logo
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
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
use std::convert::TryFrom;
use std::fmt;
use std::vec;
use std::io;
use std::path::Path;
use std::iter::FromIterator;
use std::iter::IntoIterator;

use buffered_reader::BufferedReader;

use crate::Result;
use crate::Error;
use crate::Packet;
use crate::cert::Cert;
use crate::packet::{self, Container};
use crate::parse::PacketParserResult;
use crate::parse::PacketParserBuilder;
use crate::parse::Parse;
use crate::parse::Cookie;

/// An unstructured [packet] sequence.
///
/// To parse an OpenPGP packet stream into a `PacketPile`, you can use
/// [`PacketParser`], [`PacketPileParser`], or
/// [`PacketPile::from_file`] (or related routines).
///
///   [packet]: https://tools.ietf.org/html/rfc4880#section-4
///   [`PacketParser`]: crate::parse::PacketParser
///   [`PacketPileParser`]: crate::parse::PacketPileParser
///
/// You can also convert a [`Cert`] into a `PacketPile` using
/// `PacketPile::from`.  Unlike serializing a `Cert`, this does not
/// drop any secret key material.
///
/// Normally, you'll want to convert the `PacketPile` to a `Cert` or a
/// `Message`.
///
/// # Examples
///
/// This example shows how to modify packets in PacketPile using [`pathspec`]s.
///
///   [`pathspec`]: PacketPile::path_ref()
///
/// ```rust
/// # use sequoia_openpgp as openpgp;
/// use std::convert::TryFrom;
/// use openpgp::{Packet, PacketPile};
/// use openpgp::packet::signature::Signature4;
/// use openpgp::packet::Signature;
/// use openpgp::cert::prelude::*;
/// use openpgp::parse::Parse;
/// use openpgp::serialize::Serialize;
/// use openpgp::policy::StandardPolicy;
/// use openpgp::crypto::mpi;
/// use openpgp::types::RevocationStatus;
///
/// # fn main() -> openpgp::Result<()> {
/// let (cert, revocation) = CertBuilder::new().generate()?;
///
/// let mut buffer = Vec::new();
/// cert.serialize(&mut buffer)?;
/// let packet: Packet = revocation.into();
/// packet.serialize(&mut buffer)?;
///
/// let policy = &StandardPolicy::new();
///
/// // Certificate is considered revoked because it is accompanied with its
/// // revocation signature
/// let pp: PacketPile = PacketPile::from_bytes(&buffer)?;
/// let cert = Cert::try_from(pp)?;
/// if let RevocationStatus::Revoked(_) = cert.revocation_status(policy, None) {
///     // cert is considered revoked
/// }
/// # else {
/// #     unreachable!();
/// # }
///
/// // Breaking the revocation signature changes certificate's status
/// let mut pp: PacketPile = PacketPile::from_bytes(&buffer)?;
/// if let Some(Packet::Signature(ref mut sig)) = pp.path_ref_mut(&[2]) {
///     *sig = Signature4::new(
///         sig.typ(),
///         sig.pk_algo(),
///         sig.hash_algo(),
///         sig.hashed_area().clone(),
///         sig.unhashed_area().clone(),
///         *sig.digest_prefix(),
///         // MPI is replaced with a dummy one
///         mpi::Signature::RSA {
///             s: mpi::MPI::from(vec![1, 2, 3])
///         }).into();
/// }
///
/// let cert = Cert::try_from(pp)?;
/// if let RevocationStatus::NotAsFarAsWeKnow = cert.revocation_status(policy, None) {
///     // revocation signature is broken and the cert is not revoked
///     assert_eq!(cert.bad_signatures().count(), 1);
/// }
/// # else {
/// #   unreachable!();
/// # }
/// #     Ok(())
/// # }
/// ```
#[derive(PartialEq, Clone, Default)]
pub struct PacketPile {
    /// At the top level, we have a sequence of packets, which may be
    /// containers.
    top_level: Container,
}

assert_send_and_sync!(PacketPile);

impl fmt::Debug for PacketPile {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.debug_struct("PacketPile")
            .field("packets", &self.top_level.children_ref())
            .finish()
    }
}

impl<'a> Parse<'a, PacketPile> for PacketPile {
    /// Deserializes the OpenPGP message stored in a `std::io::Read`
    /// object.
    ///
    /// Although this method is easier to use to parse a sequence of
    /// OpenPGP packets than a [`PacketParser`] or a
    /// [`PacketPileParser`], this interface buffers the whole message
    /// in memory.  Thus, the caller must be certain that the
    /// *deserialized* message is not too large.
    ///
    /// Note: this interface *does* buffer the contents of packets.
    ///
    ///   [`PacketParser`]: crate::parse::PacketParser
    ///   [`PacketPileParser`]: crate::parse::PacketPileParser
    fn from_reader<R: 'a + io::Read + Send + Sync>(reader: R) -> Result<PacketPile> {
        let bio = buffered_reader::Generic::with_cookie(
            reader, None, Cookie::default());
        PacketPile::from_buffered_reader(Box::new(bio))
    }

