Strengthen client side security

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())