Change resend to using smtp

Signed-off-by: Asai Neko <sugar@sne.moe>

config.default.yaml

@@ -20,7 +20,12 @@ search:
     host: 127.0.0.1
     api_key: ""
 email:
-    resend_api_key: abc
+    host:
+    port:
+    username:
+    password:
+    security:
+    insecure_skip_verify:
     from:
 secrets:
     jwt_secret: example

config/types.go

@@ -40,8 +40,13 @@ type search struct {
 }
 
 type email struct {
-	ResendApiKey string `yaml:"resend_api_key"`
-	From         string `yaml:"from"`
+	Host               string `yaml:"host"`
+	Port               string `yaml:"port"`
+	Username           string `yaml:"username"`
+	Password           string `yaml:"password"`
+	Security           string `yaml:"security"`
+	InsecureSkipVerify bool   `yaml:"insecure_skip_verify"`
+	From               string `yaml:"from"`
 }
 
 type secrets struct {

go.mod

@@ -64,6 +64,8 @@ require (
 	golang.org/x/text v0.32.0 // indirect
 	golang.org/x/tools v0.40.0 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
+	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
+	gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df // indirect
 	gorm.io/datatypes v1.2.7 // indirect
 	gorm.io/driver/mysql v1.5.6 // indirect
 	gorm.io/driver/postgres v1.6.0 // indirect

go.sum

@@ -139,7 +139,11 @@ golang.org/x/tools v0.40.0 h1:yLkxfA+Qnul4cs9QA3KnlFu0lVmd8JJfoq+E41uSutA=
 golang.org/x/tools v0.40.0/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
+gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc h1:2gGKlE2+asNV9m7xrywl36YYNnBG5ZQ0r/BOOxqPpmk=
+gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc/go.mod h1:m7x9LTH6d71AHyAX77c9yqWCCa3UKHcVEj9y7hAtKDk=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df h1:n7WqCuqOuCbNr617RXOY0AWRXxgwEyPp2z+p0+hgMuE=
+gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df/go.mod h1:LRQQ+SO6ZHR7tOkpBDuZnXENFzX8qRjMDMyPD6BRkCw=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gorm.io/datatypes v1.2.7 h1:ww9GAhF1aGXZY3EB3cJPJ7//JiuQo7DlQA7NNlVaTdk=

pkgs/email/email.go

@@ -0,0 +1,70 @@
+package email
+
+import (
+	"crypto/tls"
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/spf13/viper"
+	gomail "gopkg.in/gomail.v2"
+)
+
+type Client struct {
+	dialer *gomail.Dialer
+	from   string
+}
+
+func NewSMTPClient() (*Client, error) {
+	host := viper.GetString("email.host")
+	port := viper.GetInt("email.port")
+	user := viper.GetString("email.username")
+	pass := viper.GetString("email.password")
+	from := viper.GetString("email.from")
+
+	security := strings.ToLower(viper.GetString("email.security"))
+	insecure := viper.GetBool("email.insecure_skip_verify")
+
+	if host == "" || port == 0 || user == "" || pass == "" {
+		return nil, errors.New("SMTP config not set")
+	}
+
+	dialer := gomail.NewDialer(host, port, user, pass)
+
+	dialer.TLSConfig = &tls.Config{
+		ServerName:         host,
+		InsecureSkipVerify: insecure,
+	}
+
+	switch security {
+	case "ssl":
+		dialer.SSL = true
+	case "starttls":
+		dialer.SSL = false
+	case "plain", "":
+		dialer.SSL = false
+		dialer.TLSConfig = nil
+	default:
+		return nil, errors.New("unknown smtp security mode: " + security)
+	}
+
+	return &Client{
+		dialer: dialer,
+		from:   from,
+	}, nil
+}
+
+func (c *Client) Send(to, subject, html string) (string, error) {
+	m := gomail.NewMessage()
+
+	m.SetHeader("From", c.from)
+	m.SetHeader("To", to)
+	m.SetHeader("Subject", subject)
+	m.SetBody("text/html", html)
+
+	if err := c.dialer.DialAndSend(m); err != nil {
+		return "", err
+	}
+
+	return time.Now().Format(time.RFC3339Nano), nil
+}

pkgs/email/resend.go

@@ -1,87 +0,0 @@
-package email
-
-import (
-	"bytes"
-	"encoding/json"
-	"errors"
-	"net/http"
-	"time"
-
-	"github.com/spf13/viper"
-)
-
-type Client struct {
-	apiKey string
-	http   *http.Client
-}
-
-// Resend service client
-func NewResendClient() (*Client, error) {
-	key := viper.GetString("email.resend_api_key")
-	if key == "" {
-		return nil, errors.New("RESEND_API_KEY not set")
-	}
-
-	return &Client{
-		apiKey: key,
-		http: &http.Client{
-			Timeout: 10 * time.Second,
-		},
-	}, nil
-}
-
-type sendEmailRequest struct {
-	From    string   `json:"from"`
-	To      []string `json:"to"`
-	Subject string   `json:"subject"`
-	HTML    string   `json:"html,omitempty"`
-	Text    string   `json:"text,omitempty"`
-}
-
-type sendEmailResponse struct {
-	ID string `json:"id"`
-}
-
-// Send email by resend API
-func (c *Client) Send(to, subject, html string) (string, error) {
-	reqBody := sendEmailRequest{
-		From:    viper.GetString("email.from"),
-		To:      []string{to},
-		Subject: subject,
-		HTML:    html,
-	}
-
-	body, err := json.Marshal(reqBody)
-	if err != nil {
-		return "", err
-	}
-
-	req, err := http.NewRequest(
-		http.MethodPost,
-		"https://api.resend.com/emails",
-		bytes.NewReader(body),
-	)
-	if err != nil {
-		return "", err
-	}
-
-	req.Header.Set("Authorization", "Bearer "+c.apiKey)
-	req.Header.Set("Content-Type", "application/json")
-
-	resp, err := c.http.Do(req)
-	if err != nil {
-		return "", err
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode >= 300 {
-		return "", errors.New("resend send failed")
-	}
-
-	var res sendEmailResponse
-	if err := json.NewDecoder(resp.Body).Decode(&res); err != nil {
-		return "", err
-	}
-
-	return res.ID, nil
-}

service/auth/magic.go

@@ -6,8 +6,6 @@ import (
 	"nixcn-cms/pkgs/email"
 	"nixcn-cms/pkgs/turnstile"
 
-	log "github.com/sirupsen/logrus"
-
 	"github.com/gin-gonic/gin"
 	"github.com/spf13/viper"
 )
@@ -59,13 +57,12 @@ func Magic(c *gin.Context) {
 		return
 	} else {
 		// Send email using resend
-		resend, err := email.NewResendClient()
+		emailClient, err := email.NewSMTPClient()
 		if err != nil {
-			log.Error(err)
 			c.JSON(500, gin.H{"status": "invalid email config"})
 			return
 		}
-		resend.Send(
+		emailClient.Send(
 			req.Email,
 			"NixCN CMS Email Verify",
 			"<p>Click the link below to verify your email. This link will expire in 10 minutes.</p><a href="+url.String()+">"+url.String()+"</a>",