{ "$schema":                    "https://json-schema.org/draft/2020-12/schema",
  "$id":                        "https://schemas.mpai.community/PTF/V1.0/data/PolicyBinding.json",
  "title":                      "Policy Binding V1.0", "description": "Binding of a policy to an Instance Credential or Process.",
                                "type": "object", "required": ["Version", "PolicyID", "Target", "Signature"],
                                "additionalProperties": false, "properties": {

    "Header":                   { "type": "string", "pattern": "^PTF-POL-V[0-9]{1,2}[.][0-9]{1,2}$" },
    "MInstanceID":              { "type": "string" },
    "PolicyBindingID":          { "type": "string" },
    "PolicyBindingTime":        { "$ref": "https://schemas.mpai.community/OSD/V1.5/data/Time.json" },

    "PolicyID":                 { "type": "string", "description": "Identifier of the policy being bound." },

    "Target":                   { "type": "object", "required": ["Type", "ID"], "additionalProperties": false, "properties": {
      "Type":                   { "type": "string", "enum": ["AIMInstance", "ProcessInstance", "InstanceCredential"] },
      "ID":                     { "type": "string", "description": "Identifier of the target object." } } },

    "Constraints":              { "type": "array", "description": "Optional constraints associated with the policy binding.",
                                  "items": { "type": "object", "required": ["Name", "Value"], "additionalProperties": false, "properties": {
        "Name":                 { "type": "string", "description": "Constraint name." },
        "Value":                { "type": "string", "description": "Constraint value." },
        "HashAlgorithm":        { "$ref": "https://schemas.mpai.community/PTF/V1.0/data/SecurityAlgorithmTaxonomy.json#/properties/Hash",
                                  "description": "Optional hash algorithm identifier from the Security Algorithm Taxonomy." },
        "HashValue":            { "type": "string", "description": "Optional hash of the constraint value (hex or base64url)." } } } },

    "Signature":                { "type": "object", "required": ["Algorithm", "Value"],
                                  "description": "Digital signature over the policy binding using a Signature algo. from the Security Algorithm Taxonomy.",
                                  "additionalProperties": false, "properties": {
      "Algorithm":              { "$ref": "https://schemas.mpai.community/PTF/V1.0/data/SecurityAlgorithmTaxonomy.json#/properties/Signature",
                                  "description": "Signature algorithm identifier from the Security Algorithm Taxonomy." },
      "Value":                  { "type": "string", "description": "Digital signature value encoded as base64url." } } },

    "DataXMData":               { "$ref": "https://schemas.mpai.community/PTF/V1.0/data/DataExchangeMetadata.json" },
    "DescrMetadata":            { "type": "string", "maxLength": 2048 } } }