SQL Server

JWS Using HMAC SHA-256

See more JSON Web Signatures (JWS) Examples

Creates a JSON Web Signatures (JWS) using HMAC SHA-256. 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.

    -- First create the JWS Protected Header
    DECLARE @jwsProtHdr int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @jwsProtHdr OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @jwsProtHdr, 'AppendString', @success OUT, 'typ', 'JWT'
    EXEC sp_OAMethod @jwsProtHdr, 'AppendString', @success OUT, 'alg', 'HS256'

    EXEC sp_OAMethod @jwsProtHdr, 'Emit', @sTmp0 OUT
    PRINT 'JWS Protected Header: ' + @sTmp0

    -- Output:
    -- JWS Protected Header: {"typ":"JWT","alg":"HS256"}

    DECLARE @jws int
    EXEC @hr = sp_OACreate 'Chilkat.Jws', @jws OUT

    -- Set the HMAC key:
    DECLARE @hmacKey nvarchar(4000)
    SELECT @hmacKey = 'AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow'
    DECLARE @signatureIndex int
    SELECT @signatureIndex = 0
    EXEC sp_OAMethod @jws, 'SetMacKey', @success OUT, @signatureIndex, @hmacKey, 'base64url'

    -- Set the protected header:
    EXEC sp_OAMethod @jws, 'SetProtectedHeader', @success OUT, @signatureIndex, @jwsProtHdr

    -- Set the payload.
    DECLARE @bIncludeBom int
    SELECT @bIncludeBom = 0
    DECLARE @payloadStr nvarchar(4000)
    SELECT @payloadStr = 'In our village, folks say God crumbles up the old moon into stars.'
    EXEC sp_OAMethod @jws, 'SetPayload', @success OUT, @payloadStr, 'utf-8', @bIncludeBom

    -- Create the JWS
    -- By default, the compact serialization is used.
    DECLARE @jwsCompact nvarchar(4000)
    EXEC sp_OAMethod @jws, 'CreateJws', @jwsCompact OUT
    EXEC sp_OAGetProperty @jws, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @jws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jwsProtHdr
        EXEC @hr = sp_OADestroy @jws
        RETURN
      END


    PRINT 'JWS: ' + @jwsCompact

    -- sample output:
    -- JWS: eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.bsYsi8HJ0N6OqGI1hKQ9QQRNPxxA5qMpcHLtOvXatk8

    -- Now load the JWS, validate, and recover the original text.
    DECLARE @jws2 int
    EXEC @hr = sp_OACreate 'Chilkat.Jws', @jws2 OUT

    -- Load the JWS.
    EXEC sp_OAMethod @jws2, 'LoadJws', @success OUT, @jwsCompact

    -- Set the MAC key used for validation.
    SELECT @signatureIndex = 0
    EXEC sp_OAMethod @jws2, 'SetMacKey', @success OUT, @signatureIndex, @hmacKey, 'base64url'

    -- Validate the 1st (and only) signature at index 0..
    DECLARE @v int
    EXEC sp_OAMethod @jws2, 'Validate', @v OUT, @signatureIndex
    IF @v < 0
      BEGIN
        -- Perhaps Chilkat was not unlocked or the trial expired..

        PRINT 'Method call failed for some other reason.'
        EXEC sp_OAGetProperty @jws2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jwsProtHdr
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @jws2
        RETURN
      END
    IF @v = 0
      BEGIN

        PRINT 'Invalid signature.  The MAC key was incorrect, the JWS was invalid, or both.'
        EXEC @hr = sp_OADestroy @jwsProtHdr
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @jws2
        RETURN
      END

    -- If we get here, the signature was validated..

    PRINT 'Signature validated.'

    -- Recover the original content:
    EXEC sp_OAMethod @jws2, 'GetPayload', @sTmp0 OUT, 'utf-8'
    PRINT @sTmp0

    -- Examine the protected header:

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

    EXEC sp_OAMethod @jws2, 'GetProtectedH', @success OUT, @signatureIndex, @joseHeader
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @jws2, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @jwsProtHdr
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @jws2
        EXEC @hr = sp_OADestroy @joseHeader
        RETURN
      END

    EXEC sp_OASetProperty @joseHeader, 'EmitCompact', 0


    PRINT 'Protected (JOSE) header:'
    EXEC sp_OAMethod @joseHeader, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- Output:

    -- 	Signature validated.
    -- 	In our village, folks say God crumbles up the old moon into stars.
    -- 	Protected (JOSE) header:
    -- 	{ 
    -- 	  "typ": "JWT",
    -- 	  "alg": "HS256"
    -- 	} 

    EXEC @hr = sp_OADestroy @jwsProtHdr
    EXEC @hr = sp_OADestroy @jws
    EXEC @hr = sp_OADestroy @jws2
    EXEC @hr = sp_OADestroy @joseHeader


END
GO