fix(ssh): follow ssh config ProxyJump hops in tunnels

crates/dbx-core/src/connection.rs

@@ -2906,41 +2906,49 @@ impl AppState {
     pub async fn test_tunnel_profile(&self, profile: &TransportLayerConfig) -> Result<String, String> {
         match profile {
             TransportLayerConfig::Ssh(ssh) => {
-                let ssh = crate::ssh_config::resolve_ssh_tunnel_config(ssh);
-                if ssh.host.trim().is_empty() {
+                // A `~/.ssh/config` alias declaring `ProxyJump` resolves to more
+                // than one hop; every other alias (the common case) resolves to
+                // exactly one, matching `resolve_ssh_tunnel_config`.
+                let chain = crate::ssh_config::resolve_ssh_tunnel_chain(ssh);
+                let leaf = chain.last().expect("resolve_ssh_tunnel_chain always returns at least one hop");
+                if leaf.host.trim().is_empty() {
                     return Err("SSH host is required.".to_string());
                 }
-                let timeout = if ssh.connect_timeout_secs == 0 {
-                    crate::models::connection::default_ssh_connect_timeout_secs()
-                } else {
-                    ssh.connect_timeout_secs
-                };
                 // A throwaway id so the probe never reuses or evicts a live tunnel, and
                 // a sentinel forward target: SSH auth completes on connect, before any
                 // channel to this target is opened, so it need not be reachable.
                 let probe_id = format!("__tunnel_profile_test__:{}", uuid::Uuid::new_v4());
-                let result = self
-                    .tunnels
-                    .start_tunnel(
-                        &probe_id,
-                        &ssh.host,
-                        ssh.port,
-                        &ssh.host,
-                        ssh.port,
-                        &ssh.user,
-                        &ssh.password,
-                        &ssh.key_path,
-                        &ssh.key_passphrase,
-                        ssh.use_ssh_agent,
-                        &ssh.ssh_agent_sock_path,
-                        &ssh.auth_method,
-                        timeout,
-                        "127.0.0.1",
-                        1,
-                        false,
-                        ssh.allow_exec_channel_proxy,
-                    )
-                    .await;
+                let result = if chain.len() == 1 {
+                    let timeout = if leaf.connect_timeout_secs == 0 {
+                        crate::models::connection::default_ssh_connect_timeout_secs()
+                    } else {
+                        leaf.connect_timeout_secs
+                    };
+                    self.tunnels
+                        .start_tunnel(
+                            &probe_id,
+                            &leaf.host,
+                            leaf.port,
+                            &leaf.host,
+                            leaf.port,
+                            &leaf.user,
+                            &leaf.password,
+                            &leaf.key_path,
+                            &leaf.key_passphrase,
+                            leaf.use_ssh_agent,
+                            &leaf.ssh_agent_sock_path,
+                            &leaf.auth_method,
+                            timeout,
+                            "127.0.0.1",
+                            1,
+                            false,
+                            leaf.allow_exec_channel_proxy,
+                        )
+                        .await
+                        .map(|_| ())
+                } else {
+                    self.tunnels.start_chain(&probe_id, &chain, &leaf.host, leaf.port).await.map(|_| ())
+                };
                 self.tunnels.stop_tunnel(&probe_id).await;
                 result.map(|_| "SSH tunnel connection successful".to_string())
             }

crates/dbx-core/src/db/transport_layer_tunnel.rs

@@ -1,4 +1,4 @@
-use crate::models::connection::TransportLayerConfig;
+use crate::models::connection::{SshTunnelConfig, TransportLayerConfig};
 
