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
293
294
295
296
297
298
299
300
|
/*
* SPDX-FileCopyrightText: 2020 Stalwart Labs Ltd <hello@stalw.art>
*
* SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
*/
use std::time::{Duration, SystemTime};
use crate::{core::Session, scripts::ScriptResult};
use common::{
config::smtp::session::{Mechanism, Stage},
listener::SessionStream,
};
use mail_auth::spf::verify::HasValidLabels;
use smtp_proto::*;
impl<T: SessionStream> Session<T> {
pub async fn handle_ehlo(&mut self, domain: String, is_extended: bool) -> Result<(), ()> {
// Set EHLO domain
if domain != self.data.helo_domain {
// Reject non-FQDN EHLO domains - simply checks that the hostname has at least one dot
if self.params.ehlo_reject_non_fqdn && !domain.as_str().has_valid_labels() {
tracing::info!(
context = "ehlo",
event = "reject",
reason = "invalid",
domain = domain,
);
return self.write(b"550 5.5.0 Invalid EHLO domain.\r\n").await;
}
// SPF check
let prev_helo_domain = std::mem::replace(&mut self.data.helo_domain, domain);
if self.params.spf_ehlo.verify() {
let spf_output = self
.core
.core
.smtp
.resolvers
.dns
.verify_spf_helo(self.data.remote_ip, &self.data.helo_domain, &self.hostname)
.await;
tracing::debug!(
context = "spf",
event = "lookup",
identity = "ehlo",
domain = self.data.helo_domain,
result = %spf_output.result(),
);
if self
.handle_spf(&spf_output, self.params.spf_ehlo.is_strict())
.await?
{
self.data.spf_ehlo = spf_output.into();
} else {
self.data.mail_from = None;
self.data.helo_domain = prev_helo_domain;
return Ok(());
}
}
// Sieve filtering
if let Some(script) = self
.core
.core
.eval_if::<String, _>(
&self.core.core.smtp.session.ehlo.script,
self,
self.data.session_id,
)
.await
.and_then(|name| self.core.core.get_sieve_script(&name))
{
if let ScriptResult::Reject(message) = self
.run_script(script.clone(), self.build_script_parameters("ehlo"))
.await
{
tracing::info!(
context = "sieve",
event = "reject",
domain = &self.data.helo_domain,
reason = message);
self.data.mail_from = None;
self.data.helo_domain = prev_helo_domain;
self.data.spf_ehlo = None;
return self.write(message.as_bytes()).await;
}
}
// Milter filtering
if let Err(message) = self.run_milters(Stage::Ehlo, None).await {
tracing::info!(
context = "milter",
event = "reject",
domain = &self.data.helo_domain,
reason = message.message.as_ref());
self.data.mail_from = None;
self.data.helo_domain = prev_helo_domain;
self.data.spf_ehlo = None;
return self.write(message.message.as_bytes()).await;
}
// MTAHook filtering
if let Err(message) = self.run_mta_hooks(Stage::Ehlo, None).await {
tracing::info!(
context = "mta_hook",
event = "reject",
domain = &self.data.helo_domain,
reason = message.message.as_ref());
self.data.mail_from = None;
self.data.helo_domain = prev_helo_domain;
self.data.spf_ehlo = None;
return self.write(message.message.as_bytes()).await;
}
tracing::debug!(
context = "ehlo",
event = "ehlo",
domain = self.data.helo_domain,
);
}
// Reset
if self.data.mail_from.is_some() {
self.reset();
}
if !is_extended {
return self
.write(format!("250 {} you had me at HELO\r\n", self.hostname).as_bytes())
.await;
}
let mut response = EhloResponse::new(self.hostname.as_str());
response.capabilities =
EXT_ENHANCED_STATUS_CODES | EXT_8BIT_MIME | EXT_BINARY_MIME | EXT_SMTP_UTF8;
if !self.stream.is_tls() && self.instance.acceptor.is_tls() {
response.capabilities |= EXT_START_TLS;
}
let ec = &self.core.core.smtp.session.extensions;
let ac = &self.core.core.smtp.session.auth;
let dc = &self.core.core.smtp.session.data;
// Pipelining
if self
.core
.core
.eval_if(&ec.pipelining, self, self.data.session_id)
.await
.unwrap_or(true)
{
response.capabilities |= EXT_PIPELINING;
}
// Chunking
if self
.core
.core
.eval_if(&ec.chunking, self, self.data.session_id)
.await
.unwrap_or(true)
{
response.capabilities |= EXT_CHUNKING;
}
// Address Expansion
if self
.core
.core
.eval_if(&ec.expn, self, self.data.session_id)
.await
.unwrap_or(false)
{
response.capabilities |= EXT_EXPN;
}
// Recipient Verification
if self
.core
.core
.eval_if(&ec.vrfy, self, self.data.session_id)
.await
.unwrap_or(false)
{
response.capabilities |= EXT_VRFY;
}
// Require TLS
if self
.core
.core
.eval_if(&ec.requiretls, self, self.data.session_id)
.await
.unwrap_or(true)
{
response.capabilities |= EXT_REQUIRE_TLS;
}
// DSN
if self
.core
.core
.eval_if(&ec.dsn, self, self.data.session_id)
.await
.unwrap_or(false)
{
response.capabilities |= EXT_DSN;
}
// Authentication
if self.data.authenticated_as.is_empty() {
response.auth_mechanisms = self
.core
.core
.eval_if::<Mechanism, _>(&ac.mechanisms, self, self.data.session_id)
.await
.unwrap_or_default()
.into();
if response.auth_mechanisms != 0 {
response.capabilities |= EXT_AUTH;
}
}
// Future release
if let Some(value) = self
.core
.core
.eval_if::<Duration, _>(&ec.future_release, self, self.data.session_id)
.await
{
response.capabilities |= EXT_FUTURE_RELEASE;
response.future_release_interval = value.as_secs();
response.future_release_datetime = SystemTime::now()
.duration_since(SystemTime::UNIX_EPOCH)
.map(|d| d.as_secs())
.unwrap_or(0)
+ value.as_secs();
}
// Deliver By
if let Some(value) = self
.core
.core
.eval_if::<Duration, _>(&ec.deliver_by, self, self.data.session_id)
.await
{
response.capabilities |= EXT_DELIVER_BY;
response.deliver_by = value.as_secs();
}
// Priority
if let Some(value) = self
.core
.core
.eval_if::<MtPriority, _>(&ec.mt_priority, self, self.data.session_id)
.await
{
response.capabilities |= EXT_MT_PRIORITY;
response.mt_priority = value;
}
// Size
response.size = self
.core
.core
.eval_if(&dc.max_message_size, self, self.data.session_id)
.await
.unwrap_or(25 * 1024 * 1024);
if response.size > 0 {
response.capabilities |= EXT_SIZE;
}
// No soliciting
if let Some(value) = self
.core
.core
.eval_if::<String, _>(&ec.no_soliciting, self, self.data.session_id)
.await
{
response.capabilities |= EXT_NO_SOLICITING;
response.no_soliciting = if !value.is_empty() {
value.to_string().into()
} else {
None
};
}
// Generate response
let mut buf = Vec::with_capacity(64);
response.write(&mut buf).ok();
self.write(&buf).await
}
}
|
