Wrap credential and credential-holding types to prevent `Debug` leaks.

The following values are considered confidential, and should never be logged, even by accident:

* `Password`, which is a durable bearer token for a specific Login;
* `IdentitySecret`, which is an ephemeral but potentially long-lived bearer token for a specific Login; or
* `IdentityToken`, which may hold cookies containing an `IdentitySecret`.

These values are now wrapped in types whose `Debug` impls output opaque values, so that they can be included in structs that `#[derive(Debug)]` without requiring any additional care. The wrappers also avoid implementing `Display`, to prevent inadvertent `to_string()`s.

We don't bother obfuscating `IdentitySecret`s in memory or in the `.hi` database. There's no point: we'd also need to store the information needed to de-obfuscate them, and they can be freely invalidated and replaced by blanking that table and asking everyone to log in again. Passwords _are_ obfuscated for storage, as they're intended to be durable.

1 files changed, 20 insertions, 0 deletions

diff --git a/.sqlx/query-c28b9bffa73d6a861e122a73a90e3912d23bf952740fe32544bc70a44e6a2744.json b/.sqlx/query-c28b9bffa73d6a861e122a73a90e3912d23bf952740fe32544bc70a44e6a2744.json
new file mode 100644
index 0000000..5927248
--- /dev/null
+++ b/.sqlx/query-c28b9bffa73d6a861e122a73a90e3912d23bf952740fe32544bc70a44e6a2744.json
@@ -0,0 +1,20 @@
+{
+  "db_name": "SQLite",
+  "query": "\n                insert\n                into token (secret, login, issued_at, last_used_at)\n                values ($1, $2, $3, $3)\n                returning secret as \"secret!: IdentitySecret\"\n            ",
+  "describe": {
+    "columns": [
+      {
+        "name": "secret!: IdentitySecret",
+        "ordinal": 0,
+        "type_info": "Text"
+      }
+    ],
+    "parameters": {
+      "Right": 3
+    },
+    "nullable": [
+      false
+    ]
+  },
+  "hash": "c28b9bffa73d6a861e122a73a90e3912d23bf952740fe32544bc70a44e6a2744"
+}