How to pass byte array?   

Following code:

procedure TForm1.Button1Click(Sender: TObject);
var
    sha: OleVariant;
    inputBuffer: OleVariant;
    digest: OleVariant;
    i : integer;
begin
    //Create a byte array of arbitrary length, and fill it with sample data
     inputBuffer := VarArrayCreate([0, 1099], varByte);
     for i := VarArrayLowBound(inputBuffer, 1) to 
VarArrayHighBound(inputBuffer, 1) do
          inputBuffer[i] := i * 47 mod 255;

    //Create the COM object
    sha := CreateOleObject('System.Security.Cryptography.SHA1Managed');

    //use the COM object
    digest := sha.ComputeHash(inputBuffer);
end;


The ComputeHash method is declared as:
    Public Function ComputeHash (buffer As Byte() ) As Byte()
    public byte[] ComputeHash(byte[] buffer)
    public byte[] ComputeHash(byte[] buffer)
    public function ComputeHash(buffer : byte[]) : byte[]

depending on the language of your poison.

Except that when i call ComputeHash i get the exception:

    EOleSysError
    ErrorCode: 0x80070057 (E_WIN32_0057)
    Error Description: The parameter is incorrect
    Message: The parameter is incorrect


So can anyone figure out proper usage from Delphi to call this thing? Copy 
and paste the 7 lines and make it work, please?

You already have the COM object with ProgID 
"Microsoft.Security.Cryptography.SHA1Managed" registered on your computer - 
if you're running Windows.

i understand that a safearray is the kind of arrays that are used by 
variants that contains arrays. A "variant array" is a "safe array". Of 
course nobody says that the method wants a variant that contains an array. 
Perhaps it wants a safearray directly. It can't be a pointer to data bytes, 
since there's no "length". Plus, an overload of the method takes a stream.

Plus, since this technology is COM using the "COM Callable Wrapper", one 
would think it uses data types commonly used by COM (and VB).

i can call
    sha.Clear;
with no errors, i'm just unable to figure out how to pass an array of bytes 
using COM.

date: Mon, 23 Jun 2008 13:39:39 -0400   author:   Ian Boyd