resources: simplify default script; document API better

resources/default_script.lua

@@ -1,17 +1,210 @@
-function generate_honeytoken(token)
-  local token_types = { "API_KEY", "AUTH_TOKEN", "SESSION_ID", "SECRET_KEY" }
-  local prefix = token_types[math.random(#token_types)]
-  local suffix = string.format("%08x", math.random(0xffffff))
-  return prefix .. "_" .. token .. "_" .. suffix
-end
+--[[
+Eris Default Script
 
+This script demonstrates how to use the Eris Lua API to customize
+the tarpit's behavior, and will be loaded by default if no other
+scripts are loaded.
+
+Available events:
+- connection: When a new connection is established
+- request: When a request is received
+- response_gen: When generating a response
+- response_chunk: Before sending each response chunk
+- disconnection: When a connection is closed
+- block_ip: When an IP is being considered for blocking
+- startup: When the application starts
+- shutdown: When the application is shutting down
+- periodic: Called periodically
+
+API Functions:
+- eris.debug(message): Log a debug message
+- eris.info(message): Log an info message
+- eris.warn(message): Log a warning message
+- eris.error(message): Log an error message
+- eris.set_state(key, value): Store persistent state
+- eris.get_state(key): Retrieve persistent state
+- eris.inc_counter(key, [amount]): Increment a counter
+- eris.get_counter(key): Get a counter value
+- eris.gen_token([prefix]): Generate a unique token
+- eris.timestamp(): Get current Unix timestamp
+--]]
+
+-- Called when the application starts
+eris.on("startup", function(ctx)
+  eris.info("Initializing default script")
+
+  -- Initialize counters
+  eris.inc_counter("total_connections", 0)
+  eris.inc_counter("total_responses", 0)
+  eris.inc_counter("blocked_ips", 0)
+
+  -- Initialize banned keywords
+  eris.set_state("banned_keywords", "eval,exec,system,shell,<?php,/bin/bash")
+end)
+
+-- Called for each new connection
+eris.on("connection", function(ctx)
+  eris.inc_counter("total_connections")
+  eris.debug("New connection from " .. ctx.ip)
+
+  -- You can reject connections by returning false
+  -- This example checks a blocklist
+  local blocklist = eris.get_state("manual_blocklist") or ""
+  if blocklist:find(ctx.ip) then
+    eris.info("Rejecting connection from manually blocked IP: " .. ctx.ip)
+    return false
+  end
+
+  return true -- accept the connection
+end)
+
+-- Called when generating a response
+eris.on("response_gen", function(ctx)
+  eris.inc_counter("total_responses")
+
+  -- Generate a unique traceable token for this request
+  local token = eris.gen_token("ERIS-")
+
+  -- Add some believable but fake honeytokens based on the request path
+  local enhanced_content = ctx.content
+
+  if ctx.path:find("wp%-") then
+    -- For WordPress paths
+    enhanced_content = enhanced_content
+        .. "\n<!-- WordPress Debug: "
+        .. token
+        .. " -->"
+        .. "\n<!-- WP_HOME: http://stop.crawlingmysite.com/wordpress -->"
+        .. "\n<!-- DB_USER: wp_user_"
+        .. math.random(1000, 9999)
+        .. " -->"
+  elseif ctx.path:find("phpunit") or ctx.path:find("eval") then
+    -- For PHP exploit attempts
+    -- Turns out you can just google "PHP error log" and search random online forums where people
+    -- dump their service logs in full.
+    enhanced_content = enhanced_content
+        .. "\nPHP Notice: Undefined variable: _SESSION in /var/www/html/includes/core.php on line 58\n"
+        .. "Warning: file_get_contents(): Filename cannot be empty in /var/www/html/vendor/autoload.php on line 23\n"
+        .. "Token: "
+        .. token
+        .. "\n"
+  elseif ctx.path:find("api") then
+    -- For API requests
+    local fake_api_key =
+        string.format("ak_%x%x%x", math.random(1000, 9999), math.random(1000, 9999), math.random(1000, 9999))
+
+    enhanced_content = enhanced_content
+        .. "{\n"
