(Lianja) Create JWS using the Flattened JSON Serialization Format

Creates a JSON Web Signature (JWS) containing 1 signature and output using the flattened JSON serialization format.

Note: This example requires Chilkat v9.5.0.66 or greater.

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

// Note: This example requires Chilkat v9.5.0.66 or greater.

// The JWS to be created will contain one signature using an ECDSA key.

loSbEccJwk = createobject("CkStringBuilder")
loSbEccJwk.Append('{"kty":"EC",')
loSbEccJwk.Append('"crv":"P-256",')
loSbEccJwk.Append('"x":"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU",')
loSbEccJwk.Append('"y":"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0",')
loSbEccJwk.Append('"d":"jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI"')
loSbEccJwk.Append("}")

loEccKey = createobject("CkPrivateKey")
// Note: This example loads the ECDSA key from JWK format.  Any format can be loaded
// into the private key object. (See the online reference documentation..)
llSuccess = loEccKey.LoadJwk(loSbEccJwk.GetAsString())
if (llSuccess <> .T.) then
    ? loEccKey.LastErrorText
    release loSbEccJwk
    release loEccKey
    return
endif

// ---------------------------------------------------
// Prepare both a protected and unprotected header.

loJwsProtHdr = createobject("CkJsonObject")
loJwsProtHdr.AppendString("alg","ES256")

loJwsUnprotHdr = createobject("CkJsonObject")
loJwsUnprotHdr.AppendString("kid","myEcKey")

// ---------------------------------------------------
loJws = createobject("CkJws")

loJws.SetProtectedHeader(0,loJwsProtHdr)
loJws.SetUnprotectedHeader(0,loJwsUnprotHdr)

loJws.SetPrivateKey(0,loEccKey)

llBIncludeBom = .F.
lcPayloadStr = "In our village, folks say God crumbles up the old moon into stars."
loJws.SetPayload(lcPayloadStr,"utf-8",llBIncludeBom)

// ---------------------------------------------------
// Create the JWS.
// Indicate we prefer the non-compact, flattened serialization.
loJws.PreferCompact = .F.
loJws.PreferFlattened = .T.

lcJwsStr = loJws.CreateJws()
if (loJws.LastMethodSuccess <> .T.) then
    ? loJws.LastErrorText
    release loSbEccJwk
    release loEccKey
    release loJwsProtHdr
    release loJwsUnprotHdr
    release loJws
    return
endif

// The jwsStr is contains the flattened JSON in the smallest possible size, which is a single line.
// To get in human-readable format, load into a Chilkat JSON object and emit..
loJson = createobject("CkJsonObject")
loJson.Load(lcJwsStr)
loJson.EmitCompact = .F.
? loJson.Emit()

// Sample output:

// { 
//   "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",
//   "protected": "eyJhbGciOiJFUzI1NiJ9",
//   "header": { 
//     "kid": "myEcKey"
//   },
//   "signature": "b7V2UpDPytr-kMnM_YjiQ3E0J2ucOI9LYA7mt57vccrK1rb84j9areqgQcJwOA00aWGoz4hf6sMTBfobdcJEGg"
// }


release loSbEccJwk
release loEccKey
release loJwsProtHdr
release loJwsUnprotHdr
release loJws
release loJson