-
-
Notifications
You must be signed in to change notification settings - Fork 2.2k
/
smtp.v
292 lines (258 loc) · 6.68 KB
/
smtp.v
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
module smtp
/*
*
* smtp module
* Created by: nedimf (07/2020)
*/
import net
import net.ssl
import encoding.base64
import strings
import time
import io
import rand
const recv_size = 128
enum ReplyCode {
ready = 220
close = 221
auth_ok = 235
action_ok = 250
mail_start = 354
}
pub enum BodyType {
text
html
}
pub struct Client {
mut:
conn net.TcpConn
ssl_conn &ssl.SSLConn = unsafe { nil }
reader ?&io.BufferedReader
pub:
server string
port int = 25
username string
password string
from string
ssl bool
starttls bool
pub mut:
is_open bool
encrypted bool
}
pub struct Mail {
pub:
from string
to string
cc string
bcc string
date time.Time = time.now()
subject string
body_type BodyType
body string
attachments []Attachment
boundary string
}
pub struct Attachment {
filename string
bytes []u8
cid string
}
// new_client returns a new SMTP client and connects to it
pub fn new_client(config Client) !&Client {
if config.ssl && config.starttls {
return error('Can not use both implicit SSL and STARTTLS')
}
mut c := &Client{
...config
}
c.reconnect()!
return c
}
// reconnect reconnects to the SMTP server if the connection was closed
pub fn (mut c Client) reconnect() ! {
if c.is_open {
return error('Already connected to server')
}
conn := net.dial_tcp('${c.server}:${c.port}') or { return error('Connecting to server failed') }
c.conn = conn
if c.ssl {
c.connect_ssl()!
} else {
c.reader = io.new_buffered_reader(reader: c.conn)
}
c.expect_reply(.ready) or { return error('Received invalid response from server') }
c.send_ehlo() or { return error('Sending EHLO packet failed') }
if c.starttls && !c.encrypted {
c.send_starttls() or { return error('Sending STARTTLS failed') }
}
c.send_auth() or { return error('Authenticating to server failed') }
c.is_open = true
}
// send sends an email
pub fn (mut c Client) send(config Mail) ! {
if !c.is_open {
return error('Disconnected from server')
}
from := if config.from != '' { config.from } else { c.from }
c.send_mailfrom(from) or { return error('Sending mailfrom failed') }
c.send_mailto(config.to) or { return error('Sending mailto failed') }
c.send_data() or { return error('Sending mail data failed') }
c.send_body(Mail{
...config
from: from
boundary: rand.uuid_v4()
}) or { return error('Sending mail body failed') }
}
// quit closes the connection to the server
pub fn (mut c Client) quit() ! {
c.send_str('QUIT\r\n')!
c.expect_reply(.close)!
if c.encrypted {
c.ssl_conn.shutdown()!
} else {
c.conn.close()!
}
c.is_open = false
c.encrypted = false
}
fn (mut c Client) connect_ssl() ! {
c.ssl_conn = ssl.new_ssl_conn()!
c.ssl_conn.connect(mut c.conn, c.server) or {
return error('Connecting to server using OpenSSL failed: ${err}')
}
c.reader = io.new_buffered_reader(reader: c.ssl_conn)
c.encrypted = true
}
// expect_reply checks if the SMTP server replied with the expected reply code
fn (mut c Client) expect_reply(expected ReplyCode) ! {
mut str := ''
for {
str = c.reader or { return error('the Client.reader field is not set') }.read_line()!
if str.len < 4 {
return error('Invalid SMTP response: ${str}')
}
if str.runes()[3] == `-` {
continue
} else {
break
}
}
$if smtp_debug ? {
eprintln('\n\n[RECV]')
eprint(str)
}
if str.len >= 3 {
status := str[..3].int()
if unsafe { ReplyCode(status) } != expected {
return error('Received unexpected status code ${status}, expecting ${expected}')
}
} else {
return error('Received unexpected SMTP data: ${str}')
}
}
@[inline]
fn (mut c Client) send_str(s string) ! {
$if smtp_debug ? {
eprintln('\n\n[SEND START]')
eprint(s.trim_space())
eprintln('\n[SEND END]')
}
if c.encrypted {
c.ssl_conn.write(s.bytes())!
