secure_fw/services/crypto/crypto_key.c

/*
 * Copyright (c) 2018-2019, Arm Limited. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 *
 */

#include <stddef.h>
#include <stdint.h>

/* FixMe: Use PSA_ERROR_CONNECTION_REFUSED when performing parameter
 *        integrity checks but this will have to be revised
 *        when the full set of error codes mandated by PSA FF
 *        is available.
 */
#include "tfm_mbedcrypto_include.h"

#include "tfm_crypto_api.h"
#include "tfm_crypto_defs.h"
#include <stdbool.h>

#ifndef TFM_CRYPTO_MAX_KEY_HANDLES
#define TFM_CRYPTO_MAX_KEY_HANDLES (16)
#endif
struct tfm_crypto_handle_owner_s {
    int32_t owner;           /*!< Owner of the allocated handle */
    psa_key_handle_t handle; /*!< Allocated handle */
    uint8_t in_use;          /*!< Flag to indicate if this in use */
};

static struct tfm_crypto_handle_owner_s
                                 handle_owner[TFM_CRYPTO_MAX_KEY_HANDLES] = {0};
/*!
 * \defgroup public Public functions
 *
 */

/*!@{*/
psa_status_t tfm_crypto_check_handle_owner(psa_key_handle_t handle,
                                           uint32_t *index)
{
    int32_t partition_id = 0;
    uint32_t i = 0;
    psa_status_t status;

    status = tfm_crypto_get_caller_id(&partition_id);
    if (status != PSA_SUCCESS) {
        return status;
    }

    for (i = 0; i < TFM_CRYPTO_MAX_KEY_HANDLES; i++) {
        if (handle_owner[i].in_use && handle_owner[i].handle == handle) {
            if (handle_owner[i].owner == partition_id) {
                if (index != NULL) {
                    *index = i;
                }
                return PSA_SUCCESS;
            } else {
                return PSA_ERROR_NOT_PERMITTED;
            }
        }
    }

    return PSA_ERROR_INVALID_HANDLE;
}

psa_status_t tfm_crypto_allocate_key(psa_invec in_vec[],
                                     size_t in_len,
                                     psa_outvec out_vec[],
                                     size_t out_len)
{
    if ((in_len != 1) || (out_len != 1)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if ((in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) ||
        (out_vec[0].len != sizeof(psa_key_handle_t))) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    psa_key_handle_t *key_handle = out_vec[0].base;
    uint32_t i = 0;
    int32_t partition_id = 0;
    bool empty_found = false;
    psa_status_t status;

    for (i = 0; i < TFM_CRYPTO_MAX_KEY_HANDLES; i++) {
        if (handle_owner[i].in_use == TFM_CRYPTO_NOT_IN_USE) {
            empty_found = true;
            break;
        }
    }

    if (!empty_found) {
        return PSA_ERROR_INSUFFICIENT_MEMORY;
    }

    status = tfm_crypto_get_caller_id(&partition_id);
    if (status != PSA_SUCCESS) {
        return status;
    }

    status = psa_allocate_key(key_handle);

    if (status == PSA_SUCCESS) {
        handle_owner[i].owner = partition_id;
        handle_owner[i].handle = *key_handle;
        handle_owner[i].in_use = TFM_CRYPTO_IN_USE;
    }

    return status;
}

psa_status_t tfm_crypto_import_key(psa_invec in_vec[],
                                   size_t in_len,
                                   psa_outvec out_vec[],
                                   size_t out_len)
{
    (void)out_vec;

    if ((in_len != 2) || (out_len != 0)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if (in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t key = iov->key_handle;
    psa_key_type_t type = iov->type;
    const uint8_t *data = in_vec[1].base;
    size_t data_length = in_vec[1].len;
    psa_status_t status = tfm_crypto_check_handle_owner(key, NULL);

    if (status != PSA_SUCCESS) {
        return status;
    }

    return psa_import_key(key, type, data, data_length);
}

psa_status_t tfm_crypto_destroy_key(psa_invec in_vec[],
                                    size_t in_len,
                                    psa_outvec out_vec[],
                                    size_t out_len)
{
    (void)out_vec;

    if ((in_len != 1) || (out_len != 0)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if (in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t key = iov->key_handle;
    uint32_t index;
    psa_status_t status = tfm_crypto_check_handle_owner(key, &index);

