PowerBuilder

Create JWS Using Private Key on a Smart Card

See more JSON Web Signatures (JWS) Examples

Creates and validates a JSON Web Signature (JWS) using the private key associated with a certificate on a smart card. PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Cert
oleobject loo_JwsProtHdr
oleobject loo_Jws
integer li_SignatureIndex
integer li_BIncludeBom
string ls_PayloadStr
string ls_JwsCompact
oleobject loo_Jws2
oleobject loo_PubKey
integer v
oleobject loo_JoseHeader

li_Success = 0

// This requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Load the certificate from a smart card.
loo_Cert = create oleobject
li_rc = loo_Cert.ConnectToNewObject("Chilkat.Cert")
if li_rc < 0 then
    destroy loo_Cert
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Set the smarcard PIN prior to loading
loo_Cert.SmartCardPin = "123456"

// Detect the connected smartcard or USB security token and load the default certificate.
li_Success = loo_Cert.LoadFromSmartcard("")
if li_Success = 0 then
    Write-Debug loo_Cert.LastErrorText
    destroy loo_Cert
    return
end if

// Note: Chilkat provides many different ways to load a certificate from a smartcard or USB token,
// such as selecting a certificate if the card contains multiple certificates with private keys,
// or working with lower-level PKCS11 or ScMinidriver API's (both of which Chilkat provides).

// Create the JWS Protected Header
loo_JwsProtHdr = create oleobject
li_rc = loo_JwsProtHdr.ConnectToNewObject("Chilkat.JsonObject")

if loo_Cert.IsEcdsa() = 1 then
    loo_JwsProtHdr.AppendString("alg","ES256")
else
    loo_JwsProtHdr.AppendString("alg","RS256")
end if

loo_Jws = create oleobject
li_rc = loo_Jws.ConnectToNewObject("Chilkat.Jws")

// Set the protected header:
li_SignatureIndex = 0
loo_Jws.SetProtectedHeader(li_SignatureIndex,loo_JwsProtHdr)

// Provide the private key via the certificate.
// This requires Chilkat v11.5.0 or greater.
loo_Jws.SetSigningCert(li_SignatureIndex,loo_Cert)

// Set the payload.
li_BIncludeBom = 0
ls_PayloadStr = "In our village, folks say God crumbles up the old moon into stars."
loo_Jws.SetPayload(ls_PayloadStr,"utf-8",li_BIncludeBom)

// Create the JWS
// By default, the compact serialization is used.
ls_JwsCompact = loo_Jws.CreateJws()
if loo_Jws.LastMethodSuccess = 0 then
    Write-Debug loo_Jws.LastErrorText
    destroy loo_Cert
    destroy loo_JwsProtHdr
    destroy loo_Jws
    return
end if

Write-Debug "JWS: " + ls_JwsCompact

// sample output:
// JWS: eyJhbGciOiJQUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.TRWhwRo5dMv9-8OzrInfJTwmUGYgjLfHk8lqF072ND-FmLWEBnUTOpY8oJXp8FdWw2SalbdOeNlrtlJjwk4XK8Ql2iJ_2qMCtxsvLPhKBOqFoAF4aBvTOEDVJDxf0DaBSiydEEtfTVV2iwBcjWabu5J2XieR5y7QZQtuHsn7T3qKBvCcCejN3Y2oqAT3qMHvu1fTms1r_91wBn_K7Wjd9UkZ1n02qQcUHJznR_OF2BgN7_KWIDAF9ZS9keoju2NPpPelO4yxa2XUPnehY3G7dHKoCxUEQR4d2Xc5voqDASTVCDqQS4PVOZdvT3Ein6-SanAlCwbWBbkvT8g6-5PImQ

// Now load the JWS, validate, and recover the original text.
loo_Jws2 = create oleobject
li_rc = loo_Jws2.ConnectToNewObject("Chilkat.Jws")

// Load the JWS.
li_Success = loo_Jws2.LoadJws(ls_JwsCompact)

loo_PubKey = create oleobject
li_rc = loo_PubKey.ConnectToNewObject("Chilkat.PublicKey")

loo_Cert.GetPublicKey(loo_PubKey)

// Set the public key used for validation.
li_SignatureIndex = 0
loo_Jws2.SetPublicKey(li_SignatureIndex,loo_PubKey)

// Validate the 1st (and only) signature at index 0..
v = loo_Jws2.Validate(li_SignatureIndex)
if v < 0 then
    // Perhaps Chilkat was not unlocked or the trial expired..
    Write-Debug "Method call failed for some other reason."
    Write-Debug loo_Jws2.LastErrorText
    destroy loo_Cert
    destroy loo_JwsProtHdr
    destroy loo_Jws
    destroy loo_Jws2
    destroy loo_PubKey
    return
end if

if v = 0 then
    Write-Debug "Invalid signature.  The key was incorrect, the JWS was invalid, or both."
    destroy loo_Cert
    destroy loo_JwsProtHdr
    destroy loo_Jws
    destroy loo_Jws2
    destroy loo_PubKey
    return
end if

// If we get here, the signature was validated..
Write-Debug "Signature validated."

// Recover the original content:
Write-Debug loo_Jws2.GetPayload("utf-8")

// Examine the protected header:

loo_JoseHeader = create oleobject
li_rc = loo_JoseHeader.ConnectToNewObject("Chilkat.JsonObject")

li_Success = loo_Jws2.GetProtectedH(li_SignatureIndex,loo_JoseHeader)
if li_Success = 0 then
    Write-Debug loo_Jws2.LastErrorText
    destroy loo_Cert
    destroy loo_JwsProtHdr
    destroy loo_Jws
    destroy loo_Jws2
    destroy loo_PubKey
    destroy loo_JoseHeader
    return
end if

loo_JoseHeader.EmitCompact = 0

Write-Debug "Protected (JOSE) header:"
Write-Debug loo_JoseHeader.Emit()

// Output:

// 	Signature validated.
// 	In our village, folks say God crumbles up the old moon into stars.
// 	Protected (JOSE) header:
// 	{ 
// 	  "alg": "RS256"
// 	}


destroy loo_Cert
destroy loo_JwsProtHdr
destroy loo_Jws
destroy loo_Jws2
destroy loo_PubKey
destroy loo_JoseHeader