Inject the corporate CA certificate into containers

Behind a TLS-terminating corporate proxy every HTTPS call inside a container
fails — npm, pip, git, curl, the browser-view pane, and Claude Code's own API
requests. There was no mechanism at all: installing the certificate by hand
inside a container is lost on Reset and had to be repeated per project.

A global CA path in AppSettings with a per-project override on Project, taking
either a single certificate file or a directory. It is bind-mounted read-only
at /tmp/.host-ca (mirroring /tmp/.host-ssh and /tmp/.host-aws) and applied by
entrypoint.sh on every start, so it survives recreation, migration and Reset.

Four things this gets right that are easy to get wrong:

* update-ca-certificates globs *.crt case-sensitively, so a .pem that is merely
  copied in is ignored in silence. Certificates are renamed, by
  container_cert_name() in Rust and a mirrored few lines of shell.
* The system store only serves curl/git/apt. Node — and so Claude Code itself —
  needs NODE_EXTRA_CA_CERTS, Python needs REQUESTS_CA_BUNDLE/SSL_CERT_FILE, and
  Chromium reads neither: it wants ~/.pki/nssdb, seeded with certutil
  (libnss3-tools, added to the image).
* Those vars are set from Rust at creation, never exported by the entrypoint —
  a terminal is a docker exec and sees nothing the entrypoint exported. They are
  emitted empty when no CA is configured, since docker commit bakes env into the
  snapshot image.
* triple-c.ca-fingerprint hashes the certificate bytes as well as the path, so
  a CA rotated in at the same location still forces a recreation.

Verified end to end against a real container and a self-signed CA: curl, node,
python and git all complete a TLS handshake against a server signed by it and
all three fail in the same container without it; the env vars are visible from
a docker exec session; the store is cleaned when the setting is cleared.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KSP2KNPhuWKQ4DL5TZEn3k

app/src-tauri/src/docker/ca_certs.rs

@@ -0,0 +1,580 @@
+//! Corporate CA certificate injection.
+//!
+//! Users behind a TLS-terminating corporate proxy need their organisation's
+//! root CA inside every container, or **every** HTTPS call fails — npm, pip,
+//! git, curl, the Playwright browser, and Claude Code's own API calls.
+//!
+//! The mechanism follows the SSH/AWS host-mount pattern in [`super::container`]:
+//! a host path is bind-mounted **read-only** into the container and
+//! `entrypoint.sh` applies it on every start. That is what makes it durable
+//! across container recreation, base-image migration and Reset — a certificate
+//! installed by hand inside a running container is lost the first time any of
+//! those happen.
+//!
+//! ## Two things that are easy to get wrong
+//!
+//! 1. **`update-ca-certificates` only reads `*.crt`.** It globs
+//!    `/usr/local/share/ca-certificates/*.crt` case-sensitively, so a `.pem`
+//!    (the far more common export format) that is merely *copied* in is
+//!    silently ignored — no warning, no error, just a container that still
+//!    cannot speak HTTPS. Certificates must be **renamed**, which is what
+//!    [`container_cert_name`] does.
+//!
+//! 2. **The system trust store is not enough.** Only curl/git/apt read it.
+//!    Node — and therefore Claude Code itself — needs `NODE_EXTRA_CA_CERTS`,
+//!    Python/requests need `REQUESTS_CA_BUNDLE`/`SSL_CERT_FILE`, and
+//!    Chrome/Chromium read neither: they have their own NSS database at
+//!    `~/.pki/nssdb`, seeded by `certutil` in the entrypoint.
+//!
+//! ## Why the env vars are set from Rust and not exported by the entrypoint
+//!
+//! An `export` in `entrypoint.sh` reaches only the entrypoint's own children.
+//! Every terminal session is a separate `docker exec`, which inherits the
+//! *container's* configured env and sees nothing the entrypoint exported —
+//! the same lesson that forced `$BROWSER` to become an image-level `ENV` for
+//! the URL relay shim. Since the bundle path written by
+//! `update-ca-certificates` is deterministic ([`CA_BUNDLE_PATH`]), Rust can set
+//! all three vars at container creation, where `docker exec` will see them.
+
+use std::path::{Path, PathBuf};
+
+use sha2::{Digest, Sha256};
+
+/// Where the host's CA material is bind-mounted, read-only. Mirrors
+/// `/tmp/.host-ssh` and `/tmp/.host-aws`.
