bool bnConvertToString ( const IppsBigNumState *pBN, char* sBN ){
// size of Big Number
int size;
Ipp32u res = ippsGetSize_BN(pBN, &size);
if ( res != ippStsNoErr )
std::cerr << res << std::endl;
// extract Big Number value and convert it to the string presentation
Ipp8u* bnValue = new Ipp8u [size*4+4];
res = ippsGetOctString_BN(bnValue, size*4, pBN);
if ( res != ippStsNoErr ){
std::cerr << res << std::endl;
return false;
}
// save representation
for(int i=0; i<size*4; i++){
static char xlat[16] = {
'0', '1', '2', '3',
'4', '5', '6', '7',
'8', '9', 'A', 'B',
'C', 'D', 'E', 'F'
};
sBN[2*i] = xlat[(bnValue[i]&0xF0) >> 4];
sBN[2*i+1] = xlat[bnValue[i]&0x0F];
}
sBN[2*size*4] = '\0';
delete[] bnValue;
return true;
}
void PrintBigNum(BigNum const* big_num, char const* var_name) {
IppStatus sts = ippStsNoErr;
unsigned char* buf = NULL;
int ipp_word_buf_size;
if (!var_name) {
var_name = "<no name>";
}
PRINT("%s (BigNum):\n", var_name);
if (!big_num) {
MAKE_INDENT();
PRINT("<null>\n");
return;
}
if (!big_num->ipp_bn) {
MAKE_INDENT();
PRINT("<invalid>\n");
return;
}
sts = ippsGetSize_BN(big_num->ipp_bn, &ipp_word_buf_size);
if (ippStsNoErr != sts) {
MAKE_INDENT();
PRINT("<invalid>\n");
return;
}
do {
buf = SAFE_ALLOC(ipp_word_buf_size * sizeof(Ipp32u));
if (!buf) {
MAKE_INDENT();
PRINT("<invalid>\n");
break;
}
sts = ippsGetOctString_BN((Ipp8u*)buf, ipp_word_buf_size * sizeof(Ipp32u),
big_num->ipp_bn);
if (ippStsNoErr != sts) {
MAKE_INDENT();
PRINT("<invalid>\n");
break;
}
if (0 != PrintBuf((const void*)buf, ipp_word_buf_size * sizeof(Ipp32u))) {
MAKE_INDENT();
PRINT("<invalid>\n");
break;
}
} while (0);
SAFE_FREE(buf);
}
std::ostream& operator<<(std::ostream& os, const IppsBigNumState* pBN){
// size of Big Number
int size;
Ipp32u res = ippsGetSize_BN(pBN, &size);
if ( res != ippStsNoErr )
std::cerr << res << std::endl;
// extract Big Number value and convert it to the string presentation
Ipp8u* bnValue = new Ipp8u [size*4+4];
res = ippsGetOctString_BN(bnValue, size*4, pBN);
if ( res != ippStsNoErr )
std::cerr << res << std::endl;
// type value
for(int i=0; i<size*4; i++)
os<< std::setfill('0') << std::setw(2) << std::hex <<(int)bnValue[i];
delete[] bnValue;
return os;
}
/** Create an ECC public key based on a given ECC private key.
