Classic ASP

Verify JWT with EdDSA / Ed25519 Signature

See more JSON Web Token (JWT) Examples

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 Classic ASP Downloads

Download Chilkat for Classic ASP

Classic ASP

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

' 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

jsonPubKey = "{""kty"": ""OKP"",""alg"": ""EdDSA"",""crv"": ""Ed25519"",""x"": ""11qYAYKxCrfVS_7TyWQHOg7hcvPapiMlrwIaaPcHURo""}"

set pubKey = Server.CreateObject("Chilkat.PublicKey")
success = pubKey.LoadFromString(jsonPubKey)
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( pubKey.LastErrorText) & "</pre>"
    Response.End
End If

set jwt = Server.CreateObject("Chilkat.Jwt")
token = "eyJhbGciOiJFZERTQSJ9.RXhhbXBsZSBvZiBFZDI1NTE5IHNpZ25pbmc.hgyY0il_MGCjP0JzlnLWG1PPOt7-09PGcvMg3AIbQR6dWbhijcNR4ki4iylGjg5BhVsPt9g7sVvpAr_MuM0KAg"

' First verify the signature.
sigVerified = jwt.VerifyJwtPk(token,pubKey)
Response.Write "<pre>" & Server.HTMLEncode( "verified: " & sigVerified) & "</pre>"

If (sigVerified = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( jwt.LastErrorText) & "</pre>"
    Response.End
End If

' 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.
leeway = 60
bTimeValid = jwt.IsTimeValid(token,leeway)
Response.Write "<pre>" & Server.HTMLEncode( "time constraints valid: " & bTimeValid) & "</pre>"

' Recover the original data (the payload).
payload = jwt.GetPayload(token)
Response.Write "<pre>" & Server.HTMLEncode( payload) & "</pre>"

' Recover the original JOSE header in the same way:
joseHeader = jwt.GetHeader(token)
Response.Write "<pre>" & Server.HTMLEncode( joseHeader) & "</pre>"

%>
</body>
</html>