+///
+/// A *directory* on the host is mounted here as-is. A single *file* is mounted
+/// at `<CA_MOUNT_DIR>/<normalised name>` — Docker creates the parent — so the
+/// entrypoint only ever has to deal with a directory, and the certificate keeps
+/// a recognisable name instead of becoming the literal path `.host-ca`.
+pub const CA_MOUNT_DIR: &str = "/tmp/.host-ca";
+
+/// The concatenated PEM bundle `update-ca-certificates` writes on
+/// Debian/Ubuntu. Deterministic, which is what lets the env vars below be set
+/// at container-creation time, before the entrypoint has run.
+pub const CA_BUNDLE_PATH: &str = "/etc/ssl/certs/ca-certificates.crt";
+
+/// Consulted by Node — and therefore by Claude Code itself, which is the whole
+/// reason this feature exists.
+pub const NODE_EXTRA_CA_CERTS: &str = "NODE_EXTRA_CA_CERTS";
+/// Consulted by `requests` (and so by pip's vendored copy).
+pub const REQUESTS_CA_BUNDLE: &str = "REQUESTS_CA_BUNDLE";
+/// Consulted by OpenSSL, and so by Python's `ssl` module.
+pub const SSL_CERT_FILE: &str = "SSL_CERT_FILE";
+
+/// Every env var this module owns, in a fixed order.
+///
+/// Also the list that must be *cleared* when no CA is configured: `docker
+/// commit` bakes a container's env into the project's snapshot image, and
+/// create-time env replaces image `ENV` per key — so without an explicit empty
+/// value, removing the setting would leave the vars live in every future
+/// container. Empty is safe for all three (verified on Ubuntu 24.04: curl,
+/// `openssl s_client` and Python's `ssl` all behave exactly as they do with the
+/// variable unset).
+pub const CA_ENV_KEYS: &[&str] = &[NODE_EXTRA_CA_CERTS, REQUESTS_CA_BUNDLE, SSL_CERT_FILE];
+
+/// Extensions treated as certificates when the configured path is a directory.
+/// Matched case-insensitively. DER is deliberately absent — the system store
+/// and every consumer here want PEM.
+const CERT_EXTENSIONS: &[&str] = &["crt", "pem", "cer", "cert", "ca-bundle"];
+
+/// A configured CA path that has been checked and resolved into everything the
+/// container creation path needs.
+#[derive(Debug, Clone, PartialEq)]
+pub struct ResolvedCa {
+    /// The host path, as configured.
+    pub host_path: String,
+    /// Whether the host path is a directory (as opposed to a single file).
+    pub is_dir: bool,
+    /// The bind-mount target inside the container.
+    pub mount_target: String,
+    /// The certificate files found, sorted.
+    pub cert_files: Vec<PathBuf>,
+}
+
+fn sha256_hex(input: &str) -> String {
+    let mut hasher = Sha256::new();
+    hasher.update(input.as_bytes());
+    format!("{:x}", hasher.finalize())
+}
+
+/// The file name a certificate is installed as under
+/// `/usr/local/share/ca-certificates/`.
+///
+/// `update-ca-certificates` globs `*.crt` **case-sensitively**, so `.pem`,
+/// `.cer`, `.CRT` and extension-less files all have to end up as a lowercase
+/// `.crt` or they are ignored without a word. Characters outside
+/// `[A-Za-z0-9._-]` are replaced so that whitespace cannot break the shell
+/// loops that walk the store, and leading dots are stripped so a hidden file
+/// does not stay hidden.
+///
+/// `entrypoint.sh` reimplements exactly this in a few lines of shell (it has to
+/// rename the files inside the container); the two must agree, which is what
+/// the unit tests below pin down.
+pub fn container_cert_name(file_name: &str) -> String {
+    let sanitized: String = file_name
+        .chars()
+        .map(|c| {
+            if c.is_ascii_alphanumeric() || c == '.' || c == '_' || c == '-' {
+                c
+            } else {
+                '_'
+            }
+        })
+        .collect();
+    let sanitized = sanitized.trim_start_matches('.');
+    // Strip one trailing extension, whatever it is, then force `.crt`. A name
+    // with no dot keeps its whole self as the stem.
+    let stem = match sanitized.rfind('.') {
+        Some(i) => &sanitized[..i],
+        None => sanitized,
+    };
+    let stem = if stem.is_empty() { "corporate-ca" } else { stem };
+    format!("{}.crt", stem)
+}
+
+/// Whether a directory entry looks like a certificate worth installing.
