SDMP

Within the SDMP, the "container" is a JSON object defined using a schema in this document, which uses the syntax of the JSON Schema.

The container JSON object requires certain properties, but other applications may extend the container by specifying schemas to use for validation.

Container Extension

A container object is "extended" by specifying a valid JSON Schema within the object (the schemas property). The additional JSON Schema specified by the schema property entry is called the "container extension".

Every schema entry must be a valid SDMP resource URI or one of the strings of the core schemas.

Validation

The JSON object is validated using the JSON Schema method of object validation, and is validated first against the container schema (specified at the end of this document) and then validated against any other schemas specified, in the order in which they are listed.

If any of the following are true, the container object must be considered invalid:

• The container itself is considered invalid according to the container schema specified in this document (see here).
• Any entry in the schema array is an invalid SDMP resource URI.
• Any schema URI specified within the container schema list cannot be resolved by the application validating the container.
• The container is considered invalid according to any schema specified within the container.

JSON Properties

The JSON object of the container has the following required properties:

sdmp (object, required)

This root property of the object holds the metadata which describes the rest of the object.

sdmp.version (string, required)

The version of the SDMP specifications used to define and validate the properties of the container object.

This property must be a valid semver number.

Example: 0.10.6

sdmp.schemas (array, required)

Each array element of this property must be a UTF-8 encoded string which must be either:

1. a valid SDMP resource URI, which must resolve to a valid JSON schema, or
2. one of the following string values, which are schemas core to the SDMP:
   • identity
   • encrypted
   • signature
   • shared_key
   • resource
   • broadcast
   • request_journal
   • request_resource
   • response
   • message
   • receipt
   • node
   • user
   • trust
   • revoke

Example

Consider this example SDMP resource URI:

sdmp://GlvAreTo0lCSyum7Wzh8pzhxYOOu-gMIgO2N95AAwAGP6-nR8xCvWvIW0t9rF_ZZfpCY_fDV38JDFKaOU91A8Q/h6FWguOHjaB5eUCsjeSIUGxA6p2abtY6HmaUin0F_9INc60VT3IELkP-q7IuWEwBCA8SpIbkfO9ZAIj5jgusYA

If this example URI yields a valid JSON schema:

{
	"type": "object",
	"properties": {
		"hello": {
			"type": "string",
			"pattern": "^[a-z]+$"
		}
	},
	"required": [ "hello" ]
}

Then an example valid container might look like this:

{
	"sdmp": {
		"version": "0.10.6",
		"schemas": "sdmp://GlvAreTo0lCSyum7Wzh8pzhxYOOu-gMIgO2N95AAwAGP6-nR8xCvWvIW0t9rF_ZZfpCY_fDV38JDFKaOU91A8Q/h6FWguOHjaB5eUCsjeSIUGxA6p2abtY6HmaUin0F_9INc60VT3IELkP-q7IuWEwBCA8SpIbkfO9ZAIj5jgusYA"
	},
	"hello": "world"
}

An example invalid container might look like this:

{
	"sdmp": {
		"version": "0.10.6",
		"schemas": "sdmp://GlvAreTo0lCSyum7Wzh8pzhxYOOu-gMIgO2N95AAwAGP6-nR8xCvWvIW0t9rF_ZZfpCY_fDV38JDFKaOU91A8Q/h6FWguOHjaB5eUCsjeSIUGxA6p2abtY6HmaUin0F_9INc60VT3IELkP-q7IuWEwBCA8SpIbkfO9ZAIj5jgusYA"
	},
	"hello": 123
}

Note: This is invalid because the schema requires the value of the property hello to be a string.

And another example invalid container might look like this:

{
	"sdmp": {
		"version": "0.10.6",
		"schemas": "sdmp://GlvAreTo0lCSyum7Wzh8pzhxYOOu-gMIgO2N95AAwAGP6-nR8xCvWvIW0t9rF_ZZfpCY_fDV38JDFKaOU91A8Q/h6FWguOHjaB5eUCsjeSIUGxA6p2abtY6HmaUin0F_9INc60VT3IELkP-q7IuWEwBCA8SpIbkfO9ZAIj5jgusYA"
	}
}

Note: This is invalid because the schema requires that the value of the property hello be present.

JSON Schema

The exact JSON Schema for the container object is:

{
	"$schema": "http://json-schema.org/draft-04/schema#",
	"type": "object",
	"properties": {
		"sdmp": {
			"type": "object",
			"properties": {
				"version": {
					"type": "string"
				},
				"schemas": {
					"type": "array",
					"items": {
						"type": "string",
						"pattern": "^sdmp:\/\/[a-zA-Z0-9]+\/$"
					},
					"minItems": 1,
					"uniqueItems": true
				}
			},
			"required": [ "version", "schemas" ]
		}
	},
	"required": [ "sdmp" ]
}