store session-key in database (once generated on db creation), #74

Store a random session key used to sign and verify comment ownership
once the database is initialized, not on every application startup.

Currently fixed session keys in [general] session-key are migrated into
the database on startup. The configuration parser will notice you about
the change and suggest you to remove this option.

docs/docs/configuration/server.rst

@@ -43,7 +43,6 @@ session key and hostname. Here are the default values for this section:
     name =
     host = http://localhost:8080/
     max-age = 15m
-    session-key = ... ; python: binascii.b2a_hex(os.urandom(24))
     notify =
 
 dbpath
@@ -71,11 +70,6 @@ host
 
     This is useful, when your website is available on HTTP and HTTPS.
 
-session-key
-    private session key to validate client cookies. If you restart the
-    application several times per hour for whatever reason, use a fixed
-    key.
-
 max-age
     time range that allows users to edit/remove their own comments. See
     :ref:`Appendum: Timedelta <appendum-timedelta>` for valid values.
@@ -136,8 +130,7 @@ listen
 
 reload
     reload application, when the source code has changed. Useful for
-    development (don't forget to use a fixed `session-key`). Only works
-    when ``gevent`` and ``uwsgi`` are *not* available.
+    development. Only works with the internal webserver.
 
 profile
     show 10 most time consuming function in Isso after each request. Do

docs/docs/extras/deployment.rst

@@ -121,15 +121,6 @@ Next, copy'n'paste to `/var/www/isso.wsgi`:
 
     application = make_app(Config.load("/path/to/isso.cfg"))
 
-Also make sure, you set a static key because `mod_wsgi` generates a session
-key per thread/process. This may result in random 403 errors when you edit or
-delete comments.
-
-.. code-block:: ini
-
-    [general]
-    ; cat /dev/urandom | strings | grep -o '[[:alnum:]]' | head -n 30 | tr -d '\n'
-    session-key = superrandomkey1
 
 `mod_fastcgi <http://www.fastcgi.com/mod_fastcgi/docs/mod_fastcgi.html>`__
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -170,12 +161,3 @@ Next, copy'n'paste to `/var/www/isso.fcgi` (or whatever location you prefer):
 
     application = make_app(Config.load("/path/to/isso.cfg"))
     WSGIServer(application).run()
-
-Similar to mod_wsgi_, set a static session key if you are using more than one process
-to avoid random errors.
-
-.. code-block:: ini
-
-    [general]
-    ; cat /dev/urandom | strings | grep -o '[[:alnum:]]' | head -n 30 | tr -d '\n'
-    session-key = superrandomkey1

docs/isso.example.cfg

@@ -24,10 +24,6 @@ host = http://localhost/
 # 3h45m12s equals to 3 hours, 45 minutes and 12 seconds.
 max-age = 15m
 
-# private session key to validate client cookies. If you restart the application
-# several times per hour for whatever reason, use a fixed key.
-session-key = ... ; python: binascii.b2a_hex(os.urandom(24))
-
 # Select notification backend for new comments. Currently, only SMTP is
 # available.
 notify =
@@ -53,9 +49,8 @@ purge-after = 30d
 # for details).  Does not apply for uWSGI.
 listen = http://localhost:8080
 
-# reload application, when the source code has changed. Useful for development
-# (don't forget to use a fixed session-key). Only works when gevent and uwsgi
-# are not available.
+# reload application, when the source code has changed. Useful for development.
+# Only works with the internal webserver.
 reload = off
 
 # show 10 most time consuming function in Isso after each request. Do not use in

isso/__init__.py

@@ -85,7 +85,7 @@ class Isso(object):
 
         self.conf = conf
         self.db = db.SQLite3(conf.get('general', 'dbpath'), conf)
-        self.signer = URLSafeTimedSerializer(conf.get('general', 'session-key'))
+        self.signer = URLSafeTimedSerializer(self.db.preferences.get("session-key"))
         self.markup = html.Markup(conf.section('markup'))
 
         super(Isso, self).__init__(conf)
@@ -160,9 +160,6 @@ def make_app(conf=None, threading=True, multiprocessing=False, uwsgi=False):
 
     isso = App(conf)
 
