generate compliant IP-address email addresses

chatmaild/src/chatmaild/newemail.py

@@ -2,6 +2,7 @@
 
 """CGI script for creating new accounts."""
 
+import ipaddress
 import json
 import secrets
 import string
@@ -14,6 +15,16 @@ ALPHANUMERIC = string.ascii_lowercase + string.digits
 ALPHANUMERIC_PUNCT = string.ascii_letters + string.digits + string.punctuation
 
 
+def wrap_ip(host):
+    if host.startswith("[") and host.endswith("]"):
+        return host
+    try:
+        ipaddress.ip_address(host)
+        return f"[{host}]"
+    except ValueError:
+        return host
+
+
 def create_newemail_dict(config: Config):
     user = "".join(
         secrets.choice(ALPHANUMERIC) for _ in range(config.username_max_length)
@@ -22,7 +33,7 @@ def create_newemail_dict(config: Config):
         secrets.choice(ALPHANUMERIC_PUNCT)
         for _ in range(config.password_min_length + 3)
     )
-    return dict(email=f"{user}@{config.mail_domain}", password=f"{password}")
+    return dict(email=f"{user}@{wrap_ip(config.mail_domain)}", password=f"{password}")
 
 
 def create_dclogin_url(email, password):

chatmaild/src/chatmaild/tests/test_newmail.py

@@ -19,6 +19,12 @@ def test_create_newemail_dict(example_config):
     assert ac1["password"] != ac2["password"]
 
 
+def test_create_newemail_dict_ip(make_config):
+    config = make_config("1.2.3.4")
+    ac = create_newemail_dict(config)
+    assert ac["email"].endswith("@[1.2.3.4]")
+
+
 def test_create_dclogin_url():
     url = create_dclogin_url("user@example.org", "p@ss w+rd")
     assert url.startswith("dclogin:")