    /// Deserializes the OpenPGP message stored in the file named by
    /// `path`.
    ///
    /// See `from_reader` for more details and caveats.
    fn from_file<P: AsRef<Path>>(path: P) -> Result<PacketPile> {
        PacketPile::from_buffered_reader(
            Box::new(buffered_reader::File::with_cookie(path, Cookie::default())?))
    }

    /// Deserializes the OpenPGP message stored in the provided buffer.
    ///
    /// See `from_reader` for more details and caveats.
    fn from_bytes<D: AsRef<[u8]> + ?Sized>(data: &'a D) -> Result<PacketPile> {
        let bio = buffered_reader::Memory::with_cookie(
            data.as_ref(), Cookie::default());
        PacketPile::from_buffered_reader(Box::new(bio))
    }
}

impl std::str::FromStr for PacketPile {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
        Self::from_bytes(s.as_bytes())
    }
}

impl From<Vec<Packet>> for PacketPile {
    fn from(p: Vec<Packet>) -> Self {
        PacketPile { top_level: Container::from(p) }
    }
}

impl From<Packet> for PacketPile {
    fn from(p: Packet) -> Self {
        Self::from(vec![p])
    }
}

impl FromIterator<Packet> for PacketPile {
    fn from_iter<I: IntoIterator<Item=Packet>>(iter: I) -> Self {
        Self::from(Vec::from_iter(iter))
    }
}

impl From<PacketPile> for Vec<Packet> {
    fn from(pp: PacketPile) -> Self {
        pp.into_children().collect()
    }
}

impl PacketPile {
    /// Accessor for PacketPileParser.
    pub(crate) fn top_level_mut(&mut self) -> &mut Container {
        &mut self.top_level
    }

    /// Returns an error if operating on a non-container packet.
    fn error() -> crate::Error {
        crate::Error::InvalidOperation("Not a container packet".into())
    }

    /// Pretty prints the message to stderr.
    ///
    /// This function is primarily intended for debugging purposes.
    pub fn pretty_print(&self) {
        self.top_level.pretty_print(0);
    }

    /// Returns a reference to the packet at the location described by
    /// `pathspec`.
    ///
    /// `pathspec` is a slice of the form `[0, 1, 2]`.  Each element
    /// is the index of packet in a container.  Thus, the previous
    /// path specification means: return the third child of the second
    /// child of the first top-level packet.  In other words, the
    /// starred packet in the following tree:
    ///
    /// ```text
    ///         PacketPile
    ///        /     |     \
    ///       0      1      2  ...
    ///     /   \
    ///    /     \
    ///  0         1  ...
    ///        /   |   \  ...
    ///       0    1    2
    ///                 *
    /// ```
    ///
    /// And, `[10]` means return the 11th top-level packet.
    ///
    /// Note: there is no packet at the root.  Thus, the path `[]`
    /// returns None.
    ///
    /// # Examples
    ///
    /// ```rust
    /// # use sequoia_openpgp as openpgp;
    /// # use openpgp::{Result, types::{CompressionAlgorithm, DataFormat},
    /// #     Packet, PacketPile, packet::Literal, packet::CompressedData};
    /// # fn main() -> Result<()> {
    /// # let mut lit = Literal::new(DataFormat::Text);
    /// # lit.set_body(b"test".to_vec());
    /// # let packets = vec![lit.into()];
    /// let pile = PacketPile::from(packets);
    ///
    /// if let Some(packet) = pile.path_ref(&[0]) {
    ///     // There is a packet at this path.
    /// }
    /// # else {
    /// #     unreachable!();
    /// # }
    ///
    /// if let None = pile.path_ref(&[0, 1, 2]) {
    ///     // But none here.
    /// }
    /// # else {
    /// #     unreachable!();
    /// # }
    /// # Ok(())
    /// # }
    /// ```
    pub fn path_ref(&self, pathspec: &[usize]) -> Option<&Packet> {
        let mut packet : Option<&Packet> = None;

        let mut cont = Some(&self.top_level);
        for i in pathspec {
            if let Some(c) = cont.take() {
                if let Some(children) = c.children_ref() {
                    if *i < children.len() {
                        let p = &children[*i];
                        packet = Some(p);
                        cont = p.container_ref();
                        continue;
                    }
                }
            }

