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  • Committer: Package Import Robot
  • Author(s): Laszlo Boszormenyi (GCS)
  • Date: 2018-03-01 22:23:25 UTC
  • mfrom: (1.2.2)
  • Revision ID: package-import@ubuntu.com-20180301222325-7p7vc45gu3hta34d
Tags: 2.4.0-2
* Don't remove .doctrees from the manual if it doesn't exist.
* Don't specify parallel to debhelper.

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src/lib/entropy/rdseed/rdseed.cpp
 
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/*
 
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* Entropy Source Using Intel's rdseed instruction
 
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* (C) 2015 Jack Lloyd, Daniel Neus
 
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*
 
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* Botan is released under the Simplified BSD License (see license.txt)
 
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*/
 
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#include <botan/internal/rdseed.h>
 
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#include <botan/cpuid.h>
 
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#if !defined(BOTAN_USE_GCC_INLINE_ASM)
 
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  #include <immintrin.h>
 
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#endif
 
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namespace Botan {
 
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BOTAN_FUNC_ISA("rdseed")
 
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size_t Intel_Rdseed::poll(RandomNumberGenerator& rng) {
 
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   if(CPUID::has_rdseed())
 
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      {
 
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      for(size_t p = 0; p != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++p)
 
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         {
 
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         for(size_t i = 0; i != BOTAN_ENTROPY_RDSEED_RETRIES; ++i)
 
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            {
 
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            uint32_t r = 0;
 
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#if defined(BOTAN_USE_GCC_INLINE_ASM)
 
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            int cf = 0;
 
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            // Encoding of rdseed %eax
 
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            asm(".byte 0x0F, 0xC7, 0xF8; adcl $0,%1" :
 
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                "=a" (r), "=r" (cf) : "0" (r), "1" (cf) : "cc");
 
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#else
 
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            int cf = _rdseed32_step(&r);
 
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#endif
 
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            if(1 == cf)
 
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               {
 
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               rng.add_entropy_T(r);
 
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               break;
 
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               }
 
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            }
 
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         }
 
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      }
 
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   return 0;
 
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   }
 
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}