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            app_identifier: "app_test".to_string(),
203            client_id: "req-1".to_string(),
204            protocol: ProtocolVersion::V3,
205            timestamp: None,
206            issuer_schema_ids: vec![],
207            outcome: ActivityOutcome::Completed,
208            failure_reason: None,
209        }
210    }
211
212    fn temp_cache_path() -> PathBuf {
213        let mut path = std::env::temp_dir();
214        path.push(format!("walletkit-cache-{}.sqlite", Uuid::new_v4()));
215        path
216    }
217
218    fn cleanup_cache_files(path: &Path) {
219        let _ = fs::remove_file(path);
220        let _ = fs::remove_file(path.with_extension("sqlite-wal"));
221        let _ = fs::remove_file(path.with_extension("sqlite-shm"));
222    }
223
224    fn temp_lock_path() -> PathBuf {
225        let mut path = std::env::temp_dir();
226        path.push(format!("walletkit-cache-lock-{}.lock", Uuid::new_v4()));
227        path
228    }
229
230    fn cleanup_lock_file(path: &Path) {
231        let _ = fs::remove_file(path);
232    }
233
234    #[test]
235    fn test_cache_create_and_open() {
236        let path = temp_cache_path();
237        let key = SecretBox::init_with(|| [0x11u8; 32]);
238        let lock_path = temp_lock_path();
239        let db = CacheDb::new(&path, &key).expect("create cache");
240        drop(db);
241        CacheDb::new(&path, &key).expect("open cache");
242        cleanup_cache_files(&path);
243        cleanup_lock_file(&lock_path);
244    }
245
246    #[test]
247    fn test_cache_rebuild_on_corruption() {
248        let path = temp_cache_path();
249        let key = SecretBox::init_with(|| [0x22u8; 32]);
250        let lock_path = temp_lock_path();
251        let db = CacheDb::new(&path, &key).expect("create cache");
252        let oprf_seed = [0x01u8; 32];
253        let r_seed = [0x02u8; 32];
254        let now = 1_000;
255        db.session_seed_put(1, oprf_seed, r_seed, now, 1000)
256            .expect("put session seed");
257        drop(db);
258
259        fs::write(&path, b"corrupt").expect("corrupt cache file");
260
261        let db = CacheDb::new(&path, &key).expect("rebuild cache");
262        let value = db
263            .session_seed_get(1, oprf_seed, now)
264            .expect("get session seed");
265        assert!(value.is_none());
266        cleanup_cache_files(&path);
267        cleanup_lock_file(&lock_path);
268    }
269
270    #[test]
271    fn test_merkle_cache_ttl() {
272        let path = temp_cache_path();
273        let key = SecretBox::init_with(|| [0x33u8; 32]);
274        let lock_path = temp_lock_path();
275        let db = CacheDb::new(&path, &key).expect("create cache");
276        db.merkle_cache_put(&[1, 2, 3], 100, 10)
277            .expect("put merkle proof");
278        let hit = db.merkle_cache_get(105).expect("get merkle proof");
279        assert!(hit.is_some());
280        let miss = db.merkle_cache_get(111).expect("get merkle proof");
281        assert!(miss.is_none());
282        cleanup_cache_files(&path);
283        cleanup_lock_file(&lock_path);
284    }
285
286    #[test]
287    fn test_session_seed_cache_ttl() {
288        let path = temp_cache_path();
289        let key = SecretBox::init_with(|| [0x44u8; 32]);
290        let lock_path = temp_lock_path();
291        let db = CacheDb::new(&path, &key).expect("create cache");
292        let oprf_seed = [0x55u8; 32];
293        let r_seed = [0x66u8; 32];
294        let now = 100;
295        db.session_seed_put(1, oprf_seed, r_seed, now, 10)
296            .expect("put session seed");
297        let hit = db.session_seed_get(1, oprf_seed, now).expect("get");
298        assert_eq!(hit, Some(r_seed));
299        let miss = db.session_seed_get(1, oprf_seed, now + 11).expect("get");
300        assert!(miss.is_none());
301        cleanup_cache_files(&path);
302        cleanup_lock_file(&lock_path);
303    }
304
305    #[test]
306    fn test_schema_version_mismatch_resets_database() {
307        let path = temp_cache_path();
308        let key = SecretBox::init_with(|| [0x77u8; 32]);
309        let lock_path = temp_lock_path();
310        let db = CacheDb::new(&path, &key).expect("create cache");
311
312        db.record_activity(&sample_new_activity_entry(), 1000)
313            .expect("record activity");
314
315        db.session_seed_put(1, [0x01u8; 32], [0x02u8; 32], 1000, 1000)
316            .expect("put session seed");
317
318        drop(db);
319
320        let conn = walletkit_sqlite::cipher::open_encrypted(&path, &key)
321            .expect("open raw connection");
322        conn.execute(
323            "UPDATE cache_meta SET schema_version = schema_version + 1",
