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
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
|
use std::borrow::Cow;
use std::num::NonZeroU32;
use std::sync::Arc;
use anyhow::{anyhow, bail, Error, Result};
use boitalettres::proto::res::body::Data as Body;
use chrono::{Offset, TimeZone, Utc};
use futures::stream::{FuturesOrdered, StreamExt};
use imap_codec::types::address::Address;
use imap_codec::types::body::{BasicFields, Body as FetchBody, BodyStructure, SpecificFields};
use imap_codec::types::core::{Atom, IString, NString};
use imap_codec::types::datetime::MyDateTime;
use imap_codec::types::envelope::Envelope;
use imap_codec::types::fetch_attributes::{FetchAttribute, MacroOrFetchAttributes};
use imap_codec::types::flag::Flag;
use imap_codec::types::response::{Code, Data, MessageAttribute, Status};
use imap_codec::types::sequence::{self, SequenceSet};
use mail_parser::*;
use crate::mail::mailbox::Mailbox;
use crate::mail::uidindex::UidIndex;
const DEFAULT_FLAGS: [Flag; 5] = [
Flag::Seen,
Flag::Answered,
Flag::Flagged,
Flag::Deleted,
Flag::Draft,
];
/// A MailboxView is responsible for giving the client the information
/// it needs about a mailbox, such as an initial summary of the mailbox's
/// content and continuous updates indicating when the content
/// of the mailbox has been changed.
/// To do this, it keeps a variable `known_state` that corresponds to
/// what the client knows, and produces IMAP messages to be sent to the
/// client that go along updates to `known_state`.
pub struct MailboxView {
mailbox: Arc<Mailbox>,
known_state: UidIndex,
}
impl MailboxView {
/// Creates a new IMAP view into a mailbox.
/// Generates the necessary IMAP messages so that the client
/// has a satisfactory summary of the current mailbox's state.
/// These are the messages that are sent in response to a SELECT command.
pub async fn new(mailbox: Arc<Mailbox>) -> Result<(Self, Vec<Body>)> {
let state = mailbox.current_uid_index().await;
let new_view = Self {
mailbox,
known_state: state,
};
let mut data = Vec::<Body>::new();
data.push(new_view.exists()?);
data.push(new_view.recent()?);
data.extend(new_view.flags()?.into_iter());
data.push(new_view.uidvalidity()?);
data.push(new_view.uidnext()?);
if let Some(unseen) = new_view.unseen()? {
data.push(unseen);
}
Ok((new_view, data))
}
/// Looks up state changes in the mailbox and produces a set of IMAP
/// responses describing the changes.
pub async fn sync_update(&mut self) -> Result<Vec<Body>> {
self.mailbox.sync().await?;
self.update().await
}
/// Produces a set of IMAP responses describing the change between
/// what the client knows and what is actually in the mailbox.
pub async fn update(&mut self) -> Result<Vec<Body>> {
let new_view = MailboxView {
mailbox: self.mailbox.clone(),
known_state: self.mailbox.current_uid_index().await,
};
let mut data = Vec::<Body>::new();
if new_view.known_state.uidvalidity != self.known_state.uidvalidity {
// TODO: do we want to push less/more info than this?