            return None;
        }
        packet
    }

    /// Returns a mutable reference to the packet at the location
    /// described by `pathspec`.
    ///
    /// See the description of the `path_spec` for more details.
    ///
    /// # Examples
    ///
    /// ```rust
    /// # use sequoia_openpgp as openpgp;
    /// # use openpgp::{Result, types::{CompressionAlgorithm, DataFormat},
    /// #     Packet, PacketPile, packet::Literal, packet::CompressedData};
    /// # fn main() -> Result<()> {
    /// # let mut lit = Literal::new(DataFormat::Text);
    /// # lit.set_body(b"test".to_vec());
    /// # let packets = vec![lit.into()];
    /// let mut pile = PacketPile::from(packets);
    ///
    /// if let Some(ref packet) = pile.path_ref_mut(&[0]) {
    ///     // There is a packet at this path.
    /// }
    /// # else {
    /// #     unreachable!();
    /// # }
    ///
    /// if let None = pile.path_ref_mut(&[0, 1, 2]) {
    ///     // But none here.
    /// }
    /// # else {
    /// #     unreachable!();
    /// # }
    /// # Ok(())
    /// # }
    /// ```
    pub fn path_ref_mut(&mut self, pathspec: &[usize]) -> Option<&mut Packet> {
        let mut container = &mut self.top_level;

        for (level, &i) in pathspec.iter().enumerate() {
            let tmp = container;

            let p = tmp.children_mut().and_then(|c| c.get_mut(i))?;

            if level == pathspec.len() - 1 {
                return Some(p)
            }

            container = p.container_mut().unwrap();
        }

        None
    }

    /// Replaces the specified packets at the location described by
    /// `pathspec` with `packets`.
    ///
    /// If a packet is a container, the sub-tree rooted at the
    /// container is removed.
    ///
    /// Note: the number of packets to remove need not match the
    /// number of packets to insert.
    ///
    /// The removed packets are returned.
    ///
    /// If the path was invalid, then `Error::IndexOutOfRange` is
    /// returned instead.
    ///
    /// # Examples
    ///
    /// ```rust
    /// # use sequoia_openpgp as openpgp;
    /// # use openpgp::{Result, types::{CompressionAlgorithm, DataFormat},
    /// #     Packet, PacketPile, packet::Literal, packet::CompressedData};
    /// # fn main() -> Result<()> {
    /// // A compressed data packet that contains a literal data packet.
    /// let mut literal = Literal::new(DataFormat::Text);
    /// literal.set_body(b"old".to_vec());
    /// let mut compressed =
    ///     CompressedData::new(CompressionAlgorithm::Uncompressed);
    /// compressed.children_mut().unwrap().push(literal.into());
    /// let mut pile = PacketPile::from(Packet::from(compressed));
    ///
    /// // Replace the literal data packet.
    /// let mut literal = Literal::new(DataFormat::Text);
    /// literal.set_body(b"new".to_vec());
    /// pile.replace(
    ///     &[0, 0], 1,
    ///     [literal.into()].to_vec())?;
    /// # if let Some(Packet::Literal(lit)) = pile.path_ref(&[0, 0]) {
    /// #     assert_eq!(lit.body(), &b"new"[..], "{:#?}", lit);
    /// # } else {
    /// #     panic!("Unexpected packet!");
    /// # }
    /// #     Ok(())
    /// # }
    /// ```
    pub fn replace(&mut self, pathspec: &[usize], count: usize,
                   mut packets: Vec<Packet>)
        -> Result<Vec<Packet>>
    {
        let mut container = &mut self.top_level;

        for (level, &i) in pathspec.iter().enumerate() {
            let tmp = container;

            if level == pathspec.len() - 1 {
                if tmp.children_ref().map(|c| i + count > c.len())
                    .unwrap_or(true)
                {
                    return Err(Error::IndexOutOfRange.into());
                }

                // Out with the old...
                let old = tmp.children_mut()
                    .expect("checked above")
                    .drain(i..i + count)
                    .collect::<Vec<Packet>>();
                assert_eq!(old.len(), count);

                // In with the new...

                let mut tail = tmp.children_mut()
                    .expect("checked above")
                    .drain(i..)
                    .collect::<Vec<Packet>>();

                tmp.children_mut().expect("checked above").append(&mut packets);
                tmp.children_mut().expect("checked above").append(&mut tail);

                return Ok(old)
            }

            if tmp.children_ref().map(|c| i >= c.len()).unwrap_or(true) {
                return Err(Error::IndexOutOfRange.into());
            }

            match tmp.children_ref().expect("checked above")[i] {
                // The structured container types.
                Packet::CompressedData(_)
                    | Packet::SEIP(_)
                    | Packet::AED(_)
                    => (), // Ok.
                _ => return Err(Error::IndexOutOfRange.into()),
            }
            container =
                tmp.children_mut().expect("checked above")[i].container_mut()
                .expect("The above packets are structured containers");
        }

