This commit is contained in:
nora 2024-08-11 22:10:34 +02:00
parent 9c320c8b4c
commit ae5db1642c
5 changed files with 166 additions and 89 deletions

View file

@ -9,6 +9,8 @@ use crate::Result;
pub(crate) struct ServerChannelsState {
packets_to_send: VecDeque<Packet>,
channels: Vec<SessionChannel>,
channel_updates: VecDeque<ChannelUpdate>,
}
struct SessionChannel {
@ -20,11 +22,21 @@ struct SessionChannel {
sent_bytes: Vec<u8>,
}
pub struct ChannelUpdate {
pub channel: u32,
pub kind: ChannelUpdateKind,
}
pub enum ChannelUpdateKind {
ChannelData(Vec<u8>),
}
impl ServerChannelsState {
pub(crate) fn new() -> Self {
ServerChannelsState {
packets_to_send: VecDeque::new(),
channels: Vec::new(),
channel_updates: VecDeque::new(),
}
}
@ -43,12 +55,13 @@ impl ServerChannelsState {
"session" => {
let our_number = self.channels.len() as u32;
let mut confirm = Writer::new();
confirm.u8(Packet::SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
confirm.u32(our_number);
confirm.u32(sender_channel);
confirm.u32(initial_window_size);
confirm.u32(max_packet_size);
self.packets_to_send
.push_back(Packet::new_msg_channel_open_confirmation(
our_number,
sender_channel,
initial_window_size,
max_packet_size,
));
self.channels.push(SessionChannel {
we_closed: false,
@ -58,23 +71,16 @@ impl ServerChannelsState {
sent_bytes: Vec::new(),
});
self.packets_to_send.push_back(Packet {
payload: confirm.finish(),
});
debug!(?channel_type, ?our_number, "Successfully opened channel");
}
_ => {
let mut failure = Writer::new();
failure.u8(Packet::SSH_MSG_CHANNEL_OPEN_FAILURE);
failure.u32(sender_channel);
failure.u32(3); // SSH_OPEN_UNKNOWN_CHANNEL_TYPE
failure.string(b"unknown channel type");
failure.string(b"");
self.packets_to_send.push_back(Packet {
payload: failure.finish(),
});
self.packets_to_send
.push_back(Packet::new_msg_channel_open_failure(
sender_channel,
3, // SSH_OPEN_UNKNOWN_CHANNEL_TYPE
b"unknown channel type",
b"",
));
}
}
}
@ -83,33 +89,18 @@ impl ServerChannelsState {
let data = payload.string()?;
let channel = self.channel(our_channel)?;
let peer = channel.peer_channel;
channel.recv_bytes(data);
let mut reply = Writer::new();
reply.u8(Packet::SSH_MSG_CHANNEL_DATA);
reply.u32(channel.peer_channel);
reply.string(data); // echo :3
self.packets_to_send.push_back(Packet {
payload: reply.finish(),
});
let peer = channel.peer_channel;
// echo :3
self.packets_to_send
.push_back(Packet::new_msg_channel_data(peer, data));
if data.contains(&0x03 /*EOF, Ctrl-C*/) {
debug!(?our_channel, "Received EOF, closing channel");
// <https://datatracker.ietf.org/doc/html/rfc4254#section-5.3>
let mut eof = Writer::new();
eof.u8(Packet::SSH_MSG_CHANNEL_EOF);
eof.u32(peer);
self.packets_to_send.push_back(Packet {
payload: eof.finish(),
});
let mut close = Writer::new();
close.u8(Packet::SSH_MSG_CHANNEL_CLOSE);
close.u32(peer);
self.packets_to_send.push_back(Packet {
payload: close.finish(),
});
self.packets_to_send
.push_back(Packet::new_msg_channel_close(peer));
let channel = self.channel(our_channel)?;
channel.we_closed = true;
@ -120,14 +111,10 @@ impl ServerChannelsState {
let our_channel = payload.u32()?;
let channel = self.channel(our_channel)?;
if !channel.we_closed {
let mut close = Writer::new();
close.u8(Packet::SSH_MSG_CHANNEL_CLOSE);
close.u32(channel.peer_channel);
self.packets_to_send.push_back(Packet {
payload: close.finish(),
});
let close = Packet::new_msg_channel_close(channel.peer_channel);
self.packets_to_send.push_back(close);
}
self.channels.remove(our_channel as usize);
debug!("Channel has been closed");
@ -203,22 +190,18 @@ impl ServerChannelsState {
self.packets_to_send.drain(..)
}
pub(crate) fn channel_updates(&mut self) -> impl Iterator<Item = ChannelUpdate> + '_ {
self.channel_updates.drain(..)
}
fn send_channel_success(&mut self, recipient_channel: u32) {
let mut failure = Writer::new();
failure.u8(Packet::SSH_MSG_CHANNEL_SUCCESS);
failure.u32(recipient_channel);
self.packets_to_send.push_back(Packet {
payload: failure.finish(),
});
self.packets_to_send
.push_back(Packet::new_msg_channel_success(recipient_channel));
}
fn send_channel_failure(&mut self, recipient_channel: u32) {
let mut failure = Writer::new();
failure.u8(Packet::SSH_MSG_CHANNEL_FAILURE);
failure.u32(recipient_channel);
self.packets_to_send.push_back(Packet {
payload: failure.finish(),
});
self.packets_to_send
.push_back(Packet::new_msg_channel_failure(recipient_channel));
}
fn channel(&mut self, number: u32) -> Result<&mut SessionChannel> {

