From 2cc04f2be3379bfa9076672aaf496d29b8e4c7b8 Mon Sep 17 00:00:00 2001
From: Wang Zhi <yfwz100@yeah.net>
Date: Fri, 25 Aug 2023 18:19:59 +0800
Subject: [PATCH] feat: add TLS utility.

---
 pkg/tls/tls.go | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 pkg/tls/tls.go

diff --git a/pkg/tls/tls.go b/pkg/tls/tls.go
new file mode 100644
index 000000000..66d3a0e2b
--- /dev/null
+++ b/pkg/tls/tls.go
@@ -0,0 +1,71 @@
+package tls
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"os"
+
+	"github.com/OpenIMSDK/Open-IM-Server/pkg/common/config"
+)
+
+
+func decryptPEM(data []byte, passphrase []byte) ([]byte, error) {
+	if len(passphrase) == 0 {
+		return data, nil
+	}
+	b, _ := pem.Decode(data)
+	d, err := x509.DecryptPEMBlock(b, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	return pem.EncodeToMemory(&pem.Block{
+		Type:  b.Type,
+		Bytes: d,
+	}), nil
+}
+
+func readEncryptablePEMBlock(path string, pwd []byte) ([]byte, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	return decryptPEM(data, pwd)
+}
+
+// NewTLSConfig setup the TLS config from general config file.
+func NewTLSConfig(clientCertFile, clientKeyFile, caCertFile string, keyPwd []byte) *tls.Config {
+	tlsConfig := tls.Config{}
+
+	if clientCertFile != "" && clientKeyFile != "" {
+		certPEMBlock, err := os.ReadFile(clientCertFile)
+		if err != nil {
+			panic(err)
+		}
+		keyPEMBlock, err := readEncryptablePEMBlock(clientKeyFile, keyPwd)
+		if err != nil {
+			panic(err)
+		}
+		cert, err := tls.X509KeyPair(certPEMBlock, keyPEMBlock)
+		if err != nil {
+			panic(err)
+		}
+		tlsConfig.Certificates = []tls.Certificate{cert}
+	}
+
+	caCert, err := os.ReadFile(caCertFile)
+	if err != nil {
+		panic(err)
+	}
+	caCertPool := x509.NewCertPool()
+	ok := caCertPool.AppendCertsFromPEM(caCert)
+	if !ok {
+		panic(errors.New("not a valid CA cert"))
+	}
+	tlsConfig.RootCAs = caCertPool
+
+	tlsConfig.InsecureSkipVerify = config.Config.Kafka.TLS.InsecureSkipVerify
+
+	return &tlsConfig
+}