三方快捷审批回调

# 未加密（该代码为示例代码，企业须填写企业对应信息）
curl --location --request POST 'https://www.feishu.cn/approval/openapi/v2/external/instanceOperate' \
--header 'Content-Type: application/json' \
--data-raw '{
  "action_type": "APPROVE",
  "action_context": "12345",
  "user_id": "b85s39b",
  "approval_code": "A3895051-9B16-4ABA-B785-AD2986177BB1",
  "instance_id": "people_1234",
  "task_id": "step1",
  "reason": "ok",
  "attachments": [
      {
          "file_type": "IMAGE",
          "file_name": "1.png",
          "file_size": 12345,
          "url": "https://sf3-cn.feishucdn.com/obj/lark-approval-attachment/image/20200512/413342ae-957f-4c6f-8d06-7dea05875d8b"
      }
  ],
  "token": "aaaaa"
}'

# 加密
curl --location --request POST 'https://www.feishu.cn/approval/openapi/v2/external/instanceOperate' \
--header 'Content-Type: application/json' \
--data-raw '{
    "encrypt": "=sfasdfasfsdafasfaf="
}'
# 解密 示例代码

package decrypt

import (
   "crypto/aes"
   "crypto/cipher"
   "crypto/rand"
   "crypto/sha256"
   "encoding/base64"
   "fmt"
   "io"
)

func CBCDecrypter(decryptContent string, keyStr string) ([]byte, error) {
   buf, err := base64.StdEncoding.DecodeString(decryptContent)
   if err != nil {
      return nil, err
   }
   key := sha256.Sum256([]byte(keyStr))
   if len(buf)%aes.BlockSize != 0 {
      return nil, fmt.Errorf("plaintext is not a multiple of the block size")
   }
   block, err := aes.NewCipher(key[:sha256.Size])
   if err != nil {
      return nil, err
   }
   ciphertext := make([]byte, aes.BlockSize+len(buf))
   iv := ciphertext[:aes.BlockSize]
   if _, err := io.ReadFull(rand.Reader, iv); err != nil {
      return nil, err
   }
   mode := cipher.NewCBCDecrypter(block, iv)
   mode.CryptBlocks(ciphertext[aes.BlockSize:], buf)
   ciphertext = ciphertext[32:]

   plain := standardizeDataDe(ciphertext)
   return plain, nil
}

func standardizeDataDe(origData []byte) []byte {
   length := len(origData)
   unpadding := int(origData[length-1])
   if unpadding > length {
      return nil
   }
   return origData[:(length - unpadding)]
}