(SQL Server) Verify JWT with EdDSA / Ed25519 Signature

Note: This example requires Chilkat v9.5.0.84 or greater.

Demonstrates how to verify a JWT that was signed using an Ed25519 private key.

This example verifies the EdDSA signature. It also does the following:

• Checks to see if the time constraints ("nbf" and "exp") are valid.
• Recovers the original JOSE header.
• Recovers the original data.

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
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- Demonstrates how to verify a JWT with an EdDSA/Ed25519 Signature
    -- *** Requires Chilkat v9.5.0.84 or greater.

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

    -- Use this Ed25519 public key for verification

    DECLARE @jsonPubKey nvarchar(4000)
    SELECT @jsonPubKey = '{"kty": "OKP","alg": "EdDSA","crv": "Ed25519","x": "11qYAYKxCrfVS_7TyWQHOg7hcvPapiMlrwIaaPcHURo"}'

    DECLARE @pubKey int
    -- Use "Chilkat_9_5_0.PublicKey" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.PublicKey', @pubKey OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

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

    DECLARE @jwt int
    -- Use "Chilkat_9_5_0.Jwt" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Jwt', @jwt OUT

    DECLARE @token nvarchar(4000)
    SELECT @token = 'eyJhbGciOiJFZERTQSJ9.RXhhbXBsZSBvZiBFZDI1NTE5IHNpZ25pbmc.hgyY0il_MGCjP0JzlnLWG1PPOt7-09PGcvMg3AIbQR6dWbhijcNR4ki4iylGjg5BhVsPt9g7sVvpAr_MuM0KAg'

    -- First verify the signature.
    DECLARE @sigVerified int
    EXEC sp_OAMethod @jwt, 'VerifyJwtPk', @sigVerified OUT, @token, @pubKey

    PRINT 'verified: ' + @sigVerified

    IF @sigVerified = 0
      BEGIN
        EXEC sp_OAGetProperty @jwt, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @pubKey
        EXEC @hr = sp_OADestroy @jwt
        RETURN
      END

    -- Let's see if the time constraints, if any, are valid.
    -- The above JWT was created on the afternoon of 16-May-2016, with an expiration of 1 hour.
    -- If the current system time is before the "nbf" time, or after the "exp" time,
    -- then IsTimeValid will return false/0.
    -- Also, we'll allow a leeway of 60 seconds to account for any clock skew.
    -- Note: If the token has no "nbf" or "exp" claim fields, then IsTimeValid is always true.
    DECLARE @leeway int
    SELECT @leeway = 60
    DECLARE @bTimeValid int
    EXEC sp_OAMethod @jwt, 'IsTimeValid', @bTimeValid OUT, @token, @leeway

    PRINT 'time constraints valid: ' + @bTimeValid

    -- Recover the original data (the payload).
    DECLARE @payload nvarchar(4000)
    EXEC sp_OAMethod @jwt, 'GetPayload', @payload OUT, @token

    PRINT @payload

    -- Recover the original JOSE header in the same way:
    DECLARE @joseHeader nvarchar(4000)
    EXEC sp_OAMethod @jwt, 'GetHeader', @joseHeader OUT, @token

    PRINT @joseHeader

    EXEC @hr = sp_OADestroy @pubKey
    EXEC @hr = sp_OADestroy @jwt


END
GO