GolangでNCMB用の署名文字列を生成する

main.go

package main

import (
  "time"
  "net/url"
  "strings"
  "sort"
  "encoding/json"
  "crypto/hmac"
  "crypto/sha256"
  "encoding/base64"
)

func main() {
  method := "GET"
  fqdn := "mbaas.api.nifcloud.com"
  path := "/2013-09-01/classes/TestClass"
  queries := make(map[string]map[string]string)
  queries["where"] = make(map[string]string)
  queries["where"]["testKey"] = "testValue"
  applicationKey := "6145f91061916580c742f806bab67649d10f45920246ff459404c46f00ff3e56"
  clientKey := "1343d198b510a0315db1c03f3aa0e32418b7a743f8e4b47cbff670601345cf75"
  signatureMethod := "HmacSHA256"
  signatureVersion := "2"
  timestamp := time.Date(2013, 12, 02, 02, 44, 35, 452e6, time.UTC)
  signature := sign(method, fqdn, path, queries, applicationKey, clientKey, signatureMethod, signatureVersion, timestamp)
  print(signature)
}

func sign(
  method string, fqdn string, path string, 
  queries map[string]map[string]string, applicationKey string,
  clientKey string, signatureMethod string, signatureVersion string, timestamp time.Time) string {
  // マップを作成
  arySig := make(map[string]string)
  // 基本的な項目の設定
  arySig["SignatureMethod"] = signatureMethod
  arySig["SignatureVersion"] = signatureVersion
  arySig["X-NCMB-Application-Key"] = applicationKey
  arySig["X-NCMB-Timestamp"] = timestamp.Format("2006-01-02T15:04:05.000Z")
  // クエリ文字列のエスケープ
  if (len(queries) > 0) {
    for key, params := range queries {
      j, _ := json.Marshal(params)
      arySig[key] = url.QueryEscape(string(j))
    }
  }
  // ソートするために配列に入れ替え
  ary := []string{}
  for val := range arySig {
	   ary = append(ary, val)
  }
  sort.Strings(ary)
  params := []string{}
  for _, name := range ary {
    params = append(params, name + "=" + arySig[name])
  }
  // シグネチャ用文字列の作成
  signature := []string{}
  signature = append(signature, method)
  signature = append(signature, fqdn)
  signature = append(signature, path)
  signature = append(signature, strings.Join(params, "&"))
  // ハッシュ値の作成
  mac := hmac.New(sha256.New, []byte(clientKey))
  mac.Write([]byte(strings.Join(signature, "\n")))
  // 署名文字列の返却
  return base64.StdEncoding.EncodeToString(mac.Sum(nil))
}