+fn is_cert_file(path: &Path) -> bool {
+    let Some(ext) = path.extension().and_then(|e| e.to_str()) else {
+        return false;
+    };
+    let ext = ext.to_ascii_lowercase();
+    CERT_EXTENSIONS.contains(&ext.as_str())
+}
+
+/// The certificate files a configured path contributes.
+///
+/// A file is taken at face value — the user pointed at it explicitly, so its
+/// extension is not second-guessed. A directory is scanned one level deep
+/// (matching the entrypoint's `find -maxdepth 1`) and filtered by extension,
+/// so an `openssl.cnf` or a README sitting next to the certs is skipped.
+/// The result is sorted, so the fingerprint is stable across filesystem
+/// enumeration order.
+pub fn collect_cert_files(path: &Path) -> Vec<PathBuf> {
+    if path.is_file() {
+        return vec![path.to_path_buf()];
+    }
+    if !path.is_dir() {
+        return Vec::new();
+    }
+    let Ok(entries) = std::fs::read_dir(path) else {
+        return Vec::new();
+    };
+    let mut files: Vec<PathBuf> = entries
+        .filter_map(|e| e.ok())
+        .map(|e| e.path())
+        .filter(|p| p.is_file() && is_cert_file(p))
+        .collect();
+    files.sort();
+    files
+}
+
+/// Resolve the configured CA path, or explain why it cannot be used.
+///
+/// `Ok(None)` means "no CA configured", which is the overwhelmingly common
+/// case and must stay free. An `Err` aborts the container start: behind a
+/// TLS-intercepting proxy a container without the CA is broken in a dozen
+/// confusing ways, so naming the bad path once is far kinder than letting npm,
+/// pip and Claude Code each fail their own way.
+pub fn resolve(path: Option<&str>) -> Result<Option<ResolvedCa>, String> {
+    let Some(raw) = path.map(str::trim).filter(|s| !s.is_empty()) else {
+        return Ok(None);
+    };
+    let root = Path::new(raw);
+    if !root.exists() {
+        return Err(format!(
+            "Corporate CA certificate path '{}' does not exist. Update it in \
+             Settings → Certificates, or clear this project's override in \
+             Project Home → Config → Access.",
+            raw
+        ));
+    }
+
+    let is_dir = root.is_dir();
+    if !is_dir && !root.is_file() {
+        return Err(format!(
+            "Corporate CA certificate path '{}' is neither a file nor a directory.",
+            raw
+        ));
+    }
+
+    let cert_files = collect_cert_files(root);
+    if cert_files.is_empty() {
+        return Err(format!(
+            "Corporate CA certificate directory '{}' contains no certificate files \
+             (looked for {} one level deep).",
+            raw,
+            CERT_EXTENSIONS
+                .iter()
+                .map(|e| format!(".{}", e))
+                .collect::<Vec<_>>()
+                .join(", ")
+        ));
+    }
+
+    let mount_target = if is_dir {
+        CA_MOUNT_DIR.to_string()
+    } else {
+        let name = root
+            .file_name()
+            .map(|n| container_cert_name(&n.to_string_lossy()))
+            .unwrap_or_else(|| "corporate-ca.crt".to_string());
+        format!("{}/{}", CA_MOUNT_DIR, name)
+    };
+
+    Ok(Some(ResolvedCa {
+        host_path: raw.to_string(),
+        is_dir,
+        mount_target,
+        cert_files,
+    }))
+}
+
+/// Fingerprint of the CA configuration, for the `triple-c.ca-fingerprint`
+/// label.
+///
+/// `container_needs_recreation` is label-based and never diffs env or mounts,
+/// so without this, changing the CA path would silently do nothing until some
+/// unrelated setting forced a rebuild.
+///
+/// It covers **both** the resolved path *and the bytes of every certificate*,
+/// because replacing a rotated CA at the same path is at least as common as
+/// moving it — and the container's copy is made once, at start, so nothing else
+/// would notice.
+///
+/// Never returns an error: a path that has gone missing hashes differently from
+/// one that is present, which is exactly the "something changed, recreate"
+/// signal wanted here. Reporting the problem is [`resolve`]'s job.