 use super::http_tunnel::HttpTunnelManager;
 use super::proxy_tunnel::ProxyTunnelManager;
@@ -22,15 +22,20 @@ impl LayerEndpoint {
 /// the *next* one in the chain) must see the resolved host/port rather than
 /// a literal alias string, so resolution happens once up front instead of
 /// only at the `start_tunnel` call site.
-fn resolve_ssh_layers(
+///
+/// An SSH layer's alias may itself resolve to more than one hop (its
+/// `~/.ssh/config` entry declares `ProxyJump`); every other layer, and every
+/// SSH layer without `ProxyJump`, resolves to exactly one element. `None` is
+/// returned for non-SSH layers.
+fn resolve_ssh_layer_chains(
     layers: &[TransportLayerConfig],
-    resolve: impl Fn(&crate::models::connection::SshTunnelConfig) -> crate::models::connection::SshTunnelConfig,
-) -> Vec<TransportLayerConfig> {
+    resolve: impl Fn(&SshTunnelConfig) -> Vec<SshTunnelConfig>,
+) -> Vec<Option<Vec<SshTunnelConfig>>> {
     layers
         .iter()
         .map(|layer| match layer {
-            TransportLayerConfig::Ssh(ssh) => TransportLayerConfig::Ssh(resolve(ssh)),
-            other => other.clone(),
+            TransportLayerConfig::Ssh(ssh) => Some(resolve(ssh)),
+            _ => None,
         })
         .collect()
 }
@@ -117,8 +122,30 @@ async fn start_transport_layers_internal(
     }
     validate_transport_layers(layers)?;
 
-    let layers = resolve_ssh_layers(layers, crate::ssh_config::resolve_ssh_tunnel_config);
-    let layers = layers.as_slice();
+    let ssh_chains = resolve_ssh_layer_chains(layers, crate::ssh_config::resolve_ssh_tunnel_chain);
+    for (index, chain) in ssh_chains.iter().enumerate() {
+        // A multi-hop chain only knows how to dial its first hop directly
+        // (see the `start_chain` call below), so it can't yet sit behind an
+        // earlier transport layer.
+        if chain.as_ref().is_some_and(|chain| chain.len() > 1) && index != 0 {
+            return Err(format!(
+                "SSH layer {} uses a multi-hop `~/.ssh/config` ProxyJump chain, which DBX only supports as the first transport layer. Add the jump host as its own tunnel layer instead.",
+                index + 1
+            ));
+        }
+    }
+    let entry_endpoint = |index: usize| -> (String, u16) {
+        match &ssh_chains[index] {
+            Some(chain) => {
+                let first = &chain[0];
+                (first.host.clone(), first.port)
+            }
+            None => {
+                let (host, port) = layers[index].endpoint();
+                (host.to_string(), port)
+            }
+        }
+    };
 
     let mut next_connect_endpoint: Option<LayerEndpoint> = None;
     let mut final_local_port = 0;
@@ -126,85 +153,109 @@ async fn start_transport_layers_internal(
     for (index, layer) in layers.iter().enumerate() {
         let layer_id = layer_id(connection_id, index);
         let is_last = index + 1 == layers.len();
-        let (layer_host, layer_port) = layer.endpoint();
-        let connect_endpoint = next_connect_endpoint
-            .clone()
-            .unwrap_or_else(|| LayerEndpoint { host: layer_host.to_string(), port: layer_port });
+        let (layer_host, layer_port) = entry_endpoint(index);
+        let connect_endpoint =
+            next_connect_endpoint.clone().unwrap_or(LayerEndpoint { host: layer_host, port: layer_port });
         let target_endpoint = if is_last {
             LayerEndpoint { host: remote_host.to_string(), port: remote_port }
         } else {
-            let (next_host, next_port) = layers[index + 1].endpoint();
-            LayerEndpoint { host: next_host.to_string(), port: next_port }
+            let (next_host, next_port) = entry_endpoint(index + 1);
+            LayerEndpoint { host: next_host, port: next_port }
         };
 