data.push(new_view.uidvalidity()?);
data.push(new_view.exists()?);
data.push(new_view.uidnext()?);
} else {
// Calculate diff between two mailbox states
// See example in IMAP RFC in section on NOOP command:
// we want to produce something like this:
// C: a047 NOOP
// S: * 22 EXPUNGE
// S: * 23 EXISTS
// S: * 14 FETCH (UID 1305 FLAGS (\Seen \Deleted))
// S: a047 OK Noop completed
// In other words:
// - notify client of expunged mails
// - if new mails arrived, notify client of number of existing mails
// - if flags changed for existing mails, tell client
// - notify client of expunged mails
let mut n_expunge = 0;
for (i, (_uid, uuid)) in self.known_state.idx_by_uid.iter().enumerate() {
if !new_view.known_state.table.contains_key(uuid) {
data.push(Body::Data(Data::Expunge(
NonZeroU32::try_from((i + 1 - n_expunge) as u32).unwrap(),
)));
n_expunge += 1;
}
}
// - if new mails arrived, notify client of number of existing mails
if new_view.known_state.table.len() != self.known_state.table.len() - n_expunge {
data.push(new_view.exists()?);
}
// - if flags changed for existing mails, tell client
for (i, (_uid, uuid)) in new_view.known_state.idx_by_uid.iter().enumerate() {
let old_mail = self.known_state.table.get(uuid);
let new_mail = new_view.known_state.table.get(uuid);
if old_mail.is_some() && old_mail != new_mail {
if let Some((uid, flags)) = new_mail {
data.push(Body::Data(Data::Fetch {
seq_or_uid: NonZeroU32::try_from((i + 1) as u32).unwrap(),
attributes: vec![
MessageAttribute::Uid((*uid).try_into().unwrap()),
MessageAttribute::Flags(
flags.iter().filter_map(|f| string_to_flag(f)).collect(),
),
],
}));
}
}
}
}
*self = new_view;
Ok(data)
}
/// Looks up state changes in the mailbox and produces a set of IMAP
/// responses describing the new state.
pub async fn fetch(
&self,
sequence_set: &SequenceSet,
attributes: &MacroOrFetchAttributes,
uid: &bool,
) -> Result<Vec<Body>> {
if *uid {
bail!("UID FETCH not implemented");
}
let mail_vec = self
.known_state
.idx_by_uid
.iter()
.map(|(uid, uuid)| (*uid, *uuid))
.collect::<Vec<_>>();
let mut mails = vec![];
let iter_strat = sequence::Strategy::Naive {
largest: NonZeroU32::try_from((self.known_state.idx_by_uid.len() + 1) as u32).unwrap(),
};
for i in sequence_set.iter(iter_strat) {
if let Some(mail) = mail_vec.get(i.get() as usize - 1) {
mails.push((i, *mail));
} else {
bail!("No such mail: {}", i);
}
}
let mails_uuid = mails
.iter()
.map(|(_i, (_uid, uuid))| *uuid)
.collect::<Vec<_>>();
let mails_meta = self.mailbox.fetch_meta(&mails_uuid).await?;
let fetch_attrs = match attributes {
MacroOrFetchAttributes::Macro(m) => m.expand(),
MacroOrFetchAttributes::FetchAttributes(a) => a.clone(),
};
let need_body = fetch_attrs.iter().any(|x| {
matches!(
x,
FetchAttribute::Body
| FetchAttribute::BodyExt { .. }
| FetchAttribute::Rfc822
| FetchAttribute::Rfc822Text
| FetchAttribute::BodyStructure
)
});
let mails = if need_body {
let mut iter = mails
.into_iter()
.zip(mails_meta.into_iter())
.map(|((i, (uid, uuid)), meta)| async move {
let body = self.mailbox.fetch_full(uuid, &meta.message_key).await?;
Ok::<_, anyhow::Error>((i, uid, uuid, meta, Some(body)))
})
.collect::<FuturesOrdered<_>>();
let mut mails = vec![];
while let Some(m) = iter.next().await {
mails.push(m?);
}
mails
} else {
mails
.into_iter()
.zip(mails_meta.into_iter())
.map(|((i, (uid, uuid)), meta)| (i, uid, uuid, meta, None))
.collect::<Vec<_>>()
};
let mut ret = vec![];
for (i, uid, uuid, meta, body) in mails {
let mut attributes = vec![MessageAttribute::Uid(uid)];
let (_uid2, flags) = self
.known_state
.table
.get(&uuid)
.ok_or_else(|| anyhow!("Mail not in uidindex table: {}", uuid))?;
let parsed = match &body {
Some(m) => {
mail_parser::Message::parse(m).ok_or_else(|| anyhow!("Invalid mail body"))?
