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
use std::boxed::Box;
use std::convert::TryInto;
use std::iter::Peekable;
use crate::composed::message::Message;
use crate::composed::Deserializable;
use crate::errors::Result;
use crate::packet::Packet;
use crate::types::Tag;
pub struct MessageParser<I: Sized + Iterator<Item = Result<Packet>>> {
source: Peekable<I>,
}
fn next<I: Iterator<Item = Result<Packet>>>(packets: &mut Peekable<I>) -> Option<Result<Message>> {
while let Some(res) = packets.by_ref().next() {
let packet = match res {
Ok(packet) => packet,
Err(err) => return Some(Err(err)),
};
debug!("{:?}: ", packet);
let tag = packet.tag();
match tag {
Tag::LiteralData => {
return match packet.try_into() {
Ok(data) => Some(Ok(Message::Literal(data))),
Err(err) => Some(Err(err)),
};
}
Tag::CompressedData => {
return match packet.try_into() {
Ok(data) => Some(Ok(Message::Compressed(data))),
Err(err) => Some(Err(err)),
};
}
// ESK :- Public-Key Encrypted Session Key Packet |
// Symmetric-Key Encrypted Session Key Packet.
Tag::PublicKeyEncryptedSessionKey | Tag::SymKeyEncryptedSessionKey => {
return match packet.try_into() {
Ok(p) => {
let mut esk = vec![p];
let mut edata = Vec::new();
// while ESK take em
while let Some(res) = packets.next_if(|res| {
res.as_ref().is_ok_and(|p| {
p.tag() == Tag::PublicKeyEncryptedSessionKey
|| p.tag() == Tag::SymKeyEncryptedSessionKey
})
}) {
match res {
Ok(packet) => esk.push(packet.try_into().expect("peeked")),
Err(e) => return Some(Err(e)),
}
}
// while edata take em (FIXME: the message grammar only allows one "Encrypted Data" packet)
while let Some(res) = packets.next_if(|res| {
res.as_ref().is_ok_and(|p| {
p.tag() == Tag::SymEncryptedData
|| p.tag() == Tag::SymEncryptedProtectedData
})
}) {
match res {
Ok(packet) => edata.push(packet.try_into().expect("peeked")),
Err(e) => return Some(Err(e)),
}
}
Some(Ok(Message::Encrypted { esk, edata }))
}
Err(err) => Some(Err(err)),
};
}
// Encrypted Data :- Symmetrically Encrypted Data Packet |
// Symmetrically Encrypted Integrity Protected Data Packet
Tag::SymEncryptedData | Tag::SymEncryptedProtectedData => {
return match packet.try_into() {
Ok(p) => {
let esk = Vec::new();
let mut edata = vec![p];
// while edata take em (FIXME: the message grammar only allows one "Encrypted Data" packet)
while let Some(res) = packets.next_if(|res| {
res.as_ref().is_ok_and(|p| {
p.tag() == Tag::SymEncryptedData
|| p.tag() == Tag::SymEncryptedProtectedData
})
}) {
match res {
Ok(packet) => edata.push(packet.try_into().expect("peeked")),
Err(e) => return Some(Err(e)),
}
}
Some(Ok(Message::Encrypted { esk, edata }))
}
Err(err) => Some(Err(err)),
};
}
Tag::Signature => {
return match packet.try_into() {
Ok(signature) => {
let message = match next(packets.by_ref()) {
Some(Ok(m)) => Some(Box::new(m)),
Some(Err(err)) => return Some(Err(err)),
None => None,
};
Some(Ok(Message::Signed {
message,
one_pass_signature: None,
signature,
}))
}
Err(err) => Some(Err(err)),
};
}
Tag::OnePassSignature => {
return match packet.try_into() {
Ok(p) => {
let one_pass_signature = Some(p);
let message = match next(packets.by_ref()) {
Some(Ok(m)) => Some(Box::new(m)),
Some(Err(err)) => return Some(Err(err)),
None => None,
};
let signature = if let Some(res) = packets
.next_if(|res| res.as_ref().is_ok_and(|p| p.tag() == Tag::Signature))
{
match res {
Ok(packet) => packet.try_into().expect("peeked"),
Err(e) => return Some(Err(e)),
}
} else {
return Some(Err(format_err!(
"missing signature for, one pass signature"
)));
};
Some(Ok(Message::Signed {
message,
one_pass_signature,
signature,
}))
}
Err(err) => Some(Err(err)),
};
}
Tag::Marker => {
// Marker Packets are ignored
// see https://tools.ietf.org/html/rfc4880#section-5.8
}
_ => {
return Some(Err(format_err!("unexpected packet {:?}", packet.tag())));
}
}
}
None
}
impl<I: Sized + Iterator<Item = Result<Packet>>> Iterator for MessageParser<I> {
type Item = Result<Message>;
fn next(&mut self) -> Option<Self::Item> {
next(self.source.by_ref())
}
}
impl Deserializable for Message {
/// Parse a composed message.
/// Ref: https://tools.ietf.org/html/rfc4880#section-11.3
fn from_packets<'a, I: Iterator<Item = Result<Packet>> + 'a>(
packets: std::iter::Peekable<I>,
) -> Box<dyn Iterator<Item = Result<Self>> + 'a> {
Box::new(MessageParser {
source: packets.peekable(),
})
}
}