-        let local_port = match layer {
-            TransportLayerConfig::Ssh(resolved) if is_last && final_ssh_socks5 => ssh_tunnels
-                .start_socks5_proxy(
-                    &layer_id,
-                    &connect_endpoint.host,
-                    connect_endpoint.port,
-                    &resolved.host,
-                    resolved.port,
-                    &resolved.user,
-                    &resolved.password,
-                    &resolved.key_path,
-                    &resolved.key_passphrase,
-                    resolved.use_ssh_agent,
-                    &resolved.ssh_agent_sock_path,
-                    &resolved.auth_method,
-                    effective_ssh_connect_timeout_secs(resolved.connect_timeout_secs),
-                    resolved.allow_exec_channel_proxy,
-                )
-                .await
-                .map_err(|err| format!("SSH layer {} failed: {err}", index + 1))?,
-            TransportLayerConfig::Ssh(resolved) => ssh_tunnels
-                .start_tunnel_on_local_port(
-                    &layer_id,
-                    &connect_endpoint.host,
-                    connect_endpoint.port,
-                    &resolved.host,
-                    resolved.port,
-                    &resolved.user,
-                    &resolved.password,
-                    &resolved.key_path,
-                    &resolved.key_passphrase,
-                    resolved.use_ssh_agent,
-                    &resolved.ssh_agent_sock_path,
-                    &resolved.auth_method,
-                    effective_ssh_connect_timeout_secs(resolved.connect_timeout_secs),
-                    &target_endpoint.host,
-                    target_endpoint.port,
-                    is_last && resolved.expose_lan,
-                    resolved.allow_exec_channel_proxy,
-                    if is_last { final_ssh_local_port } else { None },
-                )
-                .await
-                .map_err(|err| format!("SSH layer {} failed: {err}", index + 1))?,
-            TransportLayerConfig::Proxy(proxy) => proxy_tunnels
-                .start_tunnel(
-                    &layer_id,
-                    proxy.proxy_type,
-                    &connect_endpoint.host,
-                    connect_endpoint.port,
-                    &proxy.username,
-                    &proxy.password,
-                    &target_endpoint.host,
-                    target_endpoint.port,
-                )
-                .await
-                .map_err(|err| format!("Proxy layer {} failed: {err}", index + 1))?,
-            TransportLayerConfig::HttpTunnel(http) => http_tunnels
-                .start_tunnel(
-                    &layer_id,
-                    &http.url,
-                    &http.token,
-                    http.connect_timeout_secs,
-                    &target_endpoint.host,
-                    target_endpoint.port,
-                )
-                .await
-                .map_err(|err| format!("HTTP tunnel layer {} failed: {err}", index + 1))?,
-        };
+        let local_port =
+            match (layer, &ssh_chains[index]) {
+                (TransportLayerConfig::Ssh(_), Some(chain)) if chain.len() > 1 => {
+                    if is_last && final_ssh_socks5 {
+                        return Err("Dynamic SOCKS5 routing does not support a multi-hop SSH (ProxyJump) profile yet."
+                            .to_string());
+                    }
+                    if is_last && final_ssh_local_port.is_some() {
+                        return Err("A fixed local port is not supported for a multi-hop SSH (ProxyJump) profile yet."
+                            .to_string());
+                    }
+                    ssh_tunnels
+                        .start_chain(&layer_id, chain, &target_endpoint.host, target_endpoint.port)
+                        .await
+                        .map_err(|err| format!("SSH layer {} failed: {err}", index + 1))?
