Create PKCS1 RSA Signature with PEM Private Key

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

Download Chilkat RSA Public-Key Encryption ActiveX

CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @pkey int
    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:
    EXEC sp_OAMethod @pkey, 'LoadPemFile', NULL, 'pvkey2_rsa.pem'

    DECLARE @success int

    DECLARE @pkeyXml nvarchar(4000)

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

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

    --  Any string argument automatically begins the 30-day trial.

    EXEC sp_OAMethod @rsa, 'UnlockComponent', @success OUT, '30-day trial'
    IF @success <> 1
      BEGIN
        PRINT 'RSA component unlock failed'
        RETURN
      END

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

    --  This example will sign a string, and receive the signature
    --  in a hex-encoded string.  Therefore, set the encoding mode
    --  to "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" and "md5".
    DECLARE @hexSig nvarchar(4000)

    EXEC sp_OAMethod @rsa, 'SignStringENC', @hexSig OUT, @strData, 'sha-1'


    PRINT @hexSig

    PRINT 'Success!'
END
GO