{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://meshcognition.org/spec/mmp/schema/control-encrypted.schema.json",
  "title": "MMP v2.0 control-encrypted envelope (§18.2.1)",
  "description": "The sealed envelope of one control frame. The plaintext is the minified JSON of one inner frame (control-frame.schema.json and the other inner schemas); the AAD is mmp-aead-control-v2 over version, session, direction and sequence. It shares its direction's sequence counter with cmb-encrypted.",
  "type": "object",
  "required": [
    "type",
    "protocolVersion",
    "suite",
    "sessionId",
    "sequence",
    "direction",
    "sealed"
  ],
  "additionalProperties": false,
  "properties": {
    "type": {
      "const": "control-encrypted"
    },
    "protocolVersion": {
      "const": "2.0"
    },
    "suite": {
      "const": "X25519-HKDF-SHA256-ChaCha20-Poly1305"
    },
    "sessionId": {
      "type": "string",
      "pattern": "^[0-9a-f]{32}$"
    },
    "sequence": {
      "type": "string",
      "pattern": "^(0|[1-9][0-9]{0,28})$",
      "description": "Unsigned decimal, at most 79228162514264337593543950335 (2^96 − 1), since the AEAD nonce is the sequence in 96 bits. The 29-digit pattern is necessary, not sufficient."
    },
    "direction": {
      "enum": [
        "client-to-server",
        "server-to-client"
      ]
    },
    "sealed": {
      "type": "string",
      "minLength": 22,
      "pattern": "^[A-Za-z0-9_-]+$",
      "description": "Unpadded base64url of the ciphertext followed by the 16-byte Poly1305 tag; at least the tag."
    }
  }
}