walletkit_core/storage/cache/
mod.rs

1//! Encrypted cache database for credential storage.
2
3use std::path::Path;
4
5use crate::storage::error::StorageResult;
6use crate::storage::types::{ActivityEntry, ActivityMetadata, ActivityQuery};
7use secrecy::SecretBox;
8use walletkit_db::Vault;
9
10mod activity;
11mod maintenance;
12mod merkle;
13mod nullifiers;
14mod schema;
15mod session;
16mod util;
17
18/// Encrypted cache database wrapper.
19///
20/// Stores non-authoritative, regenerable data (proof cache, session keys,
21/// replay guard). Wraps [`walletkit_db::Vault`].
22///
23/// Unlike the credential vault, cache corruption is recoverable: open
24/// failures or integrity failures trigger a wipe-and-rebuild rather than
25/// a fatal error.
26#[derive(Debug)]
27pub struct CacheDb {
28    vault: Vault,
29}
30
31impl CacheDb {
32    /// Opens or rebuilds the encrypted cache database at `path`.
33    ///
34    /// If the database is corrupted or unreadable, the file is deleted
35    /// and a fresh empty cache is created.
36    ///
37    /// # Errors
38    ///
39    /// Returns an error if the database cannot be opened or rebuilt.
40    pub fn new(
41        path: &Path,
42        k_intermediate: &SecretBox<[u8; 32]>,
43    ) -> StorageResult<Self> {
44        let vault = maintenance::open_or_rebuild(path, k_intermediate)?;
45        Ok(Self { vault })
46    }
47
48    /// Fetches a cached Merkle proof if it remains valid beyond `valid_until`.
49    ///
50    /// Returns `None` when missing or expired so callers can refetch from the
51    /// indexer without relying on stale proofs.
52    ///
53    /// # Errors
54    ///
55    /// Returns an error if the query fails.
56    pub fn merkle_cache_get(&self, valid_until: u64) -> StorageResult<Option<Vec<u8>>> {
57        merkle::get(self.vault.connection(), valid_until)
58    }
59
60    /// Inserts a cached Merkle proof with a TTL. Existing entries for the
61    /// same key are replaced.
62    ///
63    /// # Errors
64    ///
65    /// Returns an error if the insert fails.
66    pub fn merkle_cache_put(
67        &self,
68        proof_bytes: &[u8],
69        now: u64,
70        ttl_seconds: u64,
71    ) -> StorageResult<()> {
72        merkle::put(self.vault.connection(), proof_bytes, now, ttl_seconds)
73    }
74
75    /// Fetches a cached `session_id_r_seed` for the given RP and `oprf_seed`.
76    ///
77    /// Returns `None` when missing or expired.
78    ///
79    /// # Errors
80    ///
81    /// Returns an error if the query fails.
82    pub fn session_seed_get(
83        &self,
84        rp_id: u64,
85        oprf_seed: [u8; 32],
86        now: u64,
87    ) -> StorageResult<Option<[u8; 32]>> {
88        let key = util::session_cache_key(rp_id, oprf_seed);
89        session::get(self.vault.connection(), &key, now)
90    }
91
92    /// Stores a `session_id_r_seed` keyed by RP and `oprf_seed` with a TTL.
93    ///
94    /// # Errors
95    ///
96    /// Returns an error if the insert fails.
97    pub fn session_seed_put(
98        &self,
99        rp_id: u64,
100        oprf_seed: [u8; 32],
101        session_id_r_seed: [u8; 32],
102        now: u64,
103        ttl_seconds: u64,
104    ) -> StorageResult<()> {
105        let key = util::session_cache_key(rp_id, oprf_seed);
106        session::put(
107            self.vault.connection(),
108            &key,
109            session_id_r_seed,
110            now,
111            ttl_seconds,
112        )
113    }
114
115    /// Checks whether a replay guard entry exists for the given nullifier.
116    ///
117    /// # Returns
118    ///
119    /// - `true` if a replay guard entry exists (nullifier replay).
120    /// - `false` otherwise.
121    ///
122    /// # Errors
123    ///
124    /// Returns an error if the query to the cache unexpectedly fails.
125    pub fn is_nullifier_replay(
126        &self,
127        nullifier: [u8; 32],
128        now: u64,
129    ) -> StorageResult<bool> {
130        nullifiers::is_nullifier_replay(self.vault.connection(), nullifier, now)
131    }
132
133    /// After a proof has been successfully generated, creates a replay guard
134    /// entry locally to avoid future replays of the same nullifier.
135    ///
136    /// # Errors
137    ///
138    /// Returns an error if the query to the cache unexpectedly fails.
139    pub fn replay_guard_set(&self, nullifier: [u8; 32], now: u64) -> StorageResult<()> {
140        nullifiers::replay_guard_set(self.vault.connection(), nullifier, now)
141    }
142
143    /// Records an activity entry.
