fix(fips): add cipher config API, key zeroization, and provider leak guard

- Add fips_configure_cipher() to pin FIPS-approved SQLCipher PRAGMAs
  (HMAC-SHA512, PBKDF2-HMAC-SHA512, 256k iterations, 4096-byte pages)
- Call fips_configure_cipher() after sqlite3_key() in JNI and sample app
- Copy key material to OPENSSL_malloc buffer and zeroize with
  OPENSSL_cleanse after use (SP 800-132 §5.3)
- Fix provider leak: unload FIPS provider on EVP_set_default_properties
  failure to prevent silent FIPS bypass
- Delete stale DB before round-trip compliance test
- Add .codegraph/ and .grepai/ to .gitignore
- Document fips_configure_cipher API and key handling in CLAUDE.md

.gitignore

@@ -114,8 +114,10 @@ samples/android/local.properties
 .mise.local.toml
 
 # grepai
-.grepai/*.gob
-.grepai/*.lock
+.grepai/
+
+# codegraph
+.codegraph/
 
 # Secrets & Config
 .env

CLAUDE.md

@@ -92,6 +92,10 @@ Bumping `OPENSSL_VERSION` requires updating `OPENSSL_URL_HASH` and re-running FI
 
 `include/fips_init.h` + `src/fips_init.c` -- portable C API for FIPS provider bootstrap at app startup. Uses programmatic APIs (`OSSL_PROVIDER_set_default_search_path`, `OSSL_LIB_CTX_load_config`, `OSSL_PROVIDER_load`) to bypass Android's `AT_SECURE` which blocks all `OPENSSL_*` env vars in app processes.
 
+`fips_configure_cipher(sqlite3 *db)` -- must be called immediately after `sqlite3_key()` and before any I/O. Pins FIPS-approved cipher PRAGMAs: AES-256-CBC, HMAC-SHA512, PBKDF2-HMAC-SHA512 with 256k iterations, 4096-byte pages. These match SQLCipher 4.x defaults but are set explicitly for FIPS audit trail.
+
+Key material handling in JNI (`src/fips_db_jni.c`): key is copied into an `OPENSSL_malloc` buffer and zeroized with `OPENSSL_cleanse` after use per SP 800-132 §5.3.
+
 Platform-specific wrappers:
 - `src/fips_init_android.c` -- sets search path + loads config with absolute paths, then loads provider
 - `src/fips_init_ios.c` -- loads provider from bundle resource path

include/fips_init.h

@@ -35,6 +35,11 @@ fips_init_status_t fips_init(const char *module_dir, const char *conf_path);
 int fips_self_test_rerun(void);
 int fips_provider_is_active(void);
 
+// Configure a freshly keyed SQLCipher connection for FIPS-compliant operation.
+// Call immediately after sqlite3_key(). Returns SQLITE_OK (0) on success.
+typedef struct sqlite3 sqlite3;
+int fips_configure_cipher(sqlite3 *db);
+
 #ifdef __ANDROID__
 // Android convenience wrapper.
 //   files_dir:   Context.getFilesDir() — expects fips/openssl.cnf underneath

samples/android/app/src/main/cpp/fips_init.c

@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
+#include <sqlite3.h>
 #include "fips_init.h"
 #include <openssl/provider.h>
 #include <openssl/crypto.h>
@@ -117,6 +118,8 @@ fips_init_status_t fips_init(const char *module_dir, const char *conf_path) {
     // are restricted to FIPS-approved implementations only.
     if (EVP_set_default_properties(NULL, "fips=yes") != 1) {
         LOGE("Failed to set fips=yes default properties\n");
+        OSSL_PROVIDER_unload(g_fips_provider);
+        g_fips_provider = NULL;
         return FIPS_INIT_ERR_PROPERTY_SET;
     }
 
@@ -124,6 +127,31 @@ fips_init_status_t fips_init(const char *module_dir, const char *conf_path) {
     return FIPS_INIT_OK;
 }
 
+int fips_configure_cipher(sqlite3 *db) {
+    static const char *pragmas[] = {
+        "PRAGMA cipher_compatibility = 4",
+        "PRAGMA cipher_plaintext_header_size = 0",
+        "PRAGMA cipher_use_hmac = ON",
+        "PRAGMA cipher_hmac_algorithm = HMAC_SHA512",
+        "PRAGMA cipher_kdf_algorithm = PBKDF2_HMAC_SHA512",
+        "PRAGMA cipher_default_kdf_iter = 256000",
+        "PRAGMA cipher_page_size = 4096",
+        NULL,
+    };
+    for (const char **p = pragmas; *p; ++p) {
+        char *err = NULL;
+        int rc = sqlite3_exec(db, *p, NULL, NULL, &err);
+        if (rc != SQLITE_OK) {
+            LOGE("FIPS cipher config failed [%s]: %s\n", *p,
+                 err ? err : sqlite3_errmsg(db));
+            if (err) sqlite3_free(err);
+            return rc;
+        }
+        if (err) sqlite3_free(err);
+    }
+    return SQLITE_OK;
+}
+
 int fips_self_test_rerun(void) {
     if (!g_fips_provider) return 0;
     return OSSL_PROVIDER_self_test(g_fips_provider) == 1 ? 1 : 0;

samples/android/app/src/main/cpp/fips_init.h

@@ -35,6 +35,11 @@ fips_init_status_t fips_init(const char *module_dir, const char *conf_path);
 int fips_self_test_rerun(void);
 int fips_provider_is_active(void);
 
