(VB.NET) JWE using ECDH-ES, BP-256, A256GCM

See more JSON Web Encryption (JWE) Examples

Create a JWE with the following header:

	{
	  "alg": "ECDH-ES",
	  "enc": "A256GCM",
	  "exp": 1621957030,
	  "cty": "NJWT",
	  "epk": {
	    "kty": "EC",
	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
	    "crv": "BP-256"
	  }
	}

Note: This example requires Chilkat v9.5.0.87 or greater.

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

Dim success As Boolean

' Load our brainpool BP-256 public key.

' 	{
' 	  "use": "enc",
' 	  "kid": "puk_idp_enc",
' 	  "kty": "EC",
' 	  "crv": "BP-256",
' 	  "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w",
' 	  "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
' 	}

Dim json As New Chilkat.JsonObject
json.UpdateString("use","enc")
json.UpdateString("kid","puk_idp_enc")
json.UpdateString("kty","EC")
json.UpdateString("crv","BP-256")
json.UpdateString("x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w")
json.UpdateString("y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu")

Dim pubkey As New Chilkat.PublicKey

success = pubkey.LoadFromString(json.Emit())
If (success = False) Then
    Debug.WriteLine(pubkey.LastErrorText)
    Exit Sub
End If



' Build our protected header:

' 	{
' 	  "alg": "ECDH-ES",
' 	  "enc": "A256GCM",
' 	  "exp": 1621957030,
' 	  "cty": "NJWT",
' 	  "epk": {
' 	    "kty": "EC",
' 	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
' 	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
' 	    "crv": "BP-256"
' 	  }
' 	}

' Use jwt only for getting the current date/time + 3600 seconds.
Dim jwt As New Chilkat.Jwt

Dim jweProtHdr As New Chilkat.JsonObject
jweProtHdr.UpdateString("alg","ECDH-ES")
jweProtHdr.UpdateString("enc","A256GCM")
jweProtHdr.UpdateInt("exp",jwt.GenNumericDate(3600))
jweProtHdr.UpdateString("cty","NJWT")
jweProtHdr.UpdateString("epk.kty","EC")
jweProtHdr.UpdateString("epk.x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w")
jweProtHdr.UpdateString("epk.y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu")
jweProtHdr.UpdateString("epk.crv","BP-256")


Dim jwe As New Chilkat.Jwe
jwe.SetProtectedHeader(jweProtHdr)
jwe.SetPublicKey(0,pubkey)

Dim plainText As String = "This is the text to be encrypted."
Dim strJwe As String = jwe.Encrypt(plainText,"utf-8")
If (jwe.LastMethodSuccess <> True) Then
    Debug.WriteLine(jwe.LastErrorText)
    Exit Sub
End If


Debug.WriteLine(strJwe)

Debug.WriteLine("Success.")