matrix-spec/data/api/client-server/cross_signing.yaml

# Copyright 2020 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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#
#     http://www.apache.org/licenses/LICENSE-2.0
#
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# limitations under the License.
openapi: 3.1.0
info:
  title: Matrix Client-Server Cross Signing API
  version: 1.0.0
paths:
  /keys/device_signing/upload:
    post:
      x-addedInMatrixVersion: "1.1"
      x-changedInMatrixVersion:
        "1.11": UIA is not always required for this endpoint.
      summary: Upload cross-signing keys.
      description: |-
        Publishes cross-signing keys for the user.

        This API endpoint uses the [User-Interactive Authentication API](/client-server-api/#user-interactive-authentication-api).
        
        User-Interactive Authentication MUST be performed, except in these cases:
        - there is no existing cross-signing master key uploaded to the homeserver, OR
        - there is an existing cross-signing master key and it exactly matches the
          cross-signing master key provided in the request body. If there are any additional
          keys provided in the request (self-signing key, user-signing key) they MUST also
          match the existing keys stored on the server. In other words, the request contains
          no new keys.
        
        This allows clients to freely upload one set of keys, but not modify/overwrite keys if
        they already exist. Allowing clients to upload the same set of keys more than once 
        makes this endpoint idempotent in the case where the response is lost over the network,
        which would otherwise cause a UIA challenge upon retry.
      operationId: uploadCrossSigningKeys
      security:
        - accessTokenQuery: []
        - accessTokenBearer: []
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                master_key:
                  description: Optional. The user\'s master key.
                  allOf:
                    - $ref: definitions/cross_signing_key.yaml
                self_signing_key:
                  description: |-
                    Optional. The user\'s self-signing key. Must be signed by
                    the accompanying master key, or by the user\'s most recently
                    uploaded master key if no master key is included in the
                    request.
                  allOf:
                    - $ref: definitions/cross_signing_key.yaml
                user_signing_key:
                  description: |-
                    Optional. The user\'s user-signing key. Must be signed by
                    the accompanying master key, or by the user\'s most recently
                    uploaded master key if no master key is included in the
                    request.
                  allOf:
                    - $ref: definitions/cross_signing_key.yaml
                auth:
                  description: |-
                    Additional authentication information for the
                    user-interactive authentication API.
                  allOf:
                    - $ref: definitions/auth_data.yaml
              example: {
                "auth": {
                  "type": "example.type.foo",
                  "session": "xxxxx",
                  "example_credential": "verypoorsharedsecret"
                },
                "master_key": {
                  "user_id": "@alice:example.com",
                  "usage": [
                    "master"
                  ],
                  "keys": {
                    "ed25519:base64+master+public+key": "base64+master+public+key"
                  }
                },
                "self_signing_key": {
                  "user_id": "@alice:example.com",
                  "usage": [
                    "self_signing"
                  ],
                  "keys": {
                    "ed25519:base64+self+signing+public+key": "base64+self+signing+master+public+key"
                  },
                  "signatures": {
                    "@alice:example.com": {
                      "ed25519:base64+master+public+key": "signature+of+self+signing+key"
                    }
                  }
                },
                "user_signing_key": {
                  "user_id": "@alice:example.com",
                  "usage": [
                    "user_signing"
                  ],
                  "keys": {
                    "ed25519:base64+user+signing+public+key": "base64+user+signing+master+public+key"
                  },
                  "signatures": {
                    "@alice:example.com": {
                      "ed25519:base64+master+public+key": "signature+of+user+signing+key"
                    }
                  }
                }
              }
        description: The keys to be published.
        required: true
      responses:
        "200":
          description: The provided keys were successfully uploaded.
          content:
            application/json:
              schema:
                type: object
                example: {}
        "400":
          description: |-
            The input was invalid in some way. This can include one of the
            following error codes:

