| /* |
| * PSA persistent key storage |
| */ |
| /* |
| * Copyright The Mbed TLS Contributors |
| * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later |
| */ |
| |
| #include "common.h" |
| |
| #if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) |
| |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "psa/crypto.h" |
| #include "psa_crypto_storage.h" |
| #include "mbedtls/platform_util.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" |
| |
| |
| |
| /****************************************************************/ |
| /* Key storage */ |
| /****************************************************************/ |
| |
| /* Determine a file name (ITS file identifier) for the given key identifier. |
| * The file name must be distinct from any file that is used for a purpose |
| * other than storing a key. Currently, the only such file is the random seed |
| * file whose name is PSA_CRYPTO_ITS_RANDOM_SEED_UID and whose value is |
| * 0xFFFFFF52. */ |
| static psa_storage_uid_t psa_its_identifier_of_slot(mbedtls_svc_key_id_t key) |
| { |
| #if defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER) |
| /* Encode the owner in the upper 32 bits. This means that if |
| * owner values are nonzero (as they are on a PSA platform), |
| * no key file will ever have a value less than 0x100000000, so |
| * the whole range 0..0xffffffff is available for non-key files. */ |
| uint32_t unsigned_owner_id = MBEDTLS_SVC_KEY_ID_GET_OWNER_ID(key); |
| return ((uint64_t) unsigned_owner_id << 32) | |
| MBEDTLS_SVC_KEY_ID_GET_KEY_ID(key); |
| #else |
| /* Use the key id directly as a file name. |
| * psa_is_key_id_valid() in psa_crypto_slot_management.c |
| * is responsible for ensuring that key identifiers do not have a |
| * value that is reserved for non-key files. */ |
| return key; |
| #endif |
| } |
| |
| /** |
| * \brief Load persistent data for the given key slot number. |
| * |
| * This function reads data from a storage backend and returns the data in a |
| * buffer. |
| * |
| * \param key Persistent identifier of the key to be loaded. This |
| * should be an occupied storage location. |
| * \param[out] data Buffer where the data is to be written. |
| * \param data_size Size of the \c data buffer in bytes. |
| * |
| * \retval #PSA_SUCCESS \emptydescription |
| * \retval #PSA_ERROR_DATA_INVALID \emptydescription |
| * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription |
| * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription |
| * \retval #PSA_ERROR_DOES_NOT_EXIST \emptydescription |
| */ |
| static psa_status_t psa_crypto_storage_load( |
| const mbedtls_svc_key_id_t key, uint8_t *data, size_t data_size) |
| { |
| psa_status_t status; |
| psa_storage_uid_t data_identifier = psa_its_identifier_of_slot(key); |
| struct psa_storage_info_t data_identifier_info; |
| size_t data_length = 0; |
| |
| status = psa_its_get_info(data_identifier, &data_identifier_info); |
| if (status != PSA_SUCCESS) { |
| return status; |
| } |
| |
| status = psa_its_get(data_identifier, 0, (uint32_t) data_size, data, &data_length); |
| if (data_size != data_length) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| |
| return status; |
| } |
| |
| int psa_is_key_present_in_storage(const mbedtls_svc_key_id_t key) |
| { |
| psa_status_t ret; |
| psa_storage_uid_t data_identifier = psa_its_identifier_of_slot(key); |
| struct psa_storage_info_t data_identifier_info; |
| |
| ret = psa_its_get_info(data_identifier, &data_identifier_info); |
| |
| if (ret == PSA_ERROR_DOES_NOT_EXIST) { |
| return 0; |
| } |
| return 1; |
| } |
| |
| /** |
| * \brief Store persistent data for the given key slot number. |
| * |
| * This function stores the given data buffer to a persistent storage. |
| * |
| * \param key Persistent identifier of the key to be stored. This |
| * should be an unoccupied storage location. |
| * \param[in] data Buffer containing the data to be stored. |
| * \param data_length The number of bytes |