}
None => mail_parser::Message::parse(&meta.headers)
.ok_or_else(|| anyhow!("Invalid mail headers"))?,
};
for attr in fetch_attrs.iter() {
match attr {
FetchAttribute::Uid => (),
FetchAttribute::Flags => {
attributes.push(MessageAttribute::Flags(
flags.iter().filter_map(|f| string_to_flag(f)).collect(),
));
}
FetchAttribute::Rfc822Size => {
attributes.push(MessageAttribute::Rfc822Size(meta.rfc822_size as u32))
}
FetchAttribute::Rfc822Header => attributes.push(
MessageAttribute::Rfc822Header(NString(Some(IString::Literal(
meta.headers
.clone()
.try_into()
.or(Err(Error::msg("IString conversion error")))?,
)))),
),
FetchAttribute::Rfc822Text => {
let r = parsed
.raw_message.get(parsed.offset_body..parsed.offset_end)
.ok_or(Error::msg("Unable to extract email body, cursors out of bound. This is a bug."))?
.try_into()
.or(Err(Error::msg("IString conversion error")))?;
attributes.push(MessageAttribute::Rfc822Text(NString(Some(
IString::Literal(r),
))))
}
FetchAttribute::Rfc822 => {
attributes.push(MessageAttribute::Rfc822(NString(Some(IString::Literal(
body.as_ref().unwrap().clone().try_into().unwrap(),
)))))
}
FetchAttribute::Envelope => {
attributes.push(MessageAttribute::Envelope(message_envelope(&parsed)))
}
FetchAttribute::Body => attributes.push(MessageAttribute::Body(
build_imap_email_struct(&parsed, &parsed.structure)?,
)),
FetchAttribute::BodyStructure => attributes.push(MessageAttribute::Body(
build_imap_email_struct(&parsed, &parsed.structure)?,
)),
FetchAttribute::BodyExt {
section: _,
partial: _,
peek: _,
} => {
// @TODO This is a stub
let is = IString::try_from("test").unwrap();
attributes.push(MessageAttribute::BodyExt {
section: None,
origin: None,
data: NString(Some(is)),
})
}
FetchAttribute::InternalDate => {
attributes.push(MessageAttribute::InternalDate(MyDateTime(
Utc.fix()
.timestamp(i64::try_from(meta.internaldate / 1000)?, 0),
)));
}
}
}
ret.push(Body::Data(Data::Fetch {
seq_or_uid: i,
attributes,
}));
}
Ok(ret)
}
// ----
/// Produce an OK [UIDVALIDITY _] message corresponding to `known_state`
fn uidvalidity(&self) -> Result<Body> {
let uid_validity = Status::ok(
None,
Some(Code::UidValidity(self.known_state.uidvalidity)),
"UIDs valid",
)
.map_err(Error::msg)?;
Ok(Body::Status(uid_validity))
}
/// Produce an OK [UIDNEXT _] message corresponding to `known_state`
fn uidnext(&self) -> Result<Body> {
let next_uid = Status::ok(
None,
Some(Code::UidNext(self.known_state.uidnext)),
"Predict next UID",
)
.map_err(Error::msg)?;
Ok(Body::Status(next_uid))
}
/// Produces an UNSEEN message (if relevant) corresponding to the
/// first unseen message id in `known_state`
fn unseen(&self) -> Result<Option<Body>> {
let unseen = self
.known_state
.idx_by_flag
.get(&"$unseen".to_string())
.and_then(|os| os.get_min())
.cloned();
if let Some(unseen) = unseen {
let status_unseen =
Status::ok(None, Some(Code::Unseen(unseen.clone())), "First unseen UID")
.map_err(Error::msg)?;
Ok(Some(Body::Status(status_unseen)))
} else {
Ok(None)
}
}
/// Produce an EXISTS message corresponding to the number of mails
/// in `known_state`
fn exists(&self) -> Result<Body> {
let exists = u32::try_from(self.known_state.idx_by_uid.len())?;
Ok(Body::Data(Data::Exists(exists)))
}
/// Produce a RECENT message corresponding to the number of
/// recent mails in `known_state`
fn recent(&self) -> Result<Body> {
let recent = self
.known_state
.idx_by_flag
.get(&"\\Recent".to_string())
.map(|os| os.len())
.unwrap_or(0);
let recent = u32::try_from(recent)?;
Ok(Body::Data(Data::Recent(recent)))
}
/// Produce a FLAGS and a PERMANENTFLAGS message that indicates
/// the flags that are in `known_state` + default flags
fn flags(&self) -> Result<Vec<Body>> {
let mut flags: Vec<Flag> = self
.known_state
.idx_by_flag
.flags()
.map(|f| string_to_flag(f))
.flatten()
.collect();
for f in DEFAULT_FLAGS.iter() {
if !flags.contains(f) {
flags.push(f.clone());
}
}
let mut ret = vec![Body::Data(Data::Flags(flags.clone()))];
