1 1d5ddf5d 2024-02-20 o package apub
  2 1d5ddf5d 2024-02-20 o 
  3 1d5ddf5d 2024-02-20 o import (
  4 1d5ddf5d 2024-02-20 o 	"bytes"
  5 1d5ddf5d 2024-02-20 o 	"fmt"
  6 77918b00 2024-03-07 o 	"io"
  7 5acd8b1b 2024-03-21 o 	"mime/quotedprintable"
  8 1d5ddf5d 2024-02-20 o 	"net/mail"
  9 71191436 2024-02-28 o 	"net/smtp"
 10 1d5ddf5d 2024-02-20 o 	"strings"
 11 1d5ddf5d 2024-02-20 o 	"time"
 12 1d5ddf5d 2024-02-20 o )
 13 1d5ddf5d 2024-02-20 o 
 14 d3dfb672 2024-03-18 o func MarshalMail(activity *Activity, client *Client) ([]byte, error) {
 15 d3dfb672 2024-03-18 o 	msg, err := marshalMail(activity, client)
 16 d3dfb672 2024-03-18 o 	if err != nil {
 17 d3dfb672 2024-03-18 o 		return nil, err
 18 d3dfb672 2024-03-18 o 	}
 19 d3dfb672 2024-03-18 o 	return encodeMsg(msg), nil
 20 d3dfb672 2024-03-18 o }
 21 1d5ddf5d 2024-02-20 o 
 22 d3dfb672 2024-03-18 o func marshalMail(activity *Activity, client *Client) (*mail.Message, error) {
 23 d3dfb672 2024-03-18 o 	if client == nil {
 24 d3dfb672 2024-03-18 o 		client = &DefaultClient
 25 d3dfb672 2024-03-18 o 	}
 26 d3dfb672 2024-03-18 o 
 27 d3dfb672 2024-03-18 o 	msg := new(mail.Message)
 28 d3dfb672 2024-03-18 o 	msg.Header = make(mail.Header)
 29 d3dfb672 2024-03-18 o 	var actors []Actor
 30 d3dfb672 2024-03-18 o 	from, err := client.LookupActor(activity.AttributedTo)
 31 1d5ddf5d 2024-02-20 o 	if err != nil {
 32 d3dfb672 2024-03-18 o 		return nil, fmt.Errorf("build From: lookup actor %s: %w", activity.AttributedTo, err)
 33 1d5ddf5d 2024-02-20 o 	}
 34 d3dfb672 2024-03-18 o 	actors = append(actors, *from)
 35 d3dfb672 2024-03-18 o 	msg.Header["From"] = []string{from.Address().String()}
 36 1d5ddf5d 2024-02-20 o 
 37 d3dfb672 2024-03-18 o 	var addrs, collections []string
 38 d3dfb672 2024-03-18 o 	for _, id := range activity.To {
 39 d3dfb672 2024-03-18 o 		if id == PublicCollection {
 40 77918b00 2024-03-07 o 			continue
 41 77918b00 2024-03-07 o 		}
 42 d3dfb672 2024-03-18 o 
 43 d3dfb672 2024-03-18 o 		a, err := client.LookupActor(id)
 44 77918b00 2024-03-07 o 		if err != nil {
 45 d3dfb672 2024-03-18 o 			return nil, fmt.Errorf("build To: lookup actor %s: %w", id, err)
 46 77918b00 2024-03-07 o 		}
 47 d3dfb672 2024-03-18 o 		if a.Type == "Collection" || a.Type == "OrderedCollection" {
 48 d3dfb672 2024-03-18 o 			collections = append(collections, a.ID)
 49 d3dfb672 2024-03-18 o 		} else {
 50 d3dfb672 2024-03-18 o 			addrs = append(addrs, a.Address().String())
 51 d3dfb672 2024-03-18 o 			actors = append(actors, *a)
 52 d3dfb672 2024-03-18 o 		}
 53 77918b00 2024-03-07 o 	}
 54 d3dfb672 2024-03-18 o 	for _, id := range collections {
 55 d3dfb672 2024-03-18 o 		if i := indexFollowers(actors, id); i >= 0 {
 56 d3dfb672 2024-03-18 o 			addrs = append(addrs, actors[i].FollowersAddress().String())
 57 d3dfb672 2024-03-18 o 		}
 58 d3dfb672 2024-03-18 o 	}
 59 d3dfb672 2024-03-18 o 	msg.Header["To"] = addrs
 60 77918b00 2024-03-07 o 
 61 d3dfb672 2024-03-18 o 	addrs, collections = []string{}, []string{}
 62 d3dfb672 2024-03-18 o 	for _, id := range activity.CC {
