Xbase++ Requires Chilkat v11.0.0+

Validate JWS Using HMAC SHA-256

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) using HMAC SHA-256. Xbase++

LOCAL nSuccess
LOCAL oJws
LOCAL cHmacKey
LOCAL nSignatureIndex
LOCAL cJwsCompact
LOCAL v
LOCAL oJoseHeader

nSuccess := 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 a MAC key to validate and recover the protected header and payload.

oJws := CreateObject("Chilkat.Jws")

//  Set the HMAC key:
cHmacKey := "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow"
nSignatureIndex := 0
oJws:SetMacKey(nSignatureIndex, cHmacKey, "base64url")

//  Load the JWS.
cJwsCompact := "eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFtcGxlLmNvbS9pc19yb290Ijp0cnVlfQ.dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"
nSuccess := oJws:LoadJws(cJwsCompact)

//  Validate the 1st (and only) signature at index 0..
v := oJws:Validate(nSignatureIndex)
IF (v < 0)
    //  Perhaps Chilkat was not unlocked or the trial expired..
    ? "Method call failed for some other reason."
    ? oJws:LastErrorText
    oJws:destroy()
    RETURN
ENDIF

IF (v == 0)
    ? "Invalid signature.  The MAC key was incorrect, the JWS was invalid, or both."
    oJws:destroy()
    RETURN
ENDIF

//  If we get here, the signature was validated..
? "Signature validated."

//  Recover the original content:
? "Recovered content:"
? oJws:GetPayload("utf-8")

//  Examine the protected header:

oJoseHeader := CreateObject("Chilkat.JsonObject")
nSuccess := oJws:GetProtectedH(nSignatureIndex, oJoseHeader)
IF (nSuccess == 0)
    ? oJws:LastErrorText
    oJws:destroy()
    oJoseHeader:destroy()
    RETURN
ENDIF

oJoseHeader:EmitCompact := 0

? "Protected (JOSE) header:"
? oJoseHeader:Emit()

//  Output:

//  	Signature validated.
//  	Recovered content:
//  	{"iss":"joe",
//  	 "exp":1300819380,
//  	 "http://example.com/is_root":true}
//  	Protected (JOSE) header:
//  	{ 
//  	  "typ": "JWT",
//  	  "alg": "HS256"
//  	}

oJws:destroy()
oJoseHeader:destroy()