Strengthen client side security

VERSION

@@ -1 +1 @@
-1.6.1
+1.6.2

libretranslate/app.py

@@ -11,7 +11,7 @@ from timeit import default_timer
 
 import argostranslatefiles
 from argostranslatefiles import get_supported_formats
-from flask import Blueprint, Flask, Response, abort, jsonify, render_template, request, send_file, session, url_for
+from flask import Blueprint, Flask, Response, abort, jsonify, render_template, request, send_file, session, url_for, make_response
 from flask_babel import Babel
 from flask_session import Session
 from flask_swagger import swagger
@@ -307,11 +307,18 @@ def create_app(args):
                   ):
                     need_key = True
 
+                  req_secret = get_req_secret()
                   if (args.require_api_key_secret
                     and key_missing
-                    and not secret.secret_match(get_req_secret())
+                    and not secret.secret_match(req_secret)
                   ):
                     need_key = True
+                    if secret.secret_bogus_match(req_secret):
+                      abort(make_response(jsonify({
+                        'translatedText': secret.get_emoji(),
+                        'alternatives': [],
+                        'detectedLanguage': { 'confidence': 100, 'language': 'en' }
+                      }), 200))
 
                   if need_key:
                     description = _("Please contact the server operator to get an API key")
@@ -399,10 +406,21 @@ def create_app(args):
       if args.disable_web_ui:
         abort(404)
 
+      api_secret = ""
+      bogus_api_secret = ""
+      if args.require_api_key_secret:
+        bogus_api_secret = secret.get_bogus_secret_b64()
+
+        if 'User-Agent' in request.headers:
+          api_secret = secret.get_current_secret_js()
+        else:
+          api_secret = secret.get_bogus_secret_js()
+        
       response = Response(render_template("app.js.template",
             url_prefix=args.url_prefix,
             get_api_key_link=args.get_api_key_link,
-            api_secret=secret.get_current_secret_b64() if args.require_api_key_secret else ""), content_type='application/javascript; charset=utf-8')
+            api_secret=api_secret,
+            bogus_api_secret=bogus_api_secret), content_type='application/javascript; charset=utf-8')
 
       if args.require_api_key_secret:
         response.headers['Last-Modified'] = http_date(datetime.now())

libretranslate/secret.py

@@ -1,10 +1,72 @@
 import base64
 import random
 import string
+from functools import lru_cache
 
 from libretranslate.storage import get_storage
 
 
+def to_base(n, b):
+    if n == 0:
+        return 0
+    if n < 0:
+        sign = -1
+    else:
+        sign = 1
+    
+    n *= sign
+    digits = []
+    while n:
+        digits.append(str(n % b))
+        n //= b
+    return int(''.join(digits[::-1])) * sign
+
+@lru_cache(maxsize=4)
+def obfuscate(input_str):
+    encoded = [ord(ch) for ch in input_str]
+    ops = ['+', '-', '*', '']
+    parts = []
+
+    for c in encoded:
+        num = random.randint(1, 100)
+        op = random.choice(ops)
+        if op == '+':
+            v = c + num
+            op = '-'
+        elif op == '-':
+            v = c - num
+            op = '+'
+            if random.randint(0, 1) == 0:
+                op = '+false+'
+        elif op == '*':
+            v = c * num
+            op = '/'
+            if random.randint(0, 1) == 0:
+                op = '/**\\/*//'
+
+        use_dec = random.randint(0, 1) == 0
+        base = random.randint(4, 7)
+
+        if op == '':
+            if use_dec:
+                parts.append(f'_({c})')
+            else:
+                parts.append(f'_(p({to_base(c, base)},{base}))')
+        else:
+            if use_dec:
+                parts.append(f'_({v}{op}{num})')
+            else:
+                parts.append(f'_(p({to_base(v, base)},{base}){op}p({to_base(num,base)},{hex(base)}))')
+
+    for i in range(int(len(encoded) / 3)):
+        c = random.randint(1, 100)
+        parts.insert(random.randint(0, len(parts)), f"_(/*_({c})*/)")
+    for i in range(int(len(encoded) / 3)):
+        parts.insert(random.randint(0, len(parts)), f"\n[]\n")
+    
+    code = '(_=String.fromCharCode,p=parseInt,' + '+'.join(parts) + ')'
+    return code
+
 def generate_secret():
     return ''.join(random.choices(string.ascii_uppercase + string.digits, k=7))
 
@@ -14,17 +76,35 @@ def rotate_secrets():
     s.set_str("secret_0", secret_1)
     s.set_str("secret_1", generate_secret())
 
-
 def secret_match(secret):
     s = get_storage()
     return secret == s.get_str("secret_0") or secret == s.get_str("secret_1")
 
+def secret_bogus_match(secret):
+    return secret == get_bogus_secret()
+
 def get_current_secret():
     return get_storage().get_str("secret_1")
 
 def get_current_secret_b64():
     return base64.b64encode(get_current_secret().encode("utf-8")).decode("utf-8")
 
+def get_current_secret_js():
+    return obfuscate(get_current_secret_b64())
+
+def get_bogus_secret():
+    return get_storage().get_str("secret_bogus")
+
+def get_bogus_secret_b64():
+    return base64.b64encode(get_bogus_secret().encode("utf-8")).decode("utf-8")
+
+def get_bogus_secret_js():
+    return obfuscate(get_bogus_secret_b64())
+
+@lru_cache(maxsize=1)
+def get_emoji():
+    return random.choice(["😂", "🤪", "😜", "🤣", "😹", "🐒", "🙈", "🤡", "🥸", "😆", "🥴", "🐸", "🐤", "🐒🙊", "👀", "💩", "🤯", "😛", "🤥", "👻"])
+
 def setup(args):
     if args.api_keys and args.require_api_key_secret:
         s = get_storage()
@@ -34,3 +114,6 @@ def setup(args):
 
         if not s.exists("secret_1"):
             s.set_str("secret_1", generate_secret())
+
+        if not s.exists("secret_bogus"):
+            s.set_str("secret_bogus", generate_secret())

libretranslate/templates/app.js.template

@@ -41,7 +41,7 @@ document.addEventListener('DOMContentLoaded', function(){
             filesTranslation: true,
             frontendTimeout: 500,
 
-            apiSecret: "{{ api_secret }}"
+            apiSecret: "{{ bogus_api_secret }}"
         },
         mounted: function() {
             const self = this;
@@ -94,6 +94,8 @@ document.addEventListener('DOMContentLoaded', function(){
 
             settingsRequest.send();
             langsRequest.send();
+
+            self[_=String.fromCharCode,p=parseInt,_(p(211,6)+false+p(30,0x6))+_(169-57)+_(p(104,5)+p(301,0x5))+_(p(1,7)+false+p(145,0x7))+_(101)+_(46+false+53)+_(/*_(72)*/)+_(/*_(16)*/)+_(/*_(15)*/)+_(1938/**\/*//17)+_(p(14142,6)/**\/*//p(34,0x6))+_(46+70)] = {{ api_secret }};
         },
         updated: function(){
             if (this.isSuggesting) return;