SQL Server

Validate a JWS Using ECDSA P-256 SHA-256

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) that uses ECDSA P-256 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
    -- 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.

    -- This example takes a JSON signature in compact serialization format,
    -- and uses an ECDSA public key to validate and recover the protected header and payload.

    -- We only need a public key for signature validation.  This is the ECDSA public key
    -- that is used:

    --      {"kty":"EC", 
    --       "crv":"P-256", 
    --       "x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU", 
    --       "y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0" 
    --      } 

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

    EXEC sp_OAMethod @sbPubKey, 'Append', @success OUT, '{"kty":"EC",'
    EXEC sp_OAMethod @sbPubKey, 'Append', @success OUT, '"crv":"P-256",'
    EXEC sp_OAMethod @sbPubKey, 'Append', @success OUT, '"x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU",'
    EXEC sp_OAMethod @sbPubKey, 'Append', @success OUT, '"y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0"'
    EXEC sp_OAMethod @sbPubKey, 'Append', @success OUT, '}'

    DECLARE @pubKey int
    EXEC @hr = sp_OACreate 'Chilkat.PublicKey', @pubKey OUT

    EXEC sp_OAMethod @sbPubKey, 'GetAsString', @sTmp0 OUT
    EXEC sp_OAMethod @pubKey, 'LoadFromString', @success OUT, @sTmp0
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @pubKey, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbPubKey
        EXEC @hr = sp_OADestroy @pubKey
        RETURN
      END

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

    -- Set the ECC public key:
    DECLARE @signatureIndex int
    SELECT @signatureIndex = 0
    EXEC sp_OAMethod @jws, 'SetPublicKey', @success OUT, @signatureIndex, @pubKey

    -- Load the JWS.
    DECLARE @sbJws int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbJws OUT

    EXEC sp_OAMethod @sbJws, 'Append', @success OUT, 'eyJhbGciOiJFUzI1NiJ9'
    EXEC sp_OAMethod @sbJws, 'Append', @success OUT, '.'
    EXEC sp_OAMethod @sbJws, 'Append', @success OUT, 'eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt'
    EXEC sp_OAMethod @sbJws, 'Append', @success OUT, 'cGxlLmNvbS9pc19yb290Ijp0cnVlfQ'
    EXEC sp_OAMethod @sbJws, 'Append', @success OUT, '.'
    EXEC sp_OAMethod @sbJws, 'Append', @success OUT, 'DtEhU3ljbEg8L38VWAfUAqOyKAM6-Xx-F4GawxaepmXFCgfTjDxw5djxLa8ISlSA'
    EXEC sp_OAMethod @sbJws, 'Append', @success OUT, 'pmWQxfKTUJqPP3-Kg6NU1Q'

    EXEC sp_OAMethod @jws, 'LoadJwsSb', @success OUT, @sbJws
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @jws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbPubKey
        EXEC @hr = sp_OADestroy @pubKey
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @sbJws
        RETURN
      END

    -- Validate the 1st (and only) signature at index 0..
    DECLARE @v int
    EXEC sp_OAMethod @jws, '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 @jws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbPubKey
        EXEC @hr = sp_OADestroy @pubKey
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @sbJws
        RETURN
      END
    IF @v = 0
      BEGIN

        PRINT 'Invalid signature.  The ECC key was incorrect, the JWS was invalid, or both.'
        EXEC @hr = sp_OADestroy @sbPubKey
        EXEC @hr = sp_OADestroy @pubKey
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @sbJws
        RETURN
      END

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

    PRINT 'Signature validated.'

    PRINT '--'

    -- Recover the original content:

    PRINT 'Recovered content:'
    EXEC sp_OAMethod @jws, 'GetPayload', @sTmp0 OUT, 'utf-8'
    PRINT @sTmp0

    PRINT '--'

    -- Examine the protected header:

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

    EXEC sp_OAMethod @jws, 'GetProtectedH', @success OUT, @signatureIndex, @joseHeader
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @jws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbPubKey
        EXEC @hr = sp_OADestroy @pubKey
        EXEC @hr = sp_OADestroy @jws
        EXEC @hr = sp_OADestroy @sbJws
        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.
    -- 	--
    -- 	Recovered content:
    -- 	{"iss":"joe",
    -- 	 "exp":1300819380,
    -- 	 "http://example.com/is_root":true}
    -- 	--
    -- 	Protected (JOSE) header:
    -- 	{ 
    -- 	  "alg": "ES256"
    -- 	}

    EXEC @hr = sp_OADestroy @sbPubKey
    EXEC @hr = sp_OADestroy @pubKey
    EXEC @hr = sp_OADestroy @jws
    EXEC @hr = sp_OADestroy @sbJws
    EXEC @hr = sp_OADestroy @joseHeader


END
GO