mirror of
https://github.com/openappsec/attachment.git
synced 2025-12-31 13:49:09 +03:00
362 lines
14 KiB
Lua
Executable File
362 lines
14 KiB
Lua
Executable File
local module_name = ...
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local prefix = module_name:match("^(.-)handler$")
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local nano = require(prefix .. "nano_ffi")
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local kong = kong
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local NanoHandler = {}
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NanoHandler.PRIORITY = 3000
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NanoHandler.VERSION = "1.0.0"
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NanoHandler.sessions = {}
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NanoHandler.processed_requests = {}
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function NanoHandler.init_worker()
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nano.init_attachment()
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end
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function NanoHandler.access(conf)
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-- Skip inspection for health checks and internal requests
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local path = kong.request.get_path()
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local user_agent = kong.request.get_header("User-Agent") or ""
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local method = kong.request.get_method()
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-- Bypass health checks, status endpoints, and internal monitoring
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if path == "/status" or
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path == "/health" or
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path:match("^/metrics") or
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path:match("^/_health") or
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path:match("^/kong") or -- Kong admin API paths
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user_agent:match("kube%-probe") or
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user_agent:match("Prometheus") or
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user_agent:match("Go%-http%-client") or -- Common health checker
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(method == "GET" and path == "/") then -- Root path health checks
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kong.log.debug("Bypassing inspection for internal request: ", method, " ", path, " (UA: ", user_agent, ")")
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kong.ctx.plugin.bypass_inspection = true
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return
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end
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local headers = kong.request.get_headers()
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local session_id = nano.generate_session_id()
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kong.service.request.set_header("x-session-id", tostring(session_id))
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if NanoHandler.processed_requests[session_id] then
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kong.ctx.plugin.blocked = true
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return
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end
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local session_data = nano.init_session(session_id)
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if not session_data then
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kong.log.err("Failed to initialize session - failing open")
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return
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end
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kong.ctx.plugin.session_data = session_data
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kong.ctx.plugin.session_id = session_id
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local meta_data = nano.handle_start_transaction()
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if not meta_data then
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kong.log.err("Failed to handle start transaction - failing open")
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return
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end
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local req_headers = nano.handleHeaders(headers)
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if not req_headers then
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kong.log.err("Failed to handle request headers - failing open")
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return
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end
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local has_content_length = tonumber(ngx.var.http_content_length) and tonumber(ngx.var.http_content_length) > 0
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local contains_body = has_content_length and 1 or 0
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local verdict, response = nano.send_data(session_id, session_data, meta_data, req_headers, contains_body, nano.HttpChunkType.HTTP_REQUEST_FILTER)
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if verdict == nano.AttachmentVerdict.DROP then
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return result
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end
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if contains_body == 1 then
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local body = kong.request.get_raw_body()
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if body and #body > 0 then
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verdict, response = nano.send_body(session_id, session_data, body, nano.HttpChunkType.HTTP_REQUEST_BODY)
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if verdict == nano.AttachmentVerdict.DROP then
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return result
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end
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else
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kong.log.debug("Request body not in memory, attempting to read from buffer/file")
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local body_data = ngx.var.request_body
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if body_data and #body_data > 0 then
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kong.log.debug("Found request body in nginx var, size: ", #body_data)
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verdict, response = nano.send_body(session_id, session_data, body_data, nano.HttpChunkType.HTTP_REQUEST_BODY)
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if verdict == nano.AttachmentVerdict.DROP then
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return result
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end
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else
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local body_file = ngx.var.request_body_file
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if body_file then
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kong.log.debug("Reading request body from file: ", body_file)
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local file = io.open(body_file, "rb")
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if file then
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local entire_body = file:read("*all")
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file:close()
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if not entire_body then
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kong.log.err("Failed to read body file: ", body_file)
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elseif entire_body and #entire_body > 0 then
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kong.log.debug("Sending entire body of size ", #entire_body, " bytes to C module")
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verdict, response = nano.send_body(session_id, session_data, entire_body, nano.HttpChunkType.HTTP_REQUEST_BODY)
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if verdict == nano.AttachmentVerdict.DROP then
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return result
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end
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else
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kong.log.debug("Empty body file")
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end
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end
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else
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kong.log.debug("Request body expected but no body data or file available")
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end
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end
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end
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local verdict, response = nano.AttachmentVerdict.INSPECT, nil
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local ok, pcall_verdict, pcall_response = pcall(function()
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return nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_REQUEST_END)
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end)
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if not ok then
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kong.log.err("Error ending request inspection: ", pcall_verdict, " - failing open")
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return
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end
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verdict, response = pcall_verdict, pcall_response
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if verdict == nano.AttachmentVerdict.DROP then