} else {
c.conn.write(s.bytes())!
}
}
@[inline]
fn (mut c Client) send_ehlo() ! {
c.send_str('EHLO ${c.server}\r\n')!
c.expect_reply(.action_ok)!
}
@[inline]
fn (mut c Client) send_starttls() ! {
c.send_str('STARTTLS\r\n')!
c.expect_reply(.ready)!
c.connect_ssl()!
}
@[inline]
fn (mut c Client) send_auth() ! {
if c.username.len == 0 {
return
}
mut sb := strings.new_builder(100)
sb.write_u8(0)
sb.write_string(c.username)
sb.write_u8(0)
sb.write_string(c.password)
a := sb.str()
auth := 'AUTH PLAIN ${base64.encode_str(a)}\r\n'
c.send_str(auth)!
c.expect_reply(.auth_ok)!
}
fn (mut c Client) send_mailfrom(from string) ! {
c.send_str('MAIL FROM: <${from}>\r\n')!
c.expect_reply(.action_ok)!
}
fn (mut c Client) send_mailto(to string) ! {
for rcpt in to.split(';') {
c.send_str('RCPT TO: <${rcpt}>\r\n')!
c.expect_reply(.action_ok)!
}
}
fn (mut c Client) send_data() ! {
c.send_str('DATA\r\n')!
c.expect_reply(.mail_start)!
}
fn (mut c Client) send_body(cfg Mail) ! {
is_html := cfg.body_type == .html
date := cfg.date.custom_format('ddd, D MMM YYYY HH:mm ZZ')
nonascii_subject := cfg.subject.bytes().any(it < u8(` `) || it > u8(`~`))
mut sb := strings.new_builder(200)
sb.write_string('From: ${cfg.from}\r\n')
sb.write_string('To: <${cfg.to.split(';').join('>; <')}>\r\n')
sb.write_string('Cc: <${cfg.cc.split(';').join('>; <')}>\r\n')
sb.write_string('Bcc: <${cfg.bcc.split(';').join('>; <')}>\r\n')
sb.write_string('Date: ${date}\r\n')
if nonascii_subject {
// handle UTF-8 subjects according RFC 1342
sb.write_string('Subject: =?utf-8?B?' + base64.encode_str(cfg.subject) + '?=\r\n')
} else {
sb.write_string('Subject: ${cfg.subject}\r\n')
}
if cfg.attachments.len > 0 {
sb.write_string('MIME-Version: 1.0\r\n')
sb.write_string('Content-Type: multipart/mixed; boundary="${cfg.boundary}"\r\n--${cfg.boundary}\r\n')
}
if is_html {
sb.write_string('Content-Type: text/html; charset=UTF-8\r\n')
} else {
sb.write_string('Content-Type: text/plain; charset=UTF-8\r\n')
}
sb.write_string('Content-Transfer-Encoding: base64\r\n\r\n')
sb.write_string(base64.encode_str(cfg.body))
sb.write_string('\r\n')
if cfg.attachments.len > 0 {
sb.write_string('\r\n--${cfg.boundary}\r\n')
sb.write_string(cfg.attachments_to_string())
}
sb.write_string('\r\n.\r\n')
c.send_str(sb.str())!
c.expect_reply(.action_ok)!
}
fn (a &Attachment) to_string(boundary string) string {
crlf := '\r\n'
cid := if a.cid != '' {
'Content-ID: <${a.cid}>${crlf}'
} else {
''
}
return 'Content-Type: application/octet-stream${crlf}${cid}Content-Transfer-Encoding: base64${crlf}Content-Disposition: attachment; filename="${a.filename}"${crlf}${crlf}${base64.encode(a.bytes)}${crlf}--${boundary}${crlf}'
}
fn (m &Mail) attachments_to_string() string {
mut res := ''
for a in m.attachments {
res += a.to_string(m.boundary)
}
return if res.len > 0 { res[..res.len - 2] } else { '' } + '\r\n'
}