mirror of
https://github.com/openappsec/attachment.git
synced 2025-12-31 05:39:07 +03:00
380 lines
16 KiB
Lua
Executable File
380 lines
16 KiB
Lua
Executable File
local module_name = ...
|
|
local prefix = module_name:match("^(.-)handler$")
|
|
local nano = require(prefix .. "nano_ffi")
|
|
local kong = kong
|
|
|
|
local NanoHandler = {}
|
|
|
|
NanoHandler.PRIORITY = 3000
|
|
NanoHandler.VERSION = "1.0.0"
|
|
|
|
function NanoHandler.init_worker()
|
|
nano.init_attachment()
|
|
end
|
|
|
|
function NanoHandler.access(conf)
|
|
local ctx = kong.ctx.plugin
|
|
|
|
local headers = kong.request.get_headers()
|
|
local session_id = nano.generate_session_id()
|
|
kong.service.request.set_header("x-session-id", tostring(session_id))
|
|
|
|
local session_data = nano.init_session(session_id)
|
|
if not session_data then
|
|
kong.ctx.plugin.cleanup_needed = false
|
|
return
|
|
end
|
|
|
|
ctx.session_data = session_data
|
|
ctx.session_id = session_id
|
|
if nano.is_session_finalized(session_id) then
|
|
kong.log.info("Session has already been inspected, no need for further inspection")
|
|
return
|
|
end
|
|
|
|
local meta_data = nano.handle_start_transaction()
|
|
if not meta_data then
|
|
kong.log.err("Failed to handle start transaction - failing open")
|
|
ctx.cleanup_needed = true
|
|
return
|
|
end
|
|
|
|
local req_headers = nano.handleHeaders(headers)
|
|
if not req_headers then
|
|
kong.log.err("Failed to handle request headers - failing open")
|
|
ctx.cleanup_needed = true
|
|
return
|
|
end
|
|
|
|
local has_content_length = tonumber(ngx.var.http_content_length) and tonumber(ngx.var.http_content_length) > 0
|
|
local contains_body = has_content_length and 1 or 0
|
|
|
|
local verdict, response = nano.send_data(session_id, session_data, meta_data, req_headers, contains_body, nano.HttpChunkType.HTTP_REQUEST_FILTER)
|
|
if verdict ~= nano.AttachmentVerdict.INSPECT then
|
|
ctx.cleanup_needed = true
|
|
if verdict == nano.AttachmentVerdict.DROP then
|
|
return nano.handle_custom_response(session_data, response)
|
|
end
|
|
return
|
|
end
|
|
|
|
if contains_body == 1 then
|
|
local body = kong.request.get_raw_body()
|
|
if body and #body > 0 then
|
|
verdict, response = nano.send_body(session_id, session_data, body, nano.HttpChunkType.HTTP_REQUEST_BODY)
|
|
if verdict ~= nano.AttachmentVerdict.INSPECT then
|
|
ctx.cleanup_needed = true
|
|
if verdict == nano.AttachmentVerdict.DROP then
|
|
return nano.handle_custom_response(session_data, response)
|
|
end
|
|
return
|
|
end
|
|
else
|
|
local body_data = ngx.var.request_body
|
|
if body_data and #body_data > 0 then
|
|
kong.log.debug("Found request body in nginx var, size: ", #body_data)
|
|
verdict, response = nano.send_body(session_id, session_data, body_data, nano.HttpChunkType.HTTP_REQUEST_BODY)
|
|
if verdict ~= nano.AttachmentVerdict.INSPECT then
|
|
ctx.cleanup_needed = true
|
|
if verdict == nano.AttachmentVerdict.DROP then
|
|
return nano.handle_custom_response(session_data, response)
|
|
end
|
|
return
|
|
end
|
|
else
|
|
local body_file = ngx.var.request_body_file
|
|
if body_file then
|
|
local file = io.open(body_file, "rb")
|
|
if file then
|
|
local chunk_size = 8192
|
|
local chunk_count = 0
|
|
local start_time = ngx.now()
|
|
