refactor

Author: MenxLi

app/index-zh.html

@@ -23,7 +23,7 @@ <h2>图像加密工具
                 隐写：将秘密文本信息隐藏在图像中。
                 </li>
             </ul>
-            本应用完全在浏览器中运行，因此你的数据不会发送给任何服务器，始终保持安全:)
+            本应用完全在浏览器中运行，你的数据不会发送给任何服务器，绝对安全 :)
         </p>
 
         模式：
@@ -48,11 +48,11 @@ <h2>图像加密工具
 
             <div id="msgInput-container" style="display: none; flex-direction: column; margin-bottom: 0.5rem;">
                 <label for="msgInput">信息:</label>
-                <textarea id="msgInput" placeholder="Enter your message here" autocomplete="off" rows="3"></textarea>
+                <textarea id="msgInput" placeholder="请输入注入图像的秘密信息" autocomplete="off" rows="3"></textarea>
             </div>
             <div id="secretInput-container" style="display: flex; flex-direction: column; margin-bottom: 0.5rem;">
                 <label for="secretInput">密钥:</label>
-                <input id="secretInput" placeholder="Your secret key for encryption / decryption." autocomplete="off">
+                <input id="secretInput" placeholder="请输入密钥" autocomplete="off" style="font-family: monospace;">
             </div>
 
             <span style="margin-top: 0.25rem">

app/index.html

@@ -48,7 +48,7 @@ <h2>Image cipher
             </div>
             <div id="secretInput-container" style="display: flex; flex-direction: column; margin-bottom: 0.5rem;">
                 <label for="secretInput">Secret:</label>
-                <input id="secretInput" placeholder="Your secret key for encryption / decryption." autocomplete="off">
+                <input id="secretInput" placeholder="Your secret key for encryption / decryption." autocomplete="off" style="font-family: monospace;">
             </div>
 
             <span style="margin-top: 0.25rem">

app/script.js

@@ -27,7 +27,7 @@ const footer = document.getElementById('footer');
 const worker = new Worker('./worker.js', { type: 'module' });
 
 function onModeChange(mode) {
-    if (mode === 'cipher') {
+    if (mode === 'crypto') {
         msgInputContainer.style.display = 'none';
         imTypeSelect.disabled = false;
         imTypeContainer.style.display = 'block';
@@ -38,6 +38,12 @@ function onModeChange(mode) {
         imTypeSelect.disabled = true;
         imTypeContainer.style.display = 'none';
     }
+    const urlParams = new URLSearchParams(window.location.search);
+    // remove existing mode and secret params
+    urlParams.delete('mode');
+    urlParams.delete('m');
+    urlParams.set('m', mode);
+    window.history.replaceState({}, '', `${window.location.pathname}?${urlParams.toString()}`);
 }
 
 // handle initial mode setup
@@ -57,18 +63,19 @@ function onModeChange(mode) {
             onModeChange('stegano');
             break;
         case 'cipher':
+        case 'crypto':
         case 'cryptography':
         default:
             cipherModeInput.checked = true;
             steganoModeInput.checked = false;
-            onModeChange('cipher');
+            onModeChange('crypto');
             break;
     }
 }
 
 function getMode() {
     if (cipherModeInput.checked) {
-        return 'cipher';
+        return 'crypto';
     } else if (steganoModeInput.checked) {
         return 'stegano';
     }
@@ -87,8 +94,10 @@ function checkInputRaise() {
         throw new Error("No image file selected");
     }
     if (secretInput.value.trim() === '') {
-        showError("Secret cannot be empty");
-        throw new Error("Secret cannot be empty");
+        if (getMode() === 'crypto') {
+            showError("Secret cannot be empty");
+            throw new Error("Secret cannot be empty");
+        }
     }
 }
 
@@ -149,7 +158,7 @@ async function encode_image() {
 
     ensureOutput();
     switch (getMode()) {
-        case 'cipher':
+        case 'crypto':
             worker.postMessage({
                 type: 'encode', 
                 buffer: inputBlob, 
@@ -181,7 +190,7 @@ async function decode_image() {
 
     ensureOutput();
     switch (getMode()) {
-        case 'cipher':
+        case 'crypto':
             worker.postMessage({
                 type: 'decode',  
                 buffer: inputBlob, 
@@ -241,7 +250,7 @@ worker.onmessage = async (event) => {
     })
     cipherModeInput.addEventListener('change', () => {
         if (cipherModeInput.checked) {
-            onModeChange('cipher');
+            onModeChange('crypto');
         }
     })
 

app/worker.js

@@ -30,7 +30,7 @@ self.onmessage = async function(event) {
         if (type === 'stega_encode') {
             const encoded = stega_encode(buffer, message, secret, maxSide);
             self.postMessage({
-                type: 'encoded_stega',
+                type: 'stega_encode',
                 buffer: encoded,
                 format: 'png', 
             });
@@ -39,7 +39,7 @@ self.onmessage = async function(event) {
         if (type === 'stega_decode') {
             const decoded = stega_decode(buffer, secret, maxSide);
             self.postMessage({
-                type: 'decoded_stega',
+                type: 'stega_decode',
                 message: decoded,
             });
         }

src/lib.rs

@@ -120,7 +120,7 @@ pub fn encode(im: &[u8], secret: &str, max_side: i32, as_type: &str) -> Result<B
     vec2imblob(&pixels, im_opt, None, match as_type {
         "png" => ImageType::Png,
         "jpeg" => ImageType::Jpeg,
-        _ => panic!("Unsupported image type: {}", as_type),
+        _ => return Err(format!("Unsupported image type: {}", as_type)),
     })
 }
 
