From 95a940a14f26a7bacfa484a4e19b256afb4bd4a8 Mon Sep 17 00:00:00 2001
From: n9k <originalcocaineninja@protonmail.com>
Date: Wed, 22 Jun 2022 08:35:35 +0000
Subject: [PATCH] Limit number of stored failures

Failures are messages shown on the access captcha screen when the
captcha answer was not accepted for whatever reason.
---
 anonstream/__init__.py | 2 +-
 anonstream/access.py   | 5 +++++
 anonstream/config.py   | 2 ++
 config.toml            | 1 +
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/anonstream/__init__.py b/anonstream/__init__.py
index 1e4a915..f918218 100644
--- a/anonstream/__init__.py
+++ b/anonstream/__init__.py
@@ -38,7 +38,7 @@ def create_app(toml_config):
     app.captcha_factory = create_captcha_factory(app.config['CAPTCHA_FONTS'])
     app.captcha_signer = create_captcha_signer(app.config['SECRET_KEY'])
 
-    app.failures = {}
+    app.failures = OrderedDict()
 
     # State for tasks
     app.users_update_buffer = set()
diff --git a/anonstream/access.py b/anonstream/access.py
index 822acd2..3f76c02 100644
--- a/anonstream/access.py
+++ b/anonstream/access.py
@@ -2,6 +2,7 @@ import time
 
 from quart import current_app
 
+CONFIG = current_app.config
 FAILURES = current_app.failures
 
 def add_failure(message):
@@ -9,6 +10,10 @@ def add_failure(message):
     while timestamp in FAILURES:
         timestamp += 1
     FAILURES[timestamp] = message
+
+    while len(FAILURES) > CONFIG['MAX_FAILURES']:
+        FAILURES.popitem(last=False)
+
     return timestamp
 
 def pop_failure(failure_id):
diff --git a/anonstream/config.py b/anonstream/config.py
index 0c5c580..346f2c6 100644
--- a/anonstream/config.py
+++ b/anonstream/config.py
@@ -84,11 +84,13 @@ def toml_to_flask_section_names(config):
 def toml_to_flask_section_memory(config):
     cfg = config['memory']
     assert cfg['states'] >= 0
+    assert cfg['failures'] >= 0
     assert cfg['chat_scrollback'] >= 0
     assert cfg['chat_messages'] >= cfg['chat_scrollback']
     return {
         'MAX_STATES': cfg['states'],
         'MAX_CAPTCHAS': cfg['captchas'],
+        'MAX_FAILURES': cfg['failures'],
         'MAX_CHAT_MESSAGES': cfg['chat_messages'],
         'MAX_CHAT_SCROLLBACK': cfg['chat_scrollback'],
     }
diff --git a/config.toml b/config.toml
index 95b2d22..b3be6e1 100644
--- a/config.toml
+++ b/config.toml
@@ -38,6 +38,7 @@ foreground_color = "#dddddd"
 [memory]
 states = 32
 captchas = 256
+failures = 256
 chat_messages = 8192
 chat_scrollback = 256