(VB.NET) 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.

Dim sbEccJwk As New Chilkat.StringBuilder
sbEccJwk.Append("{""kty"":""EC"",")
sbEccJwk.Append("""crv"":""P-256"",")
sbEccJwk.Append("""x"":""f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU"",")
sbEccJwk.Append("""y"":""x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0"",")
sbEccJwk.Append("""d"":""jpsQnnGQmL-YBIffH1136cspYG6-0iY7X1fCE9-E9LI""")
sbEccJwk.Append("}")

Dim eccKey As New Chilkat.PrivateKey
' 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..)
Dim success As Boolean = eccKey.LoadJwk(sbEccJwk.GetAsString())
If (success <> True) Then
    Debug.WriteLine(eccKey.LastErrorText)
    Exit Sub
End If


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

Dim jwsProtHdr As New Chilkat.JsonObject
jwsProtHdr.AppendString("alg","ES256")

Dim jwsUnprotHdr As New Chilkat.JsonObject
jwsUnprotHdr.AppendString("kid","myEcKey")


' ---------------------------------------------------
Dim jws As New Chilkat.Jws

jws.SetProtectedHeader(0,jwsProtHdr)
jws.SetUnprotectedHeader(0,jwsUnprotHdr)

jws.SetPrivateKey(0,eccKey)

Dim bIncludeBom As Boolean = False
Dim payloadStr As String = "In our village, folks say God crumbles up the old moon into stars."
jws.SetPayload(payloadStr,"utf-8",bIncludeBom)

' ---------------------------------------------------
' Create the JWS.
' Indicate we prefer the non-compact, flattened serialization.
jws.PreferCompact = False
jws.PreferFlattened = True

Dim jwsStr As String = jws.CreateJws()
If (jws.LastMethodSuccess <> True) Then
    Debug.WriteLine(jws.LastErrorText)
    Exit Sub
End If


' 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..
Dim json As New Chilkat.JsonObject
json.Load(jwsStr)
json.EmitCompact = False
Debug.WriteLine(json.Emit())

' Sample output:

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