| * that make up the data. |
| * |
| * \retval #PSA_SUCCESS \emptydescription |
| * \retval #PSA_ERROR_INSUFFICIENT_STORAGE \emptydescription |
| * \retval #PSA_ERROR_ALREADY_EXISTS \emptydescription |
| * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription |
| * \retval #PSA_ERROR_DATA_INVALID \emptydescription |
| */ |
| static psa_status_t psa_crypto_storage_store(const mbedtls_svc_key_id_t key, |
| const uint8_t *data, |
| size_t data_length) |
| { |
| psa_status_t status; |
| psa_storage_uid_t data_identifier = psa_its_identifier_of_slot(key); |
| struct psa_storage_info_t data_identifier_info; |
| |
| if (psa_is_key_present_in_storage(key) == 1) { |
| return PSA_ERROR_ALREADY_EXISTS; |
| } |
| |
| status = psa_its_set(data_identifier, (uint32_t) data_length, data, 0); |
| if (status != PSA_SUCCESS) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| |
| status = psa_its_get_info(data_identifier, &data_identifier_info); |
| if (status != PSA_SUCCESS) { |
| goto exit; |
| } |
| |
| if (data_identifier_info.size != data_length) { |
| status = PSA_ERROR_DATA_INVALID; |
| goto exit; |
| } |
| |
| exit: |
| if (status != PSA_SUCCESS) { |
| /* Remove the file in case we managed to create it but something |
| * went wrong. It's ok if the file doesn't exist. If the file exists |
| * but the removal fails, we're already reporting an error so there's |
| * nothing else we can do. */ |
| (void) psa_its_remove(data_identifier); |
| } |
| return status; |
| } |
| |
| psa_status_t psa_destroy_persistent_key(const mbedtls_svc_key_id_t key) |
| { |
| psa_status_t ret; |
| psa_storage_uid_t data_identifier = psa_its_identifier_of_slot(key); |
| struct psa_storage_info_t data_identifier_info; |
| |
| ret = psa_its_get_info(data_identifier, &data_identifier_info); |
| if (ret == PSA_ERROR_DOES_NOT_EXIST) { |
| return PSA_SUCCESS; |
| } |
| |
| if (psa_its_remove(data_identifier) != PSA_SUCCESS) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| |
| ret = psa_its_get_info(data_identifier, &data_identifier_info); |
| if (ret != PSA_ERROR_DOES_NOT_EXIST) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| |
| return PSA_SUCCESS; |
| } |
| |
| /** |
| * \brief Get data length for given key slot number. |
| * |
| * \param key Persistent identifier whose stored data length |
| * is to be obtained. |
| * \param[out] data_length The number of bytes that make up the data. |
| * |
| * \retval #PSA_SUCCESS \emptydescription |
| * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription |
| * \retval #PSA_ERROR_DOES_NOT_EXIST \emptydescription |
| * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription |
| */ |
| static psa_status_t psa_crypto_storage_get_data_length( |
| const mbedtls_svc_key_id_t key, |
| size_t *data_length) |
| { |
| psa_status_t status; |
| psa_storage_uid_t data_identifier = psa_its_identifier_of_slot(key); |
| struct psa_storage_info_t data_identifier_info; |
| |
| status = psa_its_get_info(data_identifier, &data_identifier_info); |
| if (status != PSA_SUCCESS) { |
| return status; |
| } |
| |
| *data_length = (size_t) data_identifier_info.size; |
| |
| return PSA_SUCCESS; |
| } |
| |
| /** |
| * Persistent key storage magic header. |
| */ |
| #define PSA_KEY_STORAGE_MAGIC_HEADER "PSA\0KEY" |
| #define PSA_KEY_STORAGE_MAGIC_HEADER_LENGTH (sizeof(PSA_KEY_STORAGE_MAGIC_HEADER)) |
| |
| typedef struct { |
| uint8_t magic[PSA_KEY_STORAGE_MAGIC_HEADER_LENGTH]; |
| uint8_t version[4]; |
| uint8_t lifetime[sizeof(psa_key_lifetime_t)]; |
| uint8_t type[2]; |
| uint8_t bits[2]; |
| uint8_t policy[sizeof(psa_key_policy_t)]; |
| uint8_t data_len[4]; |
| uint8_t key_data[]; |
| } psa_persistent_key_storage_format; |
| |
| void psa_format_key_data_for_storage(const uint8_t *data, |
| const size_t data_length, |
| const psa_key_attributes_t *attr, |
| uint8_t *storage_data) |
| { |
| psa_persistent_key_storage_format *storage_format = |
| (psa_persistent_key_storage_format *) storage_data; |