            * `M_INVALID_SIGNATURE`: For example, the self-signing or
              user-signing key had an incorrect signature.
            * `M_MISSING_PARAM`: No master key is available.
          content:
            application/json:
              schema:
                type: object
                example: {
                  "errcode": "M_INVALID_SIGNATURE",
                  "error": "Invalid signature"
                }
        "403":
          description: |-
            The public key of one of the keys is the same as one of the user\'s
            device IDs, or the request is not authorized for any other reason.
          content:
            application/json:
              schema:
                type: object
                example: {
                  "errcode": "M_FORBIDDEN",
                  "error": "Key ID in use"
                }
      tags:
        - End-to-end encryption
  /keys/signatures/upload:
    post:
      x-addedInMatrixVersion: "1.1"
      summary: Upload cross-signing signatures.
      description: |-
        Publishes cross-signing signatures for the user.

        The signed JSON object must match the key previously uploaded or
        retrieved for the given key ID, with the exception of the `signatures`
        property, which contains the new signature(s) to add.
      operationId: uploadCrossSigningSignatures
      security:
        - accessTokenQuery: []
        - accessTokenBearer: []
      requestBody:
        content:
          application/json:
            schema:
              type: object
              description: |-
                A map of user ID to a map of key ID to signed JSON object.
              patternProperties:
                "^@":
                  x-pattern-format: mx-user-id
                  type: object
                  additionalProperties:
                    type: object
              example: {
                "@alice:example.com": {
                  "HIJKLMN": {
                    "user_id": "@alice:example.com",
                    "device_id": "HIJKLMN",
                    "algorithms": [
                      "m.olm.v1.curve25519-aes-sha256",
                      "m.megolm.v1.aes-sha"
                    ],
                    "keys": {
                      "curve25519:HIJKLMN": "base64+curve25519+key",
                      "ed25519:HIJKLMN": "base64+ed25519+key"
                    },
                    "signatures": {
                      "@alice:example.com": {
                        "ed25519:base64+self+signing+public+key": "base64+signature+of+HIJKLMN"
                      }
                    }
                  },
                  "base64+master+public+key": {
                    "user_id": "@alice:example.com",
                    "usage": [
                      "master"
                    ],
                    "keys": {
                      "ed25519:base64+master+public+key": "base64+master+public+key"
                    },
                    "signatures": {
                      "@alice:example.com": {
                        "ed25519:HIJKLMN": "base64+signature+of+master+key"
                      }
                    }
                  }
                },
                "@bob:example.com": {
                  "bobs+base64+master+public+key": {
                    "user_id": "@bob:example.com",
                    "keys": {
                      "ed25519:bobs+base64+master+public+key": "bobs+base64+master+public+key"
                    },
                    "usage": [
                      "master"
                    ],
                    "signatures": {
                      "@alice:example.com": {
                        "ed25519:base64+user+signing+public+key": "base64+signature+of+bobs+master+key"
                      }
                    }
                  }
                }
              }
        description: |-
          A map from user ID to key ID to signed JSON objects containing the
          signatures to be published.
        required: true
      responses:
        "200":
          description: The provided signatures were processed.
          content:
            application/json:
              schema:
                type: object
                properties:
                  failures:
                    type: object
                    description: |-
                      A map from user ID to key ID to an error for any signatures
                      that failed.  If a signature was invalid, the `errcode` will
                      be set to `M_INVALID_SIGNATURE`.
                    patternProperties:
                      "^@":
                        type: object
                        x-pattern-format: mx-user-id
                        additionalProperties:
                          type: object
                          title: Error
                    example:
                      "@alice:example.com":
                        HIJKLMN:
                          errcode: M_INVALID_SIGNATURE
                          error: Invalid signature
      tags:
        - End-to-end encryption
servers:
  - url: "{protocol}://{hostname}{basePath}"
    variables:
      protocol:
        enum:
          - http
          - https
        default: https
      hostname:
        default: localhost:8008
      basePath:
        default: /_matrix/client/v3
components:
  securitySchemes:
    accessTokenQuery:
      $ref: definitions/security.yaml#/accessTokenQuery
    accessTokenBearer:
      $ref: definitions/security.yaml#/accessTokenBearer