 63 d3dfb672 2024-03-18 o 		if id == PublicCollection {
 64 d3dfb672 2024-03-18 o 			continue
 65 1d5ddf5d 2024-02-20 o 		}
 66 d3dfb672 2024-03-18 o 
 67 d3dfb672 2024-03-18 o 		a, err := client.LookupActor(id)
 68 d3dfb672 2024-03-18 o 		if err != nil {
 69 d3dfb672 2024-03-18 o 			return nil, fmt.Errorf("build CC: lookup actor %s: %w", id, err)
 70 d3dfb672 2024-03-18 o 		}
 71 d3dfb672 2024-03-18 o 		if a.Type == "Collection" || a.Type == "OrderedCollection" {
 72 d3dfb672 2024-03-18 o 			collections = append(collections, a.ID)
 73 d3dfb672 2024-03-18 o 			continue
 74 d3dfb672 2024-03-18 o 		}
 75 d3dfb672 2024-03-18 o 		addrs = append(addrs, a.Address().String())
 76 d3dfb672 2024-03-18 o 		actors = append(actors, *a)
 77 1d5ddf5d 2024-02-20 o 	}
 78 d3dfb672 2024-03-18 o 	for _, id := range collections {
 79 d3dfb672 2024-03-18 o 		if i := indexFollowers(actors, id); i >= 0 {
 80 d3dfb672 2024-03-18 o 			addrs = append(addrs, actors[i].FollowersAddress().String())
 81 d3dfb672 2024-03-18 o 		}
 82 d3dfb672 2024-03-18 o 	}
 83 d3dfb672 2024-03-18 o 	msg.Header["CC"] = addrs
 84 1d5ddf5d 2024-02-20 o 
 85 af1bda8f 2024-03-18 o 	msg.Header["Date"] = []string{activity.Published.Format(time.RFC1123Z)}
 86 d3dfb672 2024-03-18 o 	msg.Header["Message-ID"] = []string{"<" + activity.ID + ">"}
 87 d3dfb672 2024-03-18 o 	msg.Header["Subject"] = []string{activity.Name}
 88 1d5ddf5d 2024-02-20 o 	if activity.Audience != "" {
 89 d3dfb672 2024-03-18 o 		msg.Header["List-ID"] = []string{"<" + activity.Audience + ">"}
 90 1d5ddf5d 2024-02-20 o 	}
 91 1d5ddf5d 2024-02-20 o 	if activity.InReplyTo != "" {
 92 d3dfb672 2024-03-18 o 		msg.Header["In-Reply-To"] = []string{"<" + activity.InReplyTo + ">"}
 93 1d5ddf5d 2024-02-20 o 	}
 94 1d5ddf5d 2024-02-20 o 
 95 d3dfb672 2024-03-18 o 	msg.Body = strings.NewReader(activity.Content)
 96 d3dfb672 2024-03-18 o 	msg.Header["Content-Type"] = []string{"text/html; charset=utf-8"}
 97 1d5ddf5d 2024-02-20 o 	if activity.Source.Content != "" && activity.Source.MediaType == "text/markdown" {
 98 d3dfb672 2024-03-18 o 		msg.Body = strings.NewReader(activity.Source.Content)
 99 d3dfb672 2024-03-18 o 		msg.Header["Content-Type"] = []string{"text/plain; charset=utf-8"}
100 184e4de6 2024-03-13 o 	} else if activity.MediaType == "text/markdown" {
101 d3dfb672 2024-03-18 o 		msg.Header["Content-Type"] = []string{"text/plain; charset=utf-8"}
102 1d5ddf5d 2024-02-20 o 	}
103 d3dfb672 2024-03-18 o 	return msg, nil
104 1d5ddf5d 2024-02-20 o }
105 71191436 2024-02-28 o 
106 d3dfb672 2024-03-18 o func indexFollowers(actors []Actor, id string) int {
107 d3dfb672 2024-03-18 o 	for i := range actors {
108 d3dfb672 2024-03-18 o 		if actors[i].Followers == id {
109 d3dfb672 2024-03-18 o 			return i
110 d3dfb672 2024-03-18 o 		}
111 d3dfb672 2024-03-18 o 	}
112 d3dfb672 2024-03-18 o 	return -1
113 d3dfb672 2024-03-18 o }
114 d3dfb672 2024-03-18 o 
115 d3dfb672 2024-03-18 o func UnmarshalMail(msg *mail.Message, client *Client) (*Activity, error) {
116 d3dfb672 2024-03-18 o 	if client == nil {
117 d3dfb672 2024-03-18 o 		client = &DefaultClient
