ssh_packet/kex/mod.rs
1//! Facilities to produce some of the _exchange hashes_.
2
3use binrw::binwrite;
4
5use super::{arch, trans};
6
7mod lengthed;
8pub use lengthed::Lengthed;
9
10/// The exchange hash for ECDH, computed as the
11/// hash of the concatenation of the following.
12///
13/// see <https://datatracker.ietf.org/doc/html/rfc5656#section-4>.
14#[binwrite]
15#[derive(Debug)]
16#[bw(big)]
17pub struct Ecdh<'b> {
18 /// Client's identification string (`\r` and `\n` excluded).
19 pub v_c: arch::Bytes<'b>,
20
21 /// Server's identification string (`\r` and `\n` excluded).
22 pub v_s: arch::Bytes<'b>,
23
24 /// Payload of the client's `SSH_MSG_KEXINIT` message.
25 pub i_c: Lengthed<&'b trans::KexInit<'b>>,
26
27 /// Payload of the server's `SSH_MSG_KEXINIT` message.
28 pub i_s: Lengthed<&'b trans::KexInit<'b>>,
29
30 /// Server's public host key.
31 pub k_s: arch::Bytes<'b>,
32
33 /// Client's ephemeral public key octet string.
34 pub q_c: arch::Bytes<'b>,
35
36 /// Server's ephemeral public key octet string.
37 pub q_s: arch::Bytes<'b>,
38
39 /// Computed shared secret.
40 pub k: arch::MpInt<'b>,
41}
42
43impl Ecdh<'_> {
44 /// Produce the exchange hash with the specified digest algorithm.
45 #[cfg(feature = "digest")]
46 #[cfg_attr(docsrs, doc(cfg(feature = "digest")))]
47 pub fn hash<D: digest::Digest>(&self) -> digest::Output<D> {
48 use binrw::BinWrite;
49
50 let mut buffer = Vec::new();
51 self.write(&mut std::io::Cursor::new(&mut buffer))
52 .expect("The binrw structure serialization failed");
53
54 D::digest(&buffer)
55 }
56}