local timeout_sec = nano.get_request_processing_timeout_sec()
|
|
kong.log.err("Request body reading timeout set to ", timeout_sec, " seconds")
|
|
|
|
while true do
|
|
ngx.update_time()
|
|
local current_time = ngx.now()
|
|
local elapsed = current_time - start_time
|
|
|
|
if elapsed > timeout_sec then
|
|
kong.log.warn("Request body reading timeout after ", elapsed, " seconds")
|
|
file:close()
|
|
return
|
|
end
|
|
|
|
local chunk = file:read(chunk_size)
|
|
if not chunk or #chunk == 0 then
|
|
kong.log.err("End of request body file reached")
|
|
break
|
|
end
|
|
|
|
chunk_count = chunk_count + 1
|
|
kong.log.debug("Sending request body chunk ", chunk_count, " of size ", #chunk, " bytes to C module")
|
|
verdict, response = nano.send_body(session_id, session_data, chunk, nano.HttpChunkType.HTTP_REQUEST_BODY)
|
|
|
|
if verdict ~= nano.AttachmentVerdict.INSPECT then
|
|
file:close()
|
|
ctx.cleanup_needed = true
|
|
if verdict == nano.AttachmentVerdict.DROP then
|
|
return nano.handle_custom_response(session_data, response)
|
|
end
|
|
return
|
|
end
|
|
end
|
|
file:close()
|
|
kong.log.debug("Sent ", chunk_count, " chunks from request body file")
|
|
end
|
|
else
|
|
kong.log.err("Request body expected but no body data or file available")
|
|
end
|
|
end
|
|
end
|
|
|
|
local ok, verdict, response = pcall(function()
|
|
return nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_REQUEST_END)
|
|
end)
|
|
|
|
kong.log.err("Error ending request inspection: ", verdict, " - failing open")
|
|
if not ok then
|
|
ctx.cleanup_needed = true
|
|
return
|
|
end
|
|
|
|
if verdict ~= nano.AttachmentVerdict.INSPECT then
|
|
ctx.cleanup_needed = true
|
|
if verdict == nano.AttachmentVerdict.DROP then
|
|
return nano.handle_custom_response(session_data, response)
|
|
end
|
|
return
|
|
end
|
|
end
|
|
end
|
|
|
|
function NanoHandler.header_filter(conf)
|
|
local ctx = kong.ctx.plugin
|
|
if nano.is_session_finalized(ctx.session_data) then
|
|
kong.log.err("Session has already been inspected, no need for further inspection")
|
|
return
|
|
end
|
|
|
|
if ctx.cleanup_needed then
|
|
kong.log.err("cleanup in header_filter, passing through")
|
|
return
|
|
end
|
|
kong.log.err("header_filter phase started")
|
|
|
|
local session_id = ctx.session_id
|
|
local session_data = ctx.session_data
|
|
|
|
local headers = kong.response.get_headers()
|
|
local header_data = nano.handleHeaders(headers)
|
|
|
|
if not header_data then
|
|
kong.log.err("Failed to handle response headers - failing open")
|
|
ctx.cleanup_needed = true
|
|
return
|
|
end
|
|
|
|
local status_code = kong.response.get_status()
|
|
local content_length = tonumber(headers["content-length"]) or 0
|
|
|
|
local verdict, response = nano.send_response_headers(session_id, session_data, header_data, status_code, content_length)
|
|
if verdict ~= nano.AttachmentVerdict.INSPECT then
|
|
ctx.cleanup_needed = true
|
|
if verdict == nano.AttachmentVerdict.DROP then
|
|
kong.log.warn("DROP verdict in header_filter - will replace response in body_filter")
|
|
ctx.blocked = true
|
|
ctx.block_response = response
|
|
end
|
|
return
|
|
end
|
|
|
|
-- Clear Content-Length since we're buffering the response
|
|
kong.log.err("Clearing Content-Length header to enable response body buffering, current value: ", tostring(content_length))
