add mask-secret tool and rule

2026-08-13 01:59:42 +00:00
parent 6290dadb62
commit 2809072812
2 changed files with 132 additions and 0 deletions
@@ -81,6 +81,31 @@ Three things still hold, because they are cheap and they outlive the session:
  warning, as a fact he may want later. Tools do this quietly — `tea` stores its
  token in plaintext at `~/.config/tea/config.yml`, and nothing announced it.

+### Mask it in the chat history once you are done
+
+When he pastes a secret, mask it in the stored history as soon as you have
+finished using it — same turn, unprompted. He reloads and sometimes shares whole
+chat histories, and that is the copy that matters to him.
+
+    printf '%s' '<secret>' | ~/projects/claude-mds/tools/mask-secret.py
+
+The script covers both readable stores — Claude Code's `~/.claude/projects/**`
+transcripts and Postgres `chat_session_events` — and replaces the value with
+asterisks of the same length, overwriting in place so the live session's
+appends are not lost. Read the header before changing it; the same-length,
+same-inode detail is load-bearing.
+
+Two habits that matter more than the cleanup:
+
+- **Keep secrets off command lines.** Pass them by stdin or an env var. Argv is
+  visible in `ps`, and every command you run is stored verbatim. Of seven copies
+  of one pasted token, four were commands — mine, not his.
+- **Expect several copies per paste.** The harness writes the `user` message, a
+  `queue-operation` record and a rolling `last-prompt` cache. Never assume one.
+
+The tool's own config keeps the real value. That is not a leak, it is how the
+tool authenticates.
+
 Never revoke, rotate or invalidate a credential on your own. That breaks things
 he did not ask you to break.