+pub fn compute_ca_fingerprint(path: Option<&str>) -> String {
+    let Some(raw) = path.map(str::trim).filter(|s| !s.is_empty()) else {
+        return String::new();
+    };
+    let mut parts: Vec<String> = vec![raw.to_string()];
+    let root = Path::new(raw);
+    if !root.exists() {
+        parts.push("<missing>".to_string());
+    } else {
+        for file in collect_cert_files(root) {
+            let name = file
+                .file_name()
+                .map(|n| container_cert_name(&n.to_string_lossy()))
+                .unwrap_or_default();
+            let digest = match std::fs::read(&file) {
+                Ok(bytes) => {
+                    let mut hasher = Sha256::new();
+                    hasher.update(&bytes);
+                    format!("{:x}", hasher.finalize())
+                }
+                Err(_) => "<unreadable>".to_string(),
+            };
+            parts.push(format!("{}:{}", name, digest));
+        }
+    }
+    sha256_hex(&parts.join("|"))
+}
+
+/// The env vars to set on the container.
+///
+/// Always returns all of [`CA_ENV_KEYS`]: pointing at the bundle when a CA is
+/// configured, empty when it is not. The empty case is not cosmetic — see the
+/// note on [`CA_ENV_KEYS`].
+pub fn ca_env_vars(resolved: Option<&ResolvedCa>) -> Vec<(&'static str, String)> {
+    let value = if resolved.is_some() { CA_BUNDLE_PATH } else { "" };
+    CA_ENV_KEYS
+        .iter()
+        .map(|key| (*key, value.to_string()))
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs;
+
+    /// A scratch directory that cleans itself up. `tempfile` is not a
+    /// dependency of this crate and this is the only test that needs one.
+    struct TempDir(PathBuf);
+
+    impl TempDir {
+        fn new(tag: &str) -> Self {
+            let mut p = std::env::temp_dir();
+            p.push(format!(
+                "triple-c-ca-test-{}-{}-{:?}",
+                tag,
+                std::process::id(),
+                std::time::SystemTime::now()
+                    .duration_since(std::time::UNIX_EPOCH)
+                    .unwrap()
+                    .as_nanos()
+            ));
+            fs::create_dir_all(&p).unwrap();
+            TempDir(p)
+        }
+        fn path(&self) -> &Path {
+            &self.0
+        }
+        fn write(&self, name: &str, contents: &str) -> PathBuf {
+            let p = self.0.join(name);
+            fs::write(&p, contents).unwrap();
+            p
+        }
+    }
+
+    impl Drop for TempDir {
+        fn drop(&mut self) {
+            let _ = fs::remove_dir_all(&self.0);
+        }
+    }
+
+    // ── container_cert_name ────────────────────────────────────────────────
+
+    #[test]
+    fn a_pem_is_renamed_to_crt_not_merely_copied() {
+        // The whole point: update-ca-certificates globs *.crt and would
+        // silently ignore corp-root.pem.
+        assert_eq!(container_cert_name("corp-root.pem"), "corp-root.crt");
+    }
+
+    #[test]
+    fn a_crt_keeps_its_name() {
+        assert_eq!(container_cert_name("corp-root.crt"), "corp-root.crt");
+    }
+
+    #[test]
+    fn other_certificate_extensions_are_renamed_too() {
+        assert_eq!(container_cert_name("zscaler.cer"), "zscaler.crt");
+        assert_eq!(container_cert_name("zscaler.cert"), "zscaler.crt");
+        assert_eq!(container_cert_name("bundle.ca-bundle"), "bundle.crt");
+    }
+
+    #[test]
+    fn an_uppercase_extension_is_lowercased() {
+        // `find -name '*.crt'` is case-sensitive, so CA.CRT would be ignored.