| |
| memcpy(storage_format->magic, PSA_KEY_STORAGE_MAGIC_HEADER, |
| PSA_KEY_STORAGE_MAGIC_HEADER_LENGTH); |
| MBEDTLS_PUT_UINT32_LE(0, storage_format->version, 0); |
| MBEDTLS_PUT_UINT32_LE(attr->lifetime, storage_format->lifetime, 0); |
| MBEDTLS_PUT_UINT16_LE((uint16_t) attr->type, storage_format->type, 0); |
| MBEDTLS_PUT_UINT16_LE((uint16_t) attr->bits, storage_format->bits, 0); |
| MBEDTLS_PUT_UINT32_LE(attr->policy.usage, storage_format->policy, 0); |
| MBEDTLS_PUT_UINT32_LE(attr->policy.alg, storage_format->policy, sizeof(uint32_t)); |
| MBEDTLS_PUT_UINT32_LE(attr->policy.alg2, storage_format->policy, 2 * sizeof(uint32_t)); |
| MBEDTLS_PUT_UINT32_LE(data_length, storage_format->data_len, 0); |
| memcpy(storage_format->key_data, data, data_length); |
| } |
| |
| static psa_status_t check_magic_header(const uint8_t *data) |
| { |
| if (memcmp(data, PSA_KEY_STORAGE_MAGIC_HEADER, |
| PSA_KEY_STORAGE_MAGIC_HEADER_LENGTH) != 0) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| return PSA_SUCCESS; |
| } |
| |
| psa_status_t psa_parse_key_data_from_storage(const uint8_t *storage_data, |
| size_t storage_data_length, |
| uint8_t **key_data, |
| size_t *key_data_length, |
| psa_key_attributes_t *attr) |
| { |
| psa_status_t status; |
| const psa_persistent_key_storage_format *storage_format = |
| (const psa_persistent_key_storage_format *) storage_data; |
| uint32_t version; |
| |
| if (storage_data_length < sizeof(*storage_format)) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| |
| status = check_magic_header(storage_data); |
| if (status != PSA_SUCCESS) { |
| return status; |
| } |
| |
| version = MBEDTLS_GET_UINT32_LE(storage_format->version, 0); |
| if (version != 0) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| |
| *key_data_length = MBEDTLS_GET_UINT32_LE(storage_format->data_len, 0); |
| if (*key_data_length > (storage_data_length - sizeof(*storage_format)) || |
| *key_data_length > PSA_CRYPTO_MAX_STORAGE_SIZE) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| |
| if (*key_data_length == 0) { |
| *key_data = NULL; |
| } else { |
| *key_data = mbedtls_calloc(1, *key_data_length); |
| if (*key_data == NULL) { |
| return PSA_ERROR_INSUFFICIENT_MEMORY; |
| } |
| memcpy(*key_data, storage_format->key_data, *key_data_length); |
| } |
| |
| attr->lifetime = MBEDTLS_GET_UINT32_LE(storage_format->lifetime, 0); |
| attr->type = MBEDTLS_GET_UINT16_LE(storage_format->type, 0); |
| attr->bits = MBEDTLS_GET_UINT16_LE(storage_format->bits, 0); |
| attr->policy.usage = MBEDTLS_GET_UINT32_LE(storage_format->policy, 0); |
| attr->policy.alg = MBEDTLS_GET_UINT32_LE(storage_format->policy, sizeof(uint32_t)); |
| attr->policy.alg2 = MBEDTLS_GET_UINT32_LE(storage_format->policy, 2 * sizeof(uint32_t)); |
| |
| return PSA_SUCCESS; |
| } |
| |
| psa_status_t psa_save_persistent_key(const psa_key_attributes_t *attr, |
| const uint8_t *data, |
| const size_t data_length) |
| { |
| size_t storage_data_length; |
| uint8_t *storage_data; |
| psa_status_t status; |
| |
| /* All keys saved to persistent storage always have a key context */ |
| if (data == NULL || data_length == 0) { |
| return PSA_ERROR_INVALID_ARGUMENT; |
| } |
| |
| if (data_length > PSA_CRYPTO_MAX_STORAGE_SIZE) { |
| return PSA_ERROR_INSUFFICIENT_STORAGE; |
| } |
| storage_data_length = data_length + sizeof(psa_persistent_key_storage_format); |
| |
| storage_data = mbedtls_calloc(1, storage_data_length); |
| if (storage_data == NULL) { |
| return PSA_ERROR_INSUFFICIENT_MEMORY; |
| } |
| |
| psa_format_key_data_for_storage(data, data_length, attr, storage_data); |
| |
| status = psa_crypto_storage_store(attr->id, |
| storage_data, storage_data_length); |
| |
| mbedtls_zeroize_and_free(storage_data, storage_data_length); |
| |
| return status; |
| } |
| |
| void psa_free_persistent_key_data(uint8_t *key_data, size_t key_data_length) |
| { |
| mbedtls_zeroize_and_free(key_data, key_data_length); |
| } |
| |