324            &[],
325        )
326        .expect("bump schema version");
327        drop(conn);
328
329        let db = CacheDb::new(&path, &key).expect("reopen cache after version bump");
330
331        let seed = db
332            .session_seed_get(1, [0x01u8; 32], 1000)
333            .expect("get session seed");
334
335        assert!(
336            seed.is_none(),
337            "cache_entries should be wiped on a schema version mismatch"
338        );
339
340        let entries = db
341            .list_activities(ActivityQuery::default(), 10, 0)
342            .expect("list activities after version bump");
343
344        assert!(
345            entries.is_empty(),
346            "activity history shares the cache schema, so it is reset too"
347        );
348
349        cleanup_cache_files(&path);
350        cleanup_lock_file(&lock_path);
351    }
352
353    #[test]
354    fn test_activity_migration_applies_to_preexisting_cache_file() {
355        let path = temp_cache_path();
356        let key = SecretBox::init_with(|| [0x88u8; 32]);
357        let lock_path = temp_lock_path();
358
359        let conn = walletkit_sqlite::cipher::open_encrypted(&path, &key)
360            .expect("create raw connection");
361        conn.execute_batch(
362            "CREATE TABLE cache_meta (
363                schema_version INTEGER NOT NULL,
364                created_at INTEGER NOT NULL,
365                updated_at INTEGER NOT NULL
366            );
367            CREATE TABLE cache_entries (
368                key_bytes BLOB NOT NULL,
369                value_bytes BLOB NOT NULL,
370                inserted_at INTEGER NOT NULL,
371                expires_at INTEGER NOT NULL,
372                PRIMARY KEY (key_bytes)
373            );
374            INSERT INTO cache_meta (schema_version, created_at, updated_at)
375            VALUES (2, 1000, 1000);
376            INSERT INTO cache_entries (key_bytes, value_bytes, inserted_at, expires_at)
377            VALUES (X'AA', X'BB', 1000, 999999999);",
378        )
379        .expect("seed legacy cache schema");
380        drop(conn);
381
382        let db = CacheDb::new(&path, &key).expect("open legacy cache file");
383
384        db.record_activity(&sample_new_activity_entry(), 1000)
385            .expect("record activity after migration");
386
387        let entries = db
388            .list_activities(ActivityQuery::default(), 10, 0)
389            .expect("list activities");
390
391        assert_eq!(entries.len(), 1, "migration should add activity_entries");
392
393        drop(db);
394
395        let conn = walletkit_sqlite::cipher::open_encrypted(&path, &key)
396            .expect("reopen raw connection");
397
398        let count = conn
399            .query_row("SELECT COUNT(*) FROM cache_entries", &[], |stmt| {
400                Ok(stmt.column_i64(0))
401            })
402            .expect("count cache_entries");
403
404        assert_eq!(
405            count, 1,
406            "pre-existing cache_entries row must survive the activity migration"
407        );
408
409        cleanup_cache_files(&path);
410        cleanup_lock_file(&lock_path);
411    }
412
413    #[test]
414    fn test_schema_version_is_recorded() {
415        let path = temp_cache_path();
416        let key = SecretBox::init_with(|| [0x99u8; 32]);
417        let lock_path = temp_lock_path();
418
419        let db = CacheDb::new(&path, &key).expect("create cache");
420        db.record_activity(&sample_new_activity_entry(), 1000)
421            .expect("record activity");
422        drop(db);
423
424        let conn = walletkit_sqlite::cipher::open_encrypted(&path, &key)
425            .expect("open raw connection");
426        let version = conn
427            .query_row("SELECT schema_version FROM cache_meta", &[], |stmt| {
428                Ok(stmt.column_i64(0))
429            })
430            .expect("read cache schema version");
431        drop(conn);
432
433        // Three migrations: cache_entries, activity init, activity rebuild.
434        assert_eq!(version, 3, "the cache schema registers as version 3");
435
436        let db = CacheDb::new(&path, &key).expect("reopen cache");
437        let entries = db
438            .list_activities(ActivityQuery::default(), 10, 0)
439            .expect("list activities");
440
441        assert_eq!(entries.len(), 1, "reopening must not restamp or reset");
442        assert_eq!(entries[0].rp_id, 1);
443        assert_eq!(entries[0].app_identifier, "app_test");
444
445        cleanup_cache_files(&path);
446        cleanup_lock_file(&lock_path);
447    }
448}
walletkit_core/storage/cache/mod.rs

walletkit_core/storage/cache/
mod.rs
