C2PA Specifications

https://spec.c2pa.org/specifications/specifications/2.3/
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C2PA Specifications define technical standards for certifying the source and provenance of media...
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### CBOR Diagnostic Examples for Original Preservation Image Representation

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

Provides examples in CBOR Diagnostic Format for the `c2pa.alternative-content-representation` assertion. These examples illustrate how to reference Original Preservation Image (OPI) data either located within an asset in MPF using `multiAssetPartIndex` or embedded directly within the manifest using `embeddedOriginalPreservationImage`.

```cbor
// The case for reference Original Preservation Image(OPI) data located within the asset in MPF. //
{
  "type": "exif.originalPreservationImage",
  "parameters": {
    "multiAssetPartIndex": 1
  }
}

// The case for recording the OPI inside the manifest. //
{
  "type": "exif.originalPreservationImage",
  "parameters": {
    "embeddedOriginalPreservationImage" : {
       "url" : "self#jumbf=c2pa.assertions/c2pa.embedded-data",
       "hash": b64'Hf0IgeqbL0m+FTTLpUWwsDGR8pvhUR1AlwvaXjQ0qGY='
   }
  }
}
```

--------------------------------

### Example C2PA v2 Action in CBOR Diagnostic Notation

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

An example demonstrating a v2 C2PA manifest structure containing a list of actions. It includes 'c2pa.filtered' and 'c2pa.cropped' actions with their respective parameters and timestamps, along with metadata.

```cbor-diag
{
  "actions": [
    {
      "action": "c2pa.filtered",
      "when": 0("2020-02-11T09:00:00Z"),
      "parameters": {
        "instanceID": 37(h'ed610ae51f604002be3dbf0c589a2f1f')
      },
      "softwareAgent" : {
          "name": "Joe's Photo Editor",
          "version": "2.0",
          "operating_system": "Windows 10"
      }
    },
    {
      "action": "c2pa.cropped",
      "when": 0("2020-02-11T09:30:00Z")
    }
  ],
  "metadata": {
    "dateTime": 0("2021-06-28T16:34:11.457Z"),
    "reviewRatings": [
      {
        "value": 1,
        "explanation": "Content bindings did not validate"
      }
    ]
  }
}
```

--------------------------------

### Basic font-info-map Example in CBOR Diagnostic Notation

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

A minimal example of the font-info-map in CBOR diagnostic notation, including only the required fields. This demonstrates the essential structure for font assertion data.

```cbor
{
    "fullName": "Example Two Italic",
    "familyName": "ExampleTwo",
    "style": "Italic",
    "weight": {
        "class": "Regular",
        "value": 400
    },
    "postScriptName": "Example-Two-Italic",
    "format": "TrueType",
    "copyrightNotice": "Copyright 2011 The Example Two Project Authors (https://www.example.com/lifonts/Example-Two), with Reserved Font Name 'Example Two'.",
    "copyrightHolder": {
        "name": "Fabrikam"
    },
    "designers": [
        {
            "person": {
              "name": "John Doe",
              "url": "https://fabrikam.example.com/jdoefonts"
            }
        }
    ]
}

```

--------------------------------

### Extended font-info-map Example with Optional Fields in CBOR Diagnostic Notation

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

An extended example of the font-info-map in CBOR diagnostic notation, showcasing the use of optional fields. This includes versioning, release URLs, and more detailed copyright and designer information.

```cbor
{
    "fullName": "Example Font Bold Italic",
    "version": "7.0.4-beta",
    "versionUrl": "https://fabrikam.example.com/release/efbi/7.0",
    "familyName": "ExampleFont",
    "style": "Italic",
    "weight": {
        "class": "Bold",
        "value": 700
    },
    "postScriptName": "ExampleFont-BoldItalic",
    "format": "OpenType",
    "copyrightNotice": "© 2017 Fabrikam, Inc. All Rights Reserved."
}

