(SQL Server) Create PKCS1 RSA Signature with PEM Private Key

See more RSA Examples

Demonstrates how to load a private key from a PEM file and create a PKCS1 RSA digital signature.

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

    DECLARE @pkey int
    -- Use "Chilkat_9_5_0.PrivateKey" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.PrivateKey', @pkey OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- Load the private key from an RSA PEM file:
    DECLARE @success int
    EXEC sp_OAMethod @pkey, 'LoadPemFile', @success OUT, 'pvkey2_rsa.pem'

    DECLARE @pkeyXml nvarchar(4000)

    -- Get the private key in XML format:
    EXEC sp_OAMethod @pkey, 'GetXml', @pkeyXml OUT

    DECLARE @rsa int
    -- Use "Chilkat_9_5_0.Rsa" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Rsa', @rsa OUT

    -- Import the private key into the RSA object:
    EXEC sp_OAMethod @rsa, 'ImportPrivateKey', @success OUT, @pkeyXml
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @rsa, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pkey
        EXEC @hr = sp_OADestroy @rsa
        RETURN
      END

    -- Get the signature as hex.
    EXEC sp_OASetProperty @rsa, 'EncodingMode', 'hex'

    DECLARE @strData nvarchar(4000)
    SELECT @strData = 'This is the string to be signed.'

    -- Sign the string using the sha-1 hash algorithm.
    -- Other valid choices are "md2", "md5", "sha256",
    -- "sha384", and "sha512".
    DECLARE @hexSig nvarchar(4000)
    EXEC sp_OAMethod @rsa, 'SignStringENC', @hexSig OUT, @strData, 'sha-1'


    PRINT @hexSig


    PRINT 'Success!'

    EXEC @hr = sp_OADestroy @pkey
    EXEC @hr = sp_OADestroy @rsa


END
GO