Improvements to domain validation

control/templates/shared/add_vhost_test.html

@@ -54,7 +54,7 @@ <h2>Test custom domain</h2>
     <input type="hidden" name="confirm" value="on">
     {% if valid[domain] == (true, true) or valid[prefixed] == (true, true) %}
         <input type="submit" class="btn btn-outline-primary" value="Looks good, add domain">
-    {% else %}
+    {% elif valid[domain] != (none, none) or valid[prefixed] != (none, none) %}
         <input type="submit" class="btn btn-outline-danger" value="Add domain anyway">
     {% endif %}
 </form>

control/webapp/member.py

@@ -1,6 +1,3 @@
-import re
-import string
-
 from flask import Blueprint, redirect, render_template, request, url_for
 from werkzeug.exceptions import Forbidden, NotFound
 
@@ -10,7 +7,10 @@
 from srcf.database import Domain
 
 from . import inspect_services, utils
-from .utils import create_job_maybe_email_and_redirect, effective_member, parse_domain_name, srcf_db_sess as sess
+from .utils import (
+    create_job_maybe_email_and_redirect, effective_member, parse_domain_name,
+    validate_domain_docroot, srcf_db_sess as sess,
+)
 
 
 bp = Blueprint("member", __name__)
@@ -252,6 +252,7 @@ def add_vhost():
 
         domain = request.form.get("domain", "").strip()
         root = request.form.get("root", "").strip()
+
         if domain:
             parsed = parse_domain_name(domain)
             if domain != parsed:
@@ -270,6 +271,11 @@ def add_vhost():
         else:
             errors["domain"] = "Please enter a domain or subdomain."
 
+        if root:
+            root, msg = validate_domain_docroot(mem, root)
+            if msg:
+                errors["root"] = msg
+
         if request.form.get("edit") or errors:
             return render_template("member/add_vhost.html", member=mem, domain=domain, root=root, errors=errors)
         elif not request.form.get("confirm"):
@@ -303,12 +309,10 @@ def change_vhost_docroot(domain):
 
     if request.method == "POST":
         root = request.form.get("root", "").strip()
-        if any([ch in root for ch in string.whitespace + "\\" + "\"" + "\'"]) or ".." in root:
-            errors["root"] = "This document root is invalid."
-        try:
-            domain = parse_domain_name(domain)
-        except ValueError as e:
-            errors["domain"] = e.args[0]
+        if root:
+            root, msg = validate_domain_docroot(mem, root)
+            if msg:
+                errors["root"] = msg
 
     if request.method == "POST" and not errors:
         return create_job_maybe_email_and_redirect(

control/webapp/society.py

@@ -1,5 +1,4 @@
 import re
-import string
 
 from flask import Blueprint, redirect, render_template, request, url_for
 from werkzeug.exceptions import BadRequest, Forbidden, NotFound
@@ -10,7 +9,10 @@
 from srcf.database import Domain
 
 from . import inspect_services, utils
-from .utils import create_job_maybe_email_and_redirect, find_mem_society, parse_domain_name, srcf_db_sess as sess
+from .utils import (
+    create_job_maybe_email_and_redirect, find_mem_society, parse_domain_name,
+    validate_domain_docroot, srcf_db_sess as sess,
+)
 
 
 bp = Blueprint("society", __name__)
@@ -286,6 +288,7 @@ def add_vhost(society):
 
         domain = request.form.get("domain", "").strip()
         root = request.form.get("root", "").strip()
+
         if domain:
             parsed = parse_domain_name(domain)
             if domain != parsed:
@@ -304,6 +307,11 @@ def add_vhost(society):
         else:
             errors["domain"] = "Please enter a domain or subdomain."
 
+        if root:
+            root, msg = validate_domain_docroot(soc, root)
+            if msg:
+                errors["root"] = msg
+
         if request.form.get("edit") or errors:
             return render_template("society/add_vhost.html", society=soc, member=mem, domain=domain, root=root, errors=errors)
         elif not request.form.get("confirm"):
@@ -337,12 +345,10 @@ def change_vhost_docroot(society, domain):
 
     if request.method == "POST":
         root = request.form.get("root", "").strip()
-        if any([ch in root for ch in string.whitespace + "\\" + "\"" + "\'"]) or ".." in root:
-            errors["root"] = "This document root is invalid."
-        try:
-            domain = parse_domain_name(domain)
-        except ValueError as e:
-            errors["domain"] = e.args[0]
+        if root:
+            root, msg = validate_domain_docroot(soc, root)
+            if msg:
+                errors["root"] = msg
 
     if request.method == "POST" and not errors:
         return create_job_maybe_email_and_redirect(

control/webapp/utils.py

@@ -1,6 +1,7 @@
 from datetime import datetime
 from functools import partial
 import os
+import string
 import sys
 import traceback
 from urllib.parse import urlparse
@@ -15,7 +16,7 @@
 
 from srcf.controllib.jobs import CreateSociety, Reactivate, Signup, SocietyJob
 from srcf.controllib.utils import email_re, is_admin, ldapsearch, mysql_conn
-from srcf.database import JobLog, queries, Session
+from srcf.database import Member, JobLog, queries, Session
 from srcf.mail import mail_sysadmins
 import ucam_webauth
 import ucam_webauth.flask_glue
@@ -91,6 +92,33 @@ def parse_domain_name(domain):
         return domain.encode("idna").decode("ascii")
 
 
+def validate_domain_docroot(owner, path):
+    if not path:
+        return path, None
+    if any(ch in path for ch in string.whitespace + "\\" + '"' + "'"):
+        return path, "Document roots cannot contain spaces, backslashes or quotes."
+    if path.startswith("public_html/"):
+        path = path.replace("public_html/", "", 1)
+    if isinstance(owner, Member):
+        username = owner.crsid
+        top = "home"
+    else:
+        username = owner.society
+        top = "societies"
+    base = os.path.join("/public", top, username, "public_html")
+    target = os.path.abspath(os.path.join(base, path))
+    if os.path.commonpath((base, target)) != base:
+        return path, "Document roots must be inside your public_html directory."
+    elif base == target:
+        return "", "We've cleared your document root as it appears to be your public_html directory."
+    elif not os.path.exists(target):
+        return path, "This document root doesn't exist, or isn't accessible to the webserver.  Create the directory first, then try again."
+    clean = target[len(base) + 1:]
+    if clean != path:
+        return clean, "We've fixed your document root to its canonical version; submit again to confirm."
+    return path, None
+
+
 # Template helpers
 def sif(variable, val):
     """"string if": `val` if `variable` is defined and truthy, else ''"""