(SQL Server) Duplicate Java Verify RSA Signature

Demonstrates how to duplicate a snippet of Java code that verifies an RSA 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 requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- This example duplicates the following Java code:

    -- import com.sun.org.apache.xml.internal.security.utils.Base64;  
    -- import java.io.ByteArrayInputStream;  
    -- import java.security.PublicKey;  
    -- import java.security.Signature;  
    -- import java.security.cert.CertificateFactory;  
    -- import java.security.cert.X509Certificate;  
    -- public class validateSazetak {  
    --   public static void main(String[] args) {  
    --   String signatureAlgorithm = "SHA256withRSA";  
    --   String base64DataToBeSigned = "Hlp...LE4=";  
    --   String base64Certificate = "MII...TlQ==";  
    --   String base64Signature = "I00...pZA==";  
    --   try {  
    --       CertificateFactory cf;  
    --       X509Certificate certificate = null;  
    --       cf = CertificateFactory.getInstance("X.509");  
    --       certificate = (X509Certificate) cf.generateCertificate(new 
    --       ByteArrayInputStream(Base64.decode(base64Certificate)));  
    --        
    --       Signature signature = Signature.getInstance(signatureAlgorithm, "SunRsaSign");  
    --       PublicKey pk = (PublicKey) certificate.getPublicKey();  
    --       signature.initVerify(pk);  
    --        
    --       byte[] hashBytes = Base64.decode(base64DataToBeSigned);  
    --       signature.update(hashBytes);  
    --        
    --       byte[] sigBytes = Base64.decode(base64Signature);  
    --       boolean validity = signature.verify(sigBytes);  
    --       System.out.println("Is valid signature:" + validity);  
    --     } catch (Exception e) {  
    --         System.out.println(e);  
    --     }  
    -- } 

    DECLARE @base64DataToBeSigned nvarchar(4000)
    SELECT @base64DataToBeSigned = 'Hlp...LE4='
    DECLARE @base64Certificate nvarchar(4000)
    SELECT @base64Certificate = 'MII...TlQ=='
    DECLARE @base64Signature nvarchar(4000)
    SELECT @base64Signature = 'I00...pZA=='

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

    DECLARE @success int
    EXEC sp_OAMethod @cert, 'LoadFromBase64', @success OUT, @base64Certificate
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @cert, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @cert
        RETURN
      END

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

    EXEC sp_OAMethod @rsa, 'SetX509Cert', @success OUT, @cert, 0
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @rsa, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @cert
        EXEC @hr = sp_OADestroy @rsa
        RETURN
      END

    EXEC sp_OASetProperty @rsa, 'EncodingMode', 'base64'
    EXEC sp_OAMethod @rsa, 'VerifyStringENC', @success OUT, @base64DataToBeSigned, 'sha256', @base64Signature
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @rsa, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @cert
        EXEC @hr = sp_OADestroy @rsa
        RETURN
      END


    PRINT 'Signature verified.'

    EXEC @hr = sp_OADestroy @cert
    EXEC @hr = sp_OADestroy @rsa


END
GO