fix: pre-landing review fixes (GST-1064: passphrases passed to a call still report; only file names and short snake_case keys are names)

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

changelog.d/gst-1064-secrets-call-literal.md

@@ -1,2 +1,2 @@
 ### Fixed
-- **The secrets check no longer reads a file name or dict key inside a call as a credential (GST-1064).** `key = json.loads(files.get("key.json", ""))` failed pregate with `PREGATE_SECRETS` (`env.kv`): eight distinct letters in `"key.json"` reach the entropy bar, so the call's argument looked like a secret. So did `token = resp.json().get("access_token")` and a `getenv` default like `"change-me-later"`. A quoted argument made only of lowercase words joined by `_`, `.` or `-` now counts as a name. A real key in quotes, in a `.env` line, or passed to a call (`decrypt("<key>")`) still reports, and the entropy bar is unchanged.
+- **The secrets check no longer reads a file name or dict key inside a call as a credential (GST-1064).** `key = json.loads(files.get("key.json", ""))` failed pregate with `PREGATE_SECRETS` (`env.kv`): eight distinct letters in `"key.json"` reach the entropy bar, so the call's argument looked like a secret. So did `token = resp.json().get("access_token")`. A quoted argument that is a lowercase file name or a snake_case key of two or three words now counts as a name. A real key in quotes, in a `.env` line, or passed to a call still reports, and so does a passphrase (`decrypt("prod-signing-key")`, a `getenv` default like `"correct-horse-battery-staple"`). The entropy bar is unchanged.

lib/redact-patterns.ts

@@ -629,13 +629,14 @@ function isBareEnvRead(span: string, match: RegExpExecArray): boolean {
 
 /**
  * True when `text` holds a quoted, non-placeholder, high-entropy literal.
- * GST-1064: lowercase letter words joined by `_`, `.` or `-` name a file, dict
- * key or default (`"key.json"`, `"access_token"`, `"change-me-later"`); eight
- * distinct letters already reach 3.0 bits, so entropy alone cannot tell them
- * from a secret. A literal with a digit, an uppercase letter or one unbroken
- * run still counts.
+ * GST-1064: a lowercase file name (`"key.json"`) or a snake_case key of two or
+ * three words (`"access_token"`) names what the call reads; eight distinct
+ * letters already reach 3.0 bits, so entropy alone cannot tell them from a
+ * secret. A passphrase still counts: kebab or dotted words
+ * (`"correct-horse-battery-staple"`), four or more snake_case words, a digit,
+ * an uppercase letter or one unbroken run.
  */
-const NAME_SHAPED_LITERAL = /^[a-z]+(?:[_.-][a-z]+)+$/;
+const NAME_SHAPED_LITERAL = /^(?:[a-z]+(?:_[a-z]+){1,2}|[a-z]+(?:[_-][a-z]+)*\.[a-z]{2,5})$/;
 function carriesSecretLiteral(text: string): boolean {
   for (const [, literal] of text.matchAll(/["']([^\s'"]{8,})["']/g))
     if (!isPlaceholderSpan(literal) && !NAME_SHAPED_LITERAL.test(literal) && shannonEntropy(literal) >= 3.0) return true;

test/redact-context-exemptions.test.ts

@@ -116,7 +116,7 @@ describe("env.kv: a name-shaped literal inside a call is a file or dict key, not
       String.raw`key = json.loads(files.get("key.json", ""))`,
       String.raw`token = resp.json().get("access_token")`,
       String.raw`    session = store.load('session.cookie')`,
-      String.raw`password = os.getenv("DB_PASSWORD", "change-me-later")`,
+      String.raw`secret = vault.read("client_secret")`,
     ],
     [
       String.raw`key = "${FAKE_KEY}"`,
@@ -125,6 +125,10 @@ describe("env.kv: a name-shaped literal inside a call is a file or dict key, not
       String.raw`token = resp.json().get("access_token", "${FAKE_KEY}")`,
       String.raw`password = os.getenv("DB_PASSWORD", "hunter2.Zx9Qw8")`,
       String.raw`key = json.loads(files.get("key.json")) or "${FAKE_KEY}"`,
+      String.raw`password = os.getenv("DB_PASSWORD", "correct-horse-battery-staple")`,
+      String.raw`api_key = decrypt("prod-signing-key")`,
+      String.raw`token = decrypt("correct_horse_battery_staple")`,
+      String.raw`key = decrypt("qwhzxkvbnmplor")`,
     ],
   );
 });