View file

@ -18,6 +18,7 @@ use sha2::Digest;
use tracing::{debug, info, trace};
use x25519_dalek::{EphemeralSecret, PublicKey};
pub use channel::ChannelUpdate;
pub use packet::Msg;
#[derive(Debug)]
@ -50,6 +51,8 @@ pub struct ServerConnection {
state: ServerState,
packet_transport: PacketTransport,
rng: Box<dyn SshRng + Send + Sync>,
channel_updates: VecDeque<ChannelUpdate>,
}
enum ServerState {
@ -118,6 +121,7 @@ impl ServerConnection {
},
packet_transport: PacketTransport::new(),
rng: Box::new(rng),
channel_updates: VecDeque::new(),
}
}
}
@ -399,21 +403,16 @@ impl ServerConnection {
info!(?password, "Got password");
// Don't worry queen, your password is correct!
let mut success = Writer::new();
success.u8(Packet::SSH_MSG_USERAUTH_SUCCESS);
self.packet_transport.queue_packet(Packet {
payload: success.finish(),
});
self.packet_transport
.queue_packet(Packet::new_msg_userauth_success());
self.state = ServerState::ConnectionOpen(ServerChannelsState::new());
}
"publickey" => {
info!("Got public key");
// Don't worry queen, your key is correct!
let mut success = Writer::new();
success.u8(Packet::SSH_MSG_USERAUTH_SUCCESS);
self.packet_transport.queue_packet(Packet {
payload: success.finish(),
});
self.packet_transport
.queue_packet(Packet::new_msg_userauth_success());
self.state = ServerState::ConnectionOpen(ServerChannelsState::new());
}
_ if *has_failed => {
@ -424,21 +423,17 @@ impl ServerConnection {
_ => {
// Initial.
let mut banner = Writer::new();
banner.u8(Packet::SSH_MSG_USERAUTH_BANNER);
banner.string(b"!! this system ONLY allows catgirls to enter !!\r\n!! all other attempts WILL be prosecuted to the full extent of the rawr !!\r\n");
banner.string(b"");
self.packet_transport.queue_packet(Packet {
payload: banner.finish(),
});
self.packet_transport.queue_packet(Packet::new_msg_userauth_banner(
b"!! this system ONLY allows catgirls to enter !!\r\n\
!! all other attempts WILL be prosecuted to the full extent of the rawr !!\r\n",
b"",
));
let mut rejection = Writer::new();
rejection.u8(Packet::SSH_MSG_USERAUTH_FAILURE);
rejection.name_list(NameList::one("publickey"));
rejection.bool(false);
self.packet_transport.queue_packet(Packet {
payload: rejection.finish(),
});
self.packet_transport
.queue_packet(Packet::new_msg_userauth_failure(
NameList::one("publickey"),
false,
));
// Stay in the same state
}
}
@ -454,17 +449,15 @@ impl ServerConnection {
for packet in con.packets_to_send() {
self.packet_transport.queue_packet(packet);
}
self.channel_updates.extend(con.channel_updates());
}
Packet::SSH_MSG_GLOBAL_REQUEST => {
let request_name = payload.utf8_string()?;
let want_reply = payload.bool()?;
debug!(?request_name, ?want_reply, "Received global request");
let mut failure = Writer::new();
failure.u8(Packet::SSH_MSG_REQUEST_FAILURE);
self.packet_transport.queue_packet(Packet {
payload: failure.finish(),
});
self.packet_transport
.queue_packet(Packet::new_msg_request_failure());
}
_ => {
todo!("packet: {packet_type}");
@ -479,6 +472,10 @@ impl ServerConnection {
pub fn next_msg_to_send(&mut self) -> Option<Msg> {
self.packet_transport.next_msg_to_send()
}
pub fn next_channel_update(&mut self) -> Option<ChannelUpdate> {
self.channel_updates.pop_front()
}
}
// hardcoded test keys. lol.

