1 files changed, 22 insertions, 70 deletions

diff --git a/src/lib/rng/rdrand_rng/rdrand_rng.cpp b/src/lib/rng/rdrand_rng/rdrand_rng.cpp
index ece3d9f39..fade5a199 100644
--- a/src/lib/rng/rdrand_rng/rdrand_rng.cpp
+++ b/src/lib/rng/rdrand_rng/rdrand_rng.cpp
@@ -6,106 +6,58 @@
 */
 
 #include <botan/rdrand_rng.h>
+#include <botan/processor_rng.h>
 #include <botan/loadstor.h>
-#include <botan/cpuid.h>
-
-#if !defined(BOTAN_USE_GCC_INLINE_ASM)
-  #include <immintrin.h>
-#endif
 
 namespace Botan {
 
-namespace {
-
-#if defined(BOTAN_TARGET_ARCH_IS_X86_64)
-   typedef uint64_t rdrand_output;
-#else
-   typedef uint32_t rdrand_output;
-#endif
-
-#if !defined(BOTAN_USE_GCC_INLINE_ASM)
-BOTAN_FUNC_ISA("rdrnd")
-#endif
-rdrand_output read_rdrand()
-   {
-   /*
-   * According to Intel, RDRAND is guaranteed to generate a random
-   * number within 10 retries on a working CPU
-   */
-   const size_t RDRAND_RETRIES = 10;
-
-   for(size_t i = 0; i < RDRAND_RETRIES; ++i)
-      {
-      rdrand_output r = 0;
-      int cf = 0;
-
-#if defined(BOTAN_USE_GCC_INLINE_ASM)
-      // same asm seq works for 32 and 64 bit
-      asm("rdrand %0; adcl $0,%1" :
-          "=r" (r), "=r" (cf) : "0" (r), "1" (cf) : "cc");
-#elif defined(BOTAN_TARGET_ARCH_IS_X86_64)
-      cf = _rdrand64_step(&r);
-#else
-      cf = _rdrand32_step(&r);
-#endif
-      if(1 == cf)
-         {
-         return r;
-         }
-      }
-
-   throw PRNG_Unseeded("RDRAND read failed");
-   }
-
-}
-
 void RDRAND_RNG::randomize(uint8_t out[], size_t out_len)
    {
-   while(out_len >= sizeof(rdrand_output))
-      {
-      const rdrand_output r = read_rdrand();
-      store_le(r, out);
-      out += sizeof(rdrand_output);
-      out_len -= sizeof(rdrand_output);
-      }
-
-   if(out_len > 0) // at most sizeof(rdrand_output)-1
-      {
-      const rdrand_output r = read_rdrand();
-      for(size_t i = 0; i != out_len; ++i)
-         out[i] = get_byte(i, r);
-      }
+   Processor_RNG rng;
+   rng.randomize(out, out_len);
    }
 
 RDRAND_RNG::RDRAND_RNG()
    {
-   if(!RDRAND_RNG::available())
-      throw Invalid_State("Current CPU does not support RDRAND instruction");
+   // Will throw if instruction is not available
+   Processor_RNG rng;
    }
 
 //static
 bool RDRAND_RNG::available()
    {
-   return CPUID::has_rdrand();
+   return Processor_RNG::available();
    }
 
 //static
 uint32_t RDRAND_RNG::rdrand()
    {
-   return static_cast<uint32_t>(read_rdrand());
+   Processor_RNG rng;
+
+   for(;;)
+      {
+      try
+         {
+         uint8_t out[4];
+         rng.randomize(out, 4);
+         return load_le<uint32_t>(out, 0);
+         }
+      catch(PRNG_Unseeded&) {}
+      }
    }
 
 //static
-BOTAN_FUNC_ISA("rdrnd")
 uint32_t RDRAND_RNG::rdrand_status(bool& ok)
    {
    ok = false;
+   Processor_RNG rng;
 
    try
       {
-      const uint32_t r = static_cast<uint32_t>(read_rdrand());
+      uint8_t out[4];
+      rng.randomize(out, 4);
       ok = true;
-      return r;
+      return load_le<uint32_t>(out, 0);
       }
    catch(PRNG_Unseeded&) {}