2 files changed, 42 insertions, 24 deletions
diff --git a/src/Core/RandomNumberGenerator.cpp b/src/Core/RandomNumberGenerator.cpp
index ab3aad6b..ae0f8248 100644
--- a/src/Core/RandomNumberGenerator.cpp
+++ b/src/Core/RandomNumberGenerator.cpp
@@ -65,45 +65,63 @@ namespace VeraCrypt
 		}
 	}
 
-	void RandomNumberGenerator::GetData (const BufferPtr &buffer, bool fast)
+	void RandomNumberGenerator::GetData (const BufferPtr &buffer, bool fast, bool allowAnyLength)
 	{
 		if (!Running)
 			throw NotInitialized (SRC_POS);
 
-		if (buffer.Size() > PoolSize)
+		if (!allowAnyLength && (buffer.Size() > PoolSize))
 			throw ParameterIncorrect (SRC_POS);
 
 		ScopeLock lock (AccessMutex);
+		size_t bufferLen = buffer.Size(), loopLen;
+		byte* pbBuffer = buffer.Get();
 
 		// Poll system for data
 		AddSystemDataToPool (fast);
 		HashMixPool();
 
-		// Transfer bytes from pool to output buffer
-		for (size_t i = 0; i < buffer.Size(); ++i)
+		while (bufferLen > 0)
 		{
-			buffer[i] += Pool[ReadOffset++];
+			if (bufferLen > PoolSize)
+			{
+				loopLen = PoolSize;
+				bufferLen -= PoolSize;
+			}
+			else
+			{
+				loopLen = bufferLen;
+				bufferLen = 0;
+			}
 
-			if (ReadOffset >= PoolSize)
-				ReadOffset = 0;
-		}
+			// Transfer bytes from pool to output buffer
+			for (size_t i = 0; i < loopLen; ++i)
+			{
+				pbBuffer[i] += Pool[ReadOffset++];
 
-		// Invert and mix the pool
-		for (size_t i = 0; i < Pool.Size(); ++i)
-		{
-			Pool[i] = ~Pool[i];
-		}
+				if (ReadOffset >= PoolSize)
+					ReadOffset = 0;
+			}
 
-		AddSystemDataToPool (true);
-		HashMixPool();
+			// Invert and mix the pool
+			for (size_t i = 0; i < Pool.Size(); ++i)
+			{
+				Pool[i] = ~Pool[i];
+			}
 
-		// XOR the current pool content into the output buffer to prevent pool state leaks
-		for (size_t i = 0; i < buffer.Size(); ++i)
-		{
-			buffer[i] ^= Pool[ReadOffset++];
+			AddSystemDataToPool (true);
+			HashMixPool();
+
+			// XOR the current pool content into the output buffer to prevent pool state leaks
+			for (size_t i = 0; i < loopLen; ++i)
+			{
+				pbBuffer[i] ^= Pool[ReadOffset++];
 
-			if (ReadOffset >= PoolSize)
-				ReadOffset = 0;
+				if (ReadOffset >= PoolSize)
+					ReadOffset = 0;
+			}
+			
+			pbBuffer += loopLen;
 		}
 	}
 
diff --git a/src/Core/RandomNumberGenerator.h b/src/Core/RandomNumberGenerator.h
index 2c7587c9..2f61cd9a 100644
--- a/src/Core/RandomNumberGenerator.h
+++ b/src/Core/RandomNumberGenerator.h
@@ -19,8 +19,8 @@ namespace VeraCrypt
 	{
 	public:
 		static void AddToPool (const ConstBufferPtr &buffer);
-		static void GetData (const BufferPtr &buffer) { GetData (buffer, false); }
-		static void GetDataFast (const BufferPtr &buffer) { GetData (buffer, true); }
+		static void GetData (const BufferPtr &buffer, bool allowAnyLength = false) { GetData (buffer, false, allowAnyLength); }
+		static void GetDataFast (const BufferPtr &buffer, bool allowAnyLength = false) { GetData (buffer, true, allowAnyLength); }
 		static shared_ptr <Hash> GetHash ();
 		static bool IsEnrichedByUser () { return EnrichedByUser; }
 		static bool IsRunning () { return Running; }
@@ -34,7 +34,7 @@ namespace VeraCrypt
 
 	protected:
 		static void AddSystemDataToPool (bool fast);
-		static void GetData (const BufferPtr &buffer, bool fast);
+		static void GetData (const BufferPtr &buffer, bool fast, bool allowAnyLength);
 		static void HashMixPool ();
 		static void Test ();
 		RandomNumberGenerator ();