    if (status != PSA_SUCCESS) {
        return status;
    }

    status = psa_destroy_key(key);

    if (status == PSA_SUCCESS) {
        handle_owner[index].owner = 0;
        handle_owner[index].handle = 0;
        handle_owner[index].in_use = TFM_CRYPTO_NOT_IN_USE;
    }

    return status;
}

psa_status_t tfm_crypto_get_key_information(psa_invec in_vec[],
                                            size_t in_len,
                                            psa_outvec out_vec[],
                                            size_t out_len)
{
    if ((in_len != 1) || (out_len != 2)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if ((in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) ||
        (out_vec[0].len != sizeof(psa_key_type_t)) ||
        (out_vec[1].len != sizeof(size_t))) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t key = iov->key_handle;
    psa_key_type_t *type = out_vec[0].base;
    size_t *bits = out_vec[1].base;

    return psa_get_key_information(key, type, bits);
}

psa_status_t tfm_crypto_export_key(psa_invec in_vec[],
                                   size_t in_len,
                                   psa_outvec out_vec[],
                                   size_t out_len)
{
    if ((in_len != 1) || (out_len != 1)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if (in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t key = iov->key_handle;
    uint8_t *data = out_vec[0].base;
    size_t data_size = out_vec[0].len;

    return psa_export_key(key, data, data_size, &(out_vec[0].len));
}

psa_status_t tfm_crypto_export_public_key(psa_invec in_vec[],
                                          size_t in_len,
                                          psa_outvec out_vec[],
                                          size_t out_len)
{
    if ((in_len != 1) || (out_len != 1)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if (in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t key = iov->key_handle;
    uint8_t *data = out_vec[0].base;
    size_t data_size = out_vec[0].len;

    return psa_export_public_key(key, data, data_size, &(out_vec[0].len));
}

psa_status_t tfm_crypto_copy_key(psa_invec in_vec[],
                                 size_t in_len,
                                 psa_outvec out_vec[],
                                 size_t out_len)
{
    (void)out_vec;

    if ((in_len != 3) || (out_len != 0)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if ((in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) ||
        (in_vec[1].len != sizeof(psa_key_handle_t)) ||
        (in_vec[2].len != sizeof(psa_key_policy_t))) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t source_handle = iov->key_handle;
    psa_key_handle_t target_handle = *((psa_key_handle_t *)in_vec[1].base);
    const psa_key_policy_t *policy = in_vec[2].base;

    return psa_copy_key(source_handle, target_handle, policy);
}

psa_status_t tfm_crypto_set_key_policy(psa_invec in_vec[],
                                       size_t in_len,
                                       psa_outvec out_vec[],
                                       size_t out_len)
{
    (void)out_vec;

    if ((in_len != 2) || (out_len != 0)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if ((in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) ||
        (in_vec[1].len != sizeof(psa_key_policy_t))) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t key = iov->key_handle;
    const psa_key_policy_t *policy = in_vec[1].base;
    psa_status_t status = tfm_crypto_check_handle_owner(key, NULL);

    if (status == PSA_SUCCESS) {
        return psa_set_key_policy(key, policy);
    } else {
        return status;
    }
}

psa_status_t tfm_crypto_get_key_policy(psa_invec in_vec[],
                                       size_t in_len,
                                       psa_outvec out_vec[],
                                       size_t out_len)
{
    if ((in_len != 1) || (out_len != 1)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if ((in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) ||
        (out_vec[0].len != sizeof(psa_key_policy_t))) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t key = iov->key_handle;
    psa_key_policy_t *policy = out_vec[0].base;

    return psa_get_key_policy(key, policy);
}

psa_status_t tfm_crypto_get_key_lifetime(psa_invec in_vec[],
                                         size_t in_len,
                                         psa_outvec out_vec[],
                                         size_t out_len)
{
    if ((in_len != 1) || (out_len != 1)) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }

    if ((in_vec[0].len != sizeof(struct tfm_crypto_pack_iovec)) ||
        (out_vec[0].len != sizeof(psa_key_lifetime_t))) {
        return PSA_ERROR_CONNECTION_REFUSED;
    }
    const struct tfm_crypto_pack_iovec *iov = in_vec[0].base;

    psa_key_handle_t key = iov->key_handle;
    psa_key_lifetime_t *lifetime = out_vec[0].base;

    return psa_get_key_lifetime(key, lifetime);
}
/*!@}*/