diff options
Diffstat (limited to 'lib/mbedtls-2.27.0/library/psa_crypto_slot_management.c')
| -rw-r--r-- | lib/mbedtls-2.27.0/library/psa_crypto_slot_management.c | 585 |
1 files changed, 585 insertions, 0 deletions
diff --git a/lib/mbedtls-2.27.0/library/psa_crypto_slot_management.c b/lib/mbedtls-2.27.0/library/psa_crypto_slot_management.c new file mode 100644 index 0000000..76d7a07 --- /dev/null +++ b/lib/mbedtls-2.27.0/library/psa_crypto_slot_management.c @@ -0,0 +1,585 @@ +/* + * PSA crypto layer on top of Mbed TLS crypto + */ +/* + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "common.h" + +#if defined(MBEDTLS_PSA_CRYPTO_C) + +#include "psa/crypto.h" + +#include "psa_crypto_core.h" +#include "psa_crypto_driver_wrappers.h" +#include "psa_crypto_slot_management.h" +#include "psa_crypto_storage.h" +#if defined(MBEDTLS_PSA_CRYPTO_SE_C) +#include "psa_crypto_se.h" +#endif + +#include <stdlib.h> +#include <string.h> +#if defined(MBEDTLS_PLATFORM_C) +#include "mbedtls/platform.h" +#else +#define mbedtls_calloc calloc +#define mbedtls_free free +#endif + +#define ARRAY_LENGTH( array ) ( sizeof( array ) / sizeof( *( array ) ) ) + +typedef struct +{ + psa_key_slot_t key_slots[MBEDTLS_PSA_KEY_SLOT_COUNT]; + unsigned key_slots_initialized : 1; +} psa_global_data_t; + +static psa_global_data_t global_data; + +int psa_is_valid_key_id( mbedtls_svc_key_id_t key, int vendor_ok ) +{ + psa_key_id_t key_id = MBEDTLS_SVC_KEY_ID_GET_KEY_ID( key ); + + if( ( PSA_KEY_ID_USER_MIN <= key_id ) && + ( key_id <= PSA_KEY_ID_USER_MAX ) ) + return( 1 ); + + if( vendor_ok && + ( PSA_KEY_ID_VENDOR_MIN <= key_id ) && + ( key_id <= PSA_KEY_ID_VENDOR_MAX ) ) + return( 1 ); + + return( 0 ); +} + +/** Get the description in memory of a key given its identifier and lock it. + * + * The descriptions of volatile keys and loaded persistent keys are + * stored in key slots. This function returns a pointer to the key slot + * containing the description of a key given its identifier. + * + * The function searches the key slots containing the description of the key + * with \p key identifier. The function does only read accesses to the key + * slots. The function does not load any persistent key thus does not access + * any storage. + * + * For volatile key identifiers, only one key slot is queried as a volatile + * key with identifier key_id can only be stored in slot of index + * ( key_id - #PSA_KEY_ID_VOLATILE_MIN ). + * + * On success, the function locks the key slot. It is the responsibility of + * the caller to unlock the key slot when it does not access it anymore. + * + * \param key Key identifier to query. + * \param[out] p_slot On success, `*p_slot` contains a pointer to the + * key slot containing the description of the key + * identified by \p key. + * + * \retval #PSA_SUCCESS + * The pointer to the key slot containing the description of the key + * identified by \p key was returned. + * \retval #PSA_ERROR_INVALID_HANDLE + * \p key is not a valid key identifier. + * \retval #PSA_ERROR_DOES_NOT_EXIST + * There is no key with key identifier \p key in the key slots. + */ +static psa_status_t psa_get_and_lock_key_slot_in_memory( + mbedtls_svc_key_id_t key, psa_key_slot_t **p_slot ) +{ + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + psa_key_id_t key_id = MBEDTLS_SVC_KEY_ID_GET_KEY_ID( key ); + size_t slot_idx; + psa_key_slot_t *slot = NULL; + + if( psa_key_id_is_volatile( key_id ) ) + { + slot = &global_data.key_slots[ key_id - PSA_KEY_ID_VOLATILE_MIN ]; + + /* + * Check if both the PSA key identifier key_id and the owner + * identifier of key match those of the key slot. + * + * Note that, if the key slot is not occupied, its PSA key identifier + * is equal to zero. This is an invalid value for a PSA key identifier + * and thus cannot be equal to the valid PSA key identifier key_id. + */ + status = mbedtls_svc_key_id_equal( key, slot->attr.id ) ? + PSA_SUCCESS : PSA_ERROR_DOES_NOT_EXIST; + } + else + { + if ( !psa_is_valid_key_id( key, 1 ) ) + return( PSA_ERROR_INVALID_HANDLE ); + + for( slot_idx = 0; slot_idx < MBEDTLS_PSA_KEY_SLOT_COUNT; slot_idx++ ) + { + slot = &global_data.key_slots[ slot_idx ]; + if( mbedtls_svc_key_id_equal( key, slot->attr.id ) ) + break; + } + status = ( slot_idx < MBEDTLS_PSA_KEY_SLOT_COUNT ) ? + PSA_SUCCESS : PSA_ERROR_DOES_NOT_EXIST; + } + + if( status == PSA_SUCCESS ) + { + status = psa_lock_key_slot( slot ); + if( status == PSA_SUCCESS ) + *p_slot = slot; + } + + return( status ); +} + +psa_status_t psa_initialize_key_slots( void ) +{ + /* Nothing to do: program startup and psa_wipe_all_key_slots() both + * guarantee that the key slots are initialized to all-zero, which + * means that all the key slots are in a valid, empty state. */ + global_data.key_slots_initialized = 1; + return( PSA_SUCCESS ); +} + +void psa_wipe_all_key_slots( void ) +{ + size_t slot_idx; + + for( slot_idx = 0; slot_idx < MBEDTLS_PSA_KEY_SLOT_COUNT; slot_idx++ ) + { + psa_key_slot_t *slot = &global_data.key_slots[ slot_idx ]; + slot->lock_count = 1; + (void) psa_wipe_key_slot( slot ); + } + global_data.key_slots_initialized = 0; +} + +psa_status_t psa_get_empty_key_slot( psa_key_id_t *volatile_key_id, + psa_key_slot_t **p_slot ) +{ + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + size_t slot_idx; + psa_key_slot_t *selected_slot, *unlocked_persistent_key_slot; + + if( ! global_data.key_slots_initialized ) + { + status = PSA_ERROR_BAD_STATE; + goto error; + } + + selected_slot = unlocked_persistent_key_slot = NULL; + for( slot_idx = 0; slot_idx < MBEDTLS_PSA_KEY_SLOT_COUNT; slot_idx++ ) + { + psa_key_slot_t *slot = &global_data.key_slots[ slot_idx ]; + if( ! psa_is_key_slot_occupied( slot ) ) + { + selected_slot = slot; + break; + } + + if( ( unlocked_persistent_key_slot == NULL ) && + ( ! PSA_KEY_LIFETIME_IS_VOLATILE( slot->attr.lifetime ) ) && + ( ! psa_is_key_slot_locked( slot ) ) ) + unlocked_persistent_key_slot = slot; + } + + /* + * If there is no unused key slot and there is at least one unlocked key + * slot containing the description of a persistent key, recycle the first + * such key slot we encountered. If we later need to operate on the + * persistent key we are evicting now, we will reload its description from + * storage. + */ + if( ( selected_slot == NULL ) && + ( unlocked_persistent_key_slot != NULL ) ) + { + selected_slot = unlocked_persistent_key_slot; + selected_slot->lock_count = 1; + psa_wipe_key_slot( selected_slot ); + } + + if( selected_slot != NULL ) + { + status = psa_lock_key_slot( selected_slot ); + if( status != PSA_SUCCESS ) + goto error; + + *volatile_key_id = PSA_KEY_ID_VOLATILE_MIN + + ( (psa_key_id_t)( selected_slot - global_data.key_slots ) ); + *p_slot = selected_slot; + + return( PSA_SUCCESS ); + } + status = PSA_ERROR_INSUFFICIENT_MEMORY; + +error: + *p_slot = NULL; + *volatile_key_id = 0; + + return( status ); +} + +#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) +static psa_status_t psa_load_persistent_key_into_slot( psa_key_slot_t *slot ) +{ + psa_status_t status = PSA_SUCCESS; + uint8_t *key_data = NULL; + size_t key_data_length = 0; + + status = psa_load_persistent_key( &slot->attr, + &key_data, &key_data_length ); + if( status != PSA_SUCCESS ) + goto exit; + +#if defined(MBEDTLS_PSA_CRYPTO_SE_C) + /* Special handling is required for loading keys associated with a + * dynamically registered SE interface. */ + const psa_drv_se_t *drv; + psa_drv_se_context_t *drv_context; + if( psa_get_se_driver( slot->attr.lifetime, &drv, &drv_context ) ) + { + psa_se_key_data_storage_t *data; + + if( key_data_length != sizeof( *data ) ) + { + status = PSA_ERROR_DATA_INVALID; + goto exit; + } + data = (psa_se_key_data_storage_t *) key_data; + status = psa_copy_key_material_into_slot( + slot, data->slot_number, sizeof( data->slot_number ) ); + goto exit; + } +#endif /* MBEDTLS_PSA_CRYPTO_SE_C */ + + status = psa_copy_key_material_into_slot( slot, key_data, key_data_length ); + +exit: + psa_free_persistent_key_data( key_data, key_data_length ); + return( status ); +} +#endif /* MBEDTLS_PSA_CRYPTO_STORAGE_C */ + +#if defined(MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS) + +static psa_status_t psa_load_builtin_key_into_slot( psa_key_slot_t *slot ) +{ + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; + psa_key_lifetime_t lifetime = PSA_KEY_LIFETIME_VOLATILE; + psa_drv_slot_number_t slot_number = 0; + size_t key_buffer_size = 0; + size_t key_buffer_length = 0; + + if( ! psa_key_id_is_builtin( + MBEDTLS_SVC_KEY_ID_GET_KEY_ID( slot->attr.id ) ) ) + { + return( PSA_ERROR_DOES_NOT_EXIST ); + } + + /* Check the platform function to see whether this key actually exists */ + status = mbedtls_psa_platform_get_builtin_key( + slot->attr.id, &lifetime, &slot_number ); + if( status != PSA_SUCCESS ) + return( status ); + + /* Set required key attributes to ensure get_builtin_key can retrieve the + * full attributes. */ + psa_set_key_id( &attributes, slot->attr.id ); + psa_set_key_lifetime( &attributes, lifetime ); + + /* Get the full key attributes from the driver in order to be able to + * calculate the required buffer size. */ + status = psa_driver_wrapper_get_builtin_key( + slot_number, &attributes, + NULL, 0, NULL ); + if( status != PSA_ERROR_BUFFER_TOO_SMALL ) + { + /* Builtin keys cannot be defined by the attributes alone */ + if( status == PSA_SUCCESS ) + status = PSA_ERROR_CORRUPTION_DETECTED; + return( status ); + } + + /* If the key should exist according to the platform, then ask the driver + * what its expected size is. */ + status = psa_driver_wrapper_get_key_buffer_size( &attributes, + &key_buffer_size ); + if( status != PSA_SUCCESS ) + return( status ); + + /* Allocate a buffer of the required size and load the builtin key directly + * into the (now properly sized) slot buffer. */ + status = psa_allocate_buffer_to_slot( slot, key_buffer_size ); + if( status != PSA_SUCCESS ) + return( status ); + + status = psa_driver_wrapper_get_builtin_key( + slot_number, &attributes, + slot->key.data, slot->key.bytes, &key_buffer_length ); + if( status != PSA_SUCCESS ) + goto exit; + + /* Copy actual key length and core attributes into the slot on success */ + slot->key.bytes = key_buffer_length; + slot->attr = attributes.core; + +exit: + if( status != PSA_SUCCESS ) + psa_remove_key_data_from_memory( slot ); + return( status ); +} +#endif /* MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS */ + +psa_status_t psa_get_and_lock_key_slot( mbedtls_svc_key_id_t key, + psa_key_slot_t **p_slot ) +{ + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + + *p_slot = NULL; + if( ! global_data.key_slots_initialized ) + return( PSA_ERROR_BAD_STATE ); + + /* + * On success, the pointer to the slot is passed directly to the caller + * thus no need to unlock the key slot here. + */ + status = psa_get_and_lock_key_slot_in_memory( key, p_slot ); + if( status != PSA_ERROR_DOES_NOT_EXIST ) + return( status ); + + /* Loading keys from storage requires support for such a mechanism */ +#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) || \ + defined(MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS) + psa_key_id_t volatile_key_id; + + status = psa_get_empty_key_slot( &volatile_key_id, p_slot ); + if( status != PSA_SUCCESS ) + return( status ); + + (*p_slot)->attr.id = key; + (*p_slot)->attr.lifetime = PSA_KEY_LIFETIME_PERSISTENT; + + status = PSA_ERROR_DOES_NOT_EXIST; +#if defined(MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS) + /* Load keys in the 'builtin' range through their own interface */ + status = psa_load_builtin_key_into_slot( *p_slot ); +#endif /* MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS */ + +#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) + if( status == PSA_ERROR_DOES_NOT_EXIST ) + status = psa_load_persistent_key_into_slot( *p_slot ); +#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */ + + if( status != PSA_SUCCESS ) + { + psa_wipe_key_slot( *p_slot ); + if( status == PSA_ERROR_DOES_NOT_EXIST ) + status = PSA_ERROR_INVALID_HANDLE; + } + else + /* Add implicit usage flags. */ + psa_extend_key_usage_flags( &(*p_slot)->attr.policy.usage ); + + return( status ); +#else /* MBEDTLS_PSA_CRYPTO_STORAGE_C || MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS */ + return( PSA_ERROR_INVALID_HANDLE ); +#endif /* MBEDTLS_PSA_CRYPTO_STORAGE_C || MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS */ +} + +psa_status_t psa_unlock_key_slot( psa_key_slot_t *slot ) +{ + if( slot == NULL ) + return( PSA_SUCCESS ); + + if( slot->lock_count > 0 ) + { + slot->lock_count--; + return( PSA_SUCCESS ); + } + + /* + * As the return error code may not be handled in case of multiple errors, + * do our best to report if the lock counter is equal to zero: if + * available call MBEDTLS_PARAM_FAILED that may terminate execution (if + * called as part of the execution of a unit test suite this will stop the + * test suite execution). + */ +#ifdef MBEDTLS_CHECK_PARAMS + MBEDTLS_PARAM_FAILED( slot->lock_count > 0 ); +#endif + + return( PSA_ERROR_CORRUPTION_DETECTED ); +} + +psa_status_t psa_validate_key_location( psa_key_lifetime_t lifetime, + psa_se_drv_table_entry_t **p_drv ) +{ + if ( psa_key_lifetime_is_external( lifetime ) ) + { +#if defined(MBEDTLS_PSA_CRYPTO_SE_C) + /* Check whether a driver is registered against this lifetime */ + psa_se_drv_table_entry_t *driver = psa_get_se_driver_entry( lifetime ); + if( driver != NULL ) + { + if (p_drv != NULL) + *p_drv = driver; + return( PSA_SUCCESS ); + } +#else /* MBEDTLS_PSA_CRYPTO_SE_C */ + (void) p_drv; +#endif /* MBEDTLS_PSA_CRYPTO_SE_C */ + +#if defined(MBEDTLS_PSA_CRYPTO_DRIVERS) + /* Key location for external keys gets checked by the wrapper */ + return( PSA_SUCCESS ); +#else /* MBEDTLS_PSA_CRYPTO_DRIVERS */ + /* No support for external lifetimes at all, or dynamic