|
|
|
|
ctx.expect_body = not (status_code == 204 or status_code == 304 or (100 <= status_code and status_code < 200) or content_length == 0)
|
|
end
|
|
|
|
function NanoHandler.body_filter(conf)
|
|
kong.log.err("Entering body_filter phase")
|
|
local ctx = kong.ctx.plugin
|
|
local chunk = ngx.arg[1]
|
|
local eof = ngx.arg[2]
|
|
|
|
|
|
local session_id = ctx.session_id
|
|
local session_data = ctx.session_data
|
|
|
|
if ctx.blocked then
|
|
kong.log.err("Sending custom block response in body_filter")
|
|
if ctx.block_response then
|
|
kong.log.err("Block response data available, preparing custom response")
|
|
local code, body, headers = nano.get_custom_response_data(session_data, ctx.block_response)
|
|
kong.log.info("Replacing response with custom response, code: ", code)
|
|
ngx.status = code
|
|
|
|
for header_name, header_value in pairs(headers) do
|
|
ngx.header[header_name] = header_value
|
|
end
|
|
|
|
if body and #body > 0 then
|
|
ngx.header["Content-Length"] = #body
|
|
ngx.arg[1] = body
|
|
else
|
|
ngx.header["Content-Length"] = 0
|
|
ngx.arg[1] = ""
|
|
end
|
|
else
|
|
kong.log.err("Missing session_data or block_response, sending empty response")
|
|
ngx.status = 403
|
|
ngx.arg[1] = ""
|
|
end
|
|
ngx.arg[2] = true
|
|
ctx.cleanup_needed = true
|
|
return
|
|
end
|
|
|
|
if nano.is_session_finalized(session_data) then
|
|
kong.log.err("Session has already been inspected, no need for further inspection")
|
|
return
|
|
end
|
|
|
|
if ctx.cleanup_needed then
|
|
kong.log.err("cleanup chunk without inspection, passing through")
|
|
return
|
|
end
|
|
|
|
if not ctx.body_filter_start_time then
|
|
ctx.body_filter_start_time = ngx.now()
|
|
ctx.body_filter_timeout_sec = nano.get_response_processing_timeout_sec()
|
|
kong.log.err("vody_filter timeout set to ", ctx.body_filter_timeout_sec, " seconds")
|
|
end
|
|
local elapsed_time = ngx.now() - ctx.body_filter_start_time
|
|
if elapsed_time > ctx.body_filter_timeout_sec then
|
|
kong.log.warn("Body filter timeout after ", elapsed_time, " seconds - failing open")
|
|
ctx.cleanup_needed = true
|
|
-- Send buffered chunks before timeout
|
|
if ctx.response_buffer and #ctx.response_buffer > 0 then
|
|
ngx.arg[1] = table.concat(ctx.response_buffer)
|
|
end
|
|
return
|
|
end
|
|
|
|
-- Initialize response buffer
|
|
if not ctx.response_buffer then
|
|
ctx.response_buffer = {}
|
|
end
|
|
|
|
if chunk and #chunk > 0 then
|
|
kong.log.err("Processing response body chunk of size ", #chunk, " bytes")
|
|
ctx.body_buffer_chunk = ctx.body_buffer_chunk or 0
|
|
ctx.body_seen = true
|
|
|
|
table.insert(ctx.response_buffer, chunk)
|
|
|
|
local verdict, response, modifications = nano.send_body(session_id, session_data, chunk, nano.HttpChunkType.HTTP_RESPONSE_BODY)
|
|
|
|
if modifications then
|
|
chunk = nano.handle_body_modifications(chunk, modifications, ctx.body_buffer_chunk)
|
|
-- Update buffered chunk with modifications
|
|
ctx.response_buffer[#ctx.response_buffer] = chunk
|
|
end
|
|
|
|
ctx.body_buffer_chunk = ctx.body_buffer_chunk + 1
|
|
|
|
if verdict ~= nano.AttachmentVerdict.INSPECT then
|
|
kong.log.err("Final verdict for response body chunk: ", verdict)
|
|
ctx.cleanup_needed = true
|
|
if verdict == nano.AttachmentVerdict.DROP then
