* Add black-box behavior tests for KMS resilience and serialization * fix(kms): repair unopenable ciphertext across backends Black-box testing of the KMS crate surfaced several defects that make encrypted data permanently unreadable. Symmetric envelopes. The Local and Vault Transit backends returned raw cipher output from `encrypt` while `decrypt` parsed a JSON envelope, so anything sealed through the master-key path could never be opened again. Local also discarded the AES-GCM nonce. Both now emit the same envelope `decrypt` consumes, matching the Static backend. Deterministic AAD. The object layer derived AEAD additional data by serializing a `HashMap` directly. Iteration order differs per instance, so a context rebuilt from storage produced different AAD bytes than the one used to seal and the object stopped opening. Ordering by key removes that dependency, matching the Static backend's existing `context_aad`. Objects written with the default single-key context are unaffected, since a one-entry map has only one serialization. Cipher in the header projection. `metadata_to_headers` recorded the SSE mode (`AES256` / `aws:kms`), which cannot represent ChaCha20-Poly1305, so a ChaCha-sealed object came back claiming `aws:kms` and was opened with the wrong cipher. The cipher now travels in `x-rustfs-encryption-algorithm` — the header the storage layer already reads but nothing ever wrote. Objects without it fall back as before. Also: the Static backend ignored `key_spec` and always issued 256-bit data keys; Local `list_keys` hardcoded `truncated: false`, ignored `marker`, and paginated over unordered `read_dir`, so a paginating client silently saw a partial key list; and Local and Vault KV2 reported `key_id: "unknown"` from `decrypt` despite the envelope naming the master key. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * test(kms): cover both Vault backends and key rotation The behavior suite ran only against Local and Static, and its own harness documented the gap: the Vault backends had no business-capability coverage at all. Setting `RUSTFS_KMS_VAULT_TOKEN` now adds Vault KV2 and Vault Transit to every `for_each_backend` spec against a live server. That lane is what surfaced the Transit envelope defect fixed in the previous commit. `rotate` and `versioning` are advertised only by the Vault backends, so until now every capability-gated branch for them took the `UnsupportedCapability` side and the working half was never asserted — a rotation that dropped prior key versions would have gone green. The new `behavior_rotation.rs` pins that half: material sealed before a rotation still opens after it, repeated rotations accumulate versions rather than overwriting a single spare, and the history survives a restart. Two test defects fixed. `objects_round_trip_across_sizes_and_algorithms` asserted a 1-byte object differs from its own ciphertext, which collides once every 256 runs; the assertion now applies only where a collision is not realistic, and small objects stay covered by the tag check and the decrypt round-trip. `test_from_env_selects_token_file` depended on `RUSTFS_KMS_VAULT_TOKEN` being absent from the caller's environment and now clears it explicitly. The snapshots directory was also removed from `.gitignore`: insta snapshots are the assertions themselves, so leaving them untracked gives CI nothing to compare against. Only `.snap.new` scratch files are ignored now. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * test(kms): adapt behavior suite to current key APIs Rebasing onto main brought four API changes the suite predates. `DeleteKeyRequest` gained `confirm_key_id`, and immediate deletion is now gated on the server's `allow_immediate_deletion`. Scheduled deletions pass `None`; the four specs that destroy a key outright echo the key id back and opt the harness config in, which is what the gate asks of a real caller. `LocalBackupExportRequest` gained `sanitized_config`. These specs cover the key-material path, so they seal no configuration and pass `None`. `KmsCacheStats` became a named struct with real hit, miss, and eviction counters. `cache_stats_returns_an_entry_count_and_no_hit_or_miss_data` existed to pin the old placeholder behavior — that the second tuple element was always zero — which main has since fixed, so it is now `cache_stats_reports_hits_and_misses_separately` and asserts the counters actually move. Starting the service provisions the reserved probe key, so it shows up in listings and backup bundles. Exact-set assertions filter it through a new `without_probe_key` helper rather than naming it, keeping those specs about the keys they seeded. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> * fix(kms): bind the AAD to the stored context bytes Review caught that canonicalizing the AAD on decrypt breaks objects sealed before canonicalization existed, and it was right. The AAD is the *serialization* of the encryption context, and `x-rustfs-encryption-context` stores that exact byte sequence: `encrypt_object` fed one `HashMap` to the AEAD and then moved the same map into the metadata the header is written from, so the stored string is byte-identical to the AAD the object was sealed under. Those objects are therefore recoverable — but only while nothing round-trips the value through a `HashMap` and re-serializes it. Recomputing sorted AAD on decrypt would have turned a readable object into a permanently unreadable one. The previous behavior was worse than the first analysis credited: it did not merely fail intermittently, it made the failure deterministic. `EncryptionMetadata` now carries `context_aad`, the bytes the object was actually sealed with. Encryption records what it fed the AEAD, the header projection stores those bytes verbatim (and preserves a legacy ordering across a re-projection rather than rewriting it into sorted form), and `headers_to_metadata` carries the stored string through untouched. Both decrypt paths, SSE-KMS and SSE-C, prefer it and fall back to canonical serialization only when no stored serialization exists. Canonicalization still applies to everything newly sealed, so the original ordering bug cannot recur. Two tests pin this: a legacy record whose sealed bytes are non-canonical must survive a full header round trip unchanged, and a context header rewritten to an equivalent-but-reordered serialization must fail authentication rather than silently re-deriving a working AAD. Both were mutation-checked against the reinstated bug on each side. Also from review: the lifecycle churn test asserted only that every request was accounted for, which holds whether the state gate exists or not, so both branches are now pinned deterministically after the churn (asserting `refused > 0` on the concurrent phase would only trade the hole for a scheduling flake). And the Local and Vault KV2 envelopes compare `encryption_context` without authenticating it — `DekCrypto` seals only the plaintext — which is now documented at both sites; closing it needs a versioned envelope, since existing ciphertext was sealed without AAD. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
3.2 KiB
KMS Crate Instructions
Applies to crates/kms/.
