_from_slice(secret);
             let decrypt_key = sha256(&dec_key_input);
-            
+
             let decrypt_iv = u128::from_be_bytes(dec_iv_bytes.try_into().unwrap());
-            
+
             let mut decryptor = AesCtr::new(&decrypt_key, decrypt_iv);
             let decrypted = decryptor.decrypt(handshake);
-            
+
             let tag_bytes: [u8; 4] = decrypted[PROTO_TAG_POS..PROTO_TAG_POS + 4]
                 .try_into()
                 .unwrap();
-            
+
             let proto_tag = match ProtoTag::from_bytes(tag_bytes) {
                 Some(tag) => tag,
                 None => continue,
             };
-            
-            let dc_idx = i16::from_le_bytes(
-                decrypted[DC_IDX_POS..DC_IDX_POS + 2].try_into().unwrap()
-            );
-            
+
+            let dc_idx =
+                i16::from_le_bytes(decrypted[DC_IDX_POS..DC_IDX_POS + 2].try_into().unwrap());
+
             let mut enc_key_input = Vec::with_capacity(PREKEY_LEN + secret.len());
             enc_key_input.extend_from_slice(enc_prekey);
             enc_key_input.extend_from_slice(secret);
             let encrypt_key = sha256(&enc_key_input);
             let encrypt_iv = u128::from_be_bytes(enc_iv_bytes.try_into().unwrap());
-            
+
             return Some((
                 ObfuscationParams {
                     decrypt_key,
@@ -91,20 +90,20 @@ impl ObfuscationParams {
                 username.clone(),
             ));
         }
-        
+
         None
     }
-    
+
     /// Create AES-CTR decryptor for client -> proxy direction
     pub fn create_decryptor(&self) -> AesCtr {
         AesCtr::new(&self.decrypt_key, self.decrypt_iv)
     }
-    
+
     /// Create AES-CTR encryptor for proxy -> client direction
     pub fn create_encryptor(&self) -> AesCtr {
         AesCtr::new(&self.encrypt_key, self.encrypt_iv)
     }
-    
+
     /// Get the combined encrypt key and IV for fast mode
     pub fn enc_key_iv(&self) -> Vec<u8> {
         let mut result = Vec::with_capacity(KEY_LEN + IV_LEN);
@@ -120,7 +119,7 @@ pub fn generate_nonce<R: FnMut(usize) -> Vec<u8>>(mut random_bytes: R) -> [u8; H
         let nonce_vec = random_bytes(HANDSHAKE_LEN);
         let mut nonce = [0u8; HANDSHAKE_LEN];
         nonce.copy_from_slice(&nonce_vec);
-        
+
         if is_valid_nonce(&nonce) {
             return nonce;
         }
@@ -132,17 +131,17 @@ pub fn is_valid_nonce(nonce: &[u8; HANDSHAKE_LEN]) -> bool {
     if RESERVED_NONCE_FIRST_BYTES.contains(&nonce[0]) {
         return false;
     }
-    
+
     let first_four: [u8; 4] = nonce[..4].try_into().unwrap();
     if RESERVED_NONCE_BEGINNINGS.contains(&first_four) {
         return false;
     }
-    
+
     let continue_four: [u8; 4] = nonce[4..8].try_into().unwrap();
     if RESERVED_NONCE_CONTINUES.contains(&continue_four) {
         return false;
     }
-    
+
     true
 }
 
@@ -153,7 +152,7 @@ pub fn prepare_tg_nonce(
     enc_key_iv: Option<&[u8]>,
 ) {
     nonce[PROTO_TAG_POS..PROTO_TAG_POS + 4].copy_from_slice(&proto_tag.to_bytes());
-    
+
     if let Some(key_iv) = enc_key_iv {
         let reversed: Vec<u8> = key_iv.iter().rev().copied().collect();
         nonce[SKIP_LEN..SKIP_LEN + KEY_LEN + IV_LEN].copy_from_slice(&reversed);
@@ -171,39 +170,39 @@ pub fn encrypt_nonce(nonce: &[u8; HANDSHAKE_LEN]) -> Vec<u8> {
     let key_iv = &nonce[SKIP_LEN..SKIP_LEN + KEY_LEN + IV_LEN];
     let enc_key = sha256(key_iv);
     let enc_iv = u128::from_be_bytes(key_iv[..IV_LEN].try_into().unwrap());
-    
+
     let mut encryptor = AesCtr::new(&enc_key, enc_iv);
-    
+
     let mut result = nonce.to_vec();
     let encrypted_part = encryptor.encrypt(&nonce[PROTO_TAG_POS..]);
     result[PROTO_TAG_POS..].copy_from_slice(&encrypted_part);
-    
+
     result
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
-    
+
     #[test]
     fn test_is_valid_nonce() {
         let mut valid = [0x42u8; HANDSHAKE_LEN];
         valid[4..8].copy_from_slice(&[1, 2, 3, 4]);
         assert!(is_valid_nonce(&valid));
-        
+
         let mut invalid = [0x00u8; HANDSHAKE_LEN];
         invalid[0] = 0xef;
         assert!(!is_valid_nonce(&invalid));
-        
+
         let mut invalid = [0x00u8; HANDSHAKE_LEN];
         invalid[..4].copy_from_slice(b"HEAD");
         assert!(!is_valid_nonce(&invalid));
-        
+
         let mut invalid = [0x42u8; HANDSHAKE_LEN];
         invalid[4..8].copy_from_slice(&[0, 0, 0, 0]);
         assert!(!is_valid_nonce(&invalid));
     }
-    
+
     #[test]
     fn test_generate_nonce() {
         let mut counter = 0u8;
@@ -211,7 +210,7 @@ mod tests {
             counter = counter.wrapping_add(1);
             vec![counter; n]
         });
-        
+
         assert!(is_valid_nonce(&nonce));
         assert_eq!(nonce.len(), HANDSHAKE_LEN);
     }