(Visual Basic 6.0) 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.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

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

Dim success As Long

' 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 ChilkatJsonObject
success = json.UpdateString("use","enc")
success = json.UpdateString("kid","puk_idp_enc")
success = json.UpdateString("kty","EC")
success = json.UpdateString("crv","BP-256")
success = json.UpdateString("x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w")
success = json.UpdateString("y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu")

Dim pubkey As New PublicKey

success = pubkey.LoadFromString(json.Emit())
If (success = 0) Then
    Debug.Print 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 ChilkatJwt

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

Dim jwe As New ChilkatJwe
success = jwe.SetProtectedHeader(jweProtHdr)
success = jwe.SetPublicKey(0,pubkey)

Dim plainText As String
plainText = "This is the text to be encrypted."
Dim strJwe As String
strJwe = jwe.Encrypt(plainText,"utf-8")
If (jwe.LastMethodSuccess <> 1) Then
    Debug.Print jwe.LastErrorText
    Exit Sub
End If

Debug.Print strJwe

Debug.Print "Success."