/*************************************************************************
* Copyright (C) 2015 Intel Corporation
*
* Licensed under the Apache License,  Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* 	http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law  or agreed  to  in  writing,  software
* distributed under  the License  is  distributed  on  an  "AS IS"  BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the  specific  language  governing  permissions  and
* limitations under the License.
*************************************************************************/

/* 
// 
//  Purpose:
//     Cryptography Primitive.
//     PRNG Functions
// 
//  Contents:
//     HW random generator
// 
// 
*/

#include "owndefs.h"

#include "owncp.h"
#include "pcpbn.h"
#include "pcptool.h"

#if !defined (_PCP_PRN_GEN_HW_H)
#define _PCP_PRN_GEN_HW_H

#if ((_IPP>=_IPP_G9) || (_IPP32E>=_IPP32E_E9))
__INLINE int cpRand_hw_sample(BNU_CHUNK_T* pSample)
{
#define LOCAL_COUNTER (8)
   int n;
   int success = 0;
   for(n=0; n<LOCAL_COUNTER && !success; n++)
      #if (_IPP_ARCH == _IPP_ARCH_IA32)
      success = _rdrand32_step(pSample);
      #elif (_IPP_ARCH == _IPP_ARCH_EM64T)
      success = _rdrand64_step(pSample);
      #else
      #error Unknown CPU arch
      #endif
   return success;
#undef LOCAL_COUNTER
}

#if (_IPP32E>=_IPP32E_E9)
__INLINE int cpRand_hw_sample32(Ipp32u* pSample)
{
#define LOCAL_COUNTER (8)
   int n;
   int success = 0;
   for(n=0; n<LOCAL_COUNTER && !success; n++)
      success = _rdrand32_step(pSample);
   return success;
#undef LOCAL_COUNTER
}
#endif

/*F*
// Name: cpRandHW_buffer
//
// Purpose: Generates a pseudorandom bit sequence
//          based on RDRAND instruction of the specified nBits length.
//
// Returns:                   Reason:
//    1                        no errors
//    0                        random bit sequence can't be generated
//
// Parameters:
//    pBuffer  pointer to the buffer
//    bufLen    buffer length
*F*/

__INLINE int cpRandHW_buffer(Ipp32u* pBuffer, int bufLen)
{
   int nSamples = bufLen/((Ipp32s)(sizeof(BNU_CHUNK_T)/sizeof(Ipp32u)));

   int n;
   /* collect nSamples randoms */
   for(n=0; n<nSamples; n++, pBuffer+=(sizeof(BNU_CHUNK_T)/sizeof(Ipp32u))) {
      if( !cpRand_hw_sample((BNU_CHUNK_T*)pBuffer))
         return 0;
   }

   #if (_IPP32E>=_IPP32E_E9)
   if( bufLen%((Ipp32s)(sizeof(BNU_CHUNK_T)/sizeof(Ipp32u))) ) {
      if( !cpRand_hw_sample32(pBuffer)) {
         return 0;
      }
   }
   #endif
   return 1;
}
#endif

#endif /* #if !defined (_PCP_PRN_GEN_HW_H) */