View file

@ -1,3 +1,5 @@
mod ctors;
use std::collections::VecDeque;
use crate::client_error;

View file

@ -0,0 +1,93 @@
use crate::packet::Packet;
use crate::parse::Writer;
#[allow(non_camel_case_types)]
mod ssh_type_to_rust {
pub(super) use {bool, u32, u8};
pub(super) type string<'a> = &'a [u8];
pub(super) type name_list<'a> = crate::parse::NameList<'a>;
}
macro_rules! ctors {
(
$(
fn $fn_name:ident(
$msg_type:ident;
$(
$name:ident: $ssh_type:ident
),*
$(,)?
);
)*
) => {
impl Packet {
$(
pub fn $fn_name(
$(
$name: ssh_type_to_rust::$ssh_type
),*
) -> Packet {
let mut w = Writer::new();
w.u8(Packet::$msg_type);
$(
w.$ssh_type($name);
)*
Packet {
payload: w.finish(),
}
}
)*
}
};
}
ctors! {
// -----
// Transport layer protocol:
// 1 to 19 Transport layer generic (e.g., disconnect, ignore, debug, etc.)
// 20 to 29 Algorithm negotiation
// 30 to 49 Key exchange method specific (numbers can be reused for different authentication methods)
// -----
// User authentication protocol:
// 50 to 59 User authentication generic
fn new_msg_userauth_failure(SSH_MSG_USERAUTH_FAILURE;
auth_options: name_list,
partial_success: bool,
);
fn new_msg_userauth_success(SSH_MSG_USERAUTH_SUCCESS;);
fn new_msg_userauth_banner(SSH_MSG_USERAUTH_BANNER; msg: string, language_tag: string);
// 60 to 79 User authentication method specific (numbers can be reused for different authentication methods)
// -----
// Connection protocol:
// 80 to 89 Connection protocol generic
fn new_msg_request_failure(SSH_MSG_REQUEST_FAILURE;);
// 90 to 127 Channel related messages
fn new_msg_channel_open_confirmation(SSH_MSG_CHANNEL_OPEN_CONFIRMATION;
peer_channel: u32,
sender_channel: u32,
initial_window_size: u32,
max_packet_size: u32,
);
fn new_msg_channel_open_failure(SSH_MSG_CHANNEL_OPEN_FAILURE;
sender_channe: u32,
reason_code: u32,
description: string,
language_tag: string,
);
fn new_msg_channel_data(SSH_MSG_CHANNEL_DATA; recipient_channel: u32, data: string);
fn new_msg_channel_eof(SSH_MSG_CHANNEL_EOF; recipient_channel: u32);
fn new_msg_channel_close(SSH_MSG_CHANNEL_CLOSE; recipient_channel: u32);
fn new_msg_channel_success(SSH_MSG_CHANNEL_SUCCESS; recipient_channel: u32);
fn new_msg_channel_failure(SSH_MSG_CHANNEL_FAILURE; recipient_channel: u32);
}