Slow progress

client.go

@@ -28,8 +28,11 @@ type Client struct {
 	// Use SSL for the connection
 	ssl bool
 
-	// Sets the client cto use STARTTTLS for the connection (is disabled when SSL is set)
-	starttls bool
+	// tlspolicy sets the client to use the provided TLSPolicy for the STARTTLS protocol
+	tlspolicy TLSPolicy
+
+	// tlsconfig represents the tls.Config setting for the STARTTLS connection
+	tlsconfig *tls.Config
 
 	// Timeout for the SMTP server connection
 	cto time.Duration
@@ -48,8 +51,8 @@ var (
 	// ErrNoHostname should be used if a Client has no hostname set
 	ErrNoHostname = errors.New("hostname for client cannot be empty")
 
-	// ErrInvalidHostname should be used if a Client has an invalid hostname set
-	//ErrInvalidHostname = errors.New("hostname for client is invalid")
+	// ErrNoSTARTTLS should be used if the target server does not support the STARTTLS protocol
+	ErrNoSTARTTLS = errors.New("target host does not support STARTTLS")
 )
 
 // NewClient returns a new Session client object
@@ -58,6 +61,8 @@ func NewClient(h string, o ...Option) (*Client, error) {
 		host:      h,
 		port:      DefaultPort,
 		cto:       DefaultTimeout,
+		tlspolicy: TLSMandatory,
+		tlsconfig: &tls.Config{ServerName: h},
 	}
 
 	// Set default HELO/EHLO hostname
@@ -110,6 +115,36 @@ func WithHELO(h string) Option {
 	}
 }
 
+// TLSPolicy returns the currently set TLSPolicy as string
+func (c *Client) TLSPolicy() string {
+	return fmt.Sprintf("%s", c.tlspolicy)
+}
+
+// SetTLSPolicy overrides the current TLSPolicy with the given TLSPolicy value
+func (c *Client) SetTLSPolicy(p TLSPolicy) {
+	c.tlspolicy = p
+}
+
+// Send sends out the mail message
+func (c *Client) Send() error {
+	return nil
+}
+
+// Close closes the connection cto the SMTP server
+func (c *Client) Close() error {
+	return c.sc.Close()
+}
+
+// setDefaultHelo retrieves the current hostname and sets it as HELO/EHLO hostname
+func (c *Client) setDefaultHelo() error {
+	hn, err := os.Hostname()
+	if err != nil {
+		return fmt.Errorf("failed cto read local hostname: %w", err)
+	}
+	c.helo = hn
+	return nil
+}
+
 // Dial establishes a connection cto the SMTP server with a default context.Background
 func (c *Client) Dial() error {
 	ctx := context.Background()
@@ -143,25 +178,14 @@ func (c *Client) DialWithContext(uctx context.Context) error {
 		return err
 	}
 
-	return nil
-}
-
-// Send sends out the mail message
-func (c *Client) Send() error {
-	return nil
-}
-
-// Close closes the connection cto the SMTP server
-func (c *Client) Close() error {
-	return c.sc.Close()
-}
-
-// setDefaultHelo retrieves the current hostname and sets it as HELO/EHLO hostname
-func (c *Client) setDefaultHelo() error {
-	hn, err := os.Hostname()
-	if err != nil {
-		return fmt.Errorf("failed cto read local hostname: %w", err)
+	if !c.ssl && c.tlspolicy != NoTLS {
+		if ok, _ := c.sc.Extension("STARTTLS"); !ok {
+			return ErrNoSTARTTLS
 		}
-	c.helo = hn
+		if err := c.sc.StartTLS(c.tlsconfig); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }

client_test.go

@@ -2,12 +2,13 @@ package mail
 
 import (
 	"testing"
+	"time"
 )
 
 // DefaultHost is used as default hostname for the Client
 const DefaultHost = "localhost"
 
-// TestWithHELo tests the WithHELO() option for the NewClient() method
+// TestWithHELO tests the WithHELO() option for the NewClient() method
 func TestWithHELO(t *testing.T) {
 	tests := []struct {
 		name  string
@@ -29,3 +30,74 @@ func TestWithHELO(t *testing.T) {
 		})
 	}
 }
+
+// TestWithPort tests the WithPort() option for the NewClient() method
+func TestWithPort(t *testing.T) {
+	tests := []struct {
+		name  string
+		value int
+		want  int
+	}{
+		{"set port to 25", 25, 25},
+		{"set port to 465", 465, 465},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c, err := NewClient(DefaultHost, WithPort(tt.value))
+			if err != nil {
+				t.Errorf("failed to create new client: %s", err)
+				return
+			}
+			if c.port != tt.want {
+				t.Errorf("failed to set custom port. Want: %d, got: %d", tt.want, c.port)
+			}
+		})
+	}
+}
+
+// TestWithTimeout tests the WithTimeout() option for the NewClient() method
+func TestWithTimeout(t *testing.T) {
+	tests := []struct {
+		name  string
+		value time.Duration
+		want  time.Duration
+	}{
+		{"set timeout to 5s", time.Second * 5, time.Second * 5},
+		{"set timeout to 30s", time.Second * 30, time.Second * 30},
+		{"set timeout to 1m", time.Minute, time.Minute},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c, err := NewClient(DefaultHost, WithTimeout(tt.value))
+			if err != nil {
+				t.Errorf("failed to create new client: %s", err)
+				return
+			}
+			if c.cto != tt.want {
+				t.Errorf("failed to set custom timeout. Want: %d, got: %d", tt.want, c.cto)
+			}
+		})
+	}
+}
+
+// TestWithSSL tests the WithSSL() option for the NewClient() method
+func TestWithSSL(t *testing.T) {
+	tests := []struct {
+		name string
+		want bool
+	}{
+		{"set SSL to true", true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c, err := NewClient(DefaultHost, WithSSL())
+			if err != nil {
+				t.Errorf("failed to create new client: %s", err)
+				return
+			}
+			if c.ssl != tt.want {
+				t.Errorf("failed to set SSL. Want: %t, got: %t", tt.want, c.ssl)
+			}
+		})
+	}
+}

cmd/main.go

@@ -9,7 +9,7 @@ import (
 )
 
 func main() {
-	c, err := mail.NewClient("localhost", mail.WithTimeout(time.Millisecond*500))
+	c, err := mail.NewClient("manjaro-vm.fritz.box", mail.WithTimeout(time.Millisecond*500))
 	if err != nil {
 		fmt.Printf("failed to create new client: %s\n", err)
 		os.Exit(1)
@@ -23,9 +23,5 @@ func main() {
 		os.Exit(1)
 	}
 	fmt.Printf("Client: %+v\n", c)
-	time.Sleep(time.Millisecond * 1500)
-	if err := c.Close(); err != nil {
-		fmt.Printf("failed to close SMTP connection: %s\n", err)
-		os.Exit(1)
-	}
+	fmt.Printf("StartTLS policy: %s\n", c.TLSPolicy())
 }

tls.go

@@ -17,3 +17,17 @@ const (
 	// NoTLS forces the transaction cto be not encrypted
 	NoTLS
 )
+
+// String is a standard method to convert a TLSPolicy into a printable format
+func (p TLSPolicy) String() string {
+	switch p {
+	case TLSMandatory:
+		return "TLSMandatory"
+	case TLSOpportunistic:
+		return "TLSOpportunistic"
+	case NoTLS:
+		return "NoTLS"
+	default:
+		return "UnknownPolicy"
+	}
+}