添加企业微信会话存档SDK (#419)

* 添加企业微信会话存档SDK

* 更新说明文档

* 更新包名为msgaudit并更新说明文档

* 迁移会话存档SDK到work目录下

* 移动RSA文件到util并添加动态库文件

* 整合企业微信和会话存档配置文件

* 修复golangcli-lint提示中的错误

* 对整个项目进行gofmt

* 更新会话存档说明文档

* 会话存档消息获取是抛出error

* 更新会话存档说明文档

Co-authored-by: Afeyer <afeyer@h5base.cn>

util/rsa.go

@@ -0,0 +1,43 @@
+package util
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/pem"
+	"errors"
+	"fmt"
+)
+
+// RSADecrypt 数据解密
+func RSADecrypt(privateKey string, ciphertext []byte) ([]byte, error) {
+	block, _ := pem.Decode([]byte(privateKey))
+	if block == nil {
+		return nil, errors.New("PrivateKey format error")
+	}
+	priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
+	if err != nil {
+		oldErr := err
+		key, err := x509.ParsePKCS8PrivateKey(block.Bytes)
+		if err != nil {
+			return nil, fmt.Errorf("ParsePKCS1PrivateKey error: %s, ParsePKCS8PrivateKey error: %s", oldErr.Error(), err.Error())
+		}
+		switch t := key.(type) {
+		case *rsa.PrivateKey:
+			priv = key.(*rsa.PrivateKey)
+		default:
+			return nil, fmt.Errorf("ParsePKCS1PrivateKey error: %s, ParsePKCS8PrivateKey error: Not supported privatekey format, should be *rsa.PrivateKey, got %T", oldErr.Error(), t)
+		}
+	}
+	return rsa.DecryptPKCS1v15(rand.Reader, priv, ciphertext)
+}
+
+// RSADecryptBase64 Base64解码后再次进行RSA解密
+func RSADecryptBase64(privateKey string, cryptoText string) ([]byte, error) {
+	encryptedData, err := base64.StdEncoding.DecodeString(cryptoText)
+	if err != nil {
+		return nil, err
+	}
+	return RSADecrypt(privateKey, encryptedData)
+}