SQL Server

AES OFB Output Feedback Mode Encryption

See more Encryption Examples

Demonstrates how to encrypt using AES OFB (Output Feedback) mode. 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
    -- This example requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OASetProperty @crypt, 'CryptAlgorithm', 'aes'
    -- Set the cipher mode to Output Feedback
    EXEC sp_OASetProperty @crypt, 'CipherMode', 'ofb'
    EXEC sp_OASetProperty @crypt, 'KeyLength', 256

    -- EncodingMode specifies the encoding of the output for
    -- encryption, and the input for decryption.
    -- It may be "hex", "url", "base64", "quoted-printable", or many other choices.
    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'hex'

    DECLARE @ivHex nvarchar(4000)
    SELECT @ivHex = '000102030405060708090A0B0C0D0E0F'
    EXEC sp_OAMethod @crypt, 'SetEncodedIV', NULL, @ivHex, 'hex'

    -- The secret key must equal the size of the key.  For
    -- 256-bit encryption, the binary secret key is 32 bytes.
    DECLARE @keyHex nvarchar(4000)
    SELECT @keyHex = '603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4'
    EXEC sp_OAMethod @crypt, 'SetEncodedKey', NULL, @keyHex, 'hex'

    -- Encrypt a string...
    DECLARE @encStr nvarchar(4000)
    EXEC sp_OAMethod @crypt, 'EncryptStringENC', @encStr OUT, 'Popular opinions, on subjects not palpable to sense, are often true, but seldom or never the whole truth. -- John Stuart Mill'

    PRINT @encStr

    DECLARE @decrypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @decrypt OUT

    EXEC sp_OASetProperty @decrypt, 'CryptAlgorithm', 'aes'
    EXEC sp_OASetProperty @decrypt, 'CipherMode', 'ofb'
    EXEC sp_OASetProperty @decrypt, 'KeyLength', 256
    EXEC sp_OASetProperty @decrypt, 'EncodingMode', 'hex'
    EXEC sp_OAMethod @decrypt, 'SetEncodedIV', NULL, @ivHex, 'hex'
    EXEC sp_OAMethod @decrypt, 'SetEncodedKey', NULL, @keyHex, 'hex'

    -- Now decrypt:
    DECLARE @decStr nvarchar(4000)
    EXEC sp_OAMethod @decrypt, 'DecryptStringENC', @decStr OUT, @encStr

    PRINT @decStr

    EXEC @hr = sp_OADestroy @crypt
    EXEC @hr = sp_OADestroy @decrypt


END
GO