144    ///
145    /// # Errors
146    ///
147    /// Returns an error if the entry is misconfigured or the insert fails.
148    pub fn record_activity(
149        &self,
150        entry: &ActivityEntry,
151        now: u64,
152    ) -> StorageResult<u64> {
153        activity::record(self.vault.connection(), entry, now)
154    }
155
156    /// Lists activity entries, most recent first.
157    ///
158    /// # Errors
159    ///
160    /// Returns an error if the query fails.
161    pub fn list_activities(
162        &self,
163        query: ActivityQuery,
164        limit: u32,
165        offset: u32,
166    ) -> StorageResult<Vec<ActivityEntry>> {
167        activity::list(self.vault.connection(), query, limit, offset)
168    }
169
170    /// Returns aggregate activity metadata.
171    ///
172    /// # Errors
173    ///
174    /// Returns an error if the query fails.
175    pub fn activity_metadata(&self) -> StorageResult<ActivityMetadata> {
176        activity::metadata(self.vault.connection())
177    }
178
179    /// Deletes all activity entries. Returns the number of entries deleted.
180    ///
181    /// # Errors
182    ///
183    /// Returns an error if the delete fails.
184    pub fn clear_activities(&self) -> StorageResult<u64> {
185        activity::clear(self.vault.connection())
186    }
187}
188
189#[cfg(test)]
190mod tests {
191    use super::*;
192    use crate::storage::types::{ActivityOutcome, ProtocolVersion};
193    use secrecy::SecretBox;
194    use std::fs;
195    use std::path::PathBuf;
196    use uuid::Uuid;
197
198    fn sample_new_activity_entry() -> ActivityEntry {
199        ActivityEntry {
200            id: None,
201            rp_id: 1,
202            client_id: "req-1".to_string(),
203            protocol: ProtocolVersion::V3,
204            timestamp: None,
205            issuer_schema_ids: vec![],
206            outcome: ActivityOutcome::Completed,
207            failure_reason: None,
208        }
209    }
210
211    fn temp_cache_path() -> PathBuf {
212        let mut path = std::env::temp_dir();
213        path.push(format!("walletkit-cache-{}.sqlite", Uuid::new_v4()));
214        path
215    }
216
217    fn cleanup_cache_files(path: &Path) {
218        let _ = fs::remove_file(path);
219        let _ = fs::remove_file(path.with_extension("sqlite-wal"));
220        let _ = fs::remove_file(path.with_extension("sqlite-shm"));
221    }
222
223    fn temp_lock_path() -> PathBuf {
224        let mut path = std::env::temp_dir();
225        path.push(format!("walletkit-cache-lock-{}.lock", Uuid::new_v4()));
226        path
227    }
228
229    fn cleanup_lock_file(path: &Path) {
230        let _ = fs::remove_file(path);
231    }
232
233    #[test]
234    fn test_cache_create_and_open() {
235        let path = temp_cache_path();
236        let key = SecretBox::init_with(|| [0x11u8; 32]);
237        let lock_path = temp_lock_path();
238        let db = CacheDb::new(&path, &key).expect("create cache");
239        drop(db);
240        CacheDb::new(&path, &key).expect("open cache");
241        cleanup_cache_files(&path);
242        cleanup_lock_file(&lock_path);
243    }
244
245    #[test]
246    fn test_cache_rebuild_on_corruption() {
247        let path = temp_cache_path();
248        let key = SecretBox::init_with(|| [0x22u8; 32]);
249        let lock_path = temp_lock_path();
250        let db = CacheDb::new(&path, &key).expect("create cache");
251        let oprf_seed = [0x01u8; 32];
252        let r_seed = [0x02u8; 32];
253        let now = 1_000;
254        db.session_seed_put(1, oprf_seed, r_seed, now, 1000)
255            .expect("put session seed");
256        drop(db);
257
258        fs::write(&path, b"corrupt").expect("corrupt cache file");
259
260        let db = CacheDb::new(&path, &key).expect("rebuild cache");
261        let value = db
262            .session_seed_get(1, oprf_seed, now)
263            .expect("get session seed");
264        assert!(value.is_none());
265        cleanup_cache_files(&path);
266        cleanup_lock_file(&lock_path);
267    }
268
269    #[test]
270    fn test_merkle_cache_ttl() {
271        let path = temp_cache_path();
272        let key = SecretBox::init_with(|| [0x33u8; 32]);
273        let lock_path = temp_lock_path();
274        let db = CacheDb::new(&path, &key).expect("create cache");
275        db.merkle_cache_put(&[1, 2, 3], 100, 10)
276            .expect("put merkle proof");
277        let hit = db.merkle_cache_get(105).expect("get merkle proof");
278        assert!(hit.is_some());
279        let miss = db.merkle_cache_get(111).expect("get merkle proof");
280        assert!(miss.is_none());
281        cleanup_cache_files(&path);
282        cleanup_lock_file(&lock_path);
283    }
284
285    #[test]
