fix(network): harden additional CA propagation

Signed-off-by: Jesse Jaggars <jjaggars@redhat.com>

Author: jhjaggars

.rpi/tasks/network-supervisor-additional-ca/01-research-questions.md

@@ -12,6 +12,14 @@ use std::fmt;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
+/// Maximum number of normalized PEM bytes accepted for destination trust.
+///
+/// This bound is shared by the gateway normalization boundary and all compute
+/// driver consumers. Kubernetes counts the `ca.crt` key and value toward its
+/// 1 MiB `ConfigMap` data limit, so reserve the six key bytes here to keep every
+/// supported driver on the same deployable boundary.
+pub const MAX_NETWORK_SUPERVISOR_TRUST_BUNDLE_BYTES: usize = 1024 * 1024 - "ca.crt".len();
+
 /// Normalized, gateway-owned trust material for sandbox destination TLS.
 ///
 /// The PEM bytes contain only canonical X.509 certificate blocks.  The type is

.rpi/tasks/network-supervisor-additional-ca/02-research.md

@@ -240,6 +240,10 @@ impl openshell_server::ComputeDriverFactory for KubernetesFactory {
         true
     }
 
+    fn supports_network_supervisor_trust(&self) -> bool {
+        true
+    }
+
     fn validate_config(
         &self,
         context: openshell_server::ComputeDriverConfigContext<'_>,
@@ -294,6 +298,10 @@ impl openshell_server::ComputeDriverFactory for DockerFactory {
         true
     }
 
+    fn supports_network_supervisor_trust(&self) -> bool {
+        true
+    }
+
     fn validate_config(
         &self,
         context: openshell_server::ComputeDriverConfigContext<'_>,
@@ -342,6 +350,10 @@ impl openshell_server::ComputeDriverFactory for PodmanFactory {
         true
     }
 
+    fn supports_network_supervisor_trust(&self) -> bool {
+        true
+    }
+
     fn validate_config(
         &self,
         context: openshell_server::ComputeDriverConfigContext<'_>,
@@ -407,6 +419,10 @@ impl openshell_server::ComputeDriverFactory for VmFactory {
         true
     }
 
+    fn supports_network_supervisor_trust(&self) -> bool {
+        true
+    }
+
     fn validate_config(
         &self,
         context: openshell_server::ComputeDriverConfigContext<'_>,
@@ -642,4 +658,17 @@ mod tests {
             expected
         );
     }
+
+    #[cfg(not(target_os = "windows"))]
+    #[test]
+    fn first_party_network_supervisor_drivers_opt_into_trust_propagation() {
+        #[cfg(feature = "compute-driver-docker")]
+        assert!(<DockerFactory as openshell_server::ComputeDriverFactory>::supports_network_supervisor_trust(&DockerFactory));
+        #[cfg(feature = "compute-driver-kubernetes")]
+        assert!(<KubernetesFactory as openshell_server::ComputeDriverFactory>::supports_network_supervisor_trust(&KubernetesFactory));
+        #[cfg(feature = "compute-driver-podman")]
+        assert!(<PodmanFactory as openshell_server::ComputeDriverFactory>::supports_network_supervisor_trust(&PodmanFactory));
+        #[cfg(feature = "compute-driver-vm")]
+        assert!(<VmFactory as openshell_server::ComputeDriverFactory>::supports_network_supervisor_trust(&VmFactory));
+    }
 }

