/// <summary>
/// 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()
{
byte[] hashBytes = new byte[16];
int hashLength = hashBytes.Length;
NativeMD5.ValidateReturnCode(NativeMethods.CryptGetHashParam(this.hashHandle, HashVal, hashBytes, ref hashLength, 0));
return(hashBytes);
}
/// <summary>
/// Initializes an implementation of the NativeMD5 class.
/// </summary>
public override void Initialize()
{
if (this.hashHandle != IntPtr.Zero)
{
NativeMethods.CryptDestroyHash(this.hashHandle);
this.hashHandle = IntPtr.Zero;
}
NativeMD5.ValidateReturnCode(NativeMethods.CryptCreateHash(this.hashProv, CalgMD5, IntPtr.Zero, 0, out this.hashHandle));
}
/// <summary>
/// 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="offset">The offset into the byte array from which to begin using data.</param>
/// <param name="dataLen">The number of bytes in the byte array to use as data.</param>
protected override void HashCore(byte[] array, int offset, int dataLen)
{
GCHandle handle = GCHandle.Alloc(array, GCHandleType.Pinned);
try
{
IntPtr buffPtr = handle.AddrOfPinnedObject();
if (offset != 0)
{
buffPtr = IntPtr.Add(buffPtr, offset);
}
NativeMD5.ValidateReturnCode(NativeMethods.CryptHashData(this.hashHandle, buffPtr, dataLen, 0));
}
finally
{
handle.Free();
}
}
/// <summary>
/// Initializes a new instance of NativeMD5.
/// </summary>
public NativeMD5()
: base()
{
NativeMD5.ValidateReturnCode(NativeMethods.CryptAcquireContextW(out this.hashProv, null, null, ProvRsaFull, CryptVerifyContext));
this.Initialize();
}
