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