+                }
+                (TransportLayerConfig::Ssh(_), Some(chain)) if is_last && final_ssh_socks5 => {
+                    let resolved = &chain[0];
+                    ssh_tunnels
+                        .start_socks5_proxy(
+                            &layer_id,
+                            &connect_endpoint.host,
+                            connect_endpoint.port,
+                            &resolved.host,
+                            resolved.port,
+                            &resolved.user,
+                            &resolved.password,
+                            &resolved.key_path,
+                            &resolved.key_passphrase,
+                            resolved.use_ssh_agent,
+                            &resolved.ssh_agent_sock_path,
+                            &resolved.auth_method,
+                            effective_ssh_connect_timeout_secs(resolved.connect_timeout_secs),
+                            resolved.allow_exec_channel_proxy,
+                        )
+                        .await
+                        .map_err(|err| format!("SSH layer {} failed: {err}", index + 1))?
+                }
+                (TransportLayerConfig::Ssh(_), Some(chain)) => {
+                    let resolved = &chain[0];
+                    ssh_tunnels
+                        .start_tunnel_on_local_port(
+                            &layer_id,
+                            &connect_endpoint.host,
+                            connect_endpoint.port,
+                            &resolved.host,
+                            resolved.port,
+                            &resolved.user,
+                            &resolved.password,
+                            &resolved.key_path,
+                            &resolved.key_passphrase,
+                            resolved.use_ssh_agent,
+                            &resolved.ssh_agent_sock_path,
+                            &resolved.auth_method,
+                            effective_ssh_connect_timeout_secs(resolved.connect_timeout_secs),
+                            &target_endpoint.host,
+                            target_endpoint.port,
+                            is_last && resolved.expose_lan,
+                            resolved.allow_exec_channel_proxy,
+                            if is_last { final_ssh_local_port } else { None },
+                        )
+                        .await
+                        .map_err(|err| format!("SSH layer {} failed: {err}", index + 1))?
+                }
+                (TransportLayerConfig::Proxy(proxy), None) => proxy_tunnels
+                    .start_tunnel(
+                        &layer_id,
+                        proxy.proxy_type,
+                        &connect_endpoint.host,
+                        connect_endpoint.port,
+                        &proxy.username,
+                        &proxy.password,
+                        &target_endpoint.host,
+                        target_endpoint.port,
+                    )
+                    .await
+                    .map_err(|err| format!("Proxy layer {} failed: {err}", index + 1))?,
+                (TransportLayerConfig::HttpTunnel(http), None) => http_tunnels
+                    .start_tunnel(
+                        &layer_id,
+                        &http.url,
+                        &http.token,
+                        http.connect_timeout_secs,
+                        &target_endpoint.host,
+                        target_endpoint.port,
+                    )
+                    .await
+                    .map_err(|err| format!("HTTP tunnel layer {} failed: {err}", index + 1))?,
+                (TransportLayerConfig::Proxy(_) | TransportLayerConfig::HttpTunnel(_), Some(_))
+                | (TransportLayerConfig::Ssh(_), None) => {
+                    unreachable!("resolve_ssh_layer_chains produces Some(_) iff the layer is TransportLayerConfig::Ssh")
+                }
+            };
 
