I realised while working on top of my patches that trying to add an identity was failing to go through on the ssh-agent. I was able to confirm on the current state of the repository that it’s the same behaviour.

You can reproduce this by creating the following file under thrussh-keys/examples/add-identity.rs:

use thrussh_keys::agent::{
    Constraint, client::AgentClient,
};
use thrussh_keys::key;

#[tokio::main]
async fn main() {
    let (pk, sk) = key::ed25519::keypair();
    let sk = key::KeyPair::Ed25519(sk);
    let mut client = AgentClient::connect_env().await.unwrap();
    client
        .add_identity(&sk, &[Constraint::KeyLifetime { seconds: 5 }])
        .await
        .unwrap()
}

If you start ssh-agent in debug mode, i.e. ssh-agent -d and then run cargo run --example add-identity you’ll see the following in the output of the ssh-agent:

debug1: new_socket: type = CONNECTION
debug2: fd 4 setting O_NONBLOCK
debug1: process_message: socket 1 (fd=4) type 25
debug2: process_add_identity: entering
parse_key_constraints: Unknown constraint 0
process_add_identity: failed to parse constraints