From 6fa48ac64b39b85b9016ebcec6804c827a35f966 Mon Sep 17 00:00:00 2001
From: "Namhyeon, Go" <gnh1201@gmail.com>
Date: Wed, 31 Jul 2024 13:39:09 +0900
Subject: [PATCH] Add elasticsearch webpage cache

---
 plugins/alwaysonline.py | 146 ++++++++++++++++++++++++++++++++++++++++
 requirements-dev.txt    |   1 +
 2 files changed, 147 insertions(+)
 create mode 100644 plugins/alwaysonline.py

diff --git a/plugins/alwaysonline.py b/plugins/alwaysonline.py
new file mode 100644
index 0000000..926107f
--- /dev/null
+++ b/plugins/alwaysonline.py
@@ -0,0 +1,146 @@
+#!/usr/bin/python3
+#
+# alwaysonline.py
+# Always Online implementation for Caterpillar Proxy
+#
+# Caterpillar Proxy - The simple web debugging proxy (formerly, php-httpproxy)
+# Namyheon Go (Catswords Research) <gnh1201@gmail.com>
+# https://github.com/gnh1201/caterpillar
+# Created at: 2024-07-31
+# Updated at: 2024-07-31
+#
+import requests
+from decouple import config
+from elasticsearch import Elasticsearch, NotFoundError
+import hashlib
+from base import Extension, Logger
+
+logger = Logger(name="wayback")
+
+try:
+    client_encoding = config("CLIENT_ENCODING")
+    es_host = config("ES_HOST")
+    es_index = config("ES_INDEX")
+except Exception as e:
+    logger.error("[*] Invalid configuration", exc_info=e)
+
+es = Elasticsearch([es_host])
+
+def generate_id(url):
+    """Generate a unique ID for a URL by hashing it."""
+    return hashlib.sha256(url.encode('utf-8')).hexdigest()
+
+def get_cached_page_from_google(url):
+    status_code, text = (0, "")
+
+    # Google Cache URL
+    google_cache_url = "https://webcache.googleusercontent.com/search?q=cache:" + url
+
+    # Send a GET request to Google Cache URL
+    response = requests.get(google_cache_url)
+
+    # Check if the request was successful (status code 200)
+    if response.status_code == 200:
+        text = response.text  # Extract content from response
+    else:
+        status_code = response.status_code
+
+    return status_code, text
+
+# API documentation: https://archive.org/help/wayback_api.php
+def get_cached_page_from_wayback(url):
+    status_code, text = (0, "")
+
+    # Wayback Machine API URL
+    wayback_api_url = "http://archive.org/wayback/available?url=" + url
+
+    # Send a GET request to Wayback Machine API
+    response = requests.get(wayback_api_url)
+
+    # Check if the request was successful (status code 200)
+    if response.status_code == 200:
+        try:
+            # Parse JSON response
+            data = response.json()
+            archived_snapshots = data.get("archived_snapshots", {})
+            closest_snapshot = archived_snapshots.get("closest", {})
+
+            # Check if the URL is available in the archive
+            if closest_snapshot:
+                archived_url = closest_snapshot.get("url", "")
+
+                # If URL is available, fetch the content of the archived page
+                if archived_url:
+                    archived_page_response = requests.get(archived_url)
+                    status_code = archived_page_response.status_code
+                    if status_code == 200:
+                        text = archived_page_response.text
+                else:
+                    status_code = 404
+            else:
+                status_code = 404
+        except:
+            status_code = 502
+    else:
+        status_code = response.status_code
+
+    return status_code, text
+
+def get_cached_page_from_elasticsearch(url):
+    url_id = generate_id(url)
+    try:
+        result = es.get(index=es_index, id=url_id)
+        return 200, result['_source']['content']
+    except NotFoundError:
+        return 404, ""
+    except Exception as e:
+        logger.error(f"Error fetching from Elasticsearch: {e}")
+        return 500, ""
+
+def cache_to_elasticsearch(url, data):
+    url_id = generate_id(url)
+    try:
+        es.index(index=es_index, id=url_id, body={"content": data.decode(client_encoding)})
+    except Exception as e:
+        logger.error(f"Error caching to Elasticsearch: {e}")
+
+class AlwaysOnline(Extension):
+    def __init__(self):
+        self.type = "connector"  # this is a connector
+        self.connection_type = "alwaysonline"
+
+    def connect(self, conn, data, webserver, port, scheme, method, url):
+        connected = False
+        cache_hit = 0
+        buffered = b""
+        
+        target_url = url.decode(client_encoding)
+        
+        if method == "GET":
+            if not connected:
+                status_code, text = get_cached_page_from_elasticsearch(target_url)
+                if status_code == 200:
+                    buffered += text.encode(client_encoding)
+                    cache_hit += 1
+                    connected = True
+
+            if not connected:
+                status_code, text = get_cached_page_from_google(target_url)
+                if status_code == 200:
+                    buffered += text.encode(client_encoding)
+                    cache_hit += 1
+                    connected = True
+
+            if not connected:
+                status_code, text = get_cached_page_from_wayback(target_url)
+                if status_code == 200:
+                    buffered += text.encode(client_encoding)
+                    cache_hit += 1
+                    connected = True
+                    
+        conn.send(buffered)
+        
+        if cache_hit == 0 and buffered:
+            cache_to_elasticsearch(target_url, buffered)
+
+        return connected
\ No newline at end of file
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 51fba0a..36bf53a 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,2 +1,3 @@
 ruff==0.5.1
+elasticsearch==8.14.0
 yara-python==4.5.1
\ No newline at end of file