Display MJPEG stream in iframe with Reverse Proxy for auth

Code:
if not server then

    local http = require("socket.http")

    local ltn12 = require("ltn12")

    local url = require("socket.url")

    local md5 = require("encdec").md5 -- Using the md5 library for hash computation



    local port = 7673



    local urlMappings = {

        ["/path1"] = "http://nodejs.org", -- Replace with the target URL for path1 -- test proxy redirect

        ["/path5"] = "https://<NVR IP>/cgi-bin/mjpg/video.cgi?channel=3&subtype=1", -- Replace with the target URL for path5

       ["/path6"] = "https://<NVR IP>/cgi-bin/snapshot.cgi?channel=1", -- Replace with the target URL for path6

        -- Add more mappings as needed

    }



    -- Set up the login credentials for digest authentication

    local username = "user"

    local password = "password"



-- Function to generate the Digest authentication header with the correct nonce

local function generateDigestHeader(uri, method, realm, nonce, qop, opaque)

    local ha1 = md5(username .. ":" .. realm .. ":" .. password)

    local ha2 = md5(method .. ":" .. uri)

    local nc = "00000001"

    local cnonce = "0a4f113b"

    local response = md5(ha1 .. ":" .. nonce .. ":" .. nc .. ":" .. cnonce .. ":" .. qop .. ":" .. ha2)

    return string.format('Digest username="%s", realm="%s", nonce="%s", uri="%s", response="%s", nc=%s, cnonce="%s", qop="%s", opaque="%s"',

        username, realm, nonce, uri, response, nc, cnonce, qop, opaque)

end



    -- Function to handle incoming queries and perform digest authentication

    function handleQuery(query)

    local method, path, _ = query:match("(%u+)%s+([^%s]+)")

    path = path:gsub("?.*", "")



    local targetURL = urlMappings[path]



    if targetURL then

        -- Perform digest authentication before sending the response

        local response_body = {}

        local response_headers = {}

        local res, status_code, response_headers, status_string = http.request {

            url = targetURL,

            headers = {

                ["Accept"] = "*/*", -- Accept all content types

            },

            method = "HEAD",

            create = function()

                local conn = socket.tcp()

                conn:settimeout(5) -- Set a timeout for the initial connection

                return conn

            end,

            sink = ltn12.sink.table(response_body),

            headers = response_headers, -- Store the response headers in the table

        }



        if res and response_headers["www-authenticate"] then

            local realm = response_headers["www-authenticate"]:match('realm="(.-)"')

            local nonce = response_headers["www-authenticate"]:match('nonce="(.-)"')

            local qop = response_headers["www-authenticate"]:match('qop="(.-)"')

            local opaque = response_headers["www-authenticate"]:match('opaque="(.-)"')



            -- Perform the actual HTTPS request with digest authentication

            local auth_response_body = {}

            local auth_res, auth_status_code, auth_response_headers, auth_status_string = http.request {

                url = targetURL,

                headers = {

                    ["Authorization"] = generateDigestHeader(targetURL, "GET", realm, nonce, qop, opaque),

                    ["Accept"] = "*/*", -- Accept all content types

                },

                method = "GET",

                sink = ltn12.sink.table(auth_response_body),

                create = function()

                    local conn = socket.tcp()

                    conn:settimeout(10) -- Set a timeout for the actual request

                    return conn

                end,

            }

        log(auth_response_headers["content-type"])



            if auth_res and auth_status_code == 200 then

                -- Check if the response is an image (e.g., for snapshot requests)

                local content_type = auth_response_headers["content-type"] or ""

                local image_types = { ["image/jpeg"] = true, ["image/png"] = true, ["image/gif"] = true }



                if image_types[content_type] then

                    -- If it's an image, set the appropriate Content-Type header

                    local response = "HTTP/1.1 200 OK\r\nContent-Type: " .. content_type .. "\r\n\r\n" .. table.concat(auth_response_body)

                    log(query, "Success - Image")

                    return response

                else

                    -- For other types of responses, pass them through as they are

                    local response = "HTTP/1.1 200 OK\r\n\r\n" .. table.concat(auth_response_body)

                    log(query, "Success - Other")

                    return response

                end

            else

                -- If the request failed, log and return a 500 error response

                log(query, "Error: Digest authentication request failed with status code " .. auth_status_code)

                return "HTTP/1.1 500 Internal Server Error\r\n\r\n"

            end

        else

            -- If the initial connection failed or no digest headers were received, log and return a 500 error response

            log(query, "Error: Failed to establish a connection with the server or no digest headers received.")

            return "HTTP/1.1 500 Internal Server Error\r\n\r\n"

        end

    else

        return "HTTP/1.1 404 Not Found\r\n\r\n"

    end

end



    -- Create a server socket to listen for incoming queries

    local server = assert(socket.bind("*", port))

    log("Proxy server is listening on localhost:" .. port .. "\n")



    while true do

        local client = server:accept()

        local query = client:receive()



        local response = handleQuery(query)

        client:send(response)

        client:close()

    end

end