flags.push(Flag::Permanent);
let permanent_flags =
Status::ok(None, Some(Code::PermanentFlags(flags)), "Flags permitted")
.map_err(Error::msg)?;
ret.push(Body::Status(permanent_flags));
Ok(ret)
}
}
fn string_to_flag(f: &str) -> Option<Flag> {
match f.chars().next() {
Some('\\') => None,
Some('$') if f == "$unseen" => None,
Some(_) => match Atom::try_from(f.clone()) {
Err(_) => {
tracing::error!(flag=%f, "Unable to encode flag as IMAP atom");
None
}
Ok(a) => Some(Flag::Keyword(a)),
},
None => None,
}
}
/// Envelope rules are defined in RFC 3501, section 7.4.2
/// https://datatracker.ietf.org/doc/html/rfc3501#section-7.4.2
///
/// Some important notes:
///
/// If the Sender or Reply-To lines are absent in the [RFC-2822]
/// header, or are present but empty, the server sets the
/// corresponding member of the envelope to be the same value as
/// the from member (the client is not expected to know to do
/// this). Note: [RFC-2822] requires that all messages have a valid
/// From header. Therefore, the from, sender, and reply-to
/// members in the envelope can not be NIL.
///
/// If the Date, Subject, In-Reply-To, and Message-ID header lines
/// are absent in the [RFC-2822] header, the corresponding member
/// of the envelope is NIL; if these header lines are present but
/// empty the corresponding member of the envelope is the empty
/// string.
//@FIXME return an error if the envelope is invalid instead of panicking
//@FIXME some fields must be defaulted if there are not set.
fn message_envelope(msg: &mail_parser::Message<'_>) -> Envelope {
let from = convert_addresses(msg.get_from()).unwrap_or(vec![]);
Envelope {
date: NString(
msg.get_date()
.map(|d| IString::try_from(d.to_iso8601()).unwrap()),
),
subject: NString(
msg.get_subject()
.map(|d| IString::try_from(d.to_string()).unwrap()),
),
from: from.clone(),
sender: convert_addresses(msg.get_sender()).unwrap_or(from.clone()),
reply_to: convert_addresses(msg.get_reply_to()).unwrap_or(from.clone()),
to: convert_addresses(msg.get_to()).unwrap_or(vec![]),
cc: convert_addresses(msg.get_cc()).unwrap_or(vec![]),
bcc: convert_addresses(msg.get_bcc()).unwrap_or(vec![]),
in_reply_to: NString(None), // @TODO
message_id: NString(
msg.get_message_id()
.map(|d| IString::try_from(d.to_string()).unwrap()),
),
}
}
fn convert_addresses(a: &mail_parser::HeaderValue<'_>) -> Option<Vec<Address>> {
match a {
mail_parser::HeaderValue::Address(a) => Some(vec![convert_address(a)]),
mail_parser::HeaderValue::AddressList(l) => {
Some(l.iter().map(|a| convert_address(a)).collect())
}
mail_parser::HeaderValue::Empty => None,
mail_parser::HeaderValue::Collection(c) => Some(
c.iter()
.map(|l| convert_addresses(l).unwrap_or(vec![]))
.flatten()
.collect(),
),
_ => {
tracing::warn!("Invalid address header");
None
}
}
}
//@FIXME Remove unwrap
fn convert_address(a: &mail_parser::Addr<'_>) -> Address {
let (user, host) = match &a.address {
None => (None, None),
Some(x) => match x.split_once('@') {
Some((u, h)) => (Some(u.to_string()), Some(h.to_string())),
None => (Some(x.to_string()), None),
},
};
Address::new(
NString(
a.name
.as_ref()
.map(|x| IString::try_from(x.to_string()).unwrap()),
),
// SMTP at-domain-list (source route) seems obsolete since at least 1991
// https://www.mhonarc.org/archive/html/ietf-822/1991-06/msg00060.html
NString(None),
NString(user.map(|x| IString::try_from(x).unwrap())),
NString(host.map(|x| IString::try_from(x).unwrap())),
)
}
/*
--CAPTURE--
b fetch 29878:29879 (BODY)
* 29878 FETCH (BODY (("text" "plain" ("charset" "utf-8") NIL NIL "quoted-printable" 3264 82)("text" "html" ("charset" "utf-8") NIL NIL "quoted-printable" 31834 643) "alternative"))
* 29879 FETCH (BODY ("text" "html" ("charset" "us-ascii") NIL NIL "7bit" 4107 131))
^^^^^^^^^^^^^^^^^^^^^^ ^^^ ^^^ ^^^^^^ ^^^^ ^^^
| | | | | | number of lines
| | | | | size
| | | | content transfer encoding
| | | description
| | id
| parameter list
b OK Fetch completed (0.001 + 0.000 secs).
