bcquality/microsoft/knowledge/security/isolatedstorage-setencrypted-for-sensitive-values.md
Jesper Schulz-Wedde a9f3c50863 Regenerate microsoft/knowledge from upstream BCApps instructions
The previous LLM-generated knowledge files contained factual
hallucinations. The most visible was the claim that `FindFirst` /
`FindLast` "forces a full-table scan" on an unfiltered record - it does
not; those APIs return a single row via the current key.

Other inaccuracies the audit found and fixed:

* `FindSet(true)` was described as "taking a LockTable". The correct
  upstream phrasing is that `FindSet(true)` sets
  `ReadIsolation::UpdLock` on the read. UpdLock and LockTable are
  related but distinct mechanisms.
* The list of production-scale tables had been invented beyond the
  upstream source (e.g. "Detailed Cust. Ledg. Entry") without a
  citation. The regenerated list matches the ten tables upstream lists
  with their P95 row counts.
* `SetLoadFields` guidance had been augmented with an extra mechanism
  claim ("the database resolves the filter using the index without
  hydrating the value") not present in upstream.

Approach: full regeneration of `microsoft/knowledge/` from the six
upstream BCApps Code Review instruction files, with Microsoft Learn /
the AL language reference as a secondary source. Every claim in every
regenerated file is anchored to a verbatim upstream quote (or a Learn
URL); the audit trail lives in artifacts/trace-<domain>.json on the
session workspace.

The PR #11 transaction/error-handling cluster is preserved verbatim:

* performance/understand-implicit-transaction-boundary.md
* performance/codeunit-run-as-atomic-sub-operation.{md,good.al,bad.al}
* performance/codeunit-run-requires-prior-commit-inside-transaction.{md,good.al,bad.al}
* performance/use-tryfunction-for-error-catching-not-rollback.{md,good.al,bad.al}
* performance/avoid-commit-inside-loops.{md,good.al,bad.al}
* security/commitbehavior-attribute-scopes-explicit-commits.{md,good.al,bad.al}
* testing/transactionmodel-attribute-governs-test-transactions.{md,good.al,bad.al}

These articles already cite Microsoft Learn and were carefully
cross-referenced; the regeneration skips their topics rather than
duplicating them.

File counts after regeneration:

  performance   35 .md  (5 preserved + 30 new)
  privacy       17 .md
  security      18 .md  (1 preserved + 17 new)
  style         33 .md
  testing        1 .md  (preserved)
  ui            19 .md
  upgrade       18 .md

Total 141 atomic knowledge files, each strictly one rule. All pass
.github/scripts/validate_frontmatter.py with 0 errors and 0 warnings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-21 09:53:09 +02:00

22 lines
1.7 KiB
Markdown

---
bc-version: [all]
domain: security
keywords: [isolatedstorage, setencrypted, encryption, secret, storage]
technologies: [al]
countries: [w1]
application-area: [all]
---
# Prefer IsolatedStorage.SetEncrypted over Set for sensitive values
## Description
`IsolatedStorage` exposes two write entry points: `Set` stores the value as-is, and `SetEncrypted` stores it encrypted at rest. Both are scoped per extension, but only `SetEncrypted` adds the additional protection that the value is not readable from the underlying storage by anything that bypasses the AL `IsolatedStorage` API. The choice between them is by intent: configuration that is not sensitive (a user preference, a default flag) can use `Set`; anything that would harm the tenant if leaked — API keys, tokens, connection strings, OAuth client secrets — uses `SetEncrypted`.
## Best Practice
Use `IsolatedStorage.SetEncrypted` for every value that meets the definition of a secret. Pair it with the matching retrieval pattern: `IsolatedStorage.Contains` to test for presence and `IsolatedStorage.Get` (preferably with a `SecretText` destination) to read. Constrain the input length before storing — long values can exceed the encrypted-storage size limit and the write will fail at runtime. See sample: `isolatedstorage-setencrypted-for-sensitive-values.good.al`.
## Anti Pattern
`IsolatedStorage.Set('ApiKey', ApiKeyValue, DataScope::Module)` — the key is now sitting in storage unencrypted, and any future incident that exposes the underlying storage exposes the key. Reviewers should flag any `IsolatedStorage.Set` whose key name or surrounding context suggests a secret (`ApiKey`, `Token`, `Password`, `Secret`, `ClientSecret`). See sample: `isolatedstorage-setencrypted-for-sensitive-values.bad.al`.