Modified files to accept argon2 as new option

app.py

@@ -1,5 +1,11 @@
 from flask import Flask, request, jsonify, render_template, abort
-import secrets, crypt, os
+from argon2 import PasswordHasher
+import secrets, os
+
+try:
+    import crypt
+except ImportError:
+    import crypt_r as crypt
 
 app = Flask(__name__, static_folder='static', template_folder='templates')
 
@@ -8,10 +14,12 @@ MIN_LEN = 16
 MIN_SALT_LEN = 8
 MAX_SALT_LEN = 16
 
+ph = PasswordHasher()
 
 ALG_PREFIX = {
     'sha512': '$6$',
     'sha256': '$5$',
+    'argon2': '$argon2id$'
 }
 
 # The main route
@@ -42,12 +50,15 @@ def do_hash():
     if len(salt) < MIN_SALT_LEN or len(salt) > MAX_SALT_LEN:
         abort(400, f'Salt must be between {MIN_SALT_LEN} and {MAX_SALT_LEN} characters')
 
-    prefix = ALG_PREFIX.get(algorithm)
+    if algorithm == 'argon2':
+        hashed = ph.hash(password + salt)
+        return jsonify({'hash': hashed})
 
+
+    prefix = ALG_PREFIX.get(algorithm)
     if prefix is None:
         abort(400, 'Unsupported algorithm')
 
-
     full_salt = f"{prefix}{salt}"
     hashed = crypt.crypt(password, full_salt)
     return jsonify({'hash': hashed})

templates/index.html

@@ -16,6 +16,7 @@
         <select id="algorithm">
             <option value="sha512">sha512-crypt ($6$)</option>
             <option value="sha256">sha256-crypt ($5$)</option>
+            <option value="argon2">argon2 ($argon2id$)</option>
         </select>