nginx授权下载，主要实现ipa和apk授权下载

download_access.lua

local require = require
local ngx = ngx
local ngx_re = require "ngx.re"
local re_find = ngx.re.find
local key = "自定义key"
local uri = ngx.var.uri

local realFile, sign, ts

if re_find(uri, [[^/[A-Za-z0-9_]+.ipa/[a-z0-9]+/[0-9]+$]], "joi") then
    local res, err = ngx_re.split(uri, "/")
    realFile = res[2]
    sign = res[3]
    ts = res[4]
else
    local args, err = ngx.req.get_uri_args()
    if err == "truncated" then
        ngx.log(ngx.ALERT, "args truncated")
        ngx.exit(444)
    end

    sign = args.sign
    ts = args.ts
end

if not sign or not ts then
    ngx.log(ngx.ALERT, "args incomplete")
    ngx.exit(444)
end

if not re_find(ts, [[^[0-9]+$]], "jo") then
    ngx.log(ngx.ALERT, "time type incorrect")
    ngx.exit(444)
end

local diffTime = tonumber(ts) - tonumber(ngx.time())
if diffTime > 300 or diffTime < -300 then
    ngx.log(ngx.ALERT, "time expired")
    ngx.exit(444)
end

local ngx_sign = ngx.md5(ts .. "#test#" .. key)
if ngx_sign == sign then
    if realFile then
        local ipa_url = "/" .. realFile .. "?sign=" .. sign .. "&ts=" .. ts
        ngx.exec(ipa_url)
    end

    return
else
    ngx.log(ngx.ALERT, "sign incorrect")
    ngx.exit(444)
end