users.go

package wechat3rd

import (
	"crypto/aes"
	"crypto/cipher"
	"encoding/base64"
	"errors"
	"github.com/l306287405/wechat3rd/core"
	"net/url"
)

type Jscode2sessionResp struct {
	core.Error
	Openid     string `json:"openid,omitempty"`
	SessionKey string `json:"session_key,omitempty"`
    Unionid    string `json:"unionid,omitempty"`
}

func (s *Server) Jscode2session(appId, jsCode string) (resp *Jscode2sessionResp) {
	var (
		req   = make(url.Values)
		u     = "https://api.weixin.qq.com/sns/component/jscode2session?"
		token string
		err   error
	)
	resp = &Jscode2sessionResp{}
	token, err = s.Token()
	if err != nil {
		resp.Err(err)
		return
	}
	req.Set("appid", appId)
	req.Set("js_code", jsCode)
	req.Set("grant_type", "authorization_code")
	req.Set("component_appid", s.cfg.AppID)
	req.Set("component_access_token", token)

	resp.Err(core.GetRequest(u, req, resp))
	return
}

// 解密用户信息
func (s *Server) AESCBCDecrypt(encryptData, key, iv string) (data []byte, err error) {
	var (
		encBytes, keyBytes, ivBytes []byte
		block                       cipher.Block
		mode                        cipher.BlockMode
	)
	encBytes, err = base64.StdEncoding.DecodeString(encryptData)
	if err != nil {
		return
	}
	keyBytes, err = base64.StdEncoding.DecodeString(key)
	if err != nil {
		return
	}
	ivBytes, err = base64.StdEncoding.DecodeString(iv)
	if err != nil {
		return
	}

	block, err = aes.NewCipher(keyBytes)
	if err != nil {
		return
	}
	if len(encBytes) < block.BlockSize() {
		err = errors.New("ciphertext too short")
		return
	}
	if len(encBytes)%block.BlockSize() != 0 {
		err = errors.New("ciphertext is not a multiple of the block size")
		return
	}
	mode = cipher.NewCBCDecrypter(block, ivBytes)
	mode.CryptBlocks(encBytes, encBytes)
	// 解填充
	encBytes = pkcs7UnPadding(encBytes)
	return encBytes, nil
}

//去除填充
func pkcs7UnPadding(origData []byte) []byte {
	length := len(origData)
	unpadding := int(origData[length-1])
	return origData[:(length - unpadding)]
}