(SQL Server) RSA Encrypt Hash using SHA256 hash function and SHA1 mask function

How can this Javascript be duplicated using Chilkat?

function a(e, t) {
                var r = s.pki.publicKeyFromPem(e)
                  , n = r.encrypt(t, "RSA-OAEP", {
                    md: s.md.sha256.create(),
                    mgf1: {
                        md: s.md.sha1.create()
                    }
                });
                return s.util.encode64(n)
            }

Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens, even using the same data and key, the result will be different -- but still valid. One should not expect to get the same output.

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

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

    DECLARE @sbPem int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbPem OUT

    DECLARE @bCrlf int
    SELECT @bCrlf = 1
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, '-----BEGIN PUBLIC KEY-----', @bCrlf
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, 'MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA33TqqLR3eeUmDtHS89qF', @bCrlf
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, '3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA', @bCrlf
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, '04DDnEFGAf+kDQiNSe2ZtqC7bnIc8+KSG/qOGQIVaay4Ucr6ovDkykO5Hxn7OU7s', @bCrlf
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, 'Jp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwF', @bCrlf
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, 'wnxCsU5+UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUE', @bCrlf
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, 'f0YN3/Q0auBkdbDR/ES2PbgKTJdkjc/rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1W', @bCrlf
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, 'SwIDAQAB', @bCrlf
    EXEC sp_OAMethod @sbPem, 'AppendLine', @success OUT, '-----END PUBLIC KEY-----', @bCrlf

    -- Load the public key object from the PEM. 
    EXEC sp_OAMethod @sbPem, 'GetAsString', @sTmp0 OUT
    EXEC sp_OAMethod @pubkey, 'LoadFromString', @success OUT, @sTmp0
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pubkey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pubkey
        EXEC @hr = sp_OADestroy @sbPem
        RETURN
      END

    DECLARE @originalData nvarchar(4000)
    SELECT @originalData = 'This is the original data to be SHA-256 hashed and RSA encrypted.'

    -- First we SHA-256 hash the original data to get the hash in base64 format:
    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT

    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'SHA-256'
    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'base64'
    DECLARE @hashBase64 nvarchar(4000)
    EXEC sp_OAMethod @crypt, 'HashStringENC', @hashBase64 OUT, @originalData

    -- Setup RSA to use OAEP padding with SHA-1 for the mask function.
    DECLARE @rsa int
    EXEC @hr = sp_OACreate 'Chilkat.Rsa', @rsa OUT

    EXEC sp_OASetProperty @rsa, 'PkcsPadding', 0
    EXEC sp_OASetProperty @rsa, 'OaepHash', 'SHA256'
    EXEC sp_OAMethod @rsa, 'UsePublicKey', @success OUT, @pubkey
    EXEC sp_OASetProperty @rsa, 'EncodingMode', 'base64'

    -- We can provide a binary encoding mode, such as "base64", "hex", "base64url", etc.
    -- for the Charset property.   The Charset property was previously limited to character encodings, such as
    -- "utf-8", "iso-8859-1", etc.  If a binary encoding is used, then the string passed in is decoded to the binary
    -- bytes as indicated.  (If an actual charset, such as "utf-8" is used, then the input string is converted to the
    -- byte representation of the charset, and then encrypted.)

    -- Given that a hash is composed of non-text binary bytes, we'll set the Charset property equal to "base64" 
    -- (because we have the base64 hash from above).
    EXEC sp_OASetProperty @rsa, 'Charset', 'base64'

    -- Note: The OAEP padding uses random bytes in the padding, and therefore each time encryption happens,
    -- even using the same data and key, the result will be different --  but still valid.  One should not expect
    -- to get the same output.
    DECLARE @bUsePrivateKey int
    SELECT @bUsePrivateKey = 0
    DECLARE @encryptedStr nvarchar(4000)
    EXEC sp_OAMethod @rsa, 'EncryptStringENC', @encryptedStr OUT, @hashBase64, @bUsePrivateKey
    EXEC sp_OAGetProperty @rsa, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @rsa, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pubkey
        EXEC @hr = sp_OADestroy @sbPem
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @rsa
        RETURN
      END


    PRINT 'Base64 RSA encrypted output: ' + @encryptedStr

    EXEC @hr = sp_OADestroy @pubkey
    EXEC @hr = sp_OADestroy @sbPem
    EXEC @hr = sp_OADestroy @crypt
    EXEC @hr = sp_OADestroy @rsa


END
GO