/// <summary> /// When overridden in a derived class, routes data written to the object into the hash algorithm for computing the hash. /// </summary> /// <param name="array">The input to compute the hash code for.</param> /// <param name="ibStart">The offset into the byte array from which to begin using data.</param> /// <param name="cbSize">The number of bytes in the byte array to use as data.</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; }
public static byte[] GetHash(byte[] input) { if (null == input) { throw new System.ArgumentNullException("input", "Unable to calculate hash over null input data"); } //Intitial values defined in RFC 1321 ABCDStruct abcd = new ABCDStruct { A = 0x67452301, B = 0xefcdab89, C = 0x98badcfe, D = 0x10325476 }; //We pass in the input array by block, the final block of data must be handled specialy for padding & length embeding 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)); }
/// <summary> /// When overridden in a derived class, finalizes the hash computation after the last data is processed by the cryptographic stream object. /// </summary> /// <returns>The computed hash code.</returns> protected override byte[] HashFinal() { base.HashValue = MD5Core.GetHashFinalBlock(_data, 0, _dataSize, _abcd, _totalLength * 8); return(base.HashValue); }