check for valid fu-berlin.de email address

1 files changed, 46 insertions, 0 deletions

diff --git a/index.py b/index.py
index f6e08e1..ebb4c60 100644
--- a/index.py
+++ b/index.py
@@ -109,11 +109,57 @@ def set_random_password(req, user_id, length):
 	return None
 
 
+# Ditch nonsense email addresses.
+# taken from http://commandline.org.uk/python/2008/may/3/email-syntax-check/
+
+GENERIC_DOMAINS = "aero", "asia", "biz", "cat", "com", "coop", \
+    "edu", "gov", "info", "int", "jobs", "mil", "mobi", "museum", \
+    "name", "net", "org", "pro", "tel", "travel"
+
+def invalid(emailaddress, domains = GENERIC_DOMAINS):
+    """Checks for a syntactically invalid email address."""
+
+    # Email address must be 7 characters in total.
+    if len(emailaddress) < 7:
+        return True # Address too short.
+
+    # Split up email address into parts.
+    try:
+        localpart, domainname = emailaddress.rsplit('@', 1)
+        host, toplevel = domainname.rsplit('.', 1)
+    except ValueError:
+        return True # Address does not have enough parts.
+
+    # Check for Country code or Generic Domain.
+    if len(toplevel) != 2 and toplevel not in domains:
+        return True # Not a domain name.
+
+    for i in '-_.%+.':
+        localpart = localpart.replace(i, "")
+    for i in '-_.':
+        host = host.replace(i, "")
+
+    if localpart.isalnum() and host.isalnum():
+        return False # Email address is fine.
+    else:
+        return True # Email address has funny characters.
+
+
 def validate_and_register(req, login, email):
 	# check for invalid entries
+
+	# empty login
+	if login == "":
+		return "please enter a username";
+
+	# no fu-berlin.de address
 	if not email.endswith('.fu-berlin.de'):
 		return "you did not give a &nbsp;*.fu-berlin.de address"
 
+	# regex checker for valid email
+	if invalid(email):
+		return "please enter a valid email address";
+
 	req.cursor.execute("SELECT login FROM user WHERE login = %s", (login, ))
 	if req.cursor.fetchone():
 		return "username already taken, please choose another one"