interface + * did not find driver for requested lifetime. */ + return( PSA_ERROR_INVALID_ARGUMENT ); +#endif /* MBEDTLS_PSA_CRYPTO_DRIVERS */ + } + else + /* Local/internal keys are always valid */ + return( PSA_SUCCESS ); +} + +psa_status_t psa_validate_key_persistence( psa_key_lifetime_t lifetime ) +{ + if ( PSA_KEY_LIFETIME_IS_VOLATILE( lifetime ) ) + { + /* Volatile keys are always supported */ + return( PSA_SUCCESS ); + } + else + { + /* Persistent keys require storage support */ +#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) + if( PSA_KEY_LIFETIME_IS_READ_ONLY( lifetime ) ) + return( PSA_ERROR_INVALID_ARGUMENT ); + else + return( PSA_SUCCESS ); +#else /* MBEDTLS_PSA_CRYPTO_STORAGE_C */ + return( PSA_ERROR_NOT_SUPPORTED ); +#endif /* !MBEDTLS_PSA_CRYPTO_STORAGE_C */ + } +} + +psa_status_t psa_open_key( mbedtls_svc_key_id_t key, psa_key_handle_t *handle ) +{ +#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) + psa_status_t status; + psa_key_slot_t *slot; + + status = psa_get_and_lock_key_slot( key, &slot ); + if( status != PSA_SUCCESS ) + { + *handle = PSA_KEY_HANDLE_INIT; + if( status == PSA_ERROR_INVALID_HANDLE ) + status = PSA_ERROR_DOES_NOT_EXIST; + + return( status ); + } + + *handle = key; + + return( psa_unlock_key_slot( slot ) ); + +#else /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */ + (void) key; + *handle = PSA_KEY_HANDLE_INIT; + return( PSA_ERROR_NOT_SUPPORTED ); +#endif /* !defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */ +} + +psa_status_t psa_close_key( psa_key_handle_t handle ) +{ + psa_status_t status; + psa_key_slot_t *slot; + + if( psa_key_handle_is_null( handle ) ) + return( PSA_SUCCESS ); + + status = psa_get_and_lock_key_slot_in_memory( handle, &slot ); + if( status != PSA_SUCCESS ) + { + if( status == PSA_ERROR_DOES_NOT_EXIST ) + status = PSA_ERROR_INVALID_HANDLE; + + return( status ); + } + if( slot->lock_count <= 1 ) + return( psa_wipe_key_slot( slot ) ); + else + return( psa_unlock_key_slot( slot ) ); +} + +psa_status_t psa_purge_key( mbedtls_svc_key_id_t key ) +{ + psa_status_t status; + psa_key_slot_t *slot; + + status = psa_get_and_lock_key_slot_in_memory( key, &slot ); + if( status != PSA_SUCCESS ) + return( status ); + + if( ( ! PSA_KEY_LIFETIME_IS_VOLATILE( slot->attr.lifetime ) ) && + ( slot->lock_count <= 1 ) ) + return( psa_wipe_key_slot( slot ) ); + else + return( psa_unlock_key_slot( slot ) ); +} + +void mbedtls_psa_get_stats( mbedtls_psa_stats_t *stats ) +{ + size_t slot_idx; + + memset( stats, 0, sizeof( *stats ) ); + + for( slot_idx = 0; slot_idx < MBEDTLS_PSA_KEY_SLOT_COUNT; slot_idx++ ) + { + const psa_key_slot_t *slot = &global_data.key_slots[ slot_idx ]; + if( psa_is_key_slot_locked( slot ) ) + { + ++stats->locked_slots; + } + if( ! psa_is_key_slot_occupied( slot ) ) + { + ++stats->empty_slots; + continue; + } + if( PSA_KEY_LIFETIME_IS_VOLATILE( slot->attr.lifetime ) ) + ++stats->volatile_slots; + else + { + psa_key_id_t id = MBEDTLS_SVC_KEY_ID_GET_KEY_ID( slot->attr.id ); + ++stats->persistent_slots; + if( id > stats->max_open_internal_key_id ) + stats->max_open_internal_key_id = id; + } + if( PSA_KEY_LIFETIME_GET_LOCATION( slot->attr.lifetime ) != + PSA_KEY_LOCATION_LOCAL_STORAGE ) + { + psa_key_id_t id = MBEDTLS_SVC_KEY_ID_GET_KEY_ID( slot->attr.id ); + ++stats->external_slots; + if( id > stats->max_open_external_key_id ) + stats->max_open_external_key_id = id; + } + } +} + +#endif /* MBEDTLS_PSA_CRYPTO_C */ |