Use GenerateWord32 impl from Crypto++ 5.4

Also see https://groups.google.com/g/cryptopp-users/c/YOl2FGXSp44

2 files changed, 7 insertions, 8 deletions

diff --git a/randpool.cpp b/randpool.cpp
index b1a4f215..e1286282 100644
--- a/randpool.cpp
+++ b/randpool.cpp
@@ -105,21 +105,21 @@ void OldRandomPool::IncorporateEntropy(const byte *input, size_t length)
 	}

 }

 

-// Endian swapped on little-endian machines. This is different

-// behavior from Crypto++ 5.4. Provide an override to correct it.

-// ConditionalByteReverse performs the correction on full words.

-// I am not sure this will affect a ranged word.

+// GenerateWord32 is overriden and provides Crypto++ 5.4 behavior.

 word32 OldRandomPool::GenerateWord32 (word32 min, word32 max)

 {

 	const word32 range = max-min;

+	const unsigned int maxBytes = BytePrecision(range);

 	const unsigned int maxBits = BitPrecision(range);

 

 	word32 value;

 

 	do

 	{

-		GenerateBlock((byte *)&value, sizeof(value));

-		value = ConditionalByteReverse(BIG_ENDIAN_ORDER, value);

+		value = 0;

+		for (int i=0; i<maxBytes; i++)

+			value = (value << 8) | GenerateByte();

+

 		value = Crop(value, maxBits);

 	} while (value > range);

 

diff --git a/randpool.h b/randpool.h
index 51140145..f5866ed8 100644
--- a/randpool.h
+++ b/randpool.h
@@ -87,8 +87,7 @@ public:
 	byte GenerateByte();

 	void GenerateBlock(byte *output, size_t size);

 

-	// Endian swapped on little-endian machines. This is different

-	// behavior from Crypto++ 5.4. Provide an override to correct it.

+	// GenerateWord32 is overriden and provides Crypto++ 5.4 behavior.

 	word32 GenerateWord32 (word32 min=0, word32 max=0xffffffffUL);

 

 protected: