| static private GetHashBlock ( byte input, ABCDStruct &ABCDValue, int ibStart ) : void | ||
| input | byte | |
| ABCDValue | ABCDStruct | |
| ibStart | int | |
| return | void | |
/// <summary>
/// Calculate the core hash
/// </summary>
/// <param name="array"></param>
/// <param name="ibStart"></param>
/// <param name="cbSize"></param>
protected override void HashCore(byte[] array, int ibStart, int cbSize)
{
int startIndex = ibStart;
int totalArrayLength = _dataSize + cbSize;
if (totalArrayLength >= 64)
{
Array.Copy(array, startIndex, _data, _dataSize, 64 - _dataSize);
// Process message of 64 bytes (512 bits)
MD5Core.GetHashBlock(_data, ref _abcd, 0);
startIndex += 64 - _dataSize;
totalArrayLength -= 64;
while (totalArrayLength >= 64)
{
Array.Copy(array, startIndex, _data, 0, 64);
MD5Core.GetHashBlock(array, ref _abcd, startIndex);
totalArrayLength -= 64;
startIndex += 64;
}
_dataSize = totalArrayLength;
Array.Copy(array, startIndex, _data, 0, totalArrayLength);
}
else
{
Array.Copy(array, startIndex, _data, _dataSize, cbSize);
_dataSize = totalArrayLength;
}
_totalLength += cbSize;
}
/// <summary>
/// Return an MD5 hash for the provided parameters
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
public static byte[] GetHash(byte[] input)
{
if (null == input)
{
throw new System.ArgumentNullException("input", "Unable to calculate hash over null input data");
}
//Initial values defined in RFC 1321
ABCDStruct abcd = new ABCDStruct();
abcd.A = 0x67452301;
abcd.B = 0xefcdab89;
abcd.C = 0x98badcfe;
abcd.D = 0x10325476;
//We pass in the input array by block, the final block of data must be handled specially for padding & length embedding
int startIndex = 0;
while (startIndex <= input.Length - 64)
{
MD5Core.GetHashBlock(input, ref abcd, startIndex);
startIndex += 64;
}
// The final data block.
return(MD5Core.GetHashFinalBlock(input, startIndex, input.Length - startIndex, abcd, (Int64)input.Length * 8));
}