json_schema: {
      "id": "https://letsencrypt.org/schema/01/jwk#",
      "$schema": "http://json-schema.org/draft-04/schema#",
      "description": "Schema for a jwk (**kty RSA/e=65537 ONLY**)",
      "type": "object",
      "required": [
          "kty",
          "e",
          "n"
      ],
      "properties": {
          "kty": {
              "enum": [
                  "RSA"
              ]
          },
          "e": {
              "enum": [
                  "AQAB"
              ]
          },
          "n": {
              "type": "string",
              "pattern": "^[-_=0-9A-Za-z]+$"
          }
      }
  }