*/
fn build_imap_email_struct<'a>(
msg: &Message<'a>,
node: &MessageStructure,
) -> Result<BodyStructure> {
match node {
MessageStructure::Part(id) => {
let part = msg.parts.get(*id).ok_or(anyhow!(
"Email part referenced in email structure is missing"
))?;
match part {
MessagePart::Multipart(_) => {
unreachable!("A multipart entry can not be found here.")
}
MessagePart::Text(bp) | MessagePart::Html(bp) => {
let (attrs, mut basic) = headers_to_basic_fields(bp)?;
// If the charset is not defined, set it to "us-ascii"
if attrs.charset.is_none() {
basic
.parameter_list
.push((unchecked_istring("charset"), unchecked_istring("us-ascii")));
}
// If the subtype is not defined, set it to "plain". MIME (RFC2045) says that subtype
// MUST be defined and hence has no default. But mail-parser does not make any
// difference between MIME and raw emails, hence raw emails have no subtypes.
let subtype = bp
.get_content_type()
.map(|h| h.c_subtype.as_ref())
.flatten()
.map(|st| IString::try_from(st.to_string()).ok())
.flatten()
.unwrap_or(unchecked_istring("plain"));
Ok(BodyStructure::Single {
body: FetchBody {
basic,
specific: SpecificFields::Text {
subtype,
number_of_lines: u32::try_from(
// We do not count the number of lines but the number of line
// feeds to have the same behavior as Dovecot and Cyrus.
// 2 lines = 1 line feed.
bp.body_raw.as_ref().iter().filter(|&c| c == &b'\n').count(),
)?,
},
},
extension: None,
})
}
MessagePart::Binary(bp) | MessagePart::InlineBinary(bp) => {
let (_, basic) = headers_to_basic_fields(bp)?;
let ct = bp
.get_content_type()
.ok_or(anyhow!("Content-Type is missing but required here."))?;
let type_ =
IString::try_from(ct.c_type.as_ref().to_string()).map_err(|_| {
anyhow!("Unable to build IString from given Content-Type type given")
})?;
let subtype = IString::try_from(
ct.c_subtype
.as_ref()
.ok_or(anyhow!("Content-Type invalid, missing subtype"))?
.to_string(),
)
.map_err(|_| {
anyhow!("Unable to build IString from given Content-Type subtype given")
})?;
Ok(BodyStructure::Single {
body: FetchBody {
basic,
specific: SpecificFields::Basic { type_, subtype },
},
extension: None,
})
}
MessagePart::Message(bp) => {
let (_, mut basic) = headers_to_basic_fields(bp)?;
// @NOTE in some cases mail-parser does not parse the MessageAttachment but
// provide it as raw body. Using `as_ref()` masks this fact: if the message is
// parsed, as_ref() will return None. But by looking quickly at the code, it
// seems that the attachment is not parsed when mail-parser encounters some
// encoding problems, so it might be better to trust mail-parser.
let inner = bp
.get_body()
.as_ref()
.ok_or(anyhow!("Unable to parse inner message."))?;
// @FIXME mail-parser does not handle ways when a MIME message contains
// a raw email and wrongly take its delimiter. We thus test the headers to
// learn if it is a RFC822 email (raw) or RFC5322 (MIME) message.