```

--------------------------------

### CBOR Example: Deletion of PDF Pages

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

An example of a CBOR object representing the deletion of a range of pages from a PDF file. It uses a 'frame' type with start and end page numbers.

```cbor
// example of deletion of some pages from a PDF //
{
  "region": [
    {
      "type": "frame",
      "frame" : {
        "start" : 27,
        "end" : 30
      }
    },
  ],
  "description": "unnecessary pages removed before distribution"
}
```

--------------------------------

### GET /services/supportedAlgorithms

Source: https://spec.c2pa.org/specifications/specifications/2.3/softbinding/Decoupled

Fetches a list of all soft binding algorithms that are currently supported by the service.

```APIDOC
## GET /services/supportedAlgorithms

### Description
Returns a list of the soft binding algorithms supported by the service.

### Method
GET

### Endpoint
/services/supportedAlgorithms

### Parameters
None

### Responses
#### Success Response (200)
- **[Schema for supported algorithms]** - Successful operation

#### Error Responses
- **500** - Service failure
```

--------------------------------

### CBOR Example: Contiguous Range of Table Cells

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

An example of a CBOR object defining a contiguous range of table cells within a document. It uses xpointer to specify the start and end cells.

```cbor
// example of a contiguous range of table cells //
{
  "region": [
    {
      "type": "textual",
      "text" : {
        "selectors" : [
          [
            {
              "selector" : {
                "fragment" : "xpointer(//table[1]/tr[1]/td[2])",
              },
              "end" : {
                "fragment" : "xpointer(//table[1]/tr[1]/td[4])",
              }
            }
          ]
	    ]
      }
    },
  ],
  "description": "cleared some table cells"
}
```

--------------------------------

### C2PA Action Template Example (CBOR Diagnostic Notation)

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

Demonstrates how to define actions and apply templates in C2PA. This example shows a template applied to specific actions and another using a wildcard for all actions. It uses CBOR diagnostic notation.

```json
{
    "actions": [
        {
            "action": "com.joesphoto.filter",
            "when": 0("2020-02-11T09:00:00Z")
        },
        {
            "action": "c2pa.edited",
            "when": 0("2020-02-11T09:10:00Z")
        },
        {
            "action": "com.joesphoto.filter",
            "when": 0("2020-02-11T09:20:00Z")
        },
        {
            "action": "c2pa.cropped",
            "when": 0("2020-02-11T09:30:00Z")
        }
    ],
    "templates": [{
        "action": "com.joesphoto.filter",
        "description": "Magic Filter",
        "digitalSourceType": "http://cv.iptc.org/newscodes/digitalsourcetype/compositeSynthetic",
        "softwareAgent" : {
            "name": "Joe's Photo Editor",
            "version": "2.0",
            "operating_system": "Windows 10"
        }
    }]
}

// example of using the special all actions/`*` template, for all actions //
{
    "actions": [
        {
            "action": "c2pa.created",
            "when": 0("2024-03-09T20:04Z")
        },
        {
            "action": "c2pa.edited",
            "when": 0("2025-02-11T09:10:00Z")
        },
        {
            "action": "c2pa.cropped",
            "when": 0("2025-02-11T09:30:00Z")
        }
    ],
    "templates": [{
        "action": "*",
        "digitalSourceType": "http://cv.iptc.org/newscodes/digitalsourcetype/humanEdits",
        "softwareAgent" : {
            "name": "Jane's Human Authoring Tool",
            "version": "1.0"
        }
    }]
}
```

--------------------------------

### GET /services/supportedAlgorithms

Source: https://spec.c2pa.org/specifications/specifications/2.3/softbinding/Decoupled

Returns a list of soft binding algorithms supported by the service. This allows clients to enumerate the names of soft binding algorithms that can be used for queries.

```APIDOC
## GET /services/supportedAlgorithms

### Description
Returns a list of the soft binding algorithms supported by the service. Enumerate the names of soft binding algorithms supported as queries by the service. See https://github.com/c2pa-org/softbinding-algorithm-list for an authoritative list of C2PA soft binding algorithm names.

### Method
GET

### Endpoint
/services/supportedAlgorithms

### Parameters
#### Query Parameters
None

### Responses
#### Success Response (200)
- **application/json** - Successful operation. The response body will contain a schema object describing the supported algorithms, including watermarks and fingerprints.

#### Response Example
```json
{
  "watermarks": [
    {
      "alg": "foo.bar.watermark.1"
    }
  ],
  "fingerprints": [
    {
      "alg": "foo.bar.fingerprint.1"
    }
  ]
}
```

#### Error Responses
- **400** - Invalid request
- **500** - Service failure
```

