Fix Padlock RNG code

1 files changed, 4 insertions, 10 deletions

diff --git a/padlkrng.cpp b/padlkrng.cpp
index 38380fee..2c776c53 100644
--- a/padlkrng.cpp
+++ b/padlkrng.cpp
@@ -49,14 +49,7 @@ void PadlockRNG::GenerateBlock(byte *output, size_t size)
 

 			// xstore-rng

 			".byte 0x0f, 0xa7, 0xc0  ;\n"

-

-#if (CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)

-			"andq %%rax, 0x1f        ;\n"

 			"movl %%eax, %0          ;\n"

-#else

-			"andl  %%eax, 0x1f       ;\n"

-			"movl  %%eax, %0         ;\n"

-#endif

 

 			: "=g" (m_msr) : "g" (m_buffer.data()), "g" (m_divisor)

 #if (CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X64)

@@ -66,7 +59,8 @@ void PadlockRNG::GenerateBlock(byte *output, size_t size)
 #endif

 		);

 

-		const size_t rem = STDMIN<size_t>(m_msr, STDMIN<size_t>(size, 16U /*buffer size*/));

+		const size_t ret = m_msr & 0x1f;

+		const size_t rem = STDMIN<size_t>(ret, STDMIN<size_t>(size, 16U /*buffer size*/));

 		std::memcpy(output, m_buffer, rem);

 		size -= rem; output += rem;

 	}

@@ -81,11 +75,11 @@ void PadlockRNG::GenerateBlock(byte *output, size_t size)
 			_emit 0x0f

 			_emit 0xa7

 			_emit 0xc0

-			and eax, 0x1f

 			mov result, eax

 		}

 

-		const size_t rem = STDMIN<size_t>(m_msr, STDMIN<size_t>(size, 16U /*buffer size*/));

+		const size_t ret = (m_msr = result) & 0x1f;

+		const size_t rem = STDMIN<size_t>(ret, STDMIN<size_t>(size, 16U /*buffer size*/));

 		std::memcpy(output, buffer, rem);

 		size -= rem; output += rem;

 	}