Look up the SE driver when creating a key

When creating a key with a lifetime that places it in a secure
element, retrieve the appropriate driver table entry.

This commit doesn't yet achieve behavior: so far the code only
retrieves the driver, it doesn't call the driver.
This commit is contained in:
Gilles Peskine 2019-06-26 18:34:38 +02:00
parent 6e59c42d1d
commit 011e4284a1
3 changed files with 93 additions and 22 deletions

View File

@ -1291,9 +1291,11 @@ static psa_status_t psa_set_key_policy_internal(
* In case of failure at any step, stop the sequence and call
* psa_fail_key_creation().
*
* \param attributes Key attributes for the new key.
* \param handle On success, a handle for the allocated slot.
* \param p_slot On success, a pointer to the prepared slot.
* \param[in] attributes Key attributes for the new key.
* \param[out] handle On success, a handle for the allocated slot.
* \param[out] p_slot On success, a pointer to the prepared slot.
* \param[out] p_drv On any return, the driver for the key, if any.
* NULL for a transparent key.
*
* \retval #PSA_SUCCESS
* The key slot is ready to receive key material.
@ -1303,11 +1305,14 @@ static psa_status_t psa_set_key_policy_internal(
static psa_status_t psa_start_key_creation(
const psa_key_attributes_t *attributes,
psa_key_handle_t *handle,
psa_key_slot_t **p_slot )
psa_key_slot_t **p_slot,
const psa_se_drv_table_entry_t **p_drv )
{
psa_status_t status;
psa_key_slot_t *slot;
*p_drv = NULL;
status = psa_internal_allocate_key_slot( handle, p_slot );
if( status != PSA_SUCCESS )
return( status );
@ -1317,10 +1322,12 @@ static psa_status_t psa_start_key_creation(
if( status != PSA_SUCCESS )
return( status );
slot->lifetime = attributes->lifetime;
if( attributes->lifetime != PSA_KEY_LIFETIME_VOLATILE )
{
status = psa_validate_persistent_key_parameters( attributes->lifetime,
attributes->id, 1 );
attributes->id,
p_drv, 1 );
if( status != PSA_SUCCESS )
return( status );
slot->persistent_storage_id = attributes->id;
@ -1338,17 +1345,22 @@ static psa_status_t psa_start_key_creation(
* See the documentation of psa_start_key_creation() for the intended use
* of this function.
*
* \param slot Pointer to the slot with key material.
* \param[in,out] slot Pointer to the slot with key material.
* \param[in] driver The secure element driver for the key,
* or NULL for a transparent key.
*
* \retval #PSA_SUCCESS
* The key was successfully created. The handle is now valid.
* \return If this function fails, the key slot is an invalid state.
* You must call psa_fail_key_creation() to wipe and free the slot.
*/
static psa_status_t psa_finish_key_creation( psa_key_slot_t *slot )
static psa_status_t psa_finish_key_creation(
psa_key_slot_t *slot,
const psa_se_drv_table_entry_t *driver )
{
psa_status_t status = PSA_SUCCESS;
(void) slot;
(void) driver;
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
if( slot->lifetime == PSA_KEY_LIFETIME_PERSISTENT )
@ -1390,12 +1402,25 @@ static psa_status_t psa_finish_key_creation( psa_key_slot_t *slot )
* See the documentation of psa_start_key_creation() for the intended use
* of this function.
*
* \param slot Pointer to the slot with key material.
* \param[in,out] slot Pointer to the slot with key material.
* \param[in] driver The secure element driver for the key,
* or NULL for a transparent key.
*/
static void psa_fail_key_creation( psa_key_slot_t *slot )
static void psa_fail_key_creation( psa_key_slot_t *slot,
const psa_se_drv_table_entry_t *driver )
{
(void) driver;
if( slot == NULL )
return;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* TOnogrepDO: If the key has already been created in the secure
* element, and the failure happened later (when saving metadata
* to internal storage), we need to destroy the key in the secure
* element. */
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
psa_wipe_key_slot( slot );
}
@ -1458,8 +1483,9 @@ psa_status_t psa_import_key( const psa_key_attributes_t *attributes,
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
const psa_se_drv_table_entry_t *driver = NULL;
status = psa_start_key_creation( attributes, handle, &slot );
status = psa_start_key_creation( attributes, handle, &slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
@ -1470,11 +1496,11 @@ psa_status_t psa_import_key( const psa_key_attributes_t *attributes,
if( status != PSA_SUCCESS )
goto exit;
status = psa_finish_key_creation( slot );
status = psa_finish_key_creation( slot, driver );
exit:
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( slot );
psa_fail_key_creation( slot, driver );
*handle = 0;
}
return( status );
@ -1514,6 +1540,7 @@ psa_status_t psa_copy_key( psa_key_handle_t source_handle,
psa_key_slot_t *source_slot = NULL;
psa_key_slot_t *target_slot = NULL;
psa_key_attributes_t actual_attributes = *specified_attributes;
const psa_se_drv_table_entry_t *driver = NULL;
status = psa_get_key_from_slot( source_handle, &source_slot,
PSA_KEY_USAGE_COPY, 0 );
@ -1530,7 +1557,7 @@ psa_status_t psa_copy_key( psa_key_handle_t source_handle,
goto exit;
status = psa_start_key_creation( &actual_attributes,
target_handle, &target_slot );
target_handle, &target_slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
@ -1538,11 +1565,11 @@ psa_status_t psa_copy_key( psa_key_handle_t source_handle,
if( status != PSA_SUCCESS )
goto exit;
status = psa_finish_key_creation( target_slot );
status = psa_finish_key_creation( target_slot, driver );
exit:
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( target_slot );
psa_fail_key_creation( target_slot, driver );
*target_handle = 0;
}
return( status );
@ -4437,7 +4464,8 @@ psa_status_t psa_key_derivation_output_key( const psa_key_attributes_t *attribut
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
status = psa_start_key_creation( attributes, handle, &slot );
const psa_se_drv_table_entry_t *driver = NULL;
status = psa_start_key_creation( attributes, handle, &slot, &driver );
if( status == PSA_SUCCESS )
{
status = psa_generate_derived_key_internal( slot,
@ -4445,10 +4473,10 @@ psa_status_t psa_key_derivation_output_key( const psa_key_attributes_t *attribut
operation );
}
if( status == PSA_SUCCESS )
status = psa_finish_key_creation( slot );
status = psa_finish_key_creation( slot, driver );
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( slot );
psa_fail_key_creation( slot, driver );
*handle = 0;
}
return( status );
@ -5467,7 +5495,8 @@ psa_status_t psa_generate_key( const psa_key_attributes_t *attributes,
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
status = psa_start_key_creation( attributes, handle, &slot );
const psa_se_drv_table_entry_t *driver = NULL;
status = psa_start_key_creation( attributes, handle, &slot, &driver );
if( status == PSA_SUCCESS )
{
status = psa_generate_key_internal(
@ -5475,10 +5504,10 @@ psa_status_t psa_generate_key( const psa_key_attributes_t *attributes,
attributes->domain_parameters, attributes->domain_parameters_size );
}
if( status == PSA_SUCCESS )
status = psa_finish_key_creation( slot );
status = psa_finish_key_creation( slot, driver );
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( slot );
psa_fail_key_creation( slot, driver );
*handle = 0;
}
return( status );

