Initial open-source release (MIT): image2api AI gateway

Full Go backend + Vue 3 frontend, OpenAI-compatible API, multi-provider
account pools, billing/admin, Docker one-command deploy with auto HTTPS.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/internal/service/smtp.go

@@ -0,0 +1,117 @@
+package service
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"net"
+	"net/smtp"
+	"strconv"
+	"strings"
+)
+
+type SMTPConfig struct {
+	Host     string
+	Port     int
+	Username string
+	Password string
+	FromAddr string
+	UseTLS   bool
+}
+
+type SMTPService struct{}
+
+func NewSMTPService() *SMTPService {
+	return &SMTPService{}
+}
+
+func (s *SMTPService) SendCode(ctx context.Context, cfg SMTPConfig, to, code, purpose string) error {
+	_ = ctx
+	if strings.TrimSpace(cfg.Host) == "" || cfg.Port <= 0 || strings.TrimSpace(cfg.FromAddr) == "" {
+		return errors.New("SMTP 未配置")
+	}
+	action := "注册"
+	if purpose == "reset" {
+		action = "找回密码"
+	}
+	subject := "Vivid AI 邮箱验证码"
+	body := fmt.Sprintf("你正在进行%s，验证码为：%s\n\n验证码 6 分钟内有效。", action, code)
+	msg := buildSMTPMessage(cfg.FromAddr, to, subject, body)
+	addr := net.JoinHostPort(cfg.Host, strconv.Itoa(cfg.Port))
+
+	if cfg.UseTLS || cfg.Port == 465 {
+		return sendMailTLS(addr, cfg, to, msg)
+	}
+	return sendMailSTARTTLS(addr, cfg, to, msg)
+}
+
+func buildSMTPMessage(from, to, subject, body string) []byte {
+	lines := []string{
+		"From: " + from,
+		"To: " + to,
+		"Subject: " + subject,
+		"MIME-Version: 1.0",
+		"Content-Type: text/plain; charset=UTF-8",
+		"",
+		body,
+	}
+	return []byte(strings.Join(lines, "\r\n"))
+}
+
+func sendMailTLS(addr string, cfg SMTPConfig, to string, msg []byte) error {
+	conn, err := tls.Dial("tcp", addr, &tls.Config{ServerName: cfg.Host})
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	client, err := smtp.NewClient(conn, cfg.Host)
+	if err != nil {
+		return err
+	}
+	defer client.Close()
+	return doSMTP(client, cfg, to, msg)
+}
+
+func sendMailSTARTTLS(addr string, cfg SMTPConfig, to string, msg []byte) error {
+	client, err := smtp.Dial(addr)
+	if err != nil {
+		return err
+	}
+	defer client.Close()
+
+	if ok, _ := client.Extension("STARTTLS"); ok {
+		if err := client.StartTLS(&tls.Config{ServerName: cfg.Host}); err != nil {
+			return err
+		}
+	}
+	return doSMTP(client, cfg, to, msg)
+}
+
+func doSMTP(client *smtp.Client, cfg SMTPConfig, to string, msg []byte) error {
+	if strings.TrimSpace(cfg.Username) != "" {
+		auth := smtp.PlainAuth("", cfg.Username, cfg.Password, cfg.Host)
+		if err := client.Auth(auth); err != nil {
+			return err
+		}
+	}
+	if err := client.Mail(cfg.FromAddr); err != nil {
+		return err
+	}
+	if err := client.Rcpt(to); err != nil {
+		return err
+	}
+	w, err := client.Data()
+	if err != nil {
+		return err
+	}
+	if _, err := w.Write(msg); err != nil {
+		_ = w.Close()
+		return err
+	}
+	if err := w.Close(); err != nil {
+		return err
+	}
+	return client.Quit()
+}