(SQL Server) Create JWT Using HS256, HS384, or HS512

Demonstrates how to create a JWT using HS256, HS384, or HS512. (HS256 is JWT's acronym for HMAC-SHA256.) When HMAC is used, the secret is a shared secret (i.e. password) that both client and server know beforehand.

This example also demonstrates how to include time constraints:

• nbf: Not Before Time
• exp: Expiration Time
• iat: Issue At Time

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
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @sTmp1 nvarchar(4000)
    -- Demonstrates how to create an HMAC JWT using a shared secret (password).

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

    DECLARE @jwt int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.Jwt', @jwt OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- Build the JOSE header
    DECLARE @jose int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.JsonObject', @jose OUT

    -- Use HS256.  Pass the string "HS384" or "HS512" to use a different algorithm.
    DECLARE @success int
    EXEC sp_OAMethod @jose, 'AppendString', @success OUT, 'alg', 'HS256'
    EXEC sp_OAMethod @jose, 'AppendString', @success OUT, 'typ', 'JWT'

    -- Now build the JWT claims (also known as the payload)
    DECLARE @claims int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.JsonObject', @claims OUT

    EXEC sp_OAMethod @claims, 'AppendString', @success OUT, 'iss', 'http://example.org'
    EXEC sp_OAMethod @claims, 'AppendString', @success OUT, 'sub', 'John'
    EXEC sp_OAMethod @claims, 'AppendString', @success OUT, 'aud', 'http://example.com'

    -- Set the timestamp of when the JWT was created to now.
    DECLARE @curDateTime int
    EXEC sp_OAMethod @jwt, 'GenNumericDate', @curDateTime OUT, 0
    EXEC sp_OAMethod @claims, 'AddIntAt', @success OUT, -1, 'iat', @curDateTime

    -- Set the "not process before" timestamp to now.
    EXEC sp_OAMethod @claims, 'AddIntAt', @success OUT, -1, 'nbf', @curDateTime

    -- Set the timestamp defining an expiration time (end time) for the token
    -- to be now + 1 hour (3600 seconds)
    EXEC sp_OAMethod @claims, 'AddIntAt', @success OUT, -1, 'exp', @curDateTime + 3600

    -- Produce the smallest possible JWT:
    EXEC sp_OASetProperty @jwt, 'AutoCompact', 1

    DECLARE @strJwt nvarchar(4000)
    EXEC sp_OAMethod @jose, 'Emit', @sTmp0 OUT
    EXEC sp_OAMethod @claims, 'Emit', @sTmp1 OUT
    EXEC sp_OAMethod @jwt, 'CreateJwt', @strJwt OUT, @sTmp0, @sTmp1, 'secret'


    PRINT @strJwt

    EXEC @hr = sp_OADestroy @jwt
    EXEC @hr = sp_OADestroy @jose
    EXEC @hr = sp_OADestroy @claims


END
GO