Resolve bao:/kv: secret refs embedded in header/env values

packages/gateway/src/secrets/store.test.ts

@@ -34,6 +34,37 @@ describe("resolveInjectionValue", () => {
     );
   });
 
+  it("resolves a bao: ref embedded in a larger value", async () => {
+    const store = new MemorySecretStore();
+    await store.put("upstreams/publora", "token", "sk_live_123");
+    await expect(
+      resolveInjectionValue("Bearer bao:upstreams/publora#token", env, store, "ctx")
+    ).resolves.toBe("Bearer sk_live_123");
+  });
+
+  it("resolves multiple embedded tokens (ref + ${VAR}) in one value", async () => {
+    const store = new MemorySecretStore();
+    await store.put("p", "a", "AAA");
+    await expect(
+      resolveInjectionValue("k=bao:p#a; e=${MY_TOKEN}; end", env, store, "ctx")
+    ).resolves.toBe("k=AAA; e=env-value; end");
+  });
+
+  it("fails an embedded bao: ref when no store is configured", async () => {
+    await expect(
+      resolveInjectionValue("Bearer bao:a#b", env, null, "ctx")
+    ).rejects.toThrow(/BAO_ADDR/);
+  });
+
+  it("returns a whole-value secret verbatim without re-scanning its contents", async () => {
+    const store = new MemorySecretStore();
+    // Secret content that itself looks like a ${VAR} / ref must not be re-resolved.
+    await store.put("p", "f", "Bearer ${MY_TOKEN} bao:x#y");
+    await expect(resolveInjectionValue("bao:p#f", env, store, "ctx")).resolves.toBe(
+      "Bearer ${MY_TOKEN} bao:x#y"
+    );
+  });
+
   it("fails a bao: ref when no store is configured", async () => {
     await expect(resolveInjectionValue("bao:a#b", env, null, "ctx")).rejects.toThrow(/BAO_ADDR/);
   });

packages/gateway/src/secrets/store.ts

@@ -6,6 +6,11 @@
  *   "kv:secret-name"   — a secret in Azure Key Vault (flat name→value, no fields)
  *   "literal ${VAR}"   — env substitution (config.ts substituteEnv)
  *
+ * Refs may be EMBEDDED in a larger value: "Bearer bao:upstreams/x#token"
+ * resolves to "Bearer <secret>". A ref token is delimited by whitespace, so
+ * paths/fields must not contain spaces. When the whole value is a single ref
+ * the secret is returned verbatim (no env-substitution of its contents).
+ *
  * Secret VALUES are never persisted in SQLite, never logged (labels and
  * sha256 prefixes only), and never returned by the admin API.
  */
@@ -60,28 +65,68 @@ export function parseSecretRef(value: string): SecretRef {
 export const secretFingerprint = (value: string): string =>
   createHash("sha256").update(value).digest("hex").slice(0, 8);
 
+/** Resolve a single, whole-value ref against the store (with the plumbing checks). */
+async function resolveRef(
+  ref: string,
+  store: SecretStore | null,
+  context: string
+): Promise<string> {
+  if (!store) {
+    throw new Error(
+      `${context} references a secret ("${ref}") but no secret store is configured — set BAO_ADDR or KEY_VAULT_URI`
+    );
+  }
+  const scheme = schemeOf(ref);
+  if (store.scheme !== scheme) {
+    throw new Error(
+      `${context} uses a "${scheme}:" ref but the configured secret store serves "${store.scheme}:" refs`
+    );
+  }
+  return store.get(parseSecretRef(ref));
+}
+
+// A ref or ${VAR} embedded in a larger string. Ref tokens use a conservative
+// path/field charset (letters, digits and - _ . /) so a ref ends cleanly at
+// surrounding punctuation — "Bearer bao:upstreams/x#token" or "…#token; more".
+// "kv:secret-name" uses the KV charset. Matched left-to-right in a single pass
+// so resolved secret contents are never re-scanned. Whole-value refs (handled
+// before this) keep the broader parseSecretRef charset for back-compat.
+const REF_CHARS = "A-Za-z0-9_./-";
+const EMBEDDED_TOKEN = new RegExp(
+  `bao:[${REF_CHARS}]+#[${REF_CHARS}]+|kv:[0-9A-Za-z-]{1,127}|\\$\\{[A-Za-z_][A-Za-z0-9_]*\\}`,
+  "g"
+);
+
 /** Resolve one injection value (header or env var) at connect time. */
 export async function resolveInjectionValue(
   value: string,
   env: NodeJS.ProcessEnv,
   store: SecretStore | null,
   context: string
 ): Promise<string> {
+  // Whole value is a single ref → return the secret verbatim (its contents are
+  // never treated as a ref or ${VAR}). Also the only path that errors on a
+  // malformed whole-value ref such as "bao:missing-hash".
   if (isSecretRef(value)) {
-    if (!store) {
-      throw new Error(
-        `${context} references a secret ("${value}") but no secret store is configured — set BAO_ADDR or KEY_VAULT_URI`
-      );
-    }
-    const scheme = schemeOf(value);
-    if (store.scheme !== scheme) {
-      throw new Error(
-        `${context} uses a "${scheme}:" ref but the configured secret store serves "${store.scheme}:" refs`
-      );
-    }
-    return store.get(parseSecretRef(value));
+    return resolveRef(value, store, context);
+  }
+  // Otherwise resolve any embedded refs / ${VAR}s in a single left-to-right
+  // pass, splicing resolved values in without re-scanning them.
+  const matches = [...value.matchAll(EMBEDDED_TOKEN)];
+  if (matches.length === 0) return value;
+  let out = "";
+  let cursor = 0;
+  for (const match of matches) {
+    const token = match[0];
+    const index = match.index ?? 0;
+    out += value.slice(cursor, index);
+    out += token.startsWith("${")
+      ? substituteEnv(token, env, context)
+      : await resolveRef(token, store, context);
+    cursor = index + token.length;
   }
-  return substituteEnv(value, env, context);
+  out += value.slice(cursor);
+  return out;
 }
 
 export async function resolveInjectionRecord(