Add WithTLSConfig method to OracleConnector for injecting custom …

…`*tls.Config`. This allows easy programmatic control over TLS negotiation. Also, include an example demonstrating its usage.

examples/mtls/main.go

@@ -0,0 +1,141 @@
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"database/sql"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+
+	go_ora "github.com/sijms/go-ora/v2"
+)
+
+func databaseConn(addr, serviceName string, tlsConfig *tls.Config) error {
+	var driver go_ora.OracleDriver
+
+	dsn := fmt.Sprintf(`oracle://%s/%s?SSL=enabled&AUTH TYPE=TCPS`, addr, serviceName)
+	conn, err := driver.OpenConnector(dsn)
+	if err != nil {
+		return err
+	}
+	oc, ok := conn.(*go_ora.OracleConnector)
+	if !ok {
+		return fmt.Errorf("failed to cast to OracleConnector")
+	}
+	oc.WithTLSConfig(tlsConfig)
+
+	dbConn := sql.OpenDB(conn)
+
+	err = dbConn.Ping()
+	if err != nil {
+		return err
+	}
+
+	var queryResultColumnOne string
+	row := dbConn.QueryRow("SELECT systimestamp FROM dual")
+	err = row.Scan(&queryResultColumnOne)
+	if err != nil {
+		return err
+	}
+
+	fmt.Println("The time in the database:", queryResultColumnOne)
+
+	return nil
+}
+
+func printHelp() {
+	helpMessage := `
+Usage: go run ./examples/mtls [OPTIONS]
+
+Options:
+  -addr string
+        Database address (e.g., localhost:2484) (required)
+  -service string
+        Database service name (required)
+  -cert string
+        Path to the user certificate (e.g., alice.crt) (required)
+  -key string
+        Path to the user key (e.g., alice.key) (required)
+  -server-ca-cert string
+        Path to the server CA certificate file (optional)
+  -insecure
+        Skip TLS certificate verification (default: false)
+  -help
+        Display help information
+`
+	fmt.Print(helpMessage)
+}
+
+func main() {
+	addr := flag.String("addr", "", "Database address (e.g., localhost:2484)")
+	serviceName := flag.String("service", "", "Database service name")
+	certFile := flag.String("cert", "", "Path to the user certificate (e.g., alice.crt)")
+	keyFile := flag.String("key", "", "Path to the user key (e.g., alice.key)")
+	serverCaCertFile := flag.String("server-ca-cert", "", "Path to the server CA certificate file (optional)")
+	insecureSkipVerify := flag.Bool("insecure", false, "Skip TLS certificate verification (default: false)")
+	help := flag.Bool("help", false, "Display help information")
+
+	flag.Parse()
+
+	// If help is requested, display the help message and exit.
+	if *help || len(os.Args) == 1 {
+		printHelp()
+		return
+	}
+
+	// Expand any environment variables in the flags
+	*addr = os.ExpandEnv(*addr)
+	*serviceName = os.ExpandEnv(*serviceName)
+	*certFile = os.ExpandEnv(*certFile)
+	*keyFile = os.ExpandEnv(*keyFile)
+	*serverCaCertFile = os.ExpandEnv(*serverCaCertFile)
+
+	// Check for required flags
+	if *addr == "" {
+		log.Fatal("database address is required; flag missing or empty")
+	}
+	if *serviceName == "" {
+		log.Fatal("database service name is required; flag missing or empty")
+	}
+	if *certFile == "" {
+		log.Fatal("path to the user certificate is required; flag missing or empty")
+	}
+	if *keyFile == "" {
+		log.Fatal("path to the user key is required; flag missing or empty")
+	}
+
+	// Load the user certificate
+	cert, err := tls.LoadX509KeyPair(*certFile, *keyFile)
+	if err != nil {
+		log.Fatalf("failed to load certificate: %v", err)
+	}
+
+	// Create a TLS config with the certificate
+	tlsConfig := &tls.Config{
+		Certificates:       []tls.Certificate{cert},
+		InsecureSkipVerify: *insecureSkipVerify,
+	}
+
+	// Load server CA certificate if the file is provided
+	if *serverCaCertFile != "" {
+		caCert, err := os.ReadFile(*serverCaCertFile)
+		if err != nil {
+			log.Fatalf("failed to read server CA certificate file: %v", err)
+		}
+
+		certPool := x509.NewCertPool()
+
+		if !certPool.AppendCertsFromPEM(caCert) {
+			log.Fatalf("failed to append server CA certificate from file: %s", *serverCaCertFile)
+		}
+
+		tlsConfig.RootCAs = certPool
+	}
+
+	// Call the database connection function
+	if err := databaseConn(*addr, *serviceName, tlsConfig); err != nil {
+		log.Fatalf("database connection error: %v", err)
+	}
+}

v2/configurations/session_info.go

@@ -2,6 +2,7 @@ package configurations
 
 import (
 	"context"
+	"crypto/tls"
 	"fmt"
 	"net"
 	"strings"
@@ -22,6 +23,7 @@ type SessionInfo struct {
 	Protocol              string
 	SSL                   bool
 	SSLVerify             bool
+	TLSConfig             *tls.Config
 	Dialer                DialerContext
 }
 

v2/connection.go

@@ -2,6 +2,7 @@ package go_ora
 
 import (
 	"context"
+	"crypto/tls"
 	"database/sql"
 	"database/sql/driver"
 	"encoding/binary"
@@ -118,6 +119,7 @@ type OracleConnector struct {
 	drv           *OracleDriver
 	connectString string
 	dialer        configurations.DialerContext
+	tlsConfig     *tls.Config
 }
 
 func NewConnector(connString string) driver.Connector {
@@ -144,6 +146,9 @@ func (connector *OracleConnector) Connect(ctx context.Context) (driver.Conn, err
 	if conn.connOption.Dialer == nil {
 		conn.connOption.Dialer = connector.dialer
 	}
+	if conn.connOption.TLSConfig == nil {
+		conn.connOption.TLSConfig = connector.tlsConfig
+	}
 	err = conn.OpenWithContext(ctx)
 	if err != nil {
 		return nil, err
@@ -163,6 +168,10 @@ func (connector *OracleConnector) Dialer(dialer configurations.DialerContext) {
 	connector.dialer = dialer
 }
 
+func (connector *OracleConnector) WithTLSConfig(config *tls.Config) {
+	connector.tlsConfig = config
+}
+
 // Open return a new open connection
 func (driver *OracleDriver) Open(name string) (driver.Conn, error) {
 	conn, err := NewConnection(name, driver.connOption)

v2/network/session.go

@@ -336,13 +336,20 @@ func (session *Session) LoadSSLData(certs, keys, certRequests [][]byte) error {
 // used to create sslConn object
 func (session *Session) negotiate() {
 	connOption := session.Context.connConfig
+	host := connOption.GetActiveServer(false)
+
+	if tlsConfig := connOption.TLSConfig; tlsConfig != nil {
+		tlsConfig.ServerName = host.Addr
+		session.sslConn = tls.Client(session.conn, tlsConfig)
+		return
+	}
+
 	if session.SSL.roots == nil && len(session.SSL.Certificates) > 0 {
 		session.SSL.roots = x509.NewCertPool()
 		for _, cert := range session.SSL.Certificates {
 			session.SSL.roots.AddCert(cert)
 		}
 	}
-	host := connOption.GetActiveServer(false)
 	config := &tls.Config{
 		ServerName: host.Addr,
 	}