Write 1.2.1 of the REST API spec (#195)

This basically adds the ability to set a CA certificate authenticator and identity in the call to startMultipeerReplciator.  The TDK client will provide the cert and private key to use for both, so the test server need only do the following:

1. Convert the PEM bytes of the certificate into an appropriate platform type for the authenticator
2. Convert Base64 PKCS#12 data into bytes for using in TLSIdentity.CreateIdentity

Author: borrrden

spec/api/api.yaml

@@ -46,6 +46,9 @@ info:
       ```
 
     Changes
+    1.2.1 (06/04/2025)
+    * Add authenticator property to [/startMultipeerReplicator](#operation/startMultipeerReplicator)
+
     1.2.0 (04/09/2025)
     * Add [/startMultipeerReplicator](#operation/startMultipeerReplicator),
     * Add [/stopMultipeerReplicator](#operation/stopMultipeerReplicator) endpoint
@@ -131,7 +134,7 @@ info:
     * Changed DocumentReplication.flags type from int to array of enums.
     * Added 'enableDocumentListener' to ReplicatorConfiguration.
     * Added a note that any enum values are case insensitive.
-  version: 1.2.0
+  version: 1.2.1
 tags:
   - name: API
     description: The API endpoints of the test server
@@ -833,16 +836,17 @@ paths:
         - API
       summary: Starts a Multipeer replicator
       description: |-
-        Starts a P2P listener so that the device can act as the passive side of a P2P replication.
+        Starts a multipeer replicator to create a mesh of connected clients.
       operationId: startMultipeerReplicator
       requestBody:
         description: |-
-          The request object containing the collections to share and, optionally, the port to listen on.
+          The request object containing the collections to share and the peer group ID.  Optionally,
+          it can contain an authenticator as well.  The default (null) behavior is accept all connections.
         content:
           application/json:
             schema:
               type: object
-              required: ['peerGroupID', 'database', 'collections']
+              required: ['peerGroupID', 'database', 'collections', 'identity']
               properties:
                 peerGroupID:
                   type: string
@@ -854,6 +858,10 @@ paths:
                   type: array
                   items:
                     $ref: "#/components/schemas/ReplicationCollection"
+                identity:
+                  $ref: '#/components/schemas/MultipeerReplicatorIdentity'
+                authenticator:
+                  $ref: '#/components/schemas/MultipeerReplicatorCAAuthenticator'
         required: true
       responses:
         '200':
@@ -1276,6 +1284,38 @@ components:
                 example: '1234567890abcdef'
               status:
                 $ref: '#/components/schemas/ReplicatorStatus'
+    MultipeerReplicatorIdentity:
+      description: |-
+        MultipeerReplicatorIdentity is used to specify a TLS certificate and key particular
+        for a multipeer replciator so that it can identify itself.
+      type: object
+      required: ['encoding', 'data']
+      properties:
+        encoding:
+          type: string
+          enum: ['PKCS12']
+          description: The type of data contained in the data field.
+        data:
+          type: string
+          format: byte
+          description: Base-64 encoded data of the format specified in encoding
+        password:
+          type: string
+          example: 'pass'
+          description: The password if the data is password protected
+    MultipeerReplicatorCAAuthenticator:
+      description: |-
+        MultipeerReplicatorCAAuthenticator is used to authenticate the replicator using a CA certificate.
+        The certificate is expected to be in PEM format, and any accepted client must have a certificate
+        signed by the CA certificate.
+      type: object
+      required: ['type', 'certificate']
+      properties:
+        'type':
+          type: string
+          enum: ['CA-CERT']
+        certificate:
+          type: string
     ResetConfiguration:
       description: |-
         ResetConfiguration describes how the databases will be setup after the reset.