(SQL Server) Generate ECDSA Key and Get Details as XML

Demonstrates how to generate an ECDSA key and gets the parts as XML.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

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

    -- Generate a random ECC private key on the secp256k1 curve.
    -- Chilkat also supports other curves, such as secp384r1, secp521r1, and secp256r1.

    -- Create a Fortuna PRNG and seed it with system entropy.
    -- This will be our source of random data for generating the ECC private key.
    DECLARE @fortuna int
    EXEC @hr = sp_OACreate 'Chilkat.Prng', @fortuna OUT

    DECLARE @entropy nvarchar(4000)
    EXEC sp_OAMethod @fortuna, 'GetEntropy', @entropy OUT, 32, 'base64'
    DECLARE @success int
    EXEC sp_OAMethod @fortuna, 'AddEntropy', @success OUT, @entropy, 'base64'

    DECLARE @privKey int
    EXEC @hr = sp_OACreate 'Chilkat.PrivateKey', @privKey OUT

    EXEC sp_OAMethod @ecc, 'GenKey', @success OUT, 'secp256k1', @fortuna, @privKey
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ecc, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @ecc
        EXEC @hr = sp_OADestroy @fortuna
        EXEC @hr = sp_OADestroy @privKey
        RETURN
      END

    -- An EC private key has this ASN.1
    -- ECPrivateKey ::= SEQUENCE {
    --     version        INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
    --     privateKey     OCTET STRING,
    --     parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
    --     publicKey  [1] BIT STRING OPTIONAL (This is the ANSI X9.63 public key format.)

    DECLARE @asn int
    EXEC @hr = sp_OACreate 'Chilkat.Asn', @asn OUT

    EXEC sp_OAMethod @privKey, 'GetPkcs1ENC', @sTmp0 OUT, 'base64'
    EXEC sp_OAMethod @asn, 'LoadEncoded', @success OUT, @sTmp0, 'base64'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @asn, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @ecc
        EXEC @hr = sp_OADestroy @fortuna
        EXEC @hr = sp_OADestroy @privKey
        EXEC @hr = sp_OADestroy @asn
        RETURN
      END

    DECLARE @xml int
    EXEC @hr = sp_OACreate 'Chilkat.Xml', @xml OUT

    EXEC sp_OAMethod @asn, 'AsnToXml', @sTmp0 OUT
    EXEC sp_OAMethod @xml, 'LoadXml', @success OUT, @sTmp0

    EXEC sp_OAMethod @xml, 'GetXml', @sTmp0 OUT
    PRINT @sTmp0

    -- The XML looks like this:
    -- <?xml version="1.0" encoding="utf-8" ?>
    -- <sequence>
    --     <int>01</int>
    --     <octets>JgJvBG+3wletkJab8iXAkpz0O8/AgWZSpkYVcB7SpnU=</octets>
    --     <contextSpecific tag="0" constructed="1">
    --         <oid>1.3.132.0.10</oid>
    --     </contextSpecific>
    -- </sequence>

    -- The 32-byte private key is in the octets..
    -- Get it as hex.
    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT

    DECLARE @privKeyHex nvarchar(4000)
    EXEC sp_OAMethod @xml, 'GetChildContent', @sTmp0 OUT, 'octets'
    EXEC sp_OAMethod @crypt, 'ReEncode', @privKeyHex OUT, @sTmp0, 'base64', 'hex'


    PRINT 'EC private key as hex = ' + @privKeyHex

    EXEC @hr = sp_OADestroy @ecc
    EXEC @hr = sp_OADestroy @fortuna
    EXEC @hr = sp_OADestroy @privKey
    EXEC @hr = sp_OADestroy @asn
    EXEC @hr = sp_OADestroy @xml
    EXEC @hr = sp_OADestroy @crypt


END
GO