Bugfix/siva.cbces - Fixup the K for AxxxCBC + ECDH-ES based JWEs

[ksivask]

1. fix the K - Please refer https://github.com/babelouest/rhonabwy/issues/28 for full details

2. display nested jwt header (for jwe)

   {
   "alg": "ECDH-ES",
   "cty": "JWT",
   "enc": "A192CBC-HS384",
   "epk": {
   "crv": "P-256",
   "kty": "EC",
   "x": "UcL8hgW6OTkqFvKS-XEiO-zwQqdqdj8myxOkVJ9f_n8",
   "y": "yDaZ0U9XD6oGzkXRnFJVWenF8sthhcTBIzSdntLMxfU"
   },
   "kid": "ExUMY91J9atex-1Ai5vbu6qJ4aAGq0RMQxo__QyZV4k",
   "typ": "JWT"
   }
   {
   "alg": "ES512",
   "kid": "HSnBqAC6TJsmCntBQrgp_BpCWZSoxygedxeE7b2SBrA",
   "typ": "JWT"
   }
   {
   "iat": 1516239022,
   "name": "JohnDoe",
   "sub": "jdoe@example.com"
   }

[babelouest]

Thanks for this!

I'll make some further reviews in a couple of days.

I've seen some code style stuff and a question concerning the for loop but I do appreciate your contribution!

[babelouest]

Thanks a lot for the bugfix @ksivask !