@@ -137,7 +137,7 @@ pub fn decode(im: &[u8], secret: &str, max_side: i32, as_type: &str) -> Result<B
     vec2imblob(&pixels, im_opt, max_side, match as_type {
         "png" => ImageType::Png,
         "jpeg" => ImageType::Jpeg,
-        _ => panic!("Unsupported image type: {}", as_type),
+        _ => return Err(format!("Unsupported image type: {}", as_type)),
     })
 }
 
@@ -152,13 +152,7 @@ pub fn stega_encode(
 
     console_log!("Encoding stega image");
     let max_side = if max_side < 1 { None } else { Some(max_side as u32) };
-    let seed: Option<f64> = match secret {
-        "" => None,
-        s => {
-            console_log!("Seed: {}", s);
-            Some(str2f(s))
-        },
-    };
+    let seed = Some(str2f(secret));
 
     let (mut im_v, im_opt) = img2vec(im, max_side)?;
     stega::inject_lsb(&mut im_v[..], message, seed)?;
@@ -174,13 +168,7 @@ pub fn stega_decode(
 ) -> Result<String, String> {
     console_log!("Decoding stega image");
     let max_side = if max_side < 1 { None } else { Some(max_side as u32) };
-    let seed: Option<f64> = match secret {
-        "" => None,
-        s => {
-            console_log!("Seed: {}", s);
-            Some(str2f(s))
-        },
-    };
+    let seed = Some(str2f(secret));
 
     let (im_v, _) = img2vec(im, max_side)?;
     stega::extract_lsb(&im_v[..], seed)

src/stega.rs

@@ -1,3 +1,5 @@
+use std::vec;
+
 use crate::logistic_map;
 use wasm_bindgen::prelude::*;
 
@@ -21,18 +23,19 @@ pub fn inject_lsb(
     let msg_len_encode = (msg_vec_raw.len() as u32).to_le_bytes();
 
     let mut msg_vec = vec![0; (im.len() + 7) / 8];
-    console_log!("Message channel length (encode): {}", msg_vec.len());
-    if msg_vec.len() < msg_len_encode.len() + msg_vec_raw.len() {
+    let msg_len = msg_len_encode.len() + msg_vec_raw.len();
+    console_log!("[lsb encode] Capacity: {}, message length: {}", msg_vec.len(), msg_len);
+
+    if msg_vec.len() < msg_len {
         return Err("Channel capacity not enough for message".to_string());
     }
 
-    // Copy the message length and raw message into the padded vector
-    for (i, &byte) in msg_len_encode.iter().enumerate() {
-        msg_vec[i] = byte;
-    }
-    for (i, &byte) in msg_vec_raw.iter().enumerate() {
-        msg_vec[i + msg_len_encode.len()] = byte;
-    }
+    msg_len_encode.iter().enumerate().for_each(
+        |(i, &byte)| { msg_vec[i] = byte; }
+    );
+    msg_vec_raw.iter().enumerate().for_each(
+        |(i, &byte)| { msg_vec[i + msg_len_encode.len()] = byte; }
+    );
 
     if let Some(seed) = encryption_seed {
         msg_vec = logistic_map::encode::<1>(&msg_vec, seed);
@@ -42,36 +45,26 @@ pub fn inject_lsb(
         let msg_idx = i / 8;
         let bit_idx = i % 8;
 
-        if msg_idx > msg_vec.len() - 1 {
-            break; // No more bits to inject
-        }
+        // No more bits to inject
+        if msg_idx > msg_vec.len() - 1 { break; } 
 
         let bit = (msg_vec[msg_idx] >> (7 - bit_idx)) & 1;
         im[i] = im[i] & 0xFE | bit; 
     }
-
     Ok(())
 }
 
 pub fn extract_lsb(
     im: &[u8],
     encryption_seed: Option<f64>,
 ) -> Result<String, String> {
-    if im.len() < 8 {
-        return Err("Image too small to contain message".to_string());
-    }
+    if im.len() < 32 { return Err("Image too small to contain message".to_string()); }
 
-    let mut msg_bits = Vec::new();
-    for i in 0..im.len() {
-        let bit = im[i] & 1; // Extract the least significant bit
-        msg_bits.push(bit);
-    }
-    let npad = msg_bits.len() % 8;
-    if npad != 0 {
-        msg_bits.extend(vec![0; 8 - npad]);
-    }
+    let npad = (im.len() + 7) / 8 * 8 - im.len();
+    let mut msg_bits: Vec<u8> = im.iter().map(|&byte| { 0x01 & byte }).collect();
+    msg_bits.extend(vec![0; npad]);
 
-    let mut msg_vec = Vec::new();
+    let mut msg_vec = Vec::with_capacity(msg_bits.len()/8);
     for i in (0..msg_bits.len()).step_by(8) {
         let byte = msg_bits[i..i + 8].iter().fold(0, |acc, &bit| (acc << 1) | bit);
         msg_vec.push(byte);
@@ -87,7 +80,6 @@ pub fn extract_lsb(
         console_err!("Message length: {}, message channel length: {}", msg_len, msg_vec.len());
         return Err("Failed to decode message".to_string());
     }
-
     let msg_raw = &msg_vec[4..4 + msg_len as usize];
 
     String::from_utf8(msg_raw.to_vec()).map_err(|e| e.to_string())