SQL Server

JWE using PBES2 Key Wrapping

See more JSON Web Encryption (JWE) Examples

Demonstrates how to create and decrypt a JWE that using PBES2 key wrapping.

This example demonstrates PBES2 with HMAC SHA-256 and A128KW wrapping. It is also possible to do the following by simply changing the "alg" parameter:

• PBES2 with HMAC SHA-384 and A192KW wrapping
• PBES2 with HMAC SHA-512 and A256KW wrapping

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..
    DECLARE @jweProtHdr int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jweProtHdr OUT

    EXEC sp_OAMethod @jweProtHdr, 'AppendString', @success OUT, 'alg', 'PBES2-HS256+A128KW'
    EXEC sp_OAMethod @jweProtHdr, 'AppendString', @success OUT, 'enc', 'A128GCM'

    -- PBES2 requires two additional parameters:
    -- 1) A random salt parameter ("p2s") containing 8 or more bytes in base64url format.
    -- 2) An iteration count parameter ("p2c").  A minimum count of 1000 is recommended.
    --    The iteration count is intended to make the PBES2 computation more expensive (time consuming)
    --    to prevent brute-force attacks.
    DECLARE @prng int
    EXEC @hr = sp_OACreate 'Chilkat.Prng', @prng OUT

    EXEC sp_OAMethod @prng, 'GenRandom', @sTmp0 OUT, 16, 'base64url'
    EXEC sp_OAMethod @jweProtHdr, 'AppendString', @success OUT, 'p2s', @sTmp0
    EXEC sp_OAMethod @jweProtHdr, 'AppendString', @success OUT, 'p2c', '1000'


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

    PRINT '--'

    -- Don't forget to actually provide the protected header to the JWE object:
    EXEC sp_OAMethod @jwe, 'SetProtectedHeader', @success OUT, @jweProtHdr

    -- Set the PBES2 password
    DECLARE @recipientIndex int
    SELECT @recipientIndex = 0
    EXEC sp_OAMethod @jwe, 'SetPassword', @success OUT, @recipientIndex, 'top secret'

    -- 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
        EXEC @hr = sp_OADestroy @prng
        RETURN
      END

    -- Show the JWE we just created:

    PRINT @strJwe

    -- Decrypt the JWE.
    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 @prng
        EXEC @hr = sp_OADestroy @jwe2
        RETURN
      END
    -- Set the PBES2 password
    EXEC sp_OAMethod @jwe2, 'SetPassword', @success OUT, @recipientIndex, 'top secret'

    -- 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 @prng
        EXEC @hr = sp_OADestroy @jwe2
        RETURN
      END


    PRINT 'original text: '

    PRINT @originalPlaintext

    -- Sample output:

    -- JWE Protected Header: {"alg":"PBES2-HS256+A128KW","enc":"A128GCM","p2s":"z39rTEfRy1T1Yn_D1mZRlg","p2c":"1000"}
    -- --
    -- eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIiwicDJzIjoiejM5clRFZlJ5MVQxWW5fRDFtWlJsZyIsInAyYyI6IjEwMDAifQ.koYt6PrFmYwcwdcT7ZcvXHA1d-Xez5h4.luGlbvEnZp-7IsBOj42Yhw.YMTcfLf8Qe4zazozGV2OAu3cUdQ8Kg.rWub47ESWkc6IqZJTvSTmg
    -- original text: 
    -- Live long and prosper.

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


END
GO