+// Configure a freshly keyed SQLCipher connection for FIPS-compliant operation.
+// Call immediately after sqlite3_key(). Returns SQLITE_OK (0) on success.
+typedef struct sqlite3 sqlite3;
+int fips_configure_cipher(sqlite3 *db);
+
 #ifdef __ANDROID__
 // Android convenience wrapper.
 //   files_dir:   Context.getFilesDir() — expects fips/openssl.cnf underneath

samples/android/app/src/main/cpp/jni_bridge.c

@@ -84,6 +84,12 @@ static int exec_sql(sqlite3 *db, const char *sql) {
     return rc;
 }
 
+static int key_and_configure(sqlite3 *db, const char *key, int key_len) {
+    int rc = sqlite3_key(db, key, key_len);
+    if (rc != SQLITE_OK) return rc;
+    return fips_configure_cipher(db);
+}
+
 JNIEXPORT jstring JNICALL
 Java_com_example_fipsdemo_FipsNative_dbRoundTrip(JNIEnv *env, jclass cls,
                                                   jstring jpath, jstring jkey) {
@@ -98,8 +104,8 @@ Java_com_example_fipsdemo_FipsNative_dbRoundTrip(JNIEnv *env, jclass cls,
         snprintf(result, sizeof(result), "FAIL: open: %s", sqlite3_errmsg(db));
         goto out;
     }
-    if (sqlite3_key(db, key, (int)strlen(key)) != SQLITE_OK) {
-        snprintf(result, sizeof(result), "FAIL: key");
+    if (key_and_configure(db, key, (int)strlen(key)) != SQLITE_OK) {
+        snprintf(result, sizeof(result), "FAIL: key/configure: %s", sqlite3_errmsg(db));
         goto out;
     }
     if (exec_sql(db, "CREATE TABLE IF NOT EXISTS demo(id INTEGER PRIMARY KEY, msg TEXT, ts REAL)") != SQLITE_OK) {
@@ -140,13 +146,13 @@ Java_com_example_fipsdemo_FipsNative_dbRekey(JNIEnv *env, jclass cls,
     jboolean ok = JNI_FALSE;
 
     if (sqlite3_open(path, &db) != SQLITE_OK) goto out;
-    if (sqlite3_key(db, oldK, (int)strlen(oldK)) != SQLITE_OK) goto out;
+    if (key_and_configure(db, oldK, (int)strlen(oldK)) != SQLITE_OK) goto out;
     if (exec_sql(db, "SELECT count(*) FROM sqlite_master") != SQLITE_OK) goto out;
     if (sqlite3_rekey(db, newK, (int)strlen(newK)) != SQLITE_OK) goto out;
     sqlite3_close(db); db = NULL;
 
     if (sqlite3_open(path, &db) != SQLITE_OK) goto out;
-    if (sqlite3_key(db, newK, (int)strlen(newK)) != SQLITE_OK) goto out;
+    if (key_and_configure(db, newK, (int)strlen(newK)) != SQLITE_OK) goto out;
     if (exec_sql(db, "SELECT count(*) FROM sqlite_master") == SQLITE_OK) ok = JNI_TRUE;
 
 out:
@@ -168,7 +174,7 @@ Java_com_example_fipsdemo_FipsNative_dbWrongKeyRejected(JNIEnv *env, jclass cls,
     jboolean rejected = JNI_FALSE;
 
     if (sqlite3_open(path, &db) == SQLITE_OK) {
-        if (sqlite3_key(db, bad, (int)strlen(bad)) == SQLITE_OK) {
+        if (key_and_configure(db, bad, (int)strlen(bad)) == SQLITE_OK) {
             int rc = sqlite3_exec(db, "SELECT count(*) FROM sqlite_master",
                                   NULL, NULL, NULL);
             rejected = (rc != SQLITE_OK) ? JNI_TRUE : JNI_FALSE;

samples/android/app/src/main/java/com/example/fipsdemo/ComplianceCheck.kt

@@ -29,6 +29,7 @@ fun runComplianceSuite(filesDir: String): List<ComplianceCheck> {
             v.startsWith("OpenSSL 3.0.") to v
         },
         check("DB Write/Read", "SQLCipher encrypted round-trip via FIPS crypto") {
+            java.io.File(dbPath).delete()
             val result = FipsNative.dbRoundTrip(dbPath, key)
             result.startsWith("OK") to result
         },

src/fips_db_jni.c

@@ -5,9 +5,11 @@
 
 #include <jni.h>
 #include <android/log.h>
+#include <openssl/crypto.h>
 #include <sqlite3.h>
 #include <string.h>
 #include <stdlib.h>
+#include "fips_init.h"
 