-    # show session-key (to see that it changes randomely if unset)
-    logger.info("session-key = %s", isso.conf.get("general", "session-key"))
-
     # check HTTP server connection
     for host in conf.getiter("general", "host"):
         with http.curl('HEAD', host, '/', 5) as resp:

isso/core.py

@@ -3,10 +3,8 @@
 from __future__ import print_function
 
 import io
-import os
 import time
 import logging
-import binascii
 import threading
 import multiprocessing
 
@@ -115,7 +113,7 @@ class Config:
     default = [
         "[general]",
         "name = ",
-        "dbpath = /tmp/isso.db", "session-key = %s" % binascii.b2a_hex(os.urandom(16)),
+        "dbpath = /tmp/isso.db",
         "host = http://localhost:8080/", "max-age = 15m",
         "notify = ",
         "[moderation]",
@@ -164,6 +162,9 @@ class Config:
                     logger.warn("use `listen = http://$host:$port` instead")
                 if item == ("smtp", "ssl"):
                     logger.warn("use `security = none | starttls | ssl` instead")
+                if item == ("general", "session-key"):
+                    logger.info("Your `session-key` has been stored in the "
+                                "database itself, this option is now unused")
 
         if rv.get("smtp", "username") and not rv.get("general", "notify"):
             logger.warn(("SMTP is no longer enabled by default, add "

isso/db/__init__.py

@@ -9,6 +9,7 @@ logger = logging.getLogger("isso")
 from isso.db.comments import Comments
 from isso.db.threads import Threads
 from isso.db.spam import Guard
+from isso.db.preferences import Preferences
 
 
 class SQLite3:
@@ -18,7 +19,7 @@ class SQLite3:
     a trigger for automated orphan removal.
     """
 
-    MAX_VERSION = 1
+    MAX_VERSION = 2
 
     def __init__(self, path, conf):
 
@@ -27,18 +28,19 @@ class SQLite3:
 
         rv = self.execute([
             "SELECT name FROM sqlite_master"
-            "   WHERE type='table' AND name IN ('threads', 'comments')"]
-        ).fetchall()
-
-        if rv:
-            self.migrate(to=SQLite3.MAX_VERSION)
-        else:
-            self.execute("PRAGMA user_version = %i" % SQLite3.MAX_VERSION)
+            "   WHERE type='table' AND name IN ('threads', 'comments', 'preferences')"]
+        ).fetchone()
 
+        self.preferences = Preferences(self)
         self.threads = Threads(self)
         self.comments = Comments(self)
         self.guard = Guard(self)
 
+        if rv is None:
+            self.execute("PRAGMA user_version = %i" % SQLite3.MAX_VERSION)
+        else:
+            self.migrate(to=SQLite3.MAX_VERSION)
+
         self.execute([
             'CREATE TRIGGER IF NOT EXISTS remove_stale_threads',
             'AFTER DELETE ON comments',
@@ -76,3 +78,14 @@ class SQLite3:
                 con.execute('UPDATE comments SET voters=?', (bf, ))
                 con.execute('PRAGMA user_version = 1')
                 logger.info("%i rows changed", con.total_changes)
+
+        # move [general] session-key to database
+        if self.version == 1:
+
+            with sqlite3.connect(self.path) as con:
+                if self.conf.has_option("general", "session-key"):
+                    con.execute('UPDATE preferences SET value=? WHERE key=?', (
+                        self.conf.get("general", "session-key"), "session-key"))
+
+                con.execute('PRAGMA user_version = 2')
+                logger.info("%i rows changed", con.total_changes)

isso/db/preferences.py

@@ -0,0 +1,36 @@
+# -*- encoding: utf-8 -*-
+
+import os
+import binascii
+
+
+class Preferences:
+
+    defaults = [
+        ("session-key", binascii.b2a_hex(os.urandom(24))),
+    ]
+
+    def __init__(self, db):
+
+        self.db = db
+        self.db.execute([
+            'CREATE TABLE IF NOT EXISTS preferences (',
+            '   key VARCHAR PRIMARY KEY, value VARCHAR',
+            ');'])
+
+        for (key, value) in Preferences.defaults:
+            if self.get(key) is None:
+                self.set(key, value)
+
+    def get(self, key, default=None):
+        rv = self.db.execute(
+                'SELECT value FROM preferences WHERE key=?', (key, )).fetchone()
+
+        if rv is None:
+            return default
+
+        return rv[0]
+
+    def set(self, key, value):
+        self.db.execute(
+            'INSERT INTO preferences (key, value) VALUES (?, ?)', (key, value))