SQL Server

Load an EC Public Key from Point Coordinates

Demonstrates the Chilkat PublicKey.LoadEcdsa method, which loads an elliptic-curve public key from its affine point coordinates. The first argument names the curve, the second is the hexadecimal x-coordinate (Qx), and the third is the y-coordinate (Qy).

Background: An EC public key is a point (x, y) on a named curve, so this loader constructs the key from those raw values directly — the option to use when a system hands you the coordinates rather than an encoded key. The curve name (for example secp256r1) is essential, since the same coordinates mean nothing without knowing which curve they lie on.

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SQL Server

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    --  Demonstrates the PublicKey.LoadEcdsa method, which loads an elliptic-curve public key from its
    --  affine point coordinates.  The 1st argument names the curve, the 2nd is the hex x-coordinate
    --  (Qx), and the 3rd is the hex y-coordinate (Qy).

    DECLARE @pubKey int
    EXEC @hr = sp_OACreate 'Chilkat.PublicKey', @pubKey OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @curveName nvarchar(4000)
    SELECT @curveName = 'secp256r1'
    DECLARE @qx nvarchar(4000)
    SELECT @qx = '1ccbe91c075fc7f4f033bfa248db8fccd3565de94bbfb12f3c59ff46c271bf83'
    DECLARE @qy nvarchar(4000)
    SELECT @qy = 'ce4014c68811f9a21a1fdb2c0e6113e06db7ca93b7404e78dc7ccd5ca89a4ca9'

    EXEC sp_OAMethod @pubKey, 'LoadEcdsa', @success OUT, @curveName, @qx, @qy
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pubKey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pubKey
        RETURN
      END


    PRINT 'Loaded an EC public key on ' + @curveName

    EXEC @hr = sp_OADestroy @pubKey


END
GO