+        assert_eq!(container_cert_name("CA.CRT"), "CA.crt");
+        assert_eq!(container_cert_name("CA.PEM"), "CA.crt");
+    }
+
+    #[test]
+    fn a_name_without_an_extension_gains_one() {
+        assert_eq!(container_cert_name("corporate-root"), "corporate-root.crt");
+    }
+
+    #[test]
+    fn only_the_last_extension_is_replaced() {
+        assert_eq!(container_cert_name("corp.root.ca.pem"), "corp.root.ca.crt");
+    }
+
+    #[test]
+    fn unsafe_characters_are_replaced() {
+        assert_eq!(
+            container_cert_name("Corp Root CA (2026).pem"),
+            "Corp_Root_CA__2026_.crt"
+        );
+        assert_eq!(container_cert_name("a/b.pem"), "a_b.crt");
+    }
+
+    #[test]
+    fn leading_dots_are_stripped_so_the_file_is_not_hidden() {
+        assert_eq!(container_cert_name(".hidden.pem"), "hidden.crt");
+    }
+
+    #[test]
+    fn a_degenerate_name_still_produces_a_usable_file() {
+        assert_eq!(container_cert_name(".pem"), "pem.crt");
+        assert_eq!(container_cert_name(""), "corporate-ca.crt");
+        assert_eq!(container_cert_name("..."), "corporate-ca.crt");
+    }
+
+    #[test]
+    fn every_produced_name_ends_in_lowercase_crt() {
+        for input in [
+            "a.pem", "b.CRT", "c", ".d.pem", "", "e f.cer", "...", "ç.pem",
+        ] {
+            let out = container_cert_name(input);
+            assert!(
+                out.ends_with(".crt"),
+                "{:?} produced {:?}, which update-ca-certificates would ignore",
+                input,
+                out
+            );
+            assert!(
+                out.chars()
+                    .all(|c| c.is_ascii_alphanumeric() || c == '.' || c == '_' || c == '-'),
+                "{:?} produced {:?}, which is not shell-safe",
+                input,
+                out
+            );
+        }
+    }
+
+    // ── fingerprint ────────────────────────────────────────────────────────
+
+    #[test]
+    fn no_configured_path_fingerprints_as_empty() {
+        assert_eq!(compute_ca_fingerprint(None), "");
+        assert_eq!(compute_ca_fingerprint(Some("")), "");
+        assert_eq!(compute_ca_fingerprint(Some("   ")), "");
+    }
+
+    #[test]
+    fn changing_the_path_changes_the_fingerprint() {
+        let a = TempDir::new("path-a");
+        let b = TempDir::new("path-b");
+        // Identical *content* in both, so only the path differs.
+        a.write("corp.pem", "CERT-BODY");
+        b.write("corp.pem", "CERT-BODY");
+
+        let fp_a = compute_ca_fingerprint(Some(a.path().to_str().unwrap()));
+        let fp_b = compute_ca_fingerprint(Some(b.path().to_str().unwrap()));
+        assert_ne!(fp_a, "");
+        assert_ne!(
+            fp_a, fp_b,
+            "two different paths must not share a fingerprint"
+        );
+    }
+
+    #[test]
+    fn changing_the_certificate_content_at_the_same_path_changes_the_fingerprint() {
+        // The case a path-only fingerprint would miss: the corporate CA is
+        // rotated and the new one dropped in at exactly the same location.
+        let dir = TempDir::new("rotate");
+        dir.write("corp.pem", "OLD-CERT");
+        let before = compute_ca_fingerprint(Some(dir.path().to_str().unwrap()));
+
+        dir.write("corp.pem", "NEW-CERT");
+        let after = compute_ca_fingerprint(Some(dir.path().to_str().unwrap()));
+
+        assert_ne!(
+            before, after,
+            "replacing the certificate at the same path must force a recreation"
+        );
+    }
+
+    #[test]
+    fn adding_or_removing_a_certificate_changes_the_fingerprint() {
+        let dir = TempDir::new("add");
+        dir.write("one.pem", "A");
+        let one = compute_ca_fingerprint(Some(dir.path().to_str().unwrap()));
+        dir.write("two.pem", "B");
+        let two = compute_ca_fingerprint(Some(dir.path().to_str().unwrap()));
+        assert_ne!(one, two);
+        fs::remove_file(dir.path().join("two.pem")).unwrap();
+        assert_eq!(compute_ca_fingerprint(Some(dir.path().to_str().unwrap())), one);
+    }
+
+    #[test]
+    fn an_unchanged_directory_fingerprints_identically() {
+        let dir = TempDir::new("stable");
+        dir.write("corp.pem", "SAME");
+        let a = compute_ca_fingerprint(Some(dir.path().to_str().unwrap()));