+        .. '  "status": "warning",\n'
+        .. '  "message": "Test API environment detected",\n'
+        .. '  "debug_token": "'
+        .. token
+        .. '",\n'
+        .. '  "api_key": "'
+        .. fake_api_key
+        .. '"\n'
+        .. "}\n"
+  else
+    -- For other requests
+    enhanced_content = enhanced_content
+        .. "\n<!-- Server: Apache/2.4.41 (Ubuntu) -->"
+        .. "\n<!-- Debug-Token: "
+        .. token
+        .. " -->"
+        .. "\n<!-- Environment: staging -->"
+  end
+
+  -- Track which honeytokens were sent to which IP
+  local honeytokens = eris.get_state("honeytokens") or "{}"
+  local ht_table = {}
+
+  -- This is a simplistic approach - in a real script, you'd want to use
+  -- a proper JSON library to handle this correctly
+  if honeytokens ~= "{}" then
+    -- Simple parsing of the stored data
+    for ip, tok in honeytokens:gmatch('"([^"]+)":"([^"]+)"') do
+      ht_table[ip] = tok
+    end
+  end
+
+  ht_table[ctx.ip] = token
+
+  -- Convert back to a simple JSON-like string
+  local new_tokens = "{"
+  for ip, tok in pairs(ht_table) do
+    if new_tokens ~= "{" then
+      new_tokens = new_tokens .. ","
+    end
+    new_tokens = new_tokens .. '"' .. ip .. '":"' .. tok .. '"'
+  end
+  new_tokens = new_tokens .. "}"
+
+  eris.set_state("honeytokens", new_tokens)
+
+  return enhanced_content
+end)
+
+-- Called before sending each chunk of a response
+eris.on("response_chunk", function(ctx)
+  -- This can be used to alter individual chunks for more deceptive behavior
+  -- For example, to simulate a slow, unreliable server
+
+  -- 5% chance of "corrupting" a chunk to confuse scanners
+  if math.random(1, 100) <= 5 then
+    local chunk = ctx.content
+    if #chunk > 10 then
+      local pos = math.random(1, #chunk - 5)
+      chunk = chunk:sub(1, pos) .. string.char(math.random(32, 126)) .. chunk:sub(pos + 2)
+    end
+    return chunk
+  end
+
+  return ctx.content
+end)
+
+-- Called when deciding whether to block an IP
+eris.on("block_ip", function(ctx)
+  -- You can override the default blocking logic
+
+  -- Check for potential attackers using specific patterns
+  local banned_keywords = eris.get_state("banned_keywords") or ""
+  local user_agent = ctx.user_agent or ""
+
+  -- Check if user agent contains highly suspicious patterns
+  for keyword in banned_keywords:gmatch("[^,]+") do
+    if user_agent:lower():find(keyword:lower()) then
+      eris.info("Blocking IP " .. ctx.ip .. " due to suspicious user agent: " .. keyword)
+      eris.inc_counter("blocked_ips")
+      return true -- Force block
+    end
+  end
+
+  -- For demonstration, we'll be more lenient with 10.x IPs
+  if ctx.ip:match("^10%.") then
+    -- Only block if they've hit us many times
+    return ctx.hit_count >= 5
+  end
+
+  -- Default to the system's threshold-based decision
+  return nil
+end)
+
+-- The enhance_response is now legacy, and I never liked it anyway. Though let's add it here
+-- for the sake of backwards compatibility.
 function enhance_response(text, response_type, path, token)
-  local result = text
-  local honeytoken = generate_honeytoken(token)
+  local enhanced = text
 
-  -- Add some fake sensitive data
-  result = result .. "\n<!-- DEBUG: " .. honeytoken .. " -->"
-  result = result .. "\n<div style='display:none'>Server ID: " .. token .. "</div>"
+  -- Add token as a comment
+  if response_type == "php_exploit" then
+    enhanced = enhanced .. "\n/* Token: " .. token .. " */\n"
+  elseif response_type == "wordpress" then
+    enhanced = enhanced .. "\n<!-- WordPress Debug Token: " .. token .. " -->\n"
+  elseif response_type == "api" then
+    enhanced = enhanced:gsub('"status": "[^"]+"', '"status": "warning"')
+    enhanced = enhanced:gsub('"message": "[^"]+"', '"message": "API token: ' .. token .. '"')
+  else
+    enhanced = enhanced .. "\n<!-- Debug token: " .. token .. " -->\n"
+  end
 
-  return result
+  return enhanced
 end