SQL Server

Get an EC Key in Raw Hex Format

See more ECC Examples

Demonstrates how to get the private and public key parts of an EC (ECDSA) key in lowercase hex formmat.

Note: This example requires Chilkat v9.5.0.83 or greater.

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 @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- Load an EC key from some format..
    DECLARE @privKey int
    EXEC @hr = sp_OACreate 'Chilkat.PrivateKey', @privKey OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- This loads an ECDSA key from an unencrypted PEM file (no password required).
    EXEC sp_OAMethod @privKey, 'LoadAnyFormatFile', @success OUT, 'qa_data/ecc/openssl_ecc_privKey.pem', ''
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @privKey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @privKey
        RETURN
      END

    -- The key type should be "ecc" to indicate an EC key.

    EXEC sp_OAGetProperty @privKey, 'KeyType', @sTmp0 OUT
    PRINT 'key type = ' + @sTmp0

    -- What is the size of the private key in bits?

    EXEC sp_OAGetProperty @privKey, 'BitLength', @iTmp0 OUT
    PRINT 'size in bits = ' + @iTmp0

    -- Get the private and public EC key parts in raw hex format:
    DECLARE @sbPubKeyHex int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbPubKeyHex OUT

    DECLARE @privKeyHex nvarchar(4000)
    EXEC sp_OAMethod @privKey, 'GetRawHex', @privKeyHex OUT, @sbPubKeyHex

    -- If the private key size in bits is 256, then we should have a 32-byte key (a 64 character hex string).

    PRINT 'private key = ' + @privKeyHex

    -- The public key is composed of the "x" and "y" parts, and is composed like this:  04||HEX(x)||HEX(y)

    EXEC sp_OAMethod @sbPubKeyHex, 'GetAsString', @sTmp0 OUT
    PRINT 'public key = ' + @sTmp0

    -- Sample output:
    -- key type = ecc
    -- size in bits = 256
    -- private key = ced36f2ba3332be439f79143d69937fc52494cd38e45243c3ea05db183919f1b
    -- public key = 045b4edcd501831740895f5907feabb71587076a6314d9d5141f9f8c33a478b8ce08b8dfd2a091eb6355803d7e729876c790bc0b176f2015f3bb103813753f676a

    EXEC @hr = sp_OADestroy @privKey
    EXEC @hr = sp_OADestroy @sbPubKeyHex


END
GO