--------------------------------

### CBOR Diagnostic Notation Example for Data Hash Assertion

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

This example demonstrates a data hash assertion in CBOR diagnostic notation. It includes the hashing algorithm ('sha256'), padding, a base64-encoded hash value, an optional name, and an exclusion range with start and length.

```cbor-diag
{
  "alg" : "sha256",
  "pad" : '0000',
  "hash": 'Auxjtmax46cC2N3Y9aFmBO9Jfay8LEwJWzBUtZ0sUM8gA=',
  "name": "JUMBF manifest"
  "exclusions": [
    {
      "start": 9960,
      "length": 4213
    }
  ],
}
```

--------------------------------

### CBOR Diagnostic Notation Example for Assertion Metadata

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

An example of assertion metadata represented in CBOR diagnostic notation (RFC 8949). This example demonstrates the structure for `reference` and `dataSource` fields within the assertion metadata.

```cbor-diag
{
  "reference": {
      "url": "self#jumbf=c2pa.assertions/c2pa.metadata",
      "alg": "sha256",
      "hash": b64'hoOspQQ1lFTy/4Tp8Epx670E5QW5NwkNR+2b30KFXug='
    },
  "dataSource": {
    "type": "localProvider.REE",
    "details": "EXIF GPS data provided by operating system geolocation API"
  }
}
```

--------------------------------

### Smart Contract K-V Stores

Source: https://spec.c2pa.org/specifications/specifications/2.3/softbinding/Decoupled

This section describes how to query a K-V store using a smart contract. It outlines the required fields and provides an example JSON structure for the query.

```APIDOC
## Smart Contract K-V Stores

### Description
This endpoint allows querying a K-V store via a smart contract. It requires the smart contract address, the function name to call, and schemas for input and output.

### Method
POST (Implied by the context of querying data)

### Endpoint
Not explicitly defined, but related to smart contract interaction.

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
- **smartContractAddress** (string) - Required - The hex address of the smart contract.
- **byBindingFunctionName** (string) - Required - The name of the function on the smart contract to query the K-V store.
- **byBindingInputSchema** (object) - Required - The schema of the input JSON string for the smart contract function.
  - **softBindingValue** (string) - Required - A base64-encoded string representing the soft binding identifier.
- **byBindingOutputSchema** (object) - Required - The schema of the output JSON string from the smart contract function.
  - **endpoints** (array) - Required - An array of URIs for Soft Binding Resolution APIs.
  - **manifestId** (string) - Optional - The unique identifier of the C2PA manifest.

### Request Example
```json
{
  "resolutionMethod": "smartContract",
  "querySmartContract": {
    "smartContractAddress": "0xABC123DEF4567890ABCDEF1234567890ABCDEF12",
    "byBindingFunctionName": "getManifestByBinding",
    "byBindingInputSchema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "type": "object",
      "properties": {
        "softBindingValue": {
          "type": "string",
          "description": "A base64-encoded string describing, in algorithm specific format, the value of the soft binding to be used as the query."
        }
      },
      "required": ["softBindingValue"],
      "additionalProperties": false
    },
    "byBindingOutputSchema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "type": "object",
      "properties": {
        "endpoints": {
          "type": "array",
          "items": {
            "type": "string",
            "format": "uri"
          },
          "description": "The URL(s) of the Softbinding Resolution API that may resolve this manifest ID."
        },
        "manifestId": {
          "type": "string",
          "description": "The optional unique identifier of the C2PA manifest, used to retrieve specific metadata. This may be absent if the manifest ID is not published within the K-V store."
        }
      },
      "required": ["endpoints"],
      "additionalProperties": false
    }
  }
}
```

### Response
#### Success Response (200)
- **endpoints** (array) - Description: The URL(s) of the Softbinding Resolution API that may resolve this manifest ID.
- **manifestId** (string) - Description: The optional unique identifier of the C2PA manifest, used to retrieve specific metadata. This may be absent if the manifest ID is not published within the K-V store.

#### Response Example
```json
{
  "endpoints": ["http://example.com/resolve"],
  "manifestId": "someManifestId123"
}
```
```

