SQL Server

JWE using AES Key Wrap and AES_128_CBC_HMAC_SHA_256

See more JSON Web Encryption (JWE) Examples

This example duplicates the example A.3 in RFC 7516 for JSON Web Encryption (JWE).

Note: This example requires Chilkat v9.5.0.66 or greater.

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

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

    -- Note: This example requires Chilkat v9.5.0.66 or greater.

    DECLARE @plaintext nvarchar(4000)
    SELECT @plaintext = 'Live long and prosper.'

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

    -- First build the JWE Protected Header: {"alg":"A128KW","enc":"A128CBC-HS256"}
    DECLARE @jweProtHdr int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jweProtHdr OUT

    EXEC sp_OAMethod @jweProtHdr, 'AppendString', @success OUT, 'alg', 'A128KW'
    EXEC sp_OAMethod @jweProtHdr, 'AppendString', @success OUT, 'enc', 'A128CBC-HS256'
    EXEC sp_OAMethod @jwe, 'SetProtectedHeader', @success OUT, @jweProtHdr


    EXEC sp_OAMethod @jweProtHdr, 'Emit', @sTmp0 OUT
    PRINT 'JWE Protected Header: ' + @sTmp0

    PRINT '--'

    -- The example A.3 in RFC 7516 uses the following 128-bit AES key,
    -- specified in JWK (JSON Web Key) format:
    --      {"kty":"oct",
    --       "k":"GawgguFyGrWKav7AX4VKUg"
    --      }
    -- This is just a way of saying: The key type ("kty") is 
    -- a bunch of octets ("k") in base64url encoding.
    -- We can simply set the AES wrapping key like this:
    DECLARE @aesWrappingKey nvarchar(4000)
    SELECT @aesWrappingKey = 'GawgguFyGrWKav7AX4VKUg'
    EXEC sp_OAMethod @jwe, 'SetWrappingKey', @success OUT, 0, @aesWrappingKey, 'base64url'

    -- Encrypt and return the JWE:
    DECLARE @strJwe nvarchar(4000)
    EXEC sp_OAMethod @jwe, 'Encrypt', @strJwe OUT, @plaintext, 'utf-8'
    EXEC sp_OAGetProperty @jwe, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @jwe, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jwe
        EXEC @hr = sp_OADestroy @jweProtHdr
        RETURN
      END

    -- Show the JWE we just created:

    PRINT @strJwe

    -- Decrypt the JWE that was just produced.
    -- 1) Load the JWE.
    -- 2) Set the AES wrapping key.
    -- 3) Decrypt.
    DECLARE @jwe2 int
    EXEC @hr = sp_OACreate 'Chilkat.Jwe', @jwe2 OUT

    EXEC sp_OAMethod @jwe2, 'LoadJwe', @success OUT, @strJwe
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @jwe2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jwe
        EXEC @hr = sp_OADestroy @jweProtHdr
        EXEC @hr = sp_OADestroy @jwe2
        RETURN
      END
    -- Set the AES wrap key.
    EXEC sp_OAMethod @jwe2, 'SetWrappingKey', @success OUT, 0, @aesWrappingKey, 'base64url'

    -- Decrypt.
    DECLARE @originalPlaintext nvarchar(4000)
    EXEC sp_OAMethod @jwe2, 'Decrypt', @originalPlaintext OUT, 0, 'utf-8'
    EXEC sp_OAGetProperty @jwe2, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @jwe2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jwe
        EXEC @hr = sp_OADestroy @jweProtHdr
        EXEC @hr = sp_OADestroy @jwe2
        RETURN
      END


    PRINT 'original text: '

    PRINT @originalPlaintext

    -- ---------------------------------------------------------------------------------
    -- It should also be possible to decrypt the JWE as shown in RFC 7516, Appendix A.3.7
    -- because it was produced using the same AES Wrap key.

    DECLARE @sbJwe int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbJwe OUT

    EXEC sp_OAMethod @sbJwe, 'Append', @success OUT, 'eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.'
    EXEC sp_OAMethod @sbJwe, 'Append', @success OUT, '6KB707dM9YTIgHtLvtgWQ8mKwboJW3of9locizkDTHzBC2IlrT1oOQ.'
    EXEC sp_OAMethod @sbJwe, 'Append', @success OUT, 'AxY8DCtDaGlsbGljb3RoZQ.'
    EXEC sp_OAMethod @sbJwe, 'Append', @success OUT, 'KDlTtXchhZTGufMYmOYGS4HffxPSUrfmqCHXaI9wOGY.'
    EXEC sp_OAMethod @sbJwe, 'Append', @success OUT, 'U0m_YmjN04DJvceFICbCVQ'

    EXEC sp_OAMethod @jwe2, 'LoadJweSb', @success OUT, @sbJwe
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @jwe2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jwe
        EXEC @hr = sp_OADestroy @jweProtHdr
        EXEC @hr = sp_OADestroy @jwe2
        EXEC @hr = sp_OADestroy @sbJwe
        RETURN
      END

    EXEC sp_OAMethod @jwe2, 'SetWrappingKey', @success OUT, 0, @aesWrappingKey, 'base64url'

    -- Decrypt.
    EXEC sp_OAMethod @jwe2, 'Decrypt', @originalPlaintext OUT, 0, 'utf-8'
    EXEC sp_OAGetProperty @jwe2, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @jwe2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jwe
        EXEC @hr = sp_OADestroy @jweProtHdr
        EXEC @hr = sp_OADestroy @jwe2
        EXEC @hr = sp_OADestroy @sbJwe
        RETURN
      END


    PRINT @originalPlaintext

    EXEC @hr = sp_OADestroy @jwe
    EXEC @hr = sp_OADestroy @jweProtHdr
    EXEC @hr = sp_OADestroy @jwe2
    EXEC @hr = sp_OADestroy @sbJwe


END
GO