c4dbd85da0bfe1a8d2fa68d089f3d07eb744daae
2
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 jaap-jan
|
c4dbd85da0 |
Add the client's SSH key model, codec, merge and cipher
The client can now seal and open an SSH key item. Nothing consumes it yet — the repository, the sync engine's per-type handling and the UI come next — but this is the layer everything above it depends on, and it is the layer where the crypto has to be right. SshKeySecret holds the private key as an ordinary string, deliberately, and says so: a .NET string cannot be wiped, so the material lives until the GC reuses the memory. libsodium's guarded memory was considered and rejected because the passphrase protecting the key, the password on the next item and the JSON the codec just parsed are all strings on the same heap — protecting one field among them reads as security and buys nothing. What the design does give is that the key never reaches the disk in plaintext, never reaches the server at all, and is handed to SSH.NET through a MemoryStream so there is no temporary key file to leak. Validation refuses a public key by name. ssh-keygen writes two files whose names differ by four characters, and pasting the wrong one otherwise produces a vault item that looks fine and fails at connection time with an authentication error that says nothing about which file you chose. The merge redacts the private key and its passphrase from the conflict log. A host conflict shows both values so the loser can be put back; doing that for a private key would write the discarded key into a log that is designed to be read rather than used and is deliberately retained after acknowledgement. Two different private keys are not something anyone reconciles by reading them side by side. And the lesson worth recording, because it nearly shipped: the first version of AadResourceTypeTests proved nothing. It checked that a key payload does not open as a host and vice versa — true however both ciphers are misconfigured, because Seal and TryOpen share one constant, so changing it changes both and the round trip still works. Sealing every private key as if it were a vault passed all twelve tests. The tests now open a sealed payload independently through ItemKeys with the resource type named out of band, and that does fail under the same sabotage. A test that only compares an implementation against itself cannot catch a self-consistent mistake. The trap it defends: SyncEntityType.SshKey is 3, AadResourceType.SshKey is 6, because the crypto enum also carries None, User, Device and Vault ahead of the item types. A cast between them is a specification violation that encrypts cleanly and would only surface when another implementation refused the item. |
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|
jaap-jan
|
8d2416a602 |
Add the encrypted local cache and the sync client
Three new client projects, and the wire-contract fix they needed. DodoSSH.Client.Domain holds the decrypted item model and the three-way merge, with no I/O at all — so the suite that decides whether a credential can be lost runs in milliseconds with nothing to mock. Scalars defer to the server on a genuine clash so every replica resolves the same triple identically and two clients cannot ping-pong; directives merge per name so two people each adding one both keep theirs; the jump chain merges as a whole value because its order is the route. Whatever loses is returned rather than dropped. DodoSSH.Client.Storage is EF Core on SQLite, no SQLCipher: the rows are already ciphertext, so an encrypted file would protect protected bytes at the cost of a native dependency. It keeps the server's state and the outbox in separate tables, which is what preserves the common ancestor a merge needs. One pending operation per item, enforced by a unique index. DodoSSH.Client.Sync is the pull/apply/push loop. Pulling never decrypts — a change with no local work pending is plumbed as ciphertext — so a first sync of thousands of items does not run twice as many AEAD operations for nothing. Contracts: EncryptedPayload gains WrappedDataKey and DataKeyId. The specification has required a per-item data key since crypto.md §3, the columns have existed since the first migration and DshAad.ItemPayload binds the id, but this record had nowhere to put either — so a spec-compliant item could not be transmitted at all. Found by writing the client that has to produce one. Also closes a hole in AadResourceType, which had no value for the HostTag and HostCredential that SyncEntityType has always listed. Four bugs the tests found, not review: - SQLite refuses to order or compare its own DateTimeOffset mapping, and throws at execution rather than model build. Collecting tombstones and listing conflicts are both that shape, so this was a crash waiting for the first user with a deleted host. Timestamps are integers now, by convention so a later field cannot be the one left unconverted. - SQLitePCLRaw 2.1.11, which EF resolves, is covered by GHSA-2m69-gcr7-jv3q. Pinned forward as a family. - Resurrecting content from a remote deletion cleared the original before queueing the copy. Two transactions, so a crash between them lost the work; reversed, and the rescued id is derived from the tombstone so a replay coalesces instead of duplicating. - Several equality assertions went through Shouldly's ShouldBe, which compares IEnumerable element-wise and so tested nothing about the Equals these types exist to provide. Corrected; the falsification that caught it went from 2 failures to 6. The push response's cursor is deliberately ignored. It sits after this client's own writes, so adopting it skips anything another client committed at a lower sequence in the window between a pull and a push — permanently. Re-reading one's own writes is idempotent and costs a page. The Contracts doc that invited the shortcut now says so. 593 tests, up from 448. The delete-versus-edit rules, the ancestor retention, the fresh operation id on coalesce and the cursor safeguard were each verified by breaking them and watching the right test fail. |