+        let b = compute_ca_fingerprint(Some(dir.path().to_str().unwrap()));
+        assert_eq!(a, b, "the fingerprint must not churn on repeated reads");
+    }
+
+    #[test]
+    fn a_missing_path_fingerprints_differently_from_a_present_one() {
+        let dir = TempDir::new("missing");
+        let present = compute_ca_fingerprint(Some(dir.path().to_str().unwrap()));
+        let missing =
+            compute_ca_fingerprint(Some(&format!("{}-gone", dir.path().to_str().unwrap())));
+        assert_ne!(present, missing);
+        assert_ne!(missing, "");
+    }
+
+    #[test]
+    fn non_certificate_files_in_the_directory_are_ignored() {
+        let dir = TempDir::new("noise");
+        dir.write("corp.pem", "CERT");
+        let before = compute_ca_fingerprint(Some(dir.path().to_str().unwrap()));
+        dir.write("README.md", "hello");
+        dir.write("openssl.cnf", "[req]");
+        assert_eq!(
+            compute_ca_fingerprint(Some(dir.path().to_str().unwrap())),
+            before
+        );
+    }
+
+    // ── resolve ────────────────────────────────────────────────────────────
+
+    #[test]
+    fn no_path_resolves_to_nothing() {
+        assert_eq!(resolve(None).unwrap(), None);
+        assert_eq!(resolve(Some("  ")).unwrap(), None);
+    }
+
+    #[test]
+    fn a_missing_path_is_an_actionable_error() {
+        let err = resolve(Some("/definitely/not/here/corp.pem")).unwrap_err();
+        assert!(err.contains("/definitely/not/here/corp.pem"), "{}", err);
+        assert!(err.contains("Settings"), "{}", err);
+    }
+
+    #[test]
+    fn an_empty_directory_is_an_actionable_error() {
+        let dir = TempDir::new("empty");
+        let err = resolve(Some(dir.path().to_str().unwrap())).unwrap_err();
+        assert!(err.contains("no certificate files"), "{}", err);
+        assert!(err.contains(".pem"), "{}", err);
+    }
+
+    #[test]
+    fn a_directory_mounts_at_the_shared_mount_point() {
+        let dir = TempDir::new("dir");
+        dir.write("corp.pem", "CERT");
+        let resolved = resolve(Some(dir.path().to_str().unwrap())).unwrap().unwrap();
+        assert!(resolved.is_dir);
+        assert_eq!(resolved.mount_target, CA_MOUNT_DIR);
+        assert_eq!(resolved.cert_files.len(), 1);
+    }
+
+    #[test]
+    fn a_single_file_mounts_under_the_mount_point_with_a_crt_name() {
+        // Mounting a file *at* /tmp/.host-ca would leave the entrypoint with no
+        // name to work from, and would make the mount point a file rather than
+        // the directory the entrypoint expects.
+        let dir = TempDir::new("file");
+        let file = dir.write("corp root.pem", "CERT");
+        let resolved = resolve(Some(file.to_str().unwrap())).unwrap().unwrap();
+        assert!(!resolved.is_dir);
+        assert_eq!(
+            resolved.mount_target,
+            format!("{}/corp_root.crt", CA_MOUNT_DIR)
+        );
+    }
+
+    #[test]
+    fn a_file_is_accepted_whatever_its_extension() {
+        // The user pointed at it explicitly; don't second-guess.
+        let dir = TempDir::new("odd-ext");
+        let file = dir.write("corp.txt", "CERT");
+        let resolved = resolve(Some(file.to_str().unwrap())).unwrap().unwrap();
+        assert_eq!(resolved.cert_files, vec![file]);
+    }
+
+    // ── env vars ───────────────────────────────────────────────────────────
+
+    #[test]
+    fn configured_ca_points_every_consumer_at_the_bundle() {
+        let dir = TempDir::new("env");
+        dir.write("corp.pem", "CERT");
+        let resolved = resolve(Some(dir.path().to_str().unwrap())).unwrap();
+        let vars = ca_env_vars(resolved.as_ref());
+        assert_eq!(
+            vars,
+            vec![
+                (NODE_EXTRA_CA_CERTS, CA_BUNDLE_PATH.to_string()),
+                (REQUESTS_CA_BUNDLE, CA_BUNDLE_PATH.to_string()),
+                (SSL_CERT_FILE, CA_BUNDLE_PATH.to_string()),
+            ]
+        );
+    }
+
+    #[test]
+    fn no_ca_clears_every_var_rather_than_omitting_it() {
+        // Omitting them would let a value baked into the project's snapshot
+        // image survive the setting being turned off.
+        let vars = ca_env_vars(None);
+        assert_eq!(vars.len(), CA_ENV_KEYS.len());
+        assert!(vars.iter().all(|(_, v)| v.is_empty()));
+    }
+}