         final_local_port = local_port;
         next_connect_endpoint = Some(LayerEndpoint::localhost(local_port));
@@ -274,35 +325,42 @@ fn plan_transport_layers(
     remote_port: u16,
     local_ports: &[u16],
 ) -> Vec<PlannedTransportLayer> {
-    plan_transport_layers_with_resolver(layers, remote_host, remote_port, local_ports, |ssh| ssh.clone())
+    plan_transport_layers_with_resolver(layers, remote_host, remote_port, local_ports, |ssh| vec![ssh.clone()])
 }
 
 /// Same as `plan_transport_layers`, but takes an explicit SSH-alias resolver
-/// so tests can exercise `~/.ssh/config` resolution without touching the real
-/// filesystem (mirrors `start_transport_layers`'s use of `resolve_ssh_layers`).
+/// so tests can exercise `~/.ssh/config` resolution (including a `ProxyJump`
+/// chain) without touching the real filesystem — mirrors `start_transport_layers`'s
+/// use of `resolve_ssh_layer_chains`. Each planned SSH layer covers only its
+/// *first* hop's connect endpoint; a chain's internal hops are exercised by
+/// `resolve_ssh_tunnel_chain`'s own unit tests in `ssh_config.rs`; not
+/// re-planned here.
 #[cfg(test)]
 fn plan_transport_layers_with_resolver(
     layers: &[TransportLayerConfig],
     remote_host: &str,
     remote_port: u16,
     local_ports: &[u16],
-    resolve: impl Fn(&crate::models::connection::SshTunnelConfig) -> crate::models::connection::SshTunnelConfig,
+    resolve: impl Fn(&crate::models::connection::SshTunnelConfig) -> Vec<crate::models::connection::SshTunnelConfig>,
 ) -> Vec<PlannedTransportLayer> {
-    let layers = resolve_ssh_layers(layers, resolve);
-    let layers = layers.as_slice();
+    let ssh_chains = resolve_ssh_layer_chains(layers, resolve);
+    let entry_endpoint = |index: usize| -> (String, u16) {
+        match &ssh_chains[index] {
+            Some(chain) => (chain[0].host.clone(), chain[0].port),
+            None => {
+                let (host, port) = layers[index].endpoint();
+                (host.to_string(), port)
+            }
+        }
+    };
     let mut planned = Vec::new();
     let mut next_connect_endpoint: Option<(String, u16)> = None;
     for (index, layer) in layers.iter().enumerate() {
         let is_last = index + 1 == layers.len();
-        let (layer_host, layer_port) = layer.endpoint();
-        let (connect_host, connect_port) =
-            next_connect_endpoint.clone().unwrap_or_else(|| (layer_host.to_string(), layer_port));
-        let (target_host, target_port) = if is_last {
-            (remote_host.to_string(), remote_port)
-        } else {
-            let (next_host, next_port) = layers[index + 1].endpoint();
-            (next_host.to_string(), next_port)
-        };
+        let (layer_host, layer_port) = entry_endpoint(index);
+        let (connect_host, connect_port) = next_connect_endpoint.clone().unwrap_or((layer_host, layer_port));
+        let (target_host, target_port) =
+            if is_last { (remote_host.to_string(), remote_port) } else { entry_endpoint(index + 1) };
         let layer_type = match layer {
             TransportLayerConfig::Ssh(_) => PlannedLayerType::Ssh,
             TransportLayerConfig::Proxy(_) => PlannedLayerType::Proxy,
@@ -442,7 +500,7 @@ mod tests {
             let mut resolved = ssh.clone();
             resolved.host = "10.0.0.5".to_string();
             resolved.port = 2222;
-            resolved
+            vec![resolved]
         });
 
         assert_eq!(
@@ -471,7 +529,7 @@ mod tests {
                 resolved.host = "10.0.0.5".to_string();
                 resolved.port = 2222;
             }
-            resolved
+            vec![resolved]
         });
 
         assert_eq!(
@@ -495,6 +553,35 @@ mod tests {
         );
     }
 
+    #[test]
+    fn proxy_jump_chain_dials_first_hop_and_forwards_to_next_layer() {
+        // Issue #7706: an SSH layer whose alias resolves to a `ProxyJump`
+        // chain must dial the outermost jump first, not the final target.
+        let layers = vec![ssh_layer("ssh-a", "target-alias", 22)];
+
+        let planned = plan_transport_layers_with_resolver(&layers, "db.internal", 5432, &[], |ssh| {
+            assert_eq!(ssh.host, "target-alias");
+            let mut jump = ssh.clone();
+            jump.host = "1.1.1.1".to_string();
+            jump.port = 22;
+            let mut target = ssh.clone();
+            target.host = "1.1.1.2".to_string();
+            target.port = 2222;
+            vec![jump, target]
+        });
+
+        assert_eq!(
+            planned,
+            vec![PlannedTransportLayer {
+                layer_type: PlannedLayerType::Ssh,
+                connect_host: "1.1.1.1".to_string(),
+                connect_port: 22,
+                remote_host: "db.internal".to_string(),
+                remote_port: 5432,
+            }]
+        );
+    }
+
     #[test]
     fn http_tunnel_first_layer_targets_next_layer() {
         let layers = vec![

crates/dbx-core/src/ssh_config.rs

@@ -17,6 +17,11 @@ pub struct SshConfigHostEntry {
     pub port: Option<u16>,
     pub user: Option<String>,
     pub identity_file: Option<String>,
+    /// The `ProxyJump` alias, if any. Only a single hop is parsed (OpenSSH's
+    /// comma-separated multi-jump form is not supported); the jump itself
+    /// may declare its own `ProxyJump`, which `resolve_ssh_tunnel_chain`
+    /// follows recursively.
+    pub proxy_jump: Option<String>,
 }
 
