(PowerBuilder) Verify JWT Using HS256, HS384, or HS512

Demonstrates how to verify a JWT that was signed using HS256, HS384, or HS512. (HS256 is JWT's acronym for HMAC-SHA256.)

This example verifies the 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 claims JSON.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Jwt
string ls_Token
integer li_SigVerified
integer li_Leeway
integer li_BTimeValid
string ls_Payload
oleobject loo_Json
integer li_Success
string ls_JoseHeader

// Demonstrates how to verify 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.

loo_Jwt = create oleobject
// Use "Chilkat_9_5_0.Jwt" for versions of Chilkat < 10.0.0
li_rc = loo_Jwt.ConnectToNewObject("Chilkat.Jwt")
if li_rc < 0 then
    destroy loo_Jwt
    MessageBox("Error","Connecting to COM object failed")
    return
end if

ls_Token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDYzNDMxODEyLCJuYmYiOjE0NjM0MzE4MTIsImV4cCI6MTQ2MzQzNTQxMn0.SHnMJ11qJH5pbp22YchT_9fL2HIx0koHiUHLG67_foU"

// First verify the signature.
// The password used to create this JWT was "secret".
li_SigVerified = loo_Jwt.VerifyJwt(ls_Token,"secret")
Write-Debug "with correct password: " + string(li_SigVerified)

// Now try with a different password:
li_SigVerified = loo_Jwt.VerifyJwt(ls_Token,"secret2")
Write-Debug "with incorrect password " + string(li_SigVerified)

// 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.
li_Leeway = 60
li_BTimeValid = loo_Jwt.IsTimeValid(ls_Token,li_Leeway)
Write-Debug "time constraints valid: " + string(li_BTimeValid)

// Now let's recover the original claims JSON (the payload).
ls_Payload = loo_Jwt.GetPayload(ls_Token)
// The payload will likely be in compact form:
Write-Debug ls_Payload

// We can format for human viewing by loading it into Chilkat's JSON object
// and emit.
loo_Json = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

li_Success = loo_Json.Load(ls_Payload)
loo_Json.EmitCompact = 0
Write-Debug loo_Json.Emit()

// We can recover the original JOSE header in the same way:
ls_JoseHeader = loo_Jwt.GetHeader(ls_Token)
// The payload will likely be in compact form:
Write-Debug ls_JoseHeader

// We can format for human viewing by loading it into Chilkat's JSON object
// and emit.
li_Success = loo_Json.Load(ls_JoseHeader)
loo_Json.EmitCompact = 0
Write-Debug loo_Json.Emit()


destroy loo_Jwt
destroy loo_Json