func getAKFromLocalFile()

in util/token.go [104:149]
42 lines of code
10 McCabe index (conditional complexity)

func getAKFromLocalFile(configFilePath string) (accessKeyID, accessKeySecret, securityToken string, expireTime time.Time, err error) {
	if _, err = os.Stat(configFilePath); err == nil {
		var akInfo AKInfo
		//获取token config json
		encodeTokenCfg, err := ioutil.ReadFile(configFilePath)
		if err != nil {
			return accessKeyID, accessKeySecret, securityToken, expireTime, err
		}
		err = json.Unmarshal(encodeTokenCfg, &akInfo)
		if err != nil {
			return accessKeyID, accessKeySecret, securityToken, expireTime, err
		}
		keyring := akInfo.Keyring
		ak, err := decrypt(akInfo.AccessKeyId, []byte(keyring))
		if err != nil {
			return accessKeyID, accessKeySecret, securityToken, expireTime, err
		}

		sk, err := decrypt(akInfo.AccessKeySecret, []byte(keyring))
		if err != nil {
			return accessKeyID, accessKeySecret, securityToken, expireTime, err
		}

		token, err := decrypt(akInfo.SecurityToken, []byte(keyring))
		if err != nil {
			return accessKeyID, accessKeySecret, securityToken, expireTime, err
		}
		layout := "2006-01-02T15:04:05Z"
		t, err := time.Parse(layout, akInfo.Expiration)
		if err != nil {
			return accessKeyID, accessKeySecret, securityToken, expireTime, err
		}
		if t.Before(time.Now()) {
			err = errors.New("invalid token which is expired")
		}
		akInfo.AccessKeyId = string(ak)
		akInfo.AccessKeySecret = string(sk)
		akInfo.SecurityToken = string(token)

		if err != nil {
			return accessKeyID, accessKeySecret, securityToken, expireTime, err
		}
		return akInfo.AccessKeyId, akInfo.AccessKeySecret, akInfo.SecurityToken, t, nil
	}
	return accessKeyID, accessKeySecret, securityToken, expireTime, errNoFile
}