118 d3dfb672 2024-03-18 o 	}
119 662ec973 2024-03-14 o 	ct := msg.Header.Get("Content-Type")
120 662ec973 2024-03-14 o 	if strings.HasPrefix(ct, "multipart") {
121 662ec973 2024-03-14 o 		return nil, fmt.Errorf("cannot unmarshal from multipart message")
122 662ec973 2024-03-14 o 	}
123 662ec973 2024-03-14 o 
124 77918b00 2024-03-07 o 	date, err := msg.Header.Date()
125 71191436 2024-02-28 o 	if err != nil {
126 77918b00 2024-03-07 o 		return nil, fmt.Errorf("parse message date: %w", err)
127 77918b00 2024-03-07 o 	}
128 77918b00 2024-03-07 o 	from, err := msg.Header.AddressList("From")
129 77918b00 2024-03-07 o 	if err != nil {
130 77918b00 2024-03-07 o 		return nil, fmt.Errorf("parse From: %w", err)
131 77918b00 2024-03-07 o 	}
132 d3dfb672 2024-03-18 o 	wfrom, err := client.Finger(from[0].Address)
133 77918b00 2024-03-07 o 	if err != nil {
134 77918b00 2024-03-07 o 		return nil, fmt.Errorf("webfinger From: %w", err)
135 77918b00 2024-03-07 o 	}
136 77918b00 2024-03-07 o 
137 25fed994 2024-03-12 o 	var wto, wcc []string
138 d802abd8 2024-03-12 o 	var tags []Activity
139 25fed994 2024-03-12 o 	if msg.Header.Get("To") != "" {
140 25fed994 2024-03-12 o 		to, err := msg.Header.AddressList("To")
141 25fed994 2024-03-12 o 		// ignore missing To line. Some ActivityPub servers only have the
142 25fed994 2024-03-12 o 		// PublicCollection listed, which we don't care about.
143 25fed994 2024-03-12 o 		if err != nil {
144 25fed994 2024-03-12 o 			return nil, fmt.Errorf("parse To address list: %w", err)
145 25fed994 2024-03-12 o 		}
146 d3dfb672 2024-03-18 o 		actors, err := client.fingerAll(to)
147 25fed994 2024-03-12 o 		if err != nil {
148 25fed994 2024-03-12 o 			return nil, fmt.Errorf("webfinger To addresses: %w", err)
149 25fed994 2024-03-12 o 		}
150 2469f664 2024-03-12 o 		wto = make([]string, len(actors))
151 2469f664 2024-03-12 o 		for i, a := range actors {
152 d802abd8 2024-03-12 o 			addr := strings.Trim(to[i].Address, "<>")
153 eec64935 2024-03-16 o 			if strings.Contains(addr, "+followers") {
154 eec64935 2024-03-16 o 				wto[i] = a.Followers
155 eec64935 2024-03-16 o 				continue
156 eec64935 2024-03-16 o 			}
157 eec64935 2024-03-16 o 			tags = append(tags, Activity{Type: "Mention", Href: a.ID, Name: "@" + addr})
158 2469f664 2024-03-12 o 			wto[i] = a.ID
159 2469f664 2024-03-12 o 		}
160 77918b00 2024-03-07 o 	}
161 77918b00 2024-03-07 o 	if msg.Header.Get("CC") != "" {
162 77918b00 2024-03-07 o 		cc, err := msg.Header.AddressList("CC")
163 77918b00 2024-03-07 o 		if err != nil {
164 77918b00 2024-03-07 o 			return nil, fmt.Errorf("parse CC address list: %w", err)
165 77918b00 2024-03-07 o 		}
166 d3dfb672 2024-03-18 o 		actors, err := client.fingerAll(cc)
167 77918b00 2024-03-07 o 		if err != nil {
168 77918b00 2024-03-07 o 			return nil, fmt.Errorf("webfinger CC addresses: %w", err)
169 77918b00 2024-03-07 o 		}
170 2469f664 2024-03-12 o 		wcc = make([]string, len(actors))
171 2469f664 2024-03-12 o 		for i, a := range actors {
172 eec64935 2024-03-16 o 			if strings.Contains(cc[i].Address, "+followers") {
