Name

lua-resty-otp - Lua OTP lib for OpenResty

Table of Contents

• Name
• Status
• Usage
  • Calculate OTP token
  • Generate QR Code
  • Verify OTP
• Bugs and Patches

Status

This library is already usable though still highly experimental.

The Lua API is still in flux and may change in the near future without notice.

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Usage

Calculate OTP token

local lib_otp = require ("resty.otp")
local TOTP = lib_otp.totp_init("JBSWY3DPEHPK3PXP")
-- UTC format of date `20200101 00:00:00` -> 946656000
-- use `ngx.time()` instead of `946656000` in prod env
ngx.say("TOTP_Token -> ", TOTP:calc_token(946656000))

Output

458138

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Generate QR Code

local lib_otp = require ("resty.otp")
local TOTP = lib_otp.totp_init("JBSWY3DPEHPK3PXP")
local url = TOTP:get_qr_url('OpenResty-TOTP', 'hello@example.com')
local html = [[
<img src='%s' />
]]

html = string.format(html, url)
ngx.header['Content-Type'] = 'text/html'
ngx.say(html)

Output

Scan the QR Code with Google Authenticator

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Verify OTP

local lib_otp = require ("resty.otp")
local TOTP = lib_otp.totp_init("JBSWY3DPEHPK3PXP")
local token = ngx.var.arg_otp
ngx.say("Verify Token : ", TOTP:verify_token(token))

Use OTP from Google Authenticator

curl localhost/check?otp=734923

Output

Verify Token : true

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Bugs and Patches

Please report bugs or submit patches by

1. Creating a ticket on the GitHub Issue Tracker.

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