 /// Reads and parses `~/.ssh/config`. Returns an empty list (not an error) if
@@ -50,6 +55,73 @@ pub fn resolve_ssh_tunnel_config(ssh: &SshTunnelConfig) -> SshTunnelConfig {
     }
 }
 
+/// Resolves `ssh.host` plus, when its `~/.ssh/config` entry (or an ancestor
+/// reached by following `ProxyJump`) declares `ProxyJump`, every jump host
+/// leading to it. The returned list is in connection order — outermost jump
+/// first, `ssh`'s own resolved config last — and always has at least one
+/// element. A chain of length 1 means there is no `ProxyJump` to honor, and
+/// behaves exactly like [`resolve_ssh_tunnel_config`].
+///
+/// Jump hosts have no dedicated credentials field in DBX's connection form,
+/// so each one inherits `ssh`'s password/key/agent settings; only the
+/// host/port/user/identity file come from its own `~/.ssh/config` entry.
+pub fn resolve_ssh_tunnel_chain(ssh: &SshTunnelConfig) -> Vec<SshTunnelConfig> {
+    resolve_chain_from_entries(ssh, &list_hosts().unwrap_or_default())
+}
+
+fn resolve_chain_from_entries(ssh: &SshTunnelConfig, entries: &[SshConfigHostEntry]) -> Vec<SshTunnelConfig> {
+    let find = |alias: &str| entries.iter().find(|entry| entry.alias == alias).cloned();
+
+    let Some(target_entry) = find(&ssh.host) else {
+        return vec![ssh.clone()];
+    };
+    let resolved_target = apply_host_entry(ssh, target_entry.clone());
+
+    let mut jump_hops = Vec::new();
+    let mut seen_aliases = std::collections::HashSet::new();
+    seen_aliases.insert(ssh.host.clone());
+    let mut next_jump = target_entry.proxy_jump.clone();
+    while let Some(alias) = next_jump {
+        // Guard against a cycle in `~/.ssh/config` (e.g. two hosts naming
+        // each other as ProxyJump) rather than looping forever.
+        if !seen_aliases.insert(alias.clone()) {
+            break;
+        }
+        let Some(entry) = find(&alias) else { break };
+        next_jump = entry.proxy_jump.clone();
+        jump_hops.push(jump_hop_from_entry(ssh, entry));
+    }
+
+    jump_hops.reverse();
+    jump_hops.push(resolved_target);
+    jump_hops
+}
+
+/// Builds a synthetic hop for a `ProxyJump` host. Unlike the leaf host in
+/// `ssh`, there's no user-filled form for this host, so its identity comes
+/// entirely from `~/.ssh/config` (falling back to the leaf's own settings
+/// for anything the config entry doesn't specify).
+fn jump_hop_from_entry(leaf: &SshTunnelConfig, entry: SshConfigHostEntry) -> SshTunnelConfig {
+    SshTunnelConfig {
+        id: format!("{}::proxyjump::{}", leaf.id, entry.alias),
+        name: entry.alias.clone(),
+        enabled: true,
+        host: entry.host_name.unwrap_or_else(|| entry.alias.clone()),
+        port: entry.port.unwrap_or(DEFAULT_PORT_SENTINEL),
+        user: entry.user.unwrap_or_else(|| leaf.user.clone()),
+        password: leaf.password.clone(),
+        key_path: entry.identity_file.unwrap_or_else(|| leaf.key_path.clone()),
+        key_passphrase: leaf.key_passphrase.clone(),
+        connect_timeout_secs: leaf.connect_timeout_secs,
+        expose_lan: false,
+        use_ssh_agent: leaf.use_ssh_agent,
+        ssh_agent_sock_path: leaf.ssh_agent_sock_path.clone(),
+        auth_method: leaf.auth_method.clone(),
+        allow_exec_channel_proxy: leaf.allow_exec_channel_proxy,
+        profile_id: String::new(),
+    }
+}
+
 /// Applies a resolved `~/.ssh/config` entry onto `ssh`, without overwriting
 /// values the user has explicitly set. The empty `auth_method` identifies
 /// legacy payloads where default values cannot be distinguished from fields
@@ -87,9 +159,11 @@ fn apply_host_entry(ssh: &SshTunnelConfig, entry: SshConfigHostEntry) -> SshTunn
 }
 
