(SQL Server) Sign JSON (or any Text) to Create a Detached PKCS7 Signature

Demonstrates how to sign JSON or any string using a certificate + private key from a .p12/.pfx to create a detached PKCS7 signature. (A detached signature is one that does not embed the original signed data.)

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

    DECLARE @crypt int
    -- Use "Chilkat_9_5_0.Crypt2" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

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

    DECLARE @success int
    EXEC sp_OAMethod @cert, 'LoadPfxFile', @success OUT, 'qa_data/pfx/cert_test123.pfx', 'test123'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @cert, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    -- Tell the crypt component to use this cert.
    EXEC sp_OAMethod @crypt, 'SetSigningCert', @success OUT, @cert
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @crypt, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'sha256'

    -- By default, all the certs in the chain of authentication are included in the signature.
    -- If desired, we can choose to only include the signing certificate:
    EXEC sp_OASetProperty @crypt, 'IncludeCertChain', 0

    -- Create the detached signature, which does NOT contain the original data.
    -- To create a PKCS7 signature that contains the original data, see CAdES Sign JSON
    EXEC sp_OASetProperty @crypt, 'Charset', 'utf-8'

    DECLARE @stringToSign nvarchar(4000)
    SELECT @stringToSign = '{ "abc": 123}'
    EXEC sp_OAMethod @crypt, 'SignString', @detachedSig OUT, @stringToSign
    EXEC sp_OAGetProperty @crypt, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @crypt, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

    -- Verify the signature against the original data.
    DECLARE @verified int
    EXEC sp_OAMethod @crypt, 'VerifyString', @verified OUT, @stringToSign, @detachedSig
    IF @verified = 0
      BEGIN
        EXEC sp_OAGetProperty @crypt, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @crypt
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END


    PRINT 'Success!'

    EXEC @hr = sp_OADestroy @crypt
    EXEC @hr = sp_OADestroy @cert


END
GO