173 eec64935 2024-03-16 o 				wcc[i] = a.Followers
174 eec64935 2024-03-16 o 				continue
175 eec64935 2024-03-16 o 			}
176 2469f664 2024-03-12 o 			wcc[i] = a.ID
177 2469f664 2024-03-12 o 		}
178 77918b00 2024-03-07 o 	}
179 77918b00 2024-03-07 o 
180 77918b00 2024-03-07 o 	buf := &bytes.Buffer{}
181 5acd8b1b 2024-03-21 o 	if msg.Header.Get("Content-Transfer-Encoding") == "quoted-printable" {
182 5acd8b1b 2024-03-21 o 		_, err = io.Copy(buf, quotedprintable.NewReader(msg.Body))
183 5acd8b1b 2024-03-21 o 	} else {
184 5acd8b1b 2024-03-21 o 		_, err = io.Copy(buf, msg.Body)
185 5acd8b1b 2024-03-21 o 	}
186 5acd8b1b 2024-03-21 o 	if err != nil {
187 77918b00 2024-03-07 o 		return nil, fmt.Errorf("read message body: %v", err)
188 77918b00 2024-03-07 o 	}
189 d3dfb672 2024-03-18 o 	content := strings.TrimSpace(strings.ReplaceAll(buf.String(), "\r", ""))
190 77918b00 2024-03-07 o 
191 77918b00 2024-03-07 o 	return &Activity{
192 186ac3bf 2024-03-12 o 		AtContext:    NormContext,
193 77918b00 2024-03-07 o 		Type:         "Note",
194 77918b00 2024-03-07 o 		AttributedTo: wfrom.ID,
195 77918b00 2024-03-07 o 		To:           wto,
196 77918b00 2024-03-07 o 		CC:           wcc,
197 77918b00 2024-03-07 o 		MediaType:    "text/markdown",
198 77918b00 2024-03-07 o 		Name:         strings.TrimSpace(msg.Header.Get("Subject")),
199 d3dfb672 2024-03-18 o 		Content:      content,
200 77918b00 2024-03-07 o 		InReplyTo:    strings.Trim(msg.Header.Get("In-Reply-To"), "<>"),
201 77918b00 2024-03-07 o 		Published:    &date,
202 d802abd8 2024-03-12 o 		Tag:          tags,
203 77918b00 2024-03-07 o 	}, nil
204 77918b00 2024-03-07 o }
205 77918b00 2024-03-07 o 
206 77918b00 2024-03-07 o func SendMail(addr string, auth smtp.Auth, from string, to []string, activity *Activity) error {
207 d3dfb672 2024-03-18 o 	msg, err := MarshalMail(activity, nil)
208 77918b00 2024-03-07 o 	if err != nil {
209 71191436 2024-02-28 o 		return fmt.Errorf("marshal to mail message: %w", err)
210 71191436 2024-02-28 o 	}
211 77918b00 2024-03-07 o 	return smtp.SendMail(addr, auth, from, to, msg)
212 71191436 2024-02-28 o }
213 d3dfb672 2024-03-18 o 
214 d3dfb672 2024-03-18 o func encodeMsg(msg *mail.Message) []byte {
215 d3dfb672 2024-03-18 o 	buf := &bytes.Buffer{}
216 d3dfb672 2024-03-18 o 	// Lead with "From", end with "Subject" to make some mail clients happy.
217 d3dfb672 2024-03-18 o 	fmt.Fprintln(buf, "From:", msg.Header.Get("From"))
218 d3dfb672 2024-03-18 o 	for k, v := range msg.Header {
219 d3dfb672 2024-03-18 o 		switch k {
220 d3dfb672 2024-03-18 o 		case "Subject", "From":
221 d3dfb672 2024-03-18 o 			continue
222 d3dfb672 2024-03-18 o 		default:
223 d3dfb672 2024-03-18 o 			fmt.Fprintf(buf, "%s: %s\n", k, strings.Join(v, ", "))
224 d3dfb672 2024-03-18 o 		}
225 d3dfb672 2024-03-18 o 	}
226 d3dfb672 2024-03-18 o 	fmt.Fprintln(buf, "Subject:", msg.Header.Get("Subject"))
227 d3dfb672 2024-03-18 o 	fmt.Fprintln(buf)
228 d3dfb672 2024-03-18 o 	io.Copy(buf, msg.Body)
229 d3dfb672 2024-03-18 o 	return buf.Bytes()
230 d3dfb672 2024-03-18 o }