View File

@ -168,8 +168,20 @@ static int psa_is_key_id_valid( psa_key_file_id_t file_id,
psa_status_t psa_validate_persistent_key_parameters(
psa_key_lifetime_t lifetime,
psa_key_file_id_t id,
const psa_se_drv_table_entry_t **p_drv,
int creating )
{
if( p_drv != NULL )
*p_drv = NULL;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( psa_key_lifetime_is_external( lifetime ) )
{
*p_drv = psa_get_se_driver_entry( lifetime );
if( *p_drv == NULL )
return( PSA_ERROR_INVALID_ARGUMENT );
}
else
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if( lifetime != PSA_KEY_LIFETIME_PERSISTENT )
return( PSA_ERROR_INVALID_ARGUMENT );
@ -194,7 +206,7 @@ psa_status_t psa_open_key( psa_key_file_id_t id, psa_key_handle_t *handle )
*handle = 0;
status = psa_validate_persistent_key_parameters(
PSA_KEY_LIFETIME_PERSISTENT, id, 0 );
PSA_KEY_LIFETIME_PERSISTENT, id, NULL, 0 );
if( status != PSA_SUCCESS )
return( status );

View File

@ -22,6 +22,9 @@
#ifndef PSA_CRYPTO_SLOT_MANAGEMENT_H
#define PSA_CRYPTO_SLOT_MANAGEMENT_H
#include "psa/crypto.h"
#include "psa_crypto_se.h"
/* Number of key slots (plus one because 0 is not used).
* The value is a compile-time constant for now, for simplicity. */
#define PSA_KEY_SLOT_COUNT 32
@ -71,6 +74,24 @@ void psa_wipe_all_key_slots( void );
psa_status_t psa_internal_allocate_key_slot( psa_key_handle_t *handle,
psa_key_slot_t **p_slot );
/** Test whether a lifetime designates a key in an external cryptoprocessor.
*
* \param lifetime The lifetime to test.
*
* \retval 1
* The lifetime designates an external key. There should be a
* registered driver for this lifetime, otherwise the key cannot
* be created or manipulated.
* \retval 0
* The lifetime designates a key that is volatile or in internal
* storage.
*/
static inline int psa_key_lifetime_is_external( psa_key_lifetime_t lifetime )
{
return( lifetime != PSA_KEY_LIFETIME_VOLATILE &&
lifetime != PSA_KEY_LIFETIME_PERSISTENT );
}
/** Test whether the given parameters are acceptable for a persistent key.
*
* This function does not access the storage in any way. It only tests
@ -78,8 +99,16 @@ psa_status_t psa_internal_allocate_key_slot( psa_key_handle_t *handle,
* It does not test whether the a file by the given id exists or could be
* created.
*
* If the key is in external storage, this function returns the corresponding
* driver.
*
* \param lifetime The lifetime to test.
* \param id The key id to test.
* \param[out] p_drv On output, if \p lifetime designates a key
* in an external processor, \c *p_drv is a pointer
* to the driver table entry fot this lifetime.
* If \p lifetime designates a transparent key,
* \c *p_drv is \c NULL.
* \param creating 0 if attempting to open an existing key.
* Nonzero if attempting to create a key.
*
@ -93,6 +122,7 @@ psa_status_t psa_internal_allocate_key_slot( psa_key_handle_t *handle,
psa_status_t psa_validate_persistent_key_parameters(
psa_key_lifetime_t lifetime,
psa_key_file_id_t id,
const psa_se_drv_table_entry_t **p_drv,
int creating );