--------------------------------

### C2PA Software Agents Example (CBOR Diagnostic Notation)

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

Illustrates how to define multiple software agents and reference them by index within C2PA actions. This allows for detailed tracking of the tools used in content creation and modification. It uses CBOR diagnostic notation.

```json
{
    "actions": [
        {
            "action": "com.joesphoto.magic-avatar",
            "when": 0("2020-02-11T09:00:00Z"),
			"softwareAgentIndex" : 0
        },
        {
            "action": "c2pa.edited",
            "when": 0("2020-02-11T09:10:00Z")
			"softwareAgentIndex" : 1
        },
        {
            "action": "com.joesphoto.beauty-filter",
            "when": 0("2020-02-11T09:20:00Z"),
			"softwareAgentIndex" : 0
        },
        {
            "action": "com.joesphoto.all-smiles",
            "when": 0("2020-02-11T09:40:00Z"),
			"softwareAgentIndex" : 0
        },
        {
            "action": "c2pa.cropped",
            "when": 0("2020-02-11T09:30:00Z")
			"softwareAgentIndex" : 1
        },
        {
            "action": "com.joesphoto.green-screen",
            "when": 0("2020-02-11T09:50:00Z"),
			"softwareAgentIndex" : 0
        }
    ],
    "softwareAgents": [
        {
			"name": "Joe's AI Filter",
			"version": "1.0",
			"operating_system": "Windows 10"
        }
        {
			"name": "Joe's Photo Editor",
			"version": "2.0",
			"operating_system": "Windows 10"
        }
    ]
}
```

--------------------------------

### C2PA Ingredient Example in CBOR Diagnostic Notation

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

An example of an ingredient assertion represented in CBOR diagnostic notation (RFC 8949). This example demonstrates the structure and typical fields, such as title, format, relationship, thumbnail, activeManifest, and claimSignature, as defined by the C2PA specifications. It serves as a practical illustration for developers working with C2PA data.

```cbor-diag
{
  "dc:title": "image 1.jpg",
  "metadata": {
    "dateTime": 0("2021-06-28T16:49:32.874Z"),
    "reviewRatings": [
      {
        "value": 5,
        "explanation": "Content bindings validated"
      }
    ]
  }
  "dc:format": "image/jpeg",
  "thumbnail": {
      "url": "self#jumbf=c2pa.assertions/c2pa.thumbnail.ingredient",
      "hash": b64'UjRAYWiAq4lfCRDmksWAlDJN/XtHHFFwMWymsZsm3j8='
  },
  "relationship": "parentOf",
  "activeManifest": {
      "url": "self#jumbf=/c2pa/urn:c2pa:5E7B01FC-4932-4BAB-AB32-D4F12A8AA322",
      "hash": b64'1kjJTO108b71cL95UxgfHD3eDgk9VrCedW8n3fYTRMk='
  },
  "claimSignature": {
      "url": "self#jumbf=/c2pa/urn:c2pa:5E7B01FC-4932-4BAB-AB32-D4F12A8AA322/c2pa.signature"
}
```

--------------------------------

### BMFF Merkle Map CBOR Diagnostic Example

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

An example of the bmff-merkle-map structure represented in CBOR diagnostic notation, illustrating the expected format and data types for its fields.

```cbor
{
  "hashes": [
    b64'TWVub3JhaA=='
  ],
  "localId": 4402,
  "location": 2203,
  "uniqueId": 1339
}

```

--------------------------------

### Event Log K-V Stores

Source: https://spec.c2pa.org/specifications/specifications/2.3/softbinding/Decoupled

