/// <summary>
/// Verify given stream data against given checksum.
/// </summary>
/// <param name="stream">Stream data to check.</param>
/// <param name="sum">Checksum.</param>
/// <returns>true if data matches checksum, false otherwise.</returns>
public bool Verify(Stream stream, byte[] sum)
{
if (sum == null)
{
throw new ArgumentNullException("sum");
}
// Crc64 sum is 8 bytes
if (sum.Length != 8)
{
return(false);
}
byte[] hexSum = Crc64ECMA.GetStreamCRC64(stream);
for (int i = 0; i < hexSum.Length; i++)
{
if (hexSum[i] != sum[i])
{
return(false);
}
}
return(true);
}
/// <summary>
/// Calculate checksum from byte table data.
/// </summary>
/// <param name="data">Data as byte table.</param>
/// <returns>Checksum.</returns>
public byte[] Calculate(byte[] data)
{
MemoryStream ms = new MemoryStream(data);
byte[] hexSum = Crc64ECMA.GetStreamCRC64(ms);
ms.Close();
return(hexSum);
}
/// <summary>
/// Verify given byte data against given checksum.
/// </summary>
/// <param name="data">Data to check as byte table.</param>
/// <param name="sum">Checksum.</param>
/// <returns>true if data matches checksum, false otherwise.</returns>
public bool Verify(byte[] data, byte[] sum)
{
if (data == null)
{
throw new ArgumentNullException("data");
}
if (sum == null)
{
throw new ArgumentNullException("sum");
}
// Crc64 sum is 4 bytes
if (sum.Length != 4)
{
return(false);
}
MemoryStream msData = new MemoryStream(data);
MemoryStream msSum = new MemoryStream(sum);
byte[] hexSum = Crc64ECMA.GetStreamCRC64(msData);
int ind = 0;
bool valid = true;
while (ind < hexSum.Length && valid)
{
if (hexSum[ind] != sum[ind])
{
valid = false;
}
else
{
++ind;
}
}
msData.Close();
msSum.Close();
return(valid);
}
/// <summary>
/// Calculate checksum from stream data.
/// </summary>
/// <param name="stream">Data as stream.</param>
/// <returns>Checksum.</returns>
public byte[] Calculate(Stream stream)
{
byte[] hexSum = Crc64ECMA.GetStreamCRC64(stream);
return(hexSum);
}