 /// Parses a minimal subset of OpenSSH client config syntax: `Host`, `HostName`,
-/// `Port`, `User`, `IdentityFile`. Wildcard host patterns (containing `*` or
-/// `?`) are skipped since they aren't usable as a literal alias in the host
-/// field. `Include` and other directives are not supported.
+/// `Port`, `User`, `IdentityFile`, `ProxyJump`. Wildcard host patterns
+/// (containing `*` or `?`) are skipped since they aren't usable as a literal
+/// alias in the host field. `Include` and other directives are not
+/// supported, and `ProxyJump`'s comma-separated multi-hop form is read as a
+/// single alias (its first hop).
 fn parse_ssh_config(content: &str) -> Vec<SshConfigHostEntry> {
     let mut entries: Vec<SshConfigHostEntry> = Vec::new();
     let mut current_aliases: Vec<String> = Vec::new();
@@ -117,6 +191,7 @@ fn parse_ssh_config(content: &str) -> Vec<SshConfigHostEntry> {
                         port: None,
                         user: None,
                         identity_file: None,
+                        proxy_jump: None,
                     });
                 }
             }
@@ -136,6 +211,18 @@ fn parse_ssh_config(content: &str) -> Vec<SshConfigHostEntry> {
             "identityfile" => set_current_field(&mut entries, &current_aliases, |entry| {
                 entry.identity_file = Some(value.to_string());
             }),
+            "proxyjump" => {
+                if let Some(first_hop) = value.split(',').next().map(str::trim).filter(|hop| !hop.is_empty()) {
+                    // A `user@host:port` jump target names an alias-incompatible
+                    // literal host; only a plain alias is resolvable here.
+                    if !first_hop.contains('@') && !first_hop.contains(':') {
+                        let first_hop = first_hop.to_string();
+                        set_current_field(&mut entries, &current_aliases, |entry| {
+                            entry.proxy_jump = Some(first_hop.clone());
+                        });
+                    }
+                }
+            }
             _ => {}
         }
     }
@@ -237,6 +324,24 @@ mod tests {
         assert_eq!(entries[0].user, Some("deploy".to_string()));
     }
 
+    #[test]
+    fn parses_proxy_jump() {
+        let entries = parse_ssh_config("Host target\n  HostName 1.1.1.2\n  ProxyJump gateway\n");
+        assert_eq!(entries[0].proxy_jump, Some("gateway".to_string()));
+    }
+
+    #[test]
+    fn proxy_jump_multi_hop_form_reads_only_the_first_hop() {
+        let entries = parse_ssh_config("Host target\n  ProxyJump gw1,gw2\n");
+        assert_eq!(entries[0].proxy_jump, Some("gw1".to_string()));
+    }
+
+    #[test]
+    fn proxy_jump_user_at_host_form_is_not_resolvable_as_an_alias() {
+        let entries = parse_ssh_config("Host target\n  ProxyJump jumper@1.1.1.1\n");
+        assert_eq!(entries[0].proxy_jump, None);
+    }
+
     fn entry(alias: &str) -> SshConfigHostEntry {
         SshConfigHostEntry {
             alias: alias.to_string(),
@@ -244,6 +349,7 @@ mod tests {
             port: Some(2222),
             user: Some("deploy".to_string()),
             identity_file: Some("~/.ssh/id_ed25519".to_string()),
+            proxy_jump: None,
         }
     }
 