*
* Parameters:
* Return: sgx_status_t - SGX_SUCCESS or failure as defined in sgx_error.h
* Input: p_att_priv_key - Input private key
* Output: p_att_pub_key - Output public key - LITTLE ENDIAN
*
*/
sgx_status_t sgx_ecc256_calculate_pub_from_priv(const sgx_ec256_private_t *p_att_priv_key, sgx_ec256_public_t *p_att_pub_key)
{
if ((p_att_priv_key == NULL) || (p_att_pub_key == NULL)) {
return SGX_ERROR_INVALID_PARAMETER;
}
IppsECCPState* p_ecc_state = NULL;
sgx_status_t ret = SGX_ERROR_UNEXPECTED;
int ctx_size = 0;
int point_size = 0;
IppsECCPPointState* public_key = NULL;
IppsBigNumState* bn_o = NULL;
IppsBigNumState* bn_x = NULL;
IppsBigNumState* bn_y = NULL;
sgx_ec256_private_t att_priv_key_be;
uint8_t* p_temp;
int size = 0;
IppsBigNumSGN sgn;
do {
//get the size of the IppsECCPState context
//
if (ippsECCPGetSize(ECC_FIELD_SIZE, &ctx_size) != ippStsNoErr) {
break;
}
//allocate ecc ctx
//
p_ecc_state = (IppsECCPState*)(malloc(ctx_size));
if (NULL == p_ecc_state) {
ret = SGX_ERROR_OUT_OF_MEMORY;
break;
}
//init ecc ctx
//
if (ippsECCPInit(ECC_FIELD_SIZE, p_ecc_state) != ippStsNoErr) {
break;
}
//set up elliptic curve domain parameters over GF(p)
//
if (ippsECCPSetStd(IppECCPStd256r1, p_ecc_state) != ippStsNoErr) {
break;
}
//get point (public key) size
//
if (ippsECCPPointGetSize(ECC_FIELD_SIZE, &point_size) != ippStsNoErr) {
break;
}
//allocate point of point_size size
//
public_key = (IppsECCPPointState*)(malloc(point_size));
if (NULL == public_key) {
ret = SGX_ERROR_OUT_OF_MEMORY;
break;
}
//init point
//
if (ippsECCPPointInit(ECC_FIELD_SIZE, public_key) != ippStsNoErr) {
break;
}
//allocate bn_o, will be used for private key
//
if (sgx_ipp_newBN(NULL, sizeof(sgx_ec256_private_t), &bn_o) != ippStsNoErr) {
break;
}
//convert private key into big endian
//
p_temp = (uint8_t*)p_att_priv_key;
for (uint32_t i = 0; i<sizeof(att_priv_key_be); i++) {
att_priv_key_be.r[i] = *(p_temp + sizeof(att_priv_key_be) - 1 - i);
}
//assign private key into bn_o
//
if (ippsSetOctString_BN(reinterpret_cast<Ipp8u *>(&att_priv_key_be), sizeof(sgx_ec256_private_t), bn_o) != ippStsNoErr) {
break;
}
//compute public key from the given private key (bn_o) of the elliptic cryptosystem (p_ecc_state) over GF(p).
//
if (ippsECCPPublicKey(bn_o, public_key, p_ecc_state) != ippStsNoErr) {
break;
}
//allocate BNs
//
if (sgx_ipp_newBN(NULL, sizeof(sgx_ec256_private_t), &bn_x) != ippStsNoErr) {
break;
}
if (sgx_ipp_newBN(NULL, sizeof(sgx_ec256_private_t), &bn_y) != ippStsNoErr) {
break;
}
//assign public key into BNs
//
if (ippsECCPGetPoint(bn_x, bn_y, public_key, p_ecc_state) != ippStsNoErr) {
break;
}
//output key in little endian order
//
//gx value
if (ippsGetSize_BN(bn_x, &size) != ippStsNoErr) {
break;
}
if (ippsGet_BN(&sgn, &size, reinterpret_cast<Ipp32u *>(p_att_pub_key->gx), bn_x) != ippStsNoErr) {
break;
}
//gy value
//
if (ippsGetSize_BN(bn_y, &size) != ippStsNoErr) {
break;
}
if (ippsGet_BN(&sgn, &size, reinterpret_cast<Ipp32u *>(p_att_pub_key->gy), bn_y) != ippStsNoErr) {
break;
}
ret = SGX_SUCCESS;
} while (0);
//in case of failure clear public key
//
if (ret != SGX_SUCCESS) {
(void)memset_s(p_att_pub_key, sizeof(sgx_ec256_public_t), 0, sizeof(sgx_ec256_public_t));
}
CLEAR_FREE_MEM(p_ecc_state, ctx_size);
CLEAR_FREE_MEM(public_key, point_size);
sgx_ipp_secure_free_BN(bn_o, sizeof(sgx_ec256_private_t));
sgx_ipp_secure_free_BN(bn_x, sizeof(sgx_ec256_private_t));
sgx_ipp_secure_free_BN(bn_y, sizeof(sgx_ec256_private_t));
return ret;
}
