1 files changed, 129 insertions, 0 deletions
diff --git a/plugins/ObjectCacheServer/src/Endpoints/PeerDiscoveryEndpoint.cs b/plugins/ObjectCacheServer/src/Endpoints/PeerDiscoveryEndpoint.cs
new file mode 100644
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+++ b/plugins/ObjectCacheServer/src/Endpoints/PeerDiscoveryEndpoint.cs
@@ -0,0 +1,129 @@
+/*
+* Copyright (c) 2023 Vaughn Nugent
+* 
+* Library: VNLib
+* Package: ObjectCacheServer
+* File: PeerDiscoveryEndpoint.cs 
+*
+* PeerDiscoveryEndpoint.cs is part of ObjectCacheServer which is part of the larger 
+* VNLib collection of libraries and utilities.
+*
+* ObjectCacheServer is free software: you can redistribute it and/or modify 
+* it under the terms of the GNU Affero General Public License as 
+* published by the Free Software Foundation, either version 3 of the
+* License, or (at your option) any later version.
+*
+* ObjectCacheServer is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU Affero General Public License for more details.
+*
+* You should have received a copy of the GNU Affero General Public License
+* along with this program.  If not, see https://www.gnu.org/licenses/.
+*/
+
+using System;
+using System.Linq;
+using System.Net;
+using System.Text.Json;
+using System.Threading.Tasks;
+
+using VNLib.Hashing;
+using VNLib.Hashing.IdentityUtility;
+using VNLib.Plugins;
+using VNLib.Plugins.Essentials;
+using VNLib.Plugins.Essentials.Endpoints;
+using VNLib.Plugins.Essentials.Extensions;
+using VNLib.Plugins.Extensions.Loading;
+using VNLib.Data.Caching.Extensions;
+using VNLib.Data.Caching.ObjectCache.Server.Distribution;
+
+namespace VNLib.Data.Caching.ObjectCache.Server.Endpoints
+{
+    [ConfigurationName("discovery_endpoint")]
+    internal sealed class PeerDiscoveryEndpoint : UnprotectedWebEndpoint
+    {
+        private readonly IPeerMonitor PeerMonitor;
+        private readonly NodeConfig Config;
+
+        public PeerDiscoveryEndpoint(PluginBase plugin, IConfigScope config)
+        {
+            string? path = config["path"].GetString();
+
+            InitPathAndLog(path, plugin.Log);
+
+            //Get the peer monitor
+            PeerMonitor = plugin.GetOrCreateSingleton<CachePeerMonitor>();
+
+            //Get the node config
+            Config = plugin.GetOrCreateSingleton<NodeConfig>();
+        }
+
+        protected override async ValueTask<VfReturnType> GetAsync(HttpEntity entity)
+        {
+            //Get auth token
+            string? authToken = entity.Server.Headers[HttpRequestHeader.Authorization];
+
+            if(string.IsNullOrWhiteSpace(authToken))
+            {
+                entity.CloseResponse(HttpStatusCode.Unauthorized);
+                return VfReturnType.VirtualSkip;
+            }
+          
+            string subject = string.Empty;
+
+            //Parse auth token
+            using(JsonWebToken jwt = JsonWebToken.Parse(authToken))
+            {
+                //try to verify against cache node first
+                if (!Config.Config.VerifyCache(jwt))
+                {
+                    //failed...
+
+                    //try to verify against client key
+                    using ReadOnlyJsonWebKey clientPub = await Config.KeyStore.GetClientPublicKeyAsync();
+
+                    if (!jwt.VerifyFromJwk(clientPub))
+                    {
+                        //invalid token
+                        entity.CloseResponse(HttpStatusCode.Unauthorized);
+                        return VfReturnType.VirtualSkip;
+                    }
+                }
+
+                using JsonDocument payload = jwt.GetPayload();
+                
+                subject = payload.RootElement.GetProperty("sub").GetString() ?? string.Empty;                
+            }
+
+            //Valid key, get peer list to send to client
+            ICachePeerAdvertisment[] peers = PeerMonitor.GetAllPeers()
+                                        .Where(static p => p.Advertisment != null)
+                                        .Select(static p => p.Advertisment!)
+                                        .ToArray();
+
+            //Build response jwt
+            using JsonWebToken response = new();
+            
+            //set header from cache config
+            response.WriteHeader(Config.Config.GetJwtHeader());
+
+            response.InitPayloadClaim()
+                .AddClaim("iss", Config.Config.NodeId)
+                //Audience is the requestor id
+                .AddClaim("sub", subject)
+                .AddClaim("iat", entity.RequestedTimeUtc.ToUnixTimeSeconds())
+                //Send all peers as a json array
+                .AddClaim("peers", peers)
+                .AddClaim("nonce", RandomHash.GetRandomBase32(24))
+                .CommitClaims();
+
+            //Sign the response
+            Config.Config.SignJwt(response);
+            
+            //Send response to client
+            entity.CloseResponse(HttpStatusCode.OK, Net.Http.ContentType.Text, response.DataBuffer);
+            return VfReturnType.VirtualSkip;
+        }
+    }
+}