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* Copyright (C) 2011-2016 Intel Corporation. All rights reserved.
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* modification, are permitted provided that the following conditions
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* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
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*/
#include "sgx_tseal.h"
#include "tSeal_internal.h"
#include "sgx_utils.h"
#include <string.h>
// sgx_seal_data_iv
//
// Parameters:
// additional_MACtext_length - [IN] length of the plaintext data stream in bytes
// p_additional_MACtext - [IN] pointer to the plaintext data stream to be GCM protected
// text2encrypt_length - [IN] length of the data stream to encrypt in bytes
// p_text2encrypt - [IN] pointer to data stream to encrypt
// p_payload_iv - [IN] Pointer to Initialization Vector to be used during AES GCM encryption
// p_key_request - [IN] Pointer to the key request structure to be utilized to obtain the SEAL key
// p_sealed_data - [OUT] pointer to the sealed data structure containing protected data
//
// Return Value:
// sgx_status_t - SGX Error code
sgx_status_t sgx_seal_data_iv(const uint32_t additional_MACtext_length,
const uint8_t *p_additional_MACtext, const uint32_t text2encrypt_length,
const uint8_t *p_text2encrypt, const uint8_t *p_payload_iv,
const sgx_key_request_t* p_key_request, sgx_sealed_data_t *p_sealed_data)
{
sgx_status_t err = SGX_ERROR_UNEXPECTED;
// Parameter checking performed in sgx_seal_data
// Get the seal key
sgx_key_128bit_t seal_key;
memset(&seal_key, 0, sizeof(sgx_key_128bit_t));
err = sgx_get_key(p_key_request, &seal_key);
if (err != SGX_SUCCESS)
{
// Clear temp state
memset_s(&seal_key, sizeof(sgx_key_128bit_t), 0, sizeof(sgx_key_128bit_t));
if (err != SGX_ERROR_OUT_OF_MEMORY)
err = SGX_ERROR_UNEXPECTED;
return err;
}
err = sgx_rijndael128GCM_encrypt(&seal_key, p_text2encrypt, text2encrypt_length,
reinterpret_cast<uint8_t *>(&(p_sealed_data->aes_data.payload)), p_payload_iv,
SGX_SEAL_IV_SIZE, p_additional_MACtext, additional_MACtext_length,
&(p_sealed_data->aes_data.payload_tag));
if (err == SGX_SUCCESS)
{
// Copy additional MAC text
uint8_t* p_aad = NULL;
if (additional_MACtext_length > 0)
{
p_aad = &(p_sealed_data->aes_data.payload[text2encrypt_length]);
memcpy(p_aad, p_additional_MACtext, additional_MACtext_length);
}
// populate the plain_text_offset, payload_size in the data_blob
p_sealed_data->plain_text_offset = text2encrypt_length;
p_sealed_data->aes_data.payload_size = additional_MACtext_length + text2encrypt_length;
}
// Clear temp state
memset_s(&seal_key, sizeof(sgx_key_128bit_t), 0, sizeof(sgx_key_128bit_t));
return err;
}
// sgx_unseal_data_helper
//
// Parameters:
// p_sealed_data - [IN] pointer to the sealed data structure containing protected data
// p_additional_MACtext - [OUT] pointer to the plaintext data stream which was GCM protected
// additional_MACtext_length - [IN] length of the plaintext data stream in bytes
// p_decrypted_text - [OUT] pointer to decrypted data stream
// decrypted_text_length - [IN] length of the decrypted data stream to encrypt in bytes
//
// Return Value:
// sgx_status_t - SGX Error code
sgx_status_t sgx_unseal_data_helper(const sgx_sealed_data_t *p_sealed_data, uint8_t *p_additional_MACtext,
uint32_t additional_MACtext_length, uint8_t *p_decrypted_text, uint32_t decrypted_text_length)
{
sgx_status_t err = SGX_ERROR_UNEXPECTED;
sgx_key_128bit_t seal_key;
memset(&seal_key, 0, sizeof(sgx_key_128bit_t));
uint8_t payload_iv[SGX_SEAL_IV_SIZE];
memset(&payload_iv, 0, SGX_SEAL_IV_SIZE);
if (decrypted_text_length > 0)
memset(p_decrypted_text, 0, decrypted_text_length);
if (additional_MACtext_length > 0)
memset(p_additional_MACtext, 0, additional_MACtext_length);
// Get the seal key
err = sgx_get_key(&p_sealed_data->key_request, &seal_key);
if (err != SGX_SUCCESS)
{
// Clear temp state
memset_s(&seal_key, sizeof(sgx_key_128bit_t), 0, sizeof(sgx_key_128bit_t));
// Provide only error codes that the calling code could act on
if ((err == SGX_ERROR_INVALID_CPUSVN) || (err == SGX_ERROR_INVALID_ISVSVN) || (err == SGX_ERROR_OUT_OF_MEMORY))
return err;
// Return error indicating the blob is corrupted
return SGX_ERROR_MAC_MISMATCH;
}
err = sgx_rijndael128GCM_decrypt(&seal_key, const_cast<uint8_t *>(p_sealed_data->aes_data.payload),
decrypted_text_length, p_decrypted_text, &payload_iv[0], SGX_SEAL_IV_SIZE,
const_cast<uint8_t *>(&(p_sealed_data->aes_data.payload[decrypted_text_length])), additional_MACtext_length,
const_cast<sgx_aes_gcm_128bit_tag_t *>(&p_sealed_data->aes_data.payload_tag));
if (err != SGX_SUCCESS)
{
// Clear temp state
memset_s(&seal_key, sizeof(sgx_key_128bit_t), 0, sizeof(sgx_key_128bit_t));
return err;
}
if (additional_MACtext_length > 0)
{
memcpy(p_additional_MACtext, &(p_sealed_data->aes_data.payload[decrypted_text_length]), additional_MACtext_length);
}
// Clear temp state
memset_s(&seal_key, sizeof(sgx_key_128bit_t), 0, sizeof(sgx_key_128bit_t));
return SGX_SUCCESS;
}