인증과 API 보안

API 보안이 중요한 이유

미들웨어로 사용하는 Plumber 필터

# library(plumber)
# pr <- plumb('api.R')
# pr |>
#   pr_filter('logger', function(req, res) {
#     cat(req$REQUEST_METHOD, req$PATH_INFO, '
')
#     plumber::forward()  # must call to continue
#   }) |>
#   pr_run(port = 8000)

API 키 인증 필터

# In api.R:
# VALID_KEY <- Sys.getenv('API_SECRET_KEY')
#
# #* @filter auth
# function(req, res) {
#   key <- req$HTTP_X_API_KEY
#   if (is.null(key) || key != VALID_KEY) {
#     res$status <- 401L
#     return(list(error = 'Unauthorized'))
#   }
#   plumber::forward()
# }

Authorization 헤더 확인

# #* @filter bearer_auth
# function(req, res) {
#   auth_header <- req$HTTP_AUTHORIZATION
#   if (is.null(auth_header) || !startsWith(auth_header, 'Bearer ')) {
#     res$status <- 401L
#     return(list(error = 'Bearer token required'))
#   }
#   token <- substring(auth_header, 8)  # strip 'Bearer '
#   if (!token_is_valid(token)) {
#     res$status <- 401L
#     return(list(error = 'Invalid token'))
#   }
#   plumber::forward()
# }

#* @preempt를 사용한 인증 건너뛰기

# #* Health check — no auth required
# #* @preempt auth
# #* @get /ping
# function() {
#   list(status = 'ok', time = as.character(Sys.time()))
# }
#
# #* Protected endpoint — goes through auth filter
# #* @get /data
# function() {
#   list(secret = 'sensitive data')
# }

pr_cors()를 사용한 CORS

# library(plumber)
# pr <- plumb('api.R')
# pr |>
#   pr_cors(
#     origin            = 'https://myapp.example.com',
#     methods           = c('GET', 'POST'),
#     headers           = c('Content-Type', 'X-API-Key'),
#     credentials       = TRUE
#   ) |>
#   pr_run(port = 8000)

입력 정제 — 사용자 입력을 절대 신뢰하지 마세요

# #* @post /search
# function(req, res) {
#   body <- jsonlite::fromJSON(req$postBody)
#   query <- body$query
#   if (!is.character(query) || nchar(query) > 200) {
#     res$status <- 400L
#     return(list(error = 'query must be a string <= 200 chars'))
#   }
#   if (grepl('[;\'"]', query)) {
#     res$status <- 400L
#     return(list(error = 'Invalid characters in query'))
#   }
#   list(results = search_db(query))
# }

요청 빈도 제한 개념

# request_log <- new.env()
#
# #* @filter rate_limit
# function(req, res) {
#   ip <- req$REMOTE_ADDR
#   now <- as.numeric(Sys.time())
#   if (!exists(ip, envir = request_log)) assign(ip, c(), envir = request_log)
#   times <- get(ip, envir = request_log)
#   times <- times[times > now - 60]   # last 60 seconds
#   if (length(times) >= 60) { res$status <- 429L; return(list(error='Too Many Requests')) }
#   assign(ip, c(times, now), envir = request_log)
#   plumber::forward()
# }

API 키를 안전하게 저장하기

# In .env (never commit this file):
# API_SECRET_KEY=my_super_secret_key_here
#
# In api.R:
# VALID_KEY <- Sys.getenv('API_SECRET_KEY', unset = '')
# if (nchar(VALID_KEY) == 0) stop('API_SECRET_KEY not set')
#
# Load .env locally (devtools::load_dot_env or Sys.setenv):
# readRenviron('.env')
cat('Sys.getenv reads API keys without exposing them in source
')

요청에 사용자 컨텍스트 연결하기

# #* @filter auth
# function(req, res) {
#   token <- req$HTTP_AUTHORIZATION
#   user <- validate_token(token)  # returns list(id=1, role='admin')
#   if (is.null(user)) { res$status <- 401L; return(list(error='Unauthorized')) }
#   req$user <- user   # attach to request
#   plumber::forward()
# }
#
# #* @get /profile
# function(req) {
#   list(user_id = req$user$id, role = req$user$role)
# }

tryCatch를 사용한 오류 처리

# #* @get /risky/<id:int>
# function(id, res) {
#   tryCatch({
#     result <- risky_db_call(id)
#     list(data = result)
#   }, error = function(e) {
#     message('Error in /risky: ', conditionMessage(e))
#     res$status <- 500L
#     list(error = 'Internal server error')
#   })
# }

빠른 확인: @preempt 주석

API 보안 복습