SQL Server

Demonstrate RSA Encrypt/Decrypt using BinData

See more RSA Examples

Demonstrates how to RSA encrypt and decrypt data contained in a Chilkat BinData object. SQL Server

-- 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

    -- The RSA public key is used for encryption, and the private key for decryption.

    -- The public key's role is to make encryption accessible to anyone while ensuring that
    -- only the private key holder can decrypt the messages.
    -- The public key is designed to be widely distributed so anyone can use it to encrypt messages
    -- intended for the owner of the private key.

    -- Load our 2048-bit RSA public key.
    DECLARE @pubKey int
    EXEC @hr = sp_OACreate 'Chilkat.PublicKey', @pubKey OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- In all Chilkat methods expecting a path, you pass either absolute or relative paths.
    EXEC sp_OAMethod @pubKey, 'LoadFromFile', @success OUT, 'rsaKeys/myTestRsaPublic.pem'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pubKey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pubKey
        RETURN
      END

    DECLARE @rsa int
    EXEC @hr = sp_OACreate 'Chilkat.Rsa', @rsa OUT

    -- Tell RSA to use the public key.
    EXEC sp_OAMethod @rsa, 'UsePublicKey', @success OUT, @pubKey

    -- RSA encryption is for small amounts of data, on the order of 200 bytes or less.
    -- The maximum number of bytes that can be RSA encrypted depends
    -- on the RSA key size and padding scheme (OAEP padding vs PKCS#1 v1.5 padding).
    -- For specific limits, see: RSA Encryption Maximum Number of Bytes

    -- Create some binary data to encrypt.
    DECLARE @bd int
    EXEC @hr = sp_OACreate 'Chilkat.BinData', @bd OUT

    DECLARE @i int
    SELECT @i = 0
    SELECT @i = 0
    WHILE @i <= 49
      BEGIN
        EXEC sp_OAMethod @bd, 'AppendByte', @success OUT, @i
        SELECT @i = @i + 1
      END

    -- Show the bytes to be encrypted in hex format:

    EXEC sp_OAMethod @bd, 'GetEncoded', @sTmp0 OUT, 'hex'
    PRINT 'To be encrypted: ' + @sTmp0

    -- To be encrypted: 000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F3031

    -- RSA encrypt the contents of the bd, replacing the contents with the RSA encrypted data.
    EXEC sp_OAMethod @rsa, 'EncryptBd', @success OUT, @bd, 0

    -- Now it is encrypted.

    EXEC sp_OAGetProperty @bd, 'NumBytes', @iTmp0 OUT
    PRINT 'Encrypted size = ' + @iTmp0
    EXEC sp_OAMethod @bd, 'GetEncoded', @sTmp0 OUT, 'hex'
    PRINT @sTmp0

    -- Encrypted size = 256
    -- 749ED9D0A8767C06C09AD9697F654F86B145F966722F9714902C4175BDBD02E68984ECF111D4D461
    -- EDB4A8E677D399D19CCA60F35C6DE9972F4262880FE9D77DB75915393E8E7DB80AAB5E383013FAEB
    -- 60C77D1E6FECC9A7C8426976416C6218FE7DA998EE063CE709E79C240F8625F4A56A0A33AFD63F7A
    -- BA26F2A692B42E878C53B78602C725FE63FF961A46A2B9D436E5E3D9D64AE3F1D1F5AD5F5B47FCD69
    -- 447306B77F2FD6D766CCAA1A110A3371586B43DF0D7FFE2220D1B305CF9371AC342F849FB0C90CD99E
    -- C176928D877FE1C0DE1A7CB6EB824FEC7E1DCF90EF2C6BA9F1DFD3EBFBE89C51AF074DC6AE02E544A78
    -- 5018C36D3D48B2EF5202AF61AC

    -- ------------------------------------------------------------------------------------------------------------------------
    -- Let's decrypt, which requires the matching private key...

    -- Load the matching 2048-bit RSA private key.
    DECLARE @privKey int
    EXEC @hr = sp_OACreate 'Chilkat.PrivateKey', @privKey OUT

    DECLARE @password nvarchar(4000)
    SELECT @password = 'secret'
    EXEC sp_OAMethod @privKey, 'LoadAnyFormatFile', @success OUT, 'rsaKeys/myTestRsaPrivate.pem', @password
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @privKey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pubKey
        EXEC @hr = sp_OADestroy @rsa
        EXEC @hr = sp_OADestroy @bd
        EXEC @hr = sp_OADestroy @privKey
        RETURN
      END

    -- Tell the RSA object to use the private key.
    EXEC sp_OAMethod @rsa, 'UsePrivateKey', @success OUT, @privKey

    -- Decrypt
    EXEC sp_OAMethod @rsa, 'DecryptBd', @success OUT, @bd, 1
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @rsa, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pubKey
        EXEC @hr = sp_OADestroy @rsa
        EXEC @hr = sp_OADestroy @bd
        EXEC @hr = sp_OADestroy @privKey
        RETURN
      END

    -- Examine the contents of bd to see if it now contains the unencrypted original data.

    EXEC sp_OAMethod @bd, 'GetEncoded', @sTmp0 OUT, 'hex'
    PRINT 'Decrypted: ' + @sTmp0

    -- Decrypted: 000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F3031

    EXEC @hr = sp_OADestroy @pubKey
    EXEC @hr = sp_OADestroy @rsa
    EXEC @hr = sp_OADestroy @bd
    EXEC @hr = sp_OADestroy @privKey


END
GO