        Err(Error::IndexOutOfRange.into())
    }

    /// Returns an iterator over all of the packet's descendants, in
    /// depth-first order.
    ///
    /// ```rust
    /// # use sequoia_openpgp as openpgp;
    /// # use openpgp::{Result, types::{CompressionAlgorithm, DataFormat},
    /// #     Packet, PacketPile, packet::Literal, packet::Tag};
    /// # use std::iter::Iterator;
    /// # fn main() -> Result<()> {
    /// let mut lit = Literal::new(DataFormat::Text);
    /// lit.set_body(b"test".to_vec());
    ///
    /// let pile = PacketPile::from(vec![lit.into()]);
    ///
    /// for packet in pile.descendants() {
    ///     assert_eq!(packet.tag(), Tag::Literal);
    /// }
    /// # Ok(())
    /// # }
    /// ```
    pub fn descendants(&self) -> packet::Iter {
        self.top_level.descendants().expect("toplevel is a container")
    }

    /// Returns an iterator over the top-level packets.
    ///
    /// ```rust
    /// # use sequoia_openpgp as openpgp;
    /// # use openpgp::{Result, types::{CompressionAlgorithm, DataFormat},
    /// #     Packet, PacketPile, packet::Literal, packet::CompressedData};
    /// # fn main() -> Result<()> {
    /// let mut lit = Literal::new(DataFormat::Text);
    /// lit.set_body(b"test".to_vec());
    ///
    /// let pile = PacketPile::from(vec![lit.into()]);
    ///
    /// assert_eq!(pile.children().len(), 1);
    /// # Ok(())
    /// # }
    /// ```
    pub fn children(&self)
        -> impl Iterator<Item=&Packet> + ExactSizeIterator + Send + Sync
    {
        self.top_level.children().expect("toplevel is a container")
    }

    /// Returns an `IntoIter` over the top-level packets.
    ///
    /// ```rust
    /// # use sequoia_openpgp as openpgp;
    /// # use openpgp::{Result, types::{CompressionAlgorithm, DataFormat},
    /// #     Packet, PacketPile, packet::Literal, packet::Tag};
    /// # fn main() -> Result<()> {
    /// let mut lit = Literal::new(DataFormat::Text);
    /// lit.set_body(b"test".to_vec());
    ///
    /// let pile = PacketPile::from(vec![lit.into()]);
    ///
    /// for packet in pile.into_children() {
    ///     assert_eq!(packet.tag(), Tag::Literal);
    /// }
    /// # Ok(())
    /// # }
    /// ```
    pub fn into_children(self)
        -> impl Iterator<Item=Packet> + ExactSizeIterator + Send + Sync
    {
        self.top_level.into_children().expect("toplevel is a container")
    }


    pub(crate) fn from_buffered_reader<'a>(bio: Box<dyn BufferedReader<Cookie> + 'a>)
            -> Result<PacketPile> {
        PacketParserBuilder::from_buffered_reader(bio)?
            .buffer_unread_content()
            .into_packet_pile()
    }
}

impl From<Cert> for PacketPile {
    /// Converts the `Cert` into a `PacketPile`.
    ///
    /// If any packets include secret key material, that secret key
    /// material is not dropped, as it is when serializing a `Cert`.
    fn from(cert: Cert) -> PacketPile {
        PacketPile::from(cert.into_packets().collect::<Vec<Packet>>())
    }
}

impl<'a> TryFrom<PacketParserResult<'a>> for PacketPile {
    type Error = anyhow::Error;

    /// Reads all of the packets from a `PacketParser`, and turns them
    /// into a message.
    ///
    /// Note: this assumes that `ppr` points to a top-level packet.
    fn try_from(ppr: PacketParserResult<'a>)
        -> Result<PacketPile>
    {
        // Things are not going to work out if we don't start with a
        // top-level packet.  We should only pop until
        // ppo.recursion_depth and leave the rest of the message, but
        // it is hard to imagine that that is what the caller wants.
        // Instead of hiding that error, fail fast.
        if let PacketParserResult::Some(ref pp) = ppr {
            if pp.recursion_depth() != 0 {
                return Err(Error::InvalidOperation(
                    format!("Expected top-level packet, \
                             but the parser is at level {}",
                            pp.recursion_depth())).into());
            }
        }

        // Create a top-level container.
        let mut top_level = Container::default();

        let mut last_position = 0;

        if ppr.is_eof() {
            // Empty message.
            return Ok(PacketPile::from(Vec::new()));
        }
        let mut pp = ppr.unwrap();

        'outer: loop {
            let recursion_depth = pp.recursion_depth();
            let (mut packet, mut ppr) = pp.recurse()?;
            let mut position = recursion_depth as isize;

            let mut relative_position : isize = position - last_position;
            assert!(relative_position <= 1);

