SE drivers: implement persistent storage
Store the persistent data of secure element drivers.
This is fully implemented, but not at all tested.
diff --git a/library/psa_crypto_se.c b/library/psa_crypto_se.c
index 7287ac0..bae44fa 100644
--- a/library/psa_crypto_se.c
+++ b/library/psa_crypto_se.c
@@ -35,6 +35,13 @@
#include "psa_crypto_se.h"
+#if defined(MBEDTLS_PSA_ITS_FILE_C)
+#include "psa_crypto_its.h"
+#else /* Native ITS implementation */
+#include "psa/error.h"
+#include "psa/internal_trusted_storage.h"
+#endif
+
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_PLATFORM_C)
#define mbedtls_calloc calloc
@@ -114,20 +121,52 @@
/* Persistent data management */
/****************************************************************/
+static psa_status_t psa_get_se_driver_its_file_uid(
+ const psa_se_drv_table_entry_t *driver,
+ psa_storage_uid_t *uid )
+{
+ if( driver->lifetime > PSA_MAX_SE_LIFETIME )
+ return( PSA_ERROR_NOT_SUPPORTED );
+ *uid = PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE + driver->lifetime;
+ return( PSA_SUCCESS );
+}
+
psa_status_t psa_load_se_persistent_data(
const psa_se_drv_table_entry_t *driver )
{
- /*TODO*/
- (void) driver;
- return( PSA_SUCCESS );
+ psa_status_t status;
+ psa_storage_uid_t uid;
+
+ status = psa_get_se_driver_its_file_uid( driver, &uid );
+ if( status != PSA_SUCCESS )
+ return( status );
+
+ return( psa_its_get( uid, 0, driver->internal.persistent_data_size,
+ driver->internal.persistent_data ) );
}
psa_status_t psa_save_se_persistent_data(
const psa_se_drv_table_entry_t *driver )
{
- /*TODO*/
- (void) driver;
- return( PSA_SUCCESS );
+ psa_status_t status;
+ psa_storage_uid_t uid;
+
+ status = psa_get_se_driver_its_file_uid( driver, &uid );
+ if( status != PSA_SUCCESS )
+ return( status );
+
+ return( psa_its_set( uid, driver->internal.persistent_data_size,
+ driver->internal.persistent_data,
+ 0 ) );
+}
+
+psa_status_t psa_destroy_se_persistent_data( psa_key_lifetime_t lifetime )
+{
+ psa_storage_uid_t uid;
+ if( lifetime > PSA_MAX_SE_LIFETIME )
+ return( PSA_ERROR_NOT_SUPPORTED );
+ uid = PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE + lifetime;
+ return( psa_its_remove( uid ) );
}
psa_status_t psa_find_se_slot_for_key(
@@ -201,6 +240,8 @@
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
+ if( lifetime > PSA_MAX_SE_LIFETIME )
+ return( PSA_ERROR_NOT_SUPPORTED );
for( i = 0; i < PSA_MAX_SE_DRIVERS; i++ )
{
@@ -227,8 +268,11 @@
status = PSA_ERROR_INSUFFICIENT_MEMORY;
goto error;
}
+ /* Load the driver's persistent data. On first use, the persistent
+ * data does not exist in storage, and is initialized to
+ * all-bits-zero by the calloc call just above. */
status = psa_load_se_persistent_data( &driver_table[i] );
- if( status != PSA_SUCCESS )
+ if( status != PSA_SUCCESS && status != PSA_ERROR_DOES_NOT_EXIST )
goto error;
}
driver_table[i].internal.persistent_data_size =
diff --git a/library/psa_crypto_se.h b/library/psa_crypto_se.h
index f1d7e7c..08e658c 100644
--- a/library/psa_crypto_se.h
+++ b/library/psa_crypto_se.h
@@ -31,6 +31,30 @@
#include "psa/crypto.h"
#include "psa/crypto_se_driver.h"
+/** The maximum lifetime value that this implementation supports
+ * for a secure element.
+ *
+ * This is not a characteristic that each PSA implementation has, but a
+ * limitation of the current implementation due to the constraints imposed
+ * by storage. See #PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE.
+ *
+ * The minimum lifetime value for a secure element is 2, like on any
+ * PSA implementation (0=volatile and 1=internal-storage are taken).
+ */
+#define PSA_MAX_SE_LIFETIME 255
+
+/** The base of the range of ITS file identifiers for secure element
+ * driver persistent data.
+ *
+ * We use a slice of the implemenation reserved range 0xffff0000..0xffffffff,
+ * specifically the range 0xfffffe00..0xfffffeff. The length of this range
+ * drives the value of #PSA_MAX_SE_LIFETIME.
+ * The identifiers 0xfffffe00 and 0xfffffe01 are actually not used since
+ * they correspond to #PSA_KEY_LIFETIME_VOLATILE and
+ * #PSA_KEY_LIFETIME_PERSISTENT which don't have a driver.
+ */
+#define PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE ( (psa_key_id_t) 0xfffffe00 )
+
/** The maximum number of registered secure element driver lifetimes. */
#define PSA_MAX_SE_DRIVERS 4
@@ -138,4 +162,13 @@
psa_status_t psa_save_se_persistent_data(
const psa_se_drv_table_entry_t *driver );
+/** Destroy the persistent data of a secure element driver.
+ *
+ * This is currently only used for testing.
+ *
+ * \param[in] lifetime The driver lifetime whose persistent data should
+ * be erased.
+ */
+psa_status_t psa_destroy_se_persistent_data( psa_key_lifetime_t lifetime );
+
#endif /* PSA_CRYPTO_SE_H */
diff --git a/tests/suites/test_suite_psa_crypto_se_driver_hal.function b/tests/suites/test_suite_psa_crypto_se_driver_hal.function
index 5a2ebe7..010f696 100644
--- a/tests/suites/test_suite_psa_crypto_se_driver_hal.function
+++ b/tests/suites/test_suite_psa_crypto_se_driver_hal.function
@@ -119,13 +119,18 @@
#define MAX_KEY_ID_FOR_TEST 10
void psa_purge_storage( void )
{
- psa_key_id_t i;
+ psa_key_id_t id;
+ psa_key_lifetime_t lifetime;
/* The tests may have potentially created key ids from 1 to
* MAX_KEY_ID_FOR_TEST. In addition, run the destroy function on key id
* 0, which file-based storage uses as a temporary file. */
- for( i = 0; i <= MAX_KEY_ID_FOR_TEST; i++ )
- psa_destroy_persistent_key( i );
+ for( id = 0; id <= MAX_KEY_ID_FOR_TEST; id++ )
+ psa_destroy_persistent_key( id );
+ /* Purge the transaction file. */
psa_crypto_stop_transaction( );
+ /* Purge driver persistent data. */
+ for( lifetime = 0; lifetime < PSA_MAX_SE_LIFETIME; lifetime++ )
+ psa_destroy_se_persistent_data( lifetime );
}
/* END_HEADER */