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return result
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end
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else
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verdict, response = nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_REQUEST_END)
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if verdict == nano.AttachmentVerdict.DROP then
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return result
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end
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end
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NanoHandler.processed_requests[session_id] = true
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end
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function NanoHandler.header_filter(conf)
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local ctx = kong.ctx.plugin
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if ctx.blocked or ctx.bypass_inspection then
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return
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end
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local session_id = ctx.session_id
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local session_data = ctx.session_data
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if not session_id or not session_data then
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kong.log.err("No session data found in header_filter")
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return
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end
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local headers = kong.response.get_headers()
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local header_data = nano.handleHeaders(headers)
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if not header_data then
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kong.log.err("Failed to handle response headers - failing open")
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return
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end
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local status_code = kong.response.get_status()
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local content_length = tonumber(headers["content-length"]) or 0
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local verdict, response = nano.send_response_headers(session_id, session_data, header_data, status_code, content_length)
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if verdict == nano.AttachmentVerdict.DROP then
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kong.ctx.plugin.blocked = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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kong.ctx.plugin.session_data = nil
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kong.ctx.plugin.session_id = nil
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return result
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end
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ctx.expect_body = not (status_code == 204 or status_code == 304 or (100 <= status_code and status_code < 200) or content_length == 0)
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end
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function NanoHandler.body_filter(conf)
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local chunk = ngx.arg[1]
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local eof = ngx.arg[2]
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local ctx = kong.ctx.plugin
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if ctx.blocked or ctx.bypass_inspection then
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return
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end
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local session_id = ctx.session_id
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local session_data = ctx.session_data
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if not session_id or not session_data or ctx.session_finalized then
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return
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end
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if not ctx.body_filter_start_time then
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ctx.body_filter_start_time = ngx.now()
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end
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local elapsed_time = ngx.now() - ctx.body_filter_start_time
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if elapsed_time > 150 then
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kong.log.warn("Body filter timeout after ", elapsed_time, " seconds - failing open")
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local verdict, response, modifications = nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_RESPONSE_END)
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if modifications then
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chunk = nano.handle_body_modifications(chunk, modifications, ctx.body_buffer_chunk or 0)
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ngx.arg[1] = chunk
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end
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if verdict == nano.AttachmentVerdict.DROP then
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ctx.blocked = true
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ctx.session_finalized = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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ctx.session_data = nil
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ctx.session_id = nil
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ngx.arg[1] = ""
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ngx.arg[2] = true
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return result
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end
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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ctx.session_finalized = true
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ctx.session_data = nil
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ctx.session_id = nil
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return
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end
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if chunk and #chunk > 0 then
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ctx.body_buffer_chunk = ctx.body_buffer_chunk or 0
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ctx.body_seen = true
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local verdict, response, modifications = nano.send_body(session_id, session_data, chunk, nano.HttpChunkType.HTTP_RESPONSE_BODY)
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if modifications then
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chunk = nano.handle_body_modifications(chunk, modifications, ctx.body_buffer_chunk)
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ngx.arg[1] = chunk
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end
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ctx.body_buffer_chunk = ctx.body_buffer_chunk + 1
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if verdict == nano.AttachmentVerdict.DROP then
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ctx.blocked = true
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ctx.session_finalized = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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ctx.session_data = nil
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ctx.session_id = nil
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ngx.arg[1] = ""
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ngx.arg[2] = true
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return result
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end
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nano.free_all_responses()
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nano.free_all_nano_str()
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end
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if eof then
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if ctx.body_seen or ctx.expect_body == false then
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local verdict, response = nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_RESPONSE_END)
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if verdict == nano.AttachmentVerdict.DROP then
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ctx.blocked = true
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ctx.session_finalized = true
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local result = nano.handle_custom_response(session_data, response)
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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ctx.session_data = nil
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ctx.session_id = nil
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ngx.arg[1] = ""
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ngx.arg[2] = true
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return result
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end
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nano.fini_session(session_data)
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nano.cleanup_all()
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collectgarbage("restart")
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collectgarbage("collect")
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ctx.session_finalized = true
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ctx.session_data = nil
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ctx.session_id = nil
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end
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end
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end
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return NanoHandler |