            // Find the right container for `packet`.
            let mut container = &mut top_level;
            // If we recurse, don't create the new container here.
            for _ in 0..(position - if relative_position > 0 { 1 } else { 0 }) {
                // Do a little dance to prevent container from
                // being reborrowed and preventing us from
                // assigning to it.
                let tmp = container;
                let packets_len =
                    tmp.children_ref().ok_or_else(Self::error)?.len();
                let p = &mut tmp.children_mut()
                    .ok_or_else(Self::error)?
                    [packets_len - 1];

                container = p.container_mut().unwrap();
            }

            if relative_position < 0 {
                relative_position = 0;
            }

            // If next packet will be inserted in the same container
            // or the current container's child, we don't need to walk
            // the tree from the root.
            loop {
                if relative_position == 1 {
                    // Create a new container.
                    let tmp = container;
                    let i =
                        tmp.children_ref().ok_or_else(Self::error)?.len() - 1;
                    container = tmp.children_mut()
                        .ok_or_else(Self::error)?
                        [i].container_mut().unwrap();
                }

                container.children_mut().unwrap().push(packet);

                if ppr.is_eof() {
                    break 'outer;
                }

                pp = ppr.unwrap();

                last_position = position;
                position = pp.recursion_depth() as isize;
                relative_position = position - last_position;
                if position < last_position {
                    // There was a pop, we need to restart from the
                    // root.
                    break;
                }

                let recursion_depth = pp.recursion_depth();
                let (packet_, ppr_) = pp.recurse()?;
                packet = packet_;
                ppr = ppr_;
                assert_eq!(position, recursion_depth as isize);
            }
        }

        Ok(PacketPile { top_level })
    }
}

impl<'a> PacketParserBuilder<'a> {
    /// Finishes configuring the `PacketParser` and returns a fully
    /// parsed message.
    ///
    /// Note: calling this function does not change the default
    /// settings.  Thus, by default, the content of packets will *not*
    /// be buffered.
    ///
    /// Note: to avoid denial of service attacks, the `PacketParser`
    /// interface should be preferred unless the size of the message
    /// is known to fit in memory.
    ///
    /// # Examples
    ///
    /// ```rust
    /// # use sequoia_openpgp as openpgp;
    /// # use openpgp::Result;
    /// # use openpgp::PacketPile;
    /// # use openpgp::parse::{Parse, PacketParser, PacketParserBuilder};
    /// # f(include_bytes!("../tests/data/keys/public-key.gpg"));
    /// #
    /// # fn f(message_data: &[u8]) -> Result<PacketPile> {
    /// let message = PacketParserBuilder::from_bytes(message_data)?
    ///     .buffer_unread_content()
    ///     .into_packet_pile()?;
    /// # return Ok(message);
    /// # }
    /// ```
    pub fn into_packet_pile(self) -> Result<PacketPile> {
        PacketPile::try_from(self.build()?)
    }
}

#[cfg(test)]
mod test {
    use super::*;

    use crate::types::CompressionAlgorithm;
    use crate::types::DataFormat::Text;
    use crate::packet::Literal;
    use crate::packet::CompressedData;
    use crate::packet::seip::SEIP1;
    use crate::packet::Tag;
    use crate::parse::Parse;

    #[test]
    fn deserialize_test_1 () {
        // XXX: This test should be more thorough.  Right now, we mostly
        // just rely on the fact that an assertion is not thrown.

        // A flat message.
        let pile = PacketPile::from_bytes(crate::tests::key("public-key.gpg"))
            .unwrap();
        eprintln!("PacketPile has {} top-level packets.",
                  pile.children().len());
        eprintln!("PacketPile: {:?}", pile);

        let mut count = 0;
        for (i, p) in pile.descendants().enumerate() {
            eprintln!("{}: {:?}", i, p);
            count += 1;
        }

        assert_eq!(count, 61);
    }

    #[cfg(feature = "compression-deflate")]
    #[test]
    fn deserialize_test_2 () {
        // A message containing a compressed packet that contains a
        // literal packet.
        let pile = PacketPile::from_bytes(
            crate::tests::message("compressed-data-algo-1.gpg")).unwrap();
        eprintln!("PacketPile has {} top-level packets.",
                  pile.children().len());
        eprintln!("PacketPile: {:?}", pile);

        let mut count = 0;
        for (i, p) in pile.descendants().enumerate() {
            eprintln!("{}: {:?}", i, p);
            count += 1;
        }
        assert_eq!(count, 2);
    }