// The correct way would be to patch mail-parser.
let raw_msg = match part.unwrap_message().get_content_type() {
Some(ContentType {
attributes: Some(_),
..
}) => {
//println!("has a content type {:?}", bp);
&inner.raw_message[..]
}
_ => {
//println!("has no content type {:?}", bp);
&inner.raw_message[..(inner.offset_last_part - inner.offset_header)]
}
};
basic.size = u32::try_from(raw_msg.len())?;
// We do not count the number of lines but the number of line
// feeds to have the same behavior as Dovecot and Cyrus.
// 2 lines = 1 line feed.
let nol = raw_msg.iter().filter(|&c| c == &b'\n').count();
Ok(BodyStructure::Single {
body: FetchBody {
basic,
specific: SpecificFields::Message {
envelope: message_envelope(inner),
body_structure: Box::new(build_imap_email_struct(
inner,
&inner.structure,
)?),
// @FIXME This solution is bad for 2 reasons:
// - RFC2045 says line endings are CRLF but we accept LF alone with
// this method. It could be a feature (be liberal in what you
// accept) but we must be sure that we don't break things.
// - It should be done during parsing, we are iterating twice on
// the same data which results in some wastes.
number_of_lines: u32::try_from(nol)?,
},
},
extension: None,
})
}
}
}
MessageStructure::List(lp) => {
let subtype = IString::try_from(
msg.get_content_type()
.ok_or(anyhow!("Content-Type is missing but required here."))?
.c_subtype
.as_ref()
.ok_or(anyhow!("Content-Type invalid, missing subtype"))?
.to_string(),
)
.map_err(|_| {
anyhow!("Unable to build IString from given Content-Type subtype given")
})?;
// @NOTE we should use try_collect() but it is unstable as of 2022-07-05
Ok(BodyStructure::Multi {
bodies: lp
.iter()
.map(|inner_node| build_imap_email_struct(msg, inner_node))
.fold(Ok(vec![]), try_collect_shime)?,
subtype,
extension_data: None,
})
}
MessageStructure::MultiPart((id, lp)) => {
let part = msg
.parts
.get(*id)
.map(|p| match p {
MessagePart::Multipart(mp) => Some(mp),
_ => None,
})
.flatten()
.ok_or(anyhow!(
"Email part referenced in email structure is missing"
))?;
let subtype = IString::try_from(
part.headers_rfc
.get(&RfcHeader::ContentType)
.ok_or(anyhow!("Content-Type is missing but required here."))?
.get_content_type()
.c_subtype
.as_ref()
.ok_or(anyhow!("Content-Type invalid, missing subtype"))?
.to_string(),
)
.map_err(|_| {
anyhow!("Unable to build IString from given Content-Type subtype given")
})?;
Ok(BodyStructure::Multi {
bodies: lp
.iter()
.map(|inner_node| build_imap_email_struct(msg, inner_node))
.fold(Ok(vec![]), try_collect_shime)?,
subtype,
extension_data: None,
/*Some(MultipartExtensionData {
parameter_list: vec![],
disposition: None,
language: None,
location: None,
extension: vec![],
})*/
})
}
}
}
fn try_collect_shime<T>(acc: Result<Vec<T>>, elem: Result<T>) -> Result<Vec<T>> {
match (acc, elem) {
(Err(e), _) | (_, Err(e)) => Err(e),
(Ok(mut ac), Ok(el)) => {
ac.push(el);
Ok(ac)
}
}
}
/// s is set to static to ensure that only compile time values
/// checked by developpers are passed.
fn unchecked_istring(s: &'static str) -> IString {
IString::try_from(s).expect("this value is expected to be a valid imap-codec::IString")
}
#[derive(Default)]
struct SpecialAttrs<'a> {
charset: Option<&'a Cow<'a, str>>,
boundary: Option<&'a Cow<'a, str>>,
}
/// Takes mail-parser Content-Type attributes, build imap-codec BasicFields.parameter_list and
/// identify some specific attributes (charset and boundary).