Change Coordination
When changing key-management behavior, verify compatibility with:
rustfs/src/storage/ecfs.rsrustfs/src/admin/handlers/kms.rsrustfs/src/admin/handlers/kms_dynamic.rsrustfs/src/admin/handlers/kms_keys.rsrustfs/src/admin/handlers/kms_management.rs
Security
- Never log plaintext keys, key material, or sensitive request payloads.
- Prefer explicit error propagation over panic paths.
Testing
For local KMS end-to-end tests, keep proxy bypass settings:
NO_PROXY=127.0.0.1,localhost HTTP_PROXY= HTTPS_PROXY= http_proxy= https_proxy= \
cargo test --package e2e_test test_local_kms_end_to_end -- --nocapture --test-threads=1
Black-box behavior suite and the Vault lane
crates/kms/tests/behavior_*.rs drive the crate through its public entry
points only. By default they run against the Local and Static backends.
Setting RUSTFS_KMS_VAULT_TOKEN adds the Vault KV2 and Vault Transit backends
to every for_each_backend spec, against a live server
(RUSTFS_KMS_VAULT_ADDR, default http://127.0.0.1:8200):
NO_PROXY=127.0.0.1,localhost HTTP_PROXY= HTTPS_PROXY= http_proxy= https_proxy= \
RUSTFS_KMS_VAULT_TOKEN=<dev-token> cargo test -p rustfs-kms
The server needs a KV v2 engine at secret/ and a Transit engine at
transit/, matching the crate's config defaults.
Run the Vault lane whenever you touch rotation or versioning. rotate and
versioning are advertised only by the Vault backends, so without it every
capability-gated branch for them takes the UnsupportedCapability side and
behavior_rotation.rs never asserts the working half — a rotation that dropped
prior key versions would go green.
The lane creates real keys under unique names (behavior-kv2-*,
behavior-transit-*) and does not remove them, so a dev Vault accumulates them
across runs. Clear them out periodically — against a dev server only:
vault list -format=json transit/keys | jq -r '.[] | select(startswith("behavior-transit-"))' | while read -r k; do vault write "transit/keys/$k/config" deletion_allowed=true >/dev/null && vault delete "transit/keys/$k"; done
vault list -format=json secret/metadata/rustfs/kms/keys | jq -r '.[] | select(startswith("behavior-kv2-"))' | xargs -I{} vault kv metadata delete secret/rustfs/kms/keys/{}
Local Key Export for SSE-S3 Migration Tests
Use the read-only local_kms_key_decrypt example to export an AES-256 Local
KMS key as the base64 value expected by RUSTFS_SSE_S3_MASTER_KEY:
export RUSTFS_KMS_LOCAL_MASTER_KEY='<local-kms-at-rest-master-key>'
export RUSTFS_SSE_S3_MASTER_KEY="$(
cargo run -q -p rustfs-kms --example local_kms_key_decrypt -- \
/absolute/path/to/<key-id>.key
)"
For a plaintext-dev-only Local KMS key file,
RUSTFS_KMS_LOCAL_MASTER_KEY is not required.
The example writes only the base64-encoded 32-byte key to stdout. Diagnostics
go to stderr. Never paste its output into logs, shell history, issue comments,
or committed configuration. The export path must remain read-only and must
reuse LocalKmsClient decoding so current Argon2id and legacy key-file
compatibility stay aligned with the backend.