    #[cfg(feature = "compression-deflate")]
    #[test]
    fn deserialize_test_3 () {
        let pile =
            PacketPile::from_bytes(crate::tests::message("signed.gpg")).unwrap();
        eprintln!("PacketPile has {} top-level packets.",
                  pile.children().len());
        eprintln!("PacketPile: {:?}", pile);

        let mut count = 0;
        for (i, p) in pile.descendants().enumerate() {
            count += 1;
            eprintln!("{}: {:?}", i, p);
        }
        // We expect 6 packets.
        assert_eq!(count, 6);
    }

    // dkg's key contains packets from different OpenPGP
    // implementations.  And, it even includes some v3 signatures.
    //
    // lutz's key is a v3 key.
    #[test]
    fn torture() {
        use std::convert::TryInto;
        use crate::parse::PacketPileParser;

        let data = crate::tests::key("dkg.gpg");
        let mut ppp: PacketPileParser =
            PacketParserBuilder::from_bytes(data).unwrap()
            //.trace()
            .buffer_unread_content()
            .try_into().unwrap();

        while ppp.is_some() {
            ppp.recurse().unwrap();
        }
        let pile = ppp.finish();
        //pile.pretty_print();
        assert_eq!(pile.children().len(), 1450);

        let data = crate::tests::key("lutz.gpg");
        let mut ppp: PacketPileParser =
            PacketParserBuilder::from_bytes(data).unwrap()
            //.trace()
            .buffer_unread_content()
            .try_into().unwrap();

        while let Ok(pp) = ppp.as_ref() {
            eprintln!("{:?}", pp);
            ppp.recurse().unwrap();
        }
        let pile = ppp.finish();
        pile.pretty_print();
        assert_eq!(pile.children().len(), 77);
    }

    #[cfg(feature = "compression-deflate")]
    #[test]
    fn compression_quine_test_1 () {
        // Use the PacketPile::from_file interface to parse an OpenPGP
        // quine.
        let max_recursion_depth = 128;
        let pile = PacketParserBuilder::from_bytes(
            crate::tests::message("compression-quine.gpg")).unwrap()
            .max_recursion_depth(max_recursion_depth)
            .into_packet_pile().unwrap();

        let mut count = 0;
        for (i, p) in pile.descendants().enumerate() {
            count += 1;
            if false {
                eprintln!("{}: p: {:?}", i, p);
            }
        }

        assert_eq!(count, 1 + max_recursion_depth);
    }

    #[cfg(feature = "compression-deflate")]
    #[test]
    fn compression_quine_test_2 () {
        // Use the iterator interface to parse an OpenPGP quine.
        let max_recursion_depth = 255;
        let mut ppr : PacketParserResult
            = PacketParserBuilder::from_bytes(
                crate::tests::message("compression-quine.gpg")).unwrap()
                .max_recursion_depth(max_recursion_depth)
                .build().unwrap();

        let mut count = 0;
        loop {
            if let PacketParserResult::Some(pp2) = ppr {
                count += 1;

                let packet_depth = pp2.recursion_depth();
                let pp2 = pp2.recurse().unwrap().1;
                assert_eq!(packet_depth, count - 1);
                if pp2.is_some() {
                    assert_eq!(pp2.as_ref().unwrap().recursion_depth(), count);
                }
                ppr = pp2;
            } else {
                break;
            }
        }
        assert_eq!(count, 1 + max_recursion_depth as isize);
    }

    #[cfg(feature = "compression-deflate")]
    #[test]
    fn consume_content_1 () {
        use std::io::Read;
        use crate::parse::PacketParser;
        // A message containing a compressed packet that contains a
        // literal packet.  When we read some of the compressed
        // packet, we expect recurse() to not recurse.

        let ppr = PacketParserBuilder::from_bytes(
                crate::tests::message("compressed-data-algo-1.gpg")).unwrap()
            .buffer_unread_content()
            .build().unwrap();

        let mut pp = ppr.unwrap();
        if let Packet::CompressedData(_) = pp.packet {
        } else {
            panic!("Expected a compressed packet!");
        }

        // Read some of the body of the compressed packet.
        let mut data = [0u8; 1];
        let amount = pp.read(&mut data).unwrap();
        assert_eq!(amount, 1);

        // recurse should now not recurse.  Since there is nothing
        // following the compressed packet, ppr should be EOF.
        let (packet, ppr) = pp.next().unwrap();
        assert!(ppr.is_eof());

        // Get the rest of the content and put the initial byte that
        // we stole back.
        let mut content = packet.processed_body().unwrap().to_vec();
        content.insert(0, data[0]);

        let ppr = PacketParser::from_bytes(&content).unwrap();
        let pp = ppr.unwrap();
        if let Packet::Literal(_) = pp.packet {
        } else {
            panic!("Expected a literal packet!");
        }