.rpi/tasks/network-supervisor-additional-ca/03-design-discussion.md

@@ -478,6 +478,7 @@ impl ProcessHandle {
         interactive: bool,
         policy: &SandboxPolicy,
         ca_paths: Option<&(PathBuf, PathBuf)>,
+        tls_environment_mode: child_env::TlsEnvironmentMode,
         provider_env: &HashMap<String, String>,
     ) -> Result<Self> {
         Self::spawn_impl(
@@ -488,6 +489,7 @@ impl ProcessHandle {
             interactive,
             policy,
             ca_paths,
+            tls_environment_mode,
             provider_env,
         )
     }
@@ -506,6 +508,7 @@ impl ProcessHandle {
         interactive: bool,
         policy: &SandboxPolicy,
         ca_paths: Option<&(PathBuf, PathBuf)>,
+        tls_environment_mode: child_env::TlsEnvironmentMode,
         provider_env: &HashMap<String, String>,
     ) -> Result<Self> {
         Self::spawn_impl(
@@ -515,6 +518,7 @@ impl ProcessHandle {
             interactive,
             policy,
             ca_paths,
+            tls_environment_mode,
             provider_env,
         )
     }
@@ -529,6 +533,7 @@ impl ProcessHandle {
         interactive: bool,
         policy: &SandboxPolicy,
         ca_paths: Option<&(PathBuf, PathBuf)>,
+        tls_environment_mode: child_env::TlsEnvironmentMode,
         provider_env: &HashMap<String, String>,
     ) -> Result<Self> {
         let mut cmd = Command::new(program);
@@ -563,12 +568,13 @@ impl ProcessHandle {
         // inherited environment. The entrypoint drops to the sandbox user
         // before `exec`; without this strip, sandbox code could recover
         // supervisor credentials from its inherited environment.
+        let user_environment = configured_user_environment();
         apply_canonical_process_environment(
             &mut cmd,
             policy,
             workspace,
             interactive,
-            &configured_user_environment(),
+            &user_environment,
         );
         strip_supervisor_only_env(&mut cmd);
 
@@ -580,9 +586,28 @@ impl ProcessHandle {
 
         strip_proxy_env(&mut cmd);
 
-        // Set TLS trust store env vars so sandbox processes trust the ephemeral CA
+        // In interception mode OpenShell trust is authoritative. In direct
+        // additional-CA mode, retain all caller values and only fill gaps.
         if let Some((ca_cert_path, combined_bundle_path)) = ca_paths {
-            for (key, value) in child_env::tls_env_vars(ca_cert_path, combined_bundle_path) {
+            // Provider credentials are injected before this point. Reassert
+            // caller TLS values in additive mode so a provider environment
+            // cannot accidentally replace a caller-selected trust store.
+            if matches!(
+                tls_environment_mode,
+                child_env::TlsEnvironmentMode::FillMissing
+            ) {
+                for (key, value) in &user_environment {
+                    if child_env::is_tls_environment_variable(key) {
+                        cmd.env(key, value);
+                    }
+                }
+            }
+            for (key, value) in child_env::tls_env_vars_for_mode(
+                ca_cert_path,
+                combined_bundle_path,
+                tls_environment_mode,
+                &user_environment,
+            ) {
                 cmd.env(key, value);
             }
         }
@@ -694,6 +719,7 @@ impl ProcessHandle {
         interactive: bool,
         policy: &SandboxPolicy,
         ca_paths: Option<&(PathBuf, PathBuf)>,
+        tls_environment_mode: child_env::TlsEnvironmentMode,
         provider_env: &HashMap<String, String>,
     ) -> Result<Self> {
         let mut cmd = Command::new(program);
@@ -728,12 +754,13 @@ impl ProcessHandle {
 
         // Strip supervisor-only identity material from the entrypoint's
         // inherited environment.
+        let user_environment = configured_user_environment();
         apply_canonical_process_environment(
             &mut cmd,
             policy,
             workspace,
             interactive,
-            &configured_user_environment(),
+            &user_environment,
         );
         strip_supervisor_only_env(&mut cmd);
 
@@ -745,9 +772,28 @@ impl ProcessHandle {
 
         strip_proxy_env(&mut cmd);
 
-        // Set TLS trust store env vars so sandbox processes trust the ephemeral CA
+        // In interception mode OpenShell trust is authoritative. In direct
+        // additional-CA mode, retain all caller values and only fill gaps.
         if let Some((ca_cert_path, combined_bundle_path)) = ca_paths {
-            for (key, value) in child_env::tls_env_vars(ca_cert_path, combined_bundle_path) {
+            // Provider credentials are injected before this point. Reassert
+            // caller TLS values in additive mode so a provider environment
+            // cannot accidentally replace a caller-selected trust store.
+            if matches!(
+                tls_environment_mode,
+                child_env::TlsEnvironmentMode::FillMissing
+            ) {
+                for (key, value) in &user_environment {
+                    if child_env::is_tls_environment_variable(key) {
+                        cmd.env(key, value);
+                    }
+                }
+            }
+            for (key, value) in child_env::tls_env_vars_for_mode(
+                ca_cert_path,
+                combined_bundle_path,
+                tls_environment_mode,
+                &user_environment,
+            ) {
                 cmd.env(key, value);
             }
         }