fn attrs_to_params<'a>(bp: &impl MimeHeaders<'a>) -> (SpecialAttrs, Vec<(IString, IString)>) {
// Try to extract Content-Type attributes from headers
let attrs = match bp
.get_content_type()
.map(|c| c.attributes.as_ref())
.flatten()
{
Some(v) => v,
_ => return (SpecialAttrs::default(), vec![]),
};
// Transform the Content-Type attributes into IMAP's parameter list
// Also collect some special attributes that might be used elsewhere
attrs.iter().fold(
(SpecialAttrs::default(), vec![]),
|(mut sa, mut param_list), (k, v)| {
let nk = k.to_lowercase();
match (IString::try_from(k.as_ref()), IString::try_from(v.as_ref())) {
(Ok(ik), Ok(iv)) => param_list.push((ik, iv)),
_ => return (sa, param_list),
};
match nk.as_str() {
"charset" => {
sa.charset = Some(v);
}
"boundary" => {
sa.boundary = Some(v);
}
_ => (),
};
(sa, param_list)
},
)
}
/// Takes mail-parser headers and build imap-codec BasicFields
/// Return some special informations too
fn headers_to_basic_fields<'a, T>(bp: &'a Part<T>) -> Result<(SpecialAttrs<'a>, BasicFields)> {
let (attrs, parameter_list) = attrs_to_params(bp);
let bf = BasicFields {
parameter_list,
id: NString(
bp.get_content_id()
.map(|ci| IString::try_from(ci.to_string()).ok())
.flatten(),
),
description: NString(
bp.get_content_description()
.map(|cd| IString::try_from(cd.to_string()).ok())
.flatten(),
),
/*
* RFC2045 - section 6.1
* "Content-Transfer-Encoding: 7BIT" is assumed if the
* Content-Transfer-Encoding header field is not present.
*/
content_transfer_encoding: bp
.get_content_transfer_encoding()
.map(|h| IString::try_from(h.to_string()).ok())
.flatten()
.unwrap_or(unchecked_istring("7bit")),
size: u32::try_from(bp.body_raw.len())?,
};
Ok((attrs, bf))
}
#[cfg(test)]
mod tests {
use super::*;
use imap_codec::codec::Encode;
use std::fs;
/// Future automated test. We use lossy utf8 conversion + lowercase everything,
/// so this test might allow invalid results. But at least it allows us to quickly test a
/// large variety of emails.
/// Keep in mind that special cases must still be tested manually!
#[test]
fn fetch_body() -> Result<()> {
let prefixes = [
"tests/emails/dxflrs/0001_simple",
"tests/emails/dxflrs/0002_mime",
"tests/emails/dxflrs/0003_mime-in-mime",
"tests/emails/dxflrs/0004_msg-in-msg",
"tests/emails/dxflrs/0005_mail-parser-readme",
//"tests/emails/dxflrs/0006_single-mime",
//"tests/emails/dxflrs/0007_raw_msg_in_rfc822",
//"tests/emails/rfc/000", // broken
// "tests/emails/rfc/001", // broken
// "tests/emails/rfc/002", // broken: dovecot adds \r when it is missing and count is as
// a character. Difference on how lines are counted too.
/*"tests/emails/rfc/003", // broken for the same reason
"tests/emails/thirdparty/000",
"tests/emails/thirdparty/001",
"tests/emails/thirdparty/002",
*/
];
for pref in prefixes.iter() {
println!("{}", pref);
let txt = fs::read(format!("{}.eml", pref))?;
let exp = fs::read(format!("{}.dovecot.body", pref))?;
let message = Message::parse(&txt).unwrap();
let mut resp = Vec::new();
MessageAttribute::Body(build_imap_email_struct(&message, &message.structure)?)
.encode(&mut resp);
let resp_str = String::from_utf8_lossy(&resp).to_lowercase();
let exp_no_parenthesis = &exp[1..exp.len() - 1];
let exp_str = String::from_utf8_lossy(exp_no_parenthesis).to_lowercase();
println!("aerogramme: {}\ndovecot: {}", resp_str, exp_str);
//println!("\n\n {} \n\n", String::from_utf8_lossy(&resp));
assert_eq!(resp_str, exp_str);
}
Ok(())
}
}
|
