RLP length with first zeros

libdevcore/RLP.cpp

@@ -149,7 +149,7 @@ unsigned RLP::length() const
 		return n - c_rlpDataImmLenStart;
 	else if (n < c_rlpListStart)
 	{
-		if ((int)m_data.size() <= n - c_rlpDataIndLenZero)
+		if ((int)m_data.size() <= n - c_rlpDataIndLenZero || m_data[1] == 0)
 			BOOST_THROW_EXCEPTION(BadRLP());
 		for (int i = 0; i < n - c_rlpDataIndLenZero; ++i)
 			ret = (ret << 8) | m_data[i + 1];
@@ -158,7 +158,7 @@ unsigned RLP::length() const
 		return n - c_rlpListStart;
 	else
 	{
-		if ((int)m_data.size() <= n - c_rlpListIndLenZero)
+		if ((int)m_data.size() <= n - c_rlpListIndLenZero || m_data[1] == 0)
 			BOOST_THROW_EXCEPTION(BadRLP());
 		for (int i = 0; i < n - c_rlpListIndLenZero; ++i)
 			ret = (ret << 8) | m_data[i + 1];

libdevcore/RLP.h

@@ -303,7 +303,7 @@ private:
 	/// Single-byte data payload.
 	bool isSingleByte() const { return !isNull() && m_data[0] < c_rlpDataImmLenStart; }
 
-	/// @returns the bytes used to encode the length of the data. Valid for all types.
+	/// @returns the amount of bytes used to encode the length of the data. Valid for all types.
 	unsigned lengthSize() const { if (isData() && m_data[0] > c_rlpDataIndLenZero) return m_data[0] - c_rlpDataIndLenZero; if (isList() && m_data[0] > c_rlpListIndLenZero) return m_data[0] - c_rlpListIndLenZero; return 0; }
 
 	/// @returns the size in bytes of the payload, as given by the RLP as opposed to as inferred from m_data.