286    fn test_session_seed_cache_ttl() {
287        let path = temp_cache_path();
288        let key = SecretBox::init_with(|| [0x44u8; 32]);
289        let lock_path = temp_lock_path();
290        let db = CacheDb::new(&path, &key).expect("create cache");
291        let oprf_seed = [0x55u8; 32];
292        let r_seed = [0x66u8; 32];
293        let now = 100;
294        db.session_seed_put(1, oprf_seed, r_seed, now, 10)
295            .expect("put session seed");
296        let hit = db.session_seed_get(1, oprf_seed, now).expect("get");
297        assert_eq!(hit, Some(r_seed));
298        let miss = db.session_seed_get(1, oprf_seed, now + 11).expect("get");
299        assert!(miss.is_none());
300        cleanup_cache_files(&path);
301        cleanup_lock_file(&lock_path);
302    }
303
304    #[test]
305    fn test_activity_survives_disposable_cache_reset() {
306        let path = temp_cache_path();
307        let key = SecretBox::init_with(|| [0x77u8; 32]);
308        let lock_path = temp_lock_path();
309        let db = CacheDb::new(&path, &key).expect("create cache");
310
311        db.record_activity(&sample_new_activity_entry(), 1000)
312            .expect("record activity");
313
314        db.session_seed_put(1, [0x01u8; 32], [0x02u8; 32], 1000, 1000)
315            .expect("put session seed");
316
317        drop(db);
318
319        let conn = walletkit_sqlite::cipher::open_encrypted(&path, &key, false)
320            .expect("open raw connection");
321        conn.execute(
322            "UPDATE cache_meta SET schema_version = schema_version + 1",
323            &[],
324        )
325        .expect("bump schema version");
326        drop(conn);
327
328        let db = CacheDb::new(&path, &key).expect("reopen cache after version bump");
329
330        let seed = db
331            .session_seed_get(1, [0x01u8; 32], 1000)
332            .expect("get session seed");
333
334        assert!(
335            seed.is_none(),
336            "disposable cache_entries should be wiped on a schema version mismatch"
337        );
338
339        let entries = db
340            .list_activities(ActivityQuery::default(), 10, 0)
341            .expect("list activities after version bump");
342
343        assert_eq!(entries.len(), 1);
344
345        cleanup_cache_files(&path);
346        cleanup_lock_file(&lock_path);
347    }
348
349    #[test]
350    fn test_activity_migration_applies_to_preexisting_cache_file() {
351        let path = temp_cache_path();
352        let key = SecretBox::init_with(|| [0x88u8; 32]);
353        let lock_path = temp_lock_path();
354
355        let conn = walletkit_sqlite::cipher::open_encrypted(&path, &key, false)
356            .expect("create raw connection");
357        conn.execute_batch(
358            "CREATE TABLE cache_meta (
359                schema_version INTEGER NOT NULL,
360                created_at INTEGER NOT NULL,
361                updated_at INTEGER NOT NULL
362            );
363            CREATE TABLE cache_entries (
364                key_bytes BLOB NOT NULL,
365                value_bytes BLOB NOT NULL,
366                inserted_at INTEGER NOT NULL,
367                expires_at INTEGER NOT NULL,
368                PRIMARY KEY (key_bytes)
369            );
370            INSERT INTO cache_meta (schema_version, created_at, updated_at)
371            VALUES (2, 1000, 1000);
372            INSERT INTO cache_entries (key_bytes, value_bytes, inserted_at, expires_at)
373            VALUES (X'AA', X'BB', 1000, 999999999);",
374        )
375        .expect("seed legacy cache schema");
376        drop(conn);
377
378        let db = CacheDb::new(&path, &key).expect("open legacy cache file");
379
380        db.record_activity(&sample_new_activity_entry(), 1000)
381            .expect("record activity after migration");
382
383        let entries = db
384            .list_activities(ActivityQuery::default(), 10, 0)
385            .expect("list activities");
386
387        assert_eq!(entries.len(), 1, "migration should add activity_entries");
388
389        drop(db);
390
391        let conn = walletkit_sqlite::cipher::open_encrypted(&path, &key, false)
392            .expect("reopen raw connection");
393
394        let count = conn
395            .query_row("SELECT COUNT(*) FROM cache_entries", &[], |stmt| {
396                Ok(stmt.column_i64(0))
397            })
398            .expect("count cache_entries");
399
400        assert_eq!(
401            count, 1,
402            "pre-existing cache_entries row must survive the activity migration"
403        );
404
405        cleanup_cache_files(&path);
406        cleanup_lock_file(&lock_path);
407    }
408}
walletkit_core/storage/cache/mod.rs

walletkit_core/storage/cache/
mod.rs