        // And we're done...
        let ppr = pp.next().unwrap().1;
        assert!(ppr.is_eof());
    }

    #[test]
    fn path_ref() {
        // 0: SEIP
        //  0: CompressedData
        //   0: Literal("one")
        //   1: Literal("two")
        //   2: Literal("three")
        //   3: Literal("four")
        let mut packets : Vec<Packet> = Vec::new();

        let text = [ &b"one"[..], &b"two"[..],
                      &b"three"[..], &b"four"[..] ].to_vec();

        let mut cd = CompressedData::new(CompressionAlgorithm::Uncompressed);
        for t in text.iter() {
            let mut lit = Literal::new(Text);
            lit.set_body(t.to_vec());
            cd = cd.push(lit.into())
        }

        let mut seip = SEIP1::new();
        seip.children_mut().unwrap().push(cd.into());
        packets.push(seip.into());

        eprintln!("{:#?}", packets);

        let mut pile = PacketPile::from(packets);

        assert_eq!(pile.path_ref(&[ 0 ]).unwrap().tag(), Tag::SEIP);
        assert_eq!(pile.path_ref_mut(&[ 0 ]).unwrap().tag(), Tag::SEIP);
        assert_eq!(pile.path_ref(&[ 0, 0 ]).unwrap().tag(),
                   Tag::CompressedData);
        assert_eq!(pile.path_ref_mut(&[ 0, 0 ]).unwrap().tag(),
                   Tag::CompressedData);

        for (i, t) in text.into_iter().enumerate() {
            assert_eq!(pile.path_ref(&[ 0, 0, i ]).unwrap().tag(),
                       Tag::Literal);
            assert_eq!(pile.path_ref_mut(&[ 0, 0, i ]).unwrap().tag(),
                       Tag::Literal);

            let packet = pile.path_ref(&[ 0, 0, i ]).unwrap();
            if let Packet::Literal(l) = packet {
                assert_eq!(l.body(), t);
            } else {
                panic!("Expected literal, got: {:?}", packet);
            }
            let packet = pile.path_ref_mut(&[ 0, 0, i ]).unwrap();
            if let Packet::Literal(l) = packet {
                assert_eq!(l.body(), t);
            } else {
                panic!("Expected literal, got: {:?}", packet);
            }
        }

        // Try a few out of bounds accesses.
        assert!(pile.path_ref(&[ 0, 0, 4 ]).is_none());
        assert!(pile.path_ref_mut(&[ 0, 0, 4 ]).is_none());

        assert!(pile.path_ref(&[ 0, 0, 5 ]).is_none());
        assert!(pile.path_ref_mut(&[ 0, 0, 5 ]).is_none());

        assert!(pile.path_ref(&[ 0, 1 ]).is_none());
        assert!(pile.path_ref_mut(&[ 0, 1 ]).is_none());

        assert!(pile.path_ref(&[ 0, 2 ]).is_none());
        assert!(pile.path_ref_mut(&[ 0, 2 ]).is_none());

        assert!(pile.path_ref(&[ 1 ]).is_none());
        assert!(pile.path_ref_mut(&[ 1 ]).is_none());

        assert!(pile.path_ref(&[ 2 ]).is_none());
        assert!(pile.path_ref_mut(&[ 2 ]).is_none());

        assert!(pile.path_ref(&[ 0, 1, 0 ]).is_none());
        assert!(pile.path_ref_mut(&[ 0, 1, 0 ]).is_none());

        assert!(pile.path_ref(&[ 0, 2, 0 ]).is_none());
        assert!(pile.path_ref_mut(&[ 0, 2, 0 ]).is_none());
    }

    #[test]
    fn replace() {
        // 0: Literal("one")
        // =>
        // 0: Literal("two")
        let mut one = Literal::new(Text);
        one.set_body(b"one".to_vec());
        let mut two = Literal::new(Text);
        two.set_body(b"two".to_vec());
        let mut packets : Vec<Packet> = Vec::new();
        packets.push(one.into());

        assert!(packets.iter().map(|p| p.tag()).collect::<Vec<Tag>>()
                == [ Tag::Literal ]);

        let mut pile = PacketPile::from(packets.clone());
        pile.replace(
            &[ 0 ], 1,
            [ two.into()
            ].to_vec()).unwrap();

        let children = pile.into_children().collect::<Vec<Packet>>();
        assert_eq!(children.len(), 1, "{:#?}", children);
        if let Packet::Literal(ref literal) = children[0] {
            assert_eq!(literal.body(), &b"two"[..], "{:#?}", literal);
        } else {
            panic!("WTF");
        }

