linux-sgx-trts-modified/sdk/tseal/tSeal_aad.cpp

/*
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 * modification, are permitted provided that the following conditions
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 *     notice, this list of conditions and the following disclaimer in
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 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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#include "sgx_tseal.h"
#include "sgx_utils.h"
#include "sgx_trts.h"
#include "tSeal_internal.h"
#include <stdlib.h>
#include <string.h>


extern "C" sgx_status_t sgx_mac_aadata(const uint32_t additional_MACtext_length,
                                        const uint8_t *p_additional_MACtext,
                                        const uint32_t sealed_data_size,
                                        sgx_sealed_data_t *p_sealed_data)
{
    sgx_status_t err = SGX_ERROR_UNEXPECTED;
    sgx_attributes_t attribute_mask;
    attribute_mask.flags = SGX_FLAGS_RESERVED | SGX_FLAGS_INITTED | SGX_FLAGS_DEBUG;
    attribute_mask.xfrm = 0x0;

    err = sgx_mac_aadata_ex(SGX_KEYPOLICY_MRSIGNER, attribute_mask, TSEAL_DEFAULT_MISCMASK, additional_MACtext_length,
        p_additional_MACtext, sealed_data_size, p_sealed_data);
    return err;
}

extern "C" sgx_status_t sgx_mac_aadata_ex(const uint16_t key_policy,
                                            const sgx_attributes_t attribute_mask,
                                            const sgx_misc_select_t misc_mask,
                                            const uint32_t additional_MACtext_length,
                                            const uint8_t *p_additional_MACtext,
                                            const uint32_t sealed_data_size,
                                            sgx_sealed_data_t *p_sealed_data)
{
    sgx_status_t err = SGX_ERROR_UNEXPECTED;
    sgx_report_t report;
    sgx_key_id_t keyID;
    sgx_key_request_t tmp_key_request;
    uint8_t payload_iv[SGX_SEAL_IV_SIZE];
    memset(&payload_iv, 0, sizeof(payload_iv));

    uint32_t sealedDataSize = sgx_calc_sealed_data_size(additional_MACtext_length, 0);
    // Check for overflow
    if (sealedDataSize == UINT32_MAX)
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }

    //
    // Check parameters
    //
    // check key_request->key_policy reserved bits are not set and one of policy bits are set
    if ((key_policy & ~(SGX_KEYPOLICY_MRENCLAVE | SGX_KEYPOLICY_MRSIGNER)) ||
        ((key_policy & (SGX_KEYPOLICY_MRENCLAVE | SGX_KEYPOLICY_MRSIGNER)) == 0))
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }
    if ((attribute_mask.flags & 0x3) != 0x3)
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }
    // The AAD must be provided
    if ((additional_MACtext_length == 0) || (p_additional_MACtext == NULL))
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }
    // Ensure AAD does not cross enclave boundary
    if (!(sgx_is_within_enclave(p_additional_MACtext, additional_MACtext_length) ||
        sgx_is_outside_enclave(p_additional_MACtext, additional_MACtext_length)))
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }
    // Ensure sealed data blob is within an enclave during the sealing process
    if ((p_sealed_data == NULL) || (!sgx_is_within_enclave(p_sealed_data, sealed_data_size)))
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }
    if (sealedDataSize != sealed_data_size)
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }
    memset(&report, 0, sizeof(sgx_report_t));
    memset(p_sealed_data, 0, sealedDataSize);
    memset(&keyID, 0, sizeof(sgx_key_id_t));
    memset(&tmp_key_request, 0, sizeof(sgx_key_request_t));

    // Get the report to obtain isv_svn and cpu_svn
    err = sgx_create_report(NULL, NULL, &report);
    if (err != SGX_SUCCESS)
    {
        goto clear_return;
    }

    // Get a random number to populate the key_id of the key_request
    err = sgx_read_rand(reinterpret_cast<uint8_t *>(&keyID), sizeof(sgx_key_id_t));
    if (err != SGX_SUCCESS)
    {
        goto clear_return;
    }

    memcpy(&(tmp_key_request.cpu_svn), &(report.body.cpu_svn), sizeof(sgx_cpu_svn_t));
    memcpy(&(tmp_key_request.isv_svn), &(report.body.isv_svn), sizeof(sgx_isv_svn_t));
    tmp_key_request.key_name = SGX_KEYSELECT_SEAL;
    tmp_key_request.key_policy = key_policy;
    tmp_key_request.attribute_mask.flags = attribute_mask.flags;
    tmp_key_request.attribute_mask.xfrm = attribute_mask.xfrm;
    memcpy(&(tmp_key_request.key_id), &keyID, sizeof(sgx_key_id_t));
    tmp_key_request.misc_mask = misc_mask;

    err = sgx_seal_data_iv(additional_MACtext_length, p_additional_MACtext,
        0, NULL, payload_iv, &tmp_key_request, p_sealed_data);

    if (err == SGX_SUCCESS)
    {
        // Copy data from the temporary key request buffer to the sealed data blob
        memcpy(&(p_sealed_data->key_request), &tmp_key_request, sizeof(sgx_key_request_t));
    }

clear_return:
    // Clear temp state
    memset_s(&report, sizeof(sgx_report_t), 0, sizeof(sgx_report_t));
    memset_s(&keyID, sizeof(sgx_key_id_t), 0, sizeof(sgx_key_id_t));
    return err;
}

extern "C" sgx_status_t sgx_unmac_aadata(const sgx_sealed_data_t *p_sealed_data,
                                        uint8_t *p_additional_MACtext,
                                        uint32_t *p_additional_MACtext_length)
{
    sgx_status_t err = SGX_ERROR_UNEXPECTED;
    // Ensure the the sgx_sealed_data_t members are all inside enclave before using them.
    if ((p_sealed_data == NULL) || (!sgx_is_within_enclave(p_sealed_data, sizeof(sgx_sealed_data_t))))
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }

    // If using this API, the sealed blob must have no encrypted data. 
    // So the encryt_text_length must be 0.
    uint32_t encrypt_text_length = sgx_get_encrypt_txt_len(p_sealed_data);
    if (encrypt_text_length != 0)
    {
        return SGX_ERROR_MAC_MISMATCH; // Return error indicating the blob is corrupted
    }

    // The sealed blob must have AAD. So the add_text_length must not be 0.
    uint32_t add_text_length = sgx_get_add_mac_txt_len(p_sealed_data);
    if (add_text_length == UINT32_MAX || add_text_length == 0)
    {
        return SGX_ERROR_MAC_MISMATCH; // Return error indicating the blob is corrupted
    }
    uint32_t sealedDataSize = sgx_calc_sealed_data_size(add_text_length, encrypt_text_length);
    if (sealedDataSize == UINT32_MAX)
    {
        return SGX_ERROR_MAC_MISMATCH; // Return error indicating the blob is corrupted
    }

    //
    // Check parameters
    //
    // Ensure sealed data blob is within an enclave during the sealing process
    if (!sgx_is_within_enclave(p_sealed_data, sealedDataSize))
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }
    if (p_additional_MACtext == NULL || p_additional_MACtext_length == NULL)
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }

    // Ensure AAD does not cross enclave boundary
    if (!(sgx_is_within_enclave(p_additional_MACtext, add_text_length) || 
        sgx_is_outside_enclave(p_additional_MACtext, add_text_length)))
    {
        return SGX_ERROR_INVALID_PARAMETER;
    }

    uint32_t additional_MACtext_length = *p_additional_MACtext_length;
    if (additional_MACtext_length < add_text_length) {
        return SGX_ERROR_INVALID_PARAMETER;
    }

    err = sgx_unseal_data_helper(p_sealed_data, p_additional_MACtext, add_text_length,
        NULL, encrypt_text_length);
    if (err == SGX_SUCCESS)
    {
        *p_additional_MACtext_length = add_text_length;
    }
    return err;
}