This section describes how to query a K-V store using event logs. It outlines the required fields and provides an example JSON structure for the query.

```APIDOC
## Event Log K-V Stores

### Description
This endpoint allows querying a K-V store by filtering event logs. It requires the smart contract address, a key topic for filtering, and a schema for parsing the output.

### Method
POST (Implied by the context of querying data)

### Endpoint
Not explicitly defined, but related to event log interaction.

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
- **smartContractAddress** (string) - Required - The hex address of the smart contract writing the event log entries.
- **keyTopic** (string) - Required - The topic used to filter event logs for the soft binding key.
- **byBindingOutputSchema** (object) - Required - JSON schema describing how to parse the endpoint and manifest ID from an event log message.
  - **endpoints** (array) - Required - An array of URIs for Soft Binding Resolution APIs.
  - **manifestId** (string) - Optional - The unique identifier of the C2PA manifest, if available.

### Request Example
```json
{
  "resolutionMethod": "eventLog",
  "queryEventLog": {
    "smartContractAddress": "0xDEF4567890ABCDEF1234567890ABCDEF12345678",
    "keyTopic": "topic1",
    "byBindingOutputSchema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "type": "object",
      "properties": {
        "endpoints": {
          "type": "array",
          "items": {
            "type": "string",
            "format": "uri"
          },
          "description": "The URL(s) of the Softbinding Resolution API that may resolve this manifest ID."
        },
        "manifestId": {
          "type": "string",
          "description": "The optional unique identifier of the C2PA manifest, used to retrieve specific metadata. This may be absent if the manifest ID is not published within the K-V store."
        }
      },
      "required": ["endpoints"],
      "additionalProperties": false
    }
  }
}
```

### Response
#### Success Response (200)
- **endpoints** (array) - Description: The URL(s) of the Softbinding Resolution API that may resolve this manifest ID.
- **manifestId** (string) - Description: The optional unique identifier of the C2PA manifest, used to retrieve specific metadata. This may be absent if the manifest ID is not published within the K-V store.

#### Response Example
```json
{
  "endpoints": ["http://example.com/resolve"],
  "manifestId": "someManifestId456"
}
```
```

--------------------------------

### CBOR Example: Textual Range in Non-Tagged PDF

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

Demonstrates a CBOR object for a textual range in a non-tagged PDF. This example specifies a page number and a rectangular area.

```cbor
// example of a textual range in a non-tagged PDF file //
//  in this case, we can only specify a page & rectangular area //
{
  "region": [
    {
      "type": "textual",
      "text" : {
        "selectors" : [
          [
            {
              "selector" : {
                "fragment" : "page=1,rect=10,10,450,500",
                "start" : 10,
                "end" : 20
              }
            }
          ]
        ]
      }
    },
  ],
  "description": "Redaction performed as per FOIA request"
}
```

--------------------------------

### CBOR Example: PNG Box Hash with Excluded XMP Box

Source: https://spec.c2pa.org/specifications/specifications/2.3/specs/C2PA_Specification

Demonstrates the CBOR diagnostic notation for a PNG file's box hash structure. This example highlights the exclusion of the XMP box by setting its 'excluded' field to true, alongside other standard PNG boxes and the C2PA box.

```cbor
// PNG Example //
// with the XMP box excluded //
{
  	"alg" : "sha256",
	"boxes": [
		{
			"names" : ["PNGh", "IHDR"],
			"hash" : b64'வுகளை',
			"pad" : b64'',
		},
		{
			"names" : ["C2PA"],
			"hash" : b64'AA==',
			"pad" : b64'',
		},
		{
			"names" : ["sBIT"],
			"hash" : b64'வுகளை',
			"pad" : b64'',
		},
		{
			"names" : ["iTXt"],
			"hash" : b64'வுகளை',
			"excluded": true,
			"pad" : b64'',
		},
		{
			"names" : ["IDAT", "IEND"],
			"hash" : b64'வுகளை',
			"pad" : b64'',
		}
	]
}
```
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