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
|
/// Generates a key, then encrypts and decrypts a message.
use std::io::{self, Write};
extern crate sequoia_openpgp as openpgp;
use crate::openpgp::crypto::SessionKey;
use crate::openpgp::types::SymmetricAlgorithm;
use crate::openpgp::serialize::stream::*;
use crate::openpgp::parse::stream::*;
const MESSAGE: &'static str = "дружба";
fn main() {
// Generate a key.
let key = generate().unwrap();
// Encrypt the message.
let mut ciphertext = Vec::new();
encrypt(&mut ciphertext, MESSAGE, &key).unwrap();
// Decrypt the message.
let mut plaintext = Vec::new();
decrypt(&mut plaintext, &ciphertext, &key).unwrap();
assert_eq!(MESSAGE.as_bytes(), &plaintext[..]);
}
/// Generates an encryption-capable key.
fn generate() -> openpgp::Result<openpgp::Cert> {
let (cert, _revocation) = openpgp::cert::CertBuilder::new()
.add_userid("someone@example.org")
.add_transport_encryption_subkey()
.generate()?;
// Save the revocation certificate somewhere.
Ok(cert)
}
/// Encrypts the given message.
fn encrypt(sink: &mut dyn Write, plaintext: &str, recipient: &openpgp::Cert)
-> openpgp::Result<()> {
// Build a vector of recipients to hand to Encryptor.
let mut recipients = recipient
.keys().policy(None).alive().revoked(false)
.for_transport_encryption()
.map(|ka| ka.key().into())
.collect::<Vec<_>>();
// Start streaming an OpenPGP message.
let message = Message::new(sink);
// We want to encrypt a literal data packet.
let mut encryptor = Encryptor::for_recipient(
message, recipients.pop().expect("No encryption key found"));
for r in recipients {
encryptor = encryptor.add_recipient(r)
}
let encryptor = encryptor.build().expect("Failed to create encryptor");
// Emit a literal data packet.
let mut literal_writer = LiteralWriter::new(encryptor).build()?;
// Encrypt the data.
literal_writer.write_all(plaintext.as_bytes())?;
// Finalize the OpenPGP message to make sure that all data is
// written.
literal_writer.finalize()?;
Ok(())
}
/// Decrypts the given message.
fn decrypt(sink: &mut dyn Write, ciphertext: &[u8], recipient: &openpgp::Cert)
-> openpgp::Result<()> {
// Make a helper that that feeds the recipient's secret key to the
// decryptor.
let helper = Helper {
secret: recipient,
};
// Now, create a decryptor with a helper using the given Certs.
let mut decryptor = Decryptor::from_bytes(ciphertext, helper, None)?;
// Decrypt the data.
io::copy(&mut decryptor, sink)?;
Ok(())
}
struct Helper<'a> {
secret: &'a openpgp::Cert,
}
impl<'a> VerificationHelper for Helper<'a> {
fn get_public_keys(&mut self, _ids: &[openpgp::KeyHandle])
-> openpgp::Result<Vec<openpgp::Cert>> {
// Return public keys for signature verification here.
Ok(Vec::new())
}
fn check(&mut self, _structure: MessageStructure)
-> openpgp::Result<()> {
// Implement your signature verification policy here.
Ok(())
}
}
impl<'a> DecryptionHelper for Helper<'a> {
fn decrypt<D>(&mut self,
pkesks: &[openpgp::packet::PKESK],
_skesks: &[openpgp::packet::SKESK],
mut decrypt: D)
-> openpgp::Result<Option<openpgp::Fingerprint>>
where D: FnMut(SymmetricAlgorithm, &SessionKey) -> openpgp::Result<()>
{
// The encryption key is the first and only subkey.
let key = self.secret.subkeys().nth(0)
.map(|binding| binding.key().clone())
.unwrap();
// The secret key is not encrypted.
let mut pair = key.mark_parts_secret().unwrap().into_keypair().unwrap();
pkesks[0].decrypt(&mut pair)
.and_then(|(algo, session_key)| decrypt(algo, &session_key))
.map(|_| None)
// XXX: In production code, return the Fingerprint of the
// recipient's Cert here
}
}
|
