ZB.MOM.WW.Secrets (0.1.3)
Installation
dotnet nuget add source --name dohertj2 --username your_username --password your_token https://gitea.dohertylan.com/api/packages/dohertj2/nuget/index.jsondotnet add package --source dohertj2 --version 0.1.3 ZB.MOM.WW.SecretsAbout this package
Envelope-encrypted (AES-256-GCM) secrets store + resolver for the ZB.MOM.WW SCADA family.
ZB.MOM.WW.Secrets
A reusable, envelope-encrypted secrets manager for the ZB.MOM.WW.* SCADA family:
store secrets (SQL passwords, API tokens, connection strings) encrypted at rest and get the
plaintext back on demand — from application code, from configuration, or from an operator UI.
Packages
| Package | Purpose |
|---|---|
ZB.MOM.WW.Secrets.Abstractions |
Contracts only (ISecretStore, ISecretResolver, IMasterKeyProvider, ISecretCipher, ISecretReplicator, ISecretCacheInvalidator, ISecretActorAccessor), value types, exceptions. Dependency-light. |
ZB.MOM.WW.Secrets |
Implementation: AES-256-GCM envelope cipher, env/file/DPAPI master-key providers, SQLite store, TTL resolver (audited), ${secret:} config expander, AddZbSecrets. |
ZB.MOM.WW.Secrets.Ui |
Blazor RCL on ZB.MOM.WW.Theme: list / add / rotate / delete + policy-gated, audited reveal. |
A secret CLI (set / get / list / rm / rotate / rewrap-all) ships in the repo (not packed).
How it protects secrets
Each value is encrypted with a fresh data key (DEK) using AES-256-GCM; the DEK is then
wrapped by a master KEK that never touches the database. The AAD binds the ciphertext
to the secret's name and the wrapped DEK to the KEK id, so rows can't be swapped and a
tampered/mis-keyed row fails closed (SecretDecryptionException) rather than returning a
wrong value. The master KEK is resolved through a pluggable IMasterKeyProvider
(environment variable, key file, or Windows DPAPI).
Wiring it up
builder.Services.AddZbSecrets(builder.Configuration, "Secrets");
// After config load, BEFORE options validation — expand ${secret:...} references:
var expander = new SecretReferenceExpander(app.Services.GetRequiredService<ISecretResolver>());
await expander.ExpandConfigurationAsync((IConfigurationRoot)builder.Configuration, ct);
// appsettings.json
"Secrets": {
"SqlitePath": "secrets.db",
"MasterKey": { "Source": "Environment", "EnvVarName": "ZB_SECRETS_MASTER_KEY" },
"RunMigrationsOnStartup": true,
"ResolveCacheTtl": "00:00:30"
},
// Keep plaintext out of config — reference a stored secret instead:
"ConnectionStrings": {
"Historian": "Server=...;User Id=sa;Password=${secret:sql/historian-password}"
}
The master key is 32 bytes, provided base64 in ZB_SECRETS_MASTER_KEY (Environment source).
A missing/invalid key fails closed at startup (MasterKeyUnavailableException).
Rotating the master KEK
Because each row is a body sealed under a per-secret DEK that is wrapped by the KEK, rotating
the master key only re-wraps DEKs — bodies are never re-encrypted and no value history changes.
The secret rewrap-all CLI verb (backed by KekRotationService) migrates every row from the
old KEK to the new one; it is idempotent and safe to re-run:
# New KEK defaults to the configured Secrets:MasterKey; supply the OLD key by env-var name or path.
ZB_SECRETS_MASTER_KEY=<new-base64> ZB_SECRETS_OLD_KEY=<old-base64> \
secret rewrap-all --old-key-env ZB_SECRETS_OLD_KEY
# → {"action":"rewrap-all","total":N,"rewrapped":N,"alreadyCurrent":0}
Run it with resolve traffic quiesced and once per independent store (once for a shared
SQL-Server store; once per node for per-node SQLite on a shared KEK). See the operator runbook:
docs/operations/kek-rotation.md.
Runtime + human access
- App code: inject
ISecretResolverand callGetAsync(name, ct). Every resolve is audited viaZB.MOM.WW.Audit(name + outcome only — the value is never logged). - Operators: mount the
ZB.MOM.WW.Secrets.Ui/admin/secretspage. The list shows metadata only; revealing a value requires thesecrets:revealauthorization policy and is audited. Add/rotate/delete requiresecrets:manage.
Clustered deployments
Secrets storage is local SQLite by default. The schema already carries the
revision / updated_utc / tombstone columns and an ISecretReplicator seam for
cluster replication, but the Akka replicator (ZB.MOM.WW.Secrets.Akka) is a deferred
follow-on. When replicating across a node pair, every node must resolve the same master
KEK (e.g. the same mounted key file) — a row wrapped by an unknown KEK fails closed.