 #define TAG "FipsDatabase"
 #define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, TAG, __VA_ARGS__)
@@ -17,32 +19,49 @@ Java_com_fips_sqlcipher_FipsDatabase_nativeOpen(JNIEnv *env, jclass cls,
                                                  jstring jpath, jstring jkey) {
     (void)cls;
     const char *path = (*env)->GetStringUTFChars(env, jpath, NULL);
-    const char *key  = (*env)->GetStringUTFChars(env, jkey, NULL);
+    const char *jkey_str = (*env)->GetStringUTFChars(env, jkey, NULL);
     sqlite3 *db = NULL;
+    jlong result = 0;
+
+    int key_len = (int)strlen(jkey_str);
+    char *key = (char *)OPENSSL_malloc(key_len + 1);
+    if (!key) {
+        (*env)->ReleaseStringUTFChars(env, jpath, path);
+        (*env)->ReleaseStringUTFChars(env, jkey, jkey_str);
+        return 0;
+    }
+    memcpy(key, jkey_str, key_len + 1);
+    (*env)->ReleaseStringUTFChars(env, jkey, jkey_str);
 
     int rc = sqlite3_open(path, &db);
     if (rc != SQLITE_OK) {
         LOGE("sqlite3_open(%s) failed: %s", path, sqlite3_errmsg(db));
         if (db) sqlite3_close(db);
-        (*env)->ReleaseStringUTFChars(env, jpath, path);
-        (*env)->ReleaseStringUTFChars(env, jkey, key);
-        return 0;
+        goto out;
     }
 
-    if (key && key[0]) {
-        rc = sqlite3_key(db, key, (int)strlen(key));
+    if (key[0]) {
+        rc = sqlite3_key(db, key, key_len);
         if (rc != SQLITE_OK) {
             LOGE("sqlite3_key failed: %s", sqlite3_errmsg(db));
             sqlite3_close(db);
-            (*env)->ReleaseStringUTFChars(env, jpath, path);
-            (*env)->ReleaseStringUTFChars(env, jkey, key);
-            return 0;
+            goto out;
+        }
+        rc = fips_configure_cipher(db);
+        if (rc != SQLITE_OK) {
+            LOGE("fips_configure_cipher failed: %s", sqlite3_errmsg(db));
+            sqlite3_close(db);
+            goto out;
         }
     }
 
+    result = (jlong)(intptr_t)db;
+
+out:
+    OPENSSL_cleanse(key, key_len);
+    OPENSSL_free(key);
     (*env)->ReleaseStringUTFChars(env, jpath, path);
-    (*env)->ReleaseStringUTFChars(env, jkey, key);
-    return (jlong)(intptr_t)db;
+    return result;
 }
 
 JNIEXPORT void JNICALL

src/fips_init.c

@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
+#include <sqlite3.h>
 #include "fips_init.h"
 #include <openssl/provider.h>
 #include <openssl/crypto.h>
@@ -117,6 +118,8 @@ fips_init_status_t fips_init(const char *module_dir, const char *conf_path) {
     // are restricted to FIPS-approved implementations only.
     if (EVP_set_default_properties(NULL, "fips=yes") != 1) {
         LOGE("Failed to set fips=yes default properties\n");
+        OSSL_PROVIDER_unload(g_fips_provider);
+        g_fips_provider = NULL;
         return FIPS_INIT_ERR_PROPERTY_SET;
     }
 
@@ -124,6 +127,31 @@ fips_init_status_t fips_init(const char *module_dir, const char *conf_path) {
     return FIPS_INIT_OK;
 }
 
+int fips_configure_cipher(sqlite3 *db) {
+    static const char *pragmas[] = {
+        "PRAGMA cipher_compatibility = 4",
+        "PRAGMA cipher_plaintext_header_size = 0",
+        "PRAGMA cipher_use_hmac = ON",
+        "PRAGMA cipher_hmac_algorithm = HMAC_SHA512",
+        "PRAGMA cipher_kdf_algorithm = PBKDF2_HMAC_SHA512",
+        "PRAGMA cipher_default_kdf_iter = 256000",
+        "PRAGMA cipher_page_size = 4096",
+        NULL,
+    };
+    for (const char **p = pragmas; *p; ++p) {
+        char *err = NULL;
+        int rc = sqlite3_exec(db, *p, NULL, NULL, &err);
+        if (rc != SQLITE_OK) {
+            LOGE("FIPS cipher config failed [%s]: %s\n", *p,
+                 err ? err : sqlite3_errmsg(db));
+            if (err) sqlite3_free(err);
+            return rc;
+        }
+        if (err) sqlite3_free(err);
+    }
+    return SQLITE_OK;
+}
+
 int fips_self_test_rerun(void) {
     if (!g_fips_provider) return 0;
     return OSSL_PROVIDER_self_test(g_fips_provider) == 1 ? 1 : 0;