common.go (3674B)
1 // GoToSocial 2 // Copyright (C) GoToSocial Authors admin@gotosocial.org 3 // SPDX-License-Identifier: AGPL-3.0-or-later 4 // 5 // This program is free software: you can redistribute it and/or modify 6 // it under the terms of the GNU Affero General Public License as published by 7 // the Free Software Foundation, either version 3 of the License, or 8 // (at your option) any later version. 9 // 10 // This program is distributed in the hope that it will be useful, 11 // but WITHOUT ANY WARRANTY; without even the implied warranty of 12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 // GNU Affero General Public License for more details. 14 // 15 // You should have received a copy of the GNU Affero General Public License 16 // along with this program. If not, see <http://www.gnu.org/licenses/>. 17 18 package email 19 20 import ( 21 "bytes" 22 "errors" 23 "fmt" 24 "net/smtp" 25 "os" 26 "path/filepath" 27 "strings" 28 "text/template" 29 30 "github.com/superseriousbusiness/gotosocial/internal/config" 31 "github.com/superseriousbusiness/gotosocial/internal/gtserror" 32 ) 33 34 func (s *sender) sendTemplate(template string, subject string, data any, toAddresses ...string) error { 35 buf := &bytes.Buffer{} 36 if err := s.template.ExecuteTemplate(buf, template, data); err != nil { 37 return err 38 } 39 40 msg, err := assembleMessage(subject, buf.String(), s.from, toAddresses...) 41 if err != nil { 42 return err 43 } 44 45 if err := smtp.SendMail(s.hostAddress, s.auth, s.from, toAddresses, msg); err != nil { 46 return gtserror.SetType(err, gtserror.TypeSMTP) 47 } 48 49 return nil 50 } 51 52 func loadTemplates(templateBaseDir string) (*template.Template, error) { 53 if !filepath.IsAbs(templateBaseDir) { 54 cwd, err := os.Getwd() 55 if err != nil { 56 return nil, fmt.Errorf("error getting current working directory: %s", err) 57 } 58 templateBaseDir = filepath.Join(cwd, templateBaseDir) 59 } 60 61 // look for all templates that start with 'email_' 62 return template.ParseGlob(filepath.Join(templateBaseDir, "email_*")) 63 } 64 65 // assembleMessage assembles a valid email message following: 66 // - https://datatracker.ietf.org/doc/html/rfc2822 67 // - https://pkg.go.dev/net/smtp#SendMail 68 func assembleMessage(mailSubject string, mailBody string, mailFrom string, mailTo ...string) ([]byte, error) { 69 if strings.ContainsAny(mailSubject, "\r\n") { 70 return nil, errors.New("email subject must not contain newline characters") 71 } 72 73 if strings.ContainsAny(mailFrom, "\r\n") { 74 return nil, errors.New("email from address must not contain newline characters") 75 } 76 77 for _, to := range mailTo { 78 if strings.ContainsAny(to, "\r\n") { 79 return nil, errors.New("email to address must not contain newline characters") 80 } 81 } 82 83 // Normalize the message body to use CRLF line endings 84 const CRLF = "\r\n" 85 mailBody = strings.ReplaceAll(mailBody, CRLF, "\n") 86 mailBody = strings.ReplaceAll(mailBody, "\n", CRLF) 87 88 msg := bytes.Buffer{} 89 switch { 90 case len(mailTo) == 1: 91 // Address email directly to the one recipient. 92 msg.WriteString("To: " + mailTo[0] + CRLF) 93 case config.GetSMTPDiscloseRecipients(): 94 // Simply address To all recipients. 95 msg.WriteString("To: " + strings.Join(mailTo, ", ") + CRLF) 96 default: 97 // Address To anonymous group. 98 // 99 // Email will be sent to all recipients but we shouldn't include Bcc header. 100 // 101 // From the smtp.SendMail function: 'Sending "Bcc" messages is accomplished by 102 // including an email address in the to parameter but not including it in the 103 // msg headers.' 104 msg.WriteString("To: Undisclosed Recipients:;" + CRLF) 105 } 106 msg.WriteString("From: " + mailFrom + CRLF) 107 msg.WriteString("Subject: " + mailSubject + CRLF) 108 msg.WriteString(CRLF) 109 msg.WriteString(mailBody) 110 msg.WriteString(CRLF) 111 112 return msg.Bytes(), nil 113 }