@@ -312,4 +418,81 @@ mod tests {
         let resolved = resolve_ssh_tunnel_config(&ssh);
         assert_eq!(resolved, ssh);
     }
+
+    fn jump_entry(alias: &str, host_name: &str, proxy_jump: Option<&str>) -> SshConfigHostEntry {
+        SshConfigHostEntry {
+            alias: alias.to_string(),
+            host_name: Some(host_name.to_string()),
+            port: None,
+            user: None,
+            identity_file: None,
+            proxy_jump: proxy_jump.map(str::to_string),
+        }
+    }
+
+    #[test]
+    fn chain_is_single_hop_without_proxy_jump() {
+        let ssh = config("myserver");
+        let chain = resolve_chain_from_entries(&ssh, std::slice::from_ref(&entry("myserver")));
+        assert_eq!(chain.len(), 1);
+        assert_eq!(chain[0].host, "10.0.0.5");
+    }
+
+    #[test]
+    fn chain_prepends_the_proxy_jump_hop_in_connection_order() {
+        // Mirrors issue #7706: `target` (ProxyJump gateway) resolves to
+        // [gateway, target], gateway dialed first.
+        let ssh = config("target");
+        let entries = [jump_entry("gateway", "1.1.1.1", None), jump_entry("target", "1.1.1.2", Some("gateway"))];
+
+        let chain = resolve_chain_from_entries(&ssh, &entries);
+
+        assert_eq!(chain.len(), 2);
+        assert_eq!(chain[0].host, "1.1.1.1");
+        assert_eq!(chain[0].name, "gateway");
+        assert_eq!(chain[1].host, "1.1.1.2");
+    }
+
+    #[test]
+    fn chain_jump_hop_inherits_leaf_credentials_when_config_has_no_identity_file() {
+        let mut ssh = config("target");
+        ssh.auth_method = "key".to_string();
+        ssh.key_path = "/home/user/.ssh/id_rsa".to_string();
+        let entries = [jump_entry("gateway", "1.1.1.1", None), jump_entry("target", "1.1.1.2", Some("gateway"))];
+
+        let chain = resolve_chain_from_entries(&ssh, &entries);
+
+        assert_eq!(chain[0].auth_method, "key");
+        assert_eq!(chain[0].key_path, "/home/user/.ssh/id_rsa");
+    }
+
+    #[test]
+    fn chain_follows_multiple_proxy_jump_hops_recursively() {
+        let ssh = config("target");
+        let entries = [
+            jump_entry("gateway-outer", "1.1.1.1", None),
+            jump_entry("gateway-inner", "1.1.1.2", Some("gateway-outer")),
+            jump_entry("target", "1.1.1.3", Some("gateway-inner")),
+        ];
+
+        let chain = resolve_chain_from_entries(&ssh, &entries);
+
+        assert_eq!(
+            chain.iter().map(|hop| hop.host.as_str()).collect::<Vec<_>>(),
+            vec!["1.1.1.1", "1.1.1.2", "1.1.1.3"]
+        );
+    }
+
+    #[test]
+    fn chain_breaks_a_proxy_jump_cycle_instead_of_looping_forever() {
+        let ssh = config("a");
+        let entries = [jump_entry("a", "1.1.1.1", Some("b")), jump_entry("b", "1.1.1.2", Some("a"))];
+
+        let chain = resolve_chain_from_entries(&ssh, &entries);
+
+        // Must terminate; the exact truncation point is an implementation
+        // detail of cycle detection, not a behavior callers rely on.
+        assert!(chain.len() <= entries.len());
+        assert_eq!(chain.last().unwrap().host, "1.1.1.1");
+    }
 }