        // We start with four packets, and replace some of them with
        // up to 3 packets.
        let initial
            = [ &b"one"[..], &b"two"[..], &b"three"[..], &b"four"[..] ].to_vec();
        let inserted
            = [ &b"a"[..], &b"b"[..], &b"c"[..] ].to_vec();

        let mut packets : Vec<Packet> = Vec::new();
        for text in initial.iter() {
            let mut lit = Literal::new(Text);
            lit.set_body(text.to_vec());
            packets.push(lit.into())
        }

        for start in 0..initial.len() + 1 {
            for delete in 0..initial.len() - start + 1 {
                for insert in 0..inserted.len() + 1 {
                    let mut pile = PacketPile::from(packets.clone());

                    let mut replacement : Vec<Packet> = Vec::new();
                    for &text in inserted[0..insert].iter() {
                        let mut lit = Literal::new(Text);
                        lit.set_body(text.to_vec());
                        replacement.push(lit.into());
                    }

                    pile.replace(&[ start ], delete, replacement).unwrap();

                    let values = pile
                        .children()
                        .map(|p| {
                            if let Packet::Literal(ref literal) = p {
                                literal.body()
                            } else {
                                panic!("Expected a literal packet, got: {:?}", p);
                            }
                        })
                        .collect::<Vec<&[u8]>>();

                    assert_eq!(values.len(), initial.len() - delete + insert);

                    assert_eq!(values[..start],
                               initial[..start]);
                    assert_eq!(values[start..start + insert],
                               inserted[..insert]);
                    assert_eq!(values[start + insert..],
                               initial[start + delete..]);
                }
            }
        }


        // Like above, but the packets to replace are not at the
        // top-level, but in a compressed data packet.

        let initial
            = [ &b"one"[..], &b"two"[..], &b"three"[..], &b"four"[..] ].to_vec();
        let inserted
            = [ &b"a"[..], &b"b"[..], &b"c"[..] ].to_vec();

        let mut cd = CompressedData::new(CompressionAlgorithm::Uncompressed);
        for l in initial.iter() {
            let mut lit = Literal::new(Text);
            lit.set_body(l.to_vec());
            cd = cd.push(lit.into());
        }

        for start in 0..initial.len() + 1 {
            for delete in 0..initial.len() - start + 1 {
                for insert in 0..inserted.len() + 1 {
                    let mut pile = PacketPile::from(
                        vec![ cd.clone().into() ]);

                    let mut replacement : Vec<Packet> = Vec::new();
                    for &text in inserted[0..insert].iter() {
                        let mut lit = Literal::new(Text);
                        lit.set_body(text.to_vec());
                        replacement.push(lit.into());
                    }

                    pile.replace(&[ 0, start ], delete, replacement).unwrap();

                    let top_level = pile.children().collect::<Vec<&Packet>>();
                    assert_eq!(top_level.len(), 1);

                    let values = top_level[0]
                        .children().unwrap()
                        .map(|p| {
                            if let Packet::Literal(ref literal) = p {
                                literal.body()
                            } else {
                                panic!("Expected a literal packet, got: {:?}", p);
                            }
                        })
                        .collect::<Vec<&[u8]>>();

                    assert_eq!(values.len(), initial.len() - delete + insert);

                    assert_eq!(values[..start],
                               initial[..start]);
                    assert_eq!(values[start..start + insert],
                               inserted[..insert]);
                    assert_eq!(values[start + insert..],
                               initial[start + delete..]);
                }
            }
        }

        // Make sure out-of-range accesses error out.
        let mut one = Literal::new(Text);
        one.set_body(b"one".to_vec());
        let mut packets : Vec<Packet> = Vec::new();
        packets.push(one.into());
        let mut pile = PacketPile::from(packets.clone());

        assert!(pile.replace(&[ 1 ], 0, Vec::new()).is_ok());
        assert!(pile.replace(&[ 2 ], 0, Vec::new()).is_err());
        assert!(pile.replace(&[ 0 ], 2, Vec::new()).is_err());
        assert!(pile.replace(&[ 0, 0 ], 0, Vec::new()).is_err());
        assert!(pile.replace(&[ 0, 1 ], 0, Vec::new()).is_err());

        // Try the same thing, but with a container.
        let mut packets : Vec<Packet> = Vec::new();
        packets.push(CompressedData::new(CompressionAlgorithm::Uncompressed)
                     .into());
        let mut pile = PacketPile::from(packets.clone());

        assert!(pile.replace(&[ 1 ], 0, Vec::new()).is_ok());
        assert!(pile.replace(&[ 2 ], 0, Vec::new()).is_err());
        assert!(pile.replace(&[ 0 ], 2, Vec::new()).is_err());
        // Since this is a container, this should be okay.
        assert!(pile.replace(&[ 0, 0 ], 0, Vec::new()).is_ok());
        assert!(pile.replace(&[ 0, 1 ], 0, Vec::new()).is_err());
    }
}