| psa_status_t psa_load_persistent_key(psa_key_attributes_t *attr, |
| uint8_t **data, |
| size_t *data_length) |
| { |
| psa_status_t status = PSA_SUCCESS; |
| uint8_t *loaded_data; |
| size_t storage_data_length = 0; |
| mbedtls_svc_key_id_t key = attr->id; |
| |
| status = psa_crypto_storage_get_data_length(key, &storage_data_length); |
| if (status != PSA_SUCCESS) { |
| return status; |
| } |
| |
| loaded_data = mbedtls_calloc(1, storage_data_length); |
| |
| if (loaded_data == NULL) { |
| return PSA_ERROR_INSUFFICIENT_MEMORY; |
| } |
| |
| status = psa_crypto_storage_load(key, loaded_data, storage_data_length); |
| if (status != PSA_SUCCESS) { |
| goto exit; |
| } |
| |
| status = psa_parse_key_data_from_storage(loaded_data, storage_data_length, |
| data, data_length, attr); |
| |
| /* All keys saved to persistent storage always have a key context */ |
| if (status == PSA_SUCCESS && |
| (*data == NULL || *data_length == 0)) { |
| status = PSA_ERROR_STORAGE_FAILURE; |
| } |
| |
| exit: |
| mbedtls_zeroize_and_free(loaded_data, storage_data_length); |
| return status; |
| } |
| |
| |
| |
| /****************************************************************/ |
| /* Transactions */ |
| /****************************************************************/ |
| |
| #if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS) |
| |
| psa_crypto_transaction_t psa_crypto_transaction; |
| |
| psa_status_t psa_crypto_save_transaction(void) |
| { |
| struct psa_storage_info_t p_info; |
| psa_status_t status; |
| status = psa_its_get_info(PSA_CRYPTO_ITS_TRANSACTION_UID, &p_info); |
| if (status == PSA_SUCCESS) { |
| /* This shouldn't happen: we're trying to start a transaction while |
| * there is still a transaction that hasn't been replayed. */ |
| return PSA_ERROR_CORRUPTION_DETECTED; |
| } else if (status != PSA_ERROR_DOES_NOT_EXIST) { |
| return status; |
| } |
| return psa_its_set(PSA_CRYPTO_ITS_TRANSACTION_UID, |
| sizeof(psa_crypto_transaction), |
| &psa_crypto_transaction, |
| 0); |
| } |
| |
| psa_status_t psa_crypto_load_transaction(void) |
| { |
| psa_status_t status; |
| size_t length; |
| status = psa_its_get(PSA_CRYPTO_ITS_TRANSACTION_UID, 0, |
| sizeof(psa_crypto_transaction), |
| &psa_crypto_transaction, &length); |
| if (status != PSA_SUCCESS) { |
| return status; |
| } |
| if (length != sizeof(psa_crypto_transaction)) { |
| return PSA_ERROR_DATA_INVALID; |
| } |
| return PSA_SUCCESS; |
| } |
| |
| psa_status_t psa_crypto_stop_transaction(void) |
| { |
| psa_status_t status = psa_its_remove(PSA_CRYPTO_ITS_TRANSACTION_UID); |
| /* Whether or not updating the storage succeeded, the transaction is |
| * finished now. It's too late to go back, so zero out the in-memory |
| * data. */ |
| memset(&psa_crypto_transaction, 0, sizeof(psa_crypto_transaction)); |
| return status; |
| } |
| |
| #endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */ |
| |
| |
| |
| /****************************************************************/ |
| /* Random generator state */ |
| /****************************************************************/ |
| |
| #if defined(MBEDTLS_PSA_INJECT_ENTROPY) |
| psa_status_t mbedtls_psa_storage_inject_entropy(const unsigned char *seed, |
| size_t seed_size) |
| { |
| psa_status_t status; |
| struct psa_storage_info_t p_info; |
| |
| status = psa_its_get_info(PSA_CRYPTO_ITS_RANDOM_SEED_UID, &p_info); |
| |
| if (PSA_ERROR_DOES_NOT_EXIST == status) { /* No seed exists */ |
| status = psa_its_set(PSA_CRYPTO_ITS_RANDOM_SEED_UID, seed_size, seed, 0); |
| } else if (PSA_SUCCESS == status) { |
| /* You should not be here. Seed needs to be injected only once */ |
| status = PSA_ERROR_NOT_PERMITTED; |
| } |
| return status; |
| } |
| #endif /* MBEDTLS_PSA_INJECT_ENTROPY */ |
| |
| |
| |
| /****************************************************************/ |
| /* The end */ |
| /****************************************************************/ |
| |
| #endif /* MBEDTLS_PSA_CRYPTO_STORAGE_C */ |