|
|
kong.log.warn("DROP verdict in body_filter - replacing with custom response")
|
|
local code, body, headers = nano.get_custom_response_data(session_data, response)
|
|
ngx.status = code
|
|
for header_name, header_value in pairs(headers) do
|
|
ngx.header[header_name] = header_value
|
|
end
|
|
if body and #body > 0 then
|
|
ngx.header["Content-Length"] = #body
|
|
ngx.arg[1] = body
|
|
else
|
|
ngx.header["Content-Length"] = 0
|
|
ngx.arg[1] = ""
|
|
end
|
|
ngx.arg[2] = true
|
|
return
|
|
else
|
|
kong.log.err("ACCEPT verdict in body_filter - flushing buffer and switching to pass-through chucnk :" , ctx.body_buffer_chunk)
|
|
local buffered_data = table.concat(ctx.response_buffer)
|
|
kong.log.err("Flushing ", #ctx.response_buffer, " buffered chunks (", #buffered_data, " bytes) before switching to pass-through")
|
|
ngx.arg[1] = buffered_data
|
|
ctx.response_buffer = nil
|
|
return
|
|
end
|
|
end
|
|
kong.log.err("Response body chunk of size ", #chunk, " bytes inspected and passed")
|
|
-- Don't send chunk yet - hold it in buffer
|
|
ngx.arg[1] = ""
|
|
return
|
|
end
|
|
|
|
if eof then
|
|
kong.log.err("End of response body reached in body_filter, eof=true")
|
|
|
|
if ctx.body_seen or ctx.expect_body == false then
|
|
kong.log.err("Calling end_inspection for response")
|
|
local verdict, response = nano.end_inspection(session_id, session_data, nano.HttpChunkType.HTTP_RESPONSE_END)
|
|
if verdict ~= nano.AttachmentVerdict.INSPECT then
|
|
kong.log.debug("Final verdict after end_inspection: ", verdict)
|
|
ctx.cleanup_needed = true
|
|
if verdict == nano.AttachmentVerdict.DROP then
|
|
kong.log.warn("DROP verdict at EOF - replacing with custom response")
|
|
local code, body, headers = nano.get_custom_response_data(session_data, response)
|
|
ngx.status = code
|
|
for header_name, header_value in pairs(headers) do
|
|
ngx.header[header_name] = header_value
|
|
end
|
|
if body and #body > 0 then
|
|
ngx.header["Content-Length"] = #body
|
|
ngx.arg[1] = body
|
|
else
|
|
ngx.header["Content-Length"] = 0
|
|
ngx.arg[1] = ""
|
|
end
|
|
ngx.arg[2] = true
|
|
return
|
|
else
|
|
-- ACCEPT verdict at EOF
|
|
kong.log.err("ACCEPT verdict at EOF - will flush buffered response")
|
|
end
|
|
end
|
|
end
|
|
|
|
-- Send buffered response (for INSPECT or ACCEPT verdicts)
|
|
kong.log.err("Response fully inspected and passed - flushing buffered chunks , total buffered chunks: ", #ctx.response_buffer)
|
|
if ctx.response_buffer and #ctx.response_buffer > 0 then
|
|
local buffered_data = table.concat(ctx.response_buffer)
|
|
kong.log.err("Flushing ", #ctx.response_buffer, " buffered chunks, total size: ", #buffered_data, " bytes")
|
|
-- Set Content-Length for the buffered data
|
|
ngx.header["Content-Length"] = #buffered_data
|
|
ngx.arg[1] = buffered_data
|
|
else
|
|
kong.log.err("No buffered chunks to flush")
|
|
ngx.header["Content-Length"] = 0
|
|
end
|
|
ngx.arg[2] = true
|
|
ctx.cleanup_needed = true
|
|
end
|
|
end
|
|
|
|
function NanoHandler.log(conf)
|
|
local ctx = kong.ctx.plugin
|
|
if ctx.cleanup_needed then
|
|
nano.fini_session(ctx.session_data)
|
|
nano.cleanup_all()
|
|
ctx.session_data = nil
|
|
ctx.session_id = nil
|
|
collectgarbage("collect")
|
|
end
|
|
end
|
|
|
|
return NanoHandler |