Resolving with zone files from Sia

lib/handover.js

@@ -8,6 +8,7 @@
 const {wire, util} = require('bns');
 const {BufferReader} = require('bufio');
 const Ethereum = require('./ethereum');
+const Sia = require('./sia');
 
 const plugin = exports;
 
@@ -23,6 +24,11 @@ class Plugin {
       projectSecret: node.config.str('handover-infura-projectsecret')
     });
 
+    this.sia = new Sia({
+      logger: node.logger.context('handover:sia'),
+      portal: node.config.str('handover-sia-portal', 'siasky.net') // or skyportal.xyz, etc.
+    });
+
     // Plugin can not operate if node doesn't have DNS resolvers
     if (!this.ns || !this.node.rs)
       return;
@@ -66,6 +72,23 @@ class Plugin {
             return this.sendSOA(name);
           }
           break;
+
+        case '_sia.':
+          if (type === wire.types.DS) {
+            // TODO: plugin should have ephemeral DNSSEC keys.
+            // We should return that here, signed by HNS root ZSK.
+          } else {
+            return this.sendSOA(name);
+          }
+          break;
+        case '_siaregistry.':
+          if (type === wire.types.DS) {
+            // TODO: plugin should have ephemeral DNSSEC keys.
+            // We should return that here, signed by HNS root ZSK.
+          } else {
+            return this.sendSOA(name);
+          }
+          break;
       }
 
       // Next, try actually resolving the name with the HNS root zone.
@@ -85,7 +108,7 @@ class Plugin {
         // and query it for the user's original request
         if (rr.data.ns.slice(-5) === '.eth.') {
           // If the recursive is being minimal, don't look up the name.
-          // Send the SOA back and get the full query from the recursive .
+          // Send the SOA back and get the full query from the recursive.
           if (labels.length < 2) {
             return this.sendSOA(name);
           }
@@ -107,7 +130,7 @@ class Plugin {
         // the user's original request
         if (rr.data.ns.slice(-6) === '._eth.') {
           // If the recursive is being minimal, don't look up the name.
-          // Send the SOA back and get the full query from the recursive .
+          // Send the SOA back and get the full query from the recursive.
           if (labels.length < 2) {
             return this.sendSOA(name);
           }
@@ -124,14 +147,55 @@ class Plugin {
             rr.data.ns
           );
         }
+
+        // Resolve DNS by looking up the zone file at the specified
+        // skylink and query it for the user's original request
+        if (rr.data.ns.slice(-6) === '._sia.') {
+          if (labels.length < 1) {
+            return this.sendSOA(name);
+          }
+          this.logger.debug(
+            'Intercepted referral to ._sia: %s %s -> %s NS: %s',
+            name,
+            wire.typesByVal[type],
+            rr.name,
+            rr.data.ns
+          );
+          data = await this.sia.resolveDnsFromSkylink(
+            name,
+            type,
+            rr.data.ns
+          );
+        }
+
+        // Resolve DNS by looking up the specified sia registry entry
+        // for the zone file skylink address, then query the zone file
+        // for the user's original request
+        if (rr.data.ns.slice(-14) === '._siaregistry.') {
+          if (labels.length === 0) {
+            return this.sendSOA(name);
+          }
+          this.logger.debug(
+            'Intercepted referral to ._siaregistry: %s %s -> %s NS: %s',
+            name,
+            wire.typesByVal[type],
+            rr.name,
+            rr.data.ns
+          );
+          data = await this.sia.resolveDnsFromRegistry(
+            name,
+            type,
+            rr.data.ns
+          );
+        }
       }
 
-      // If the Ethereum stuff came up empty, return the
+      // If the above scheme resolvers came up empty, return the
       // HNS root server response unmodified.
       if (!data || data.length === 0)
         return res;
 
-      // If we did get an answer from Ethereum, mark the response
+      // If we did get an answer from the resolvers, mark the response
       // as authoritative and insert the new answer.
       this.logger.debug('Returning answers from alternate naming system');
       const replacementRes = new wire.Message();
@@ -141,7 +205,7 @@ class Plugin {
         replacementRes.answer.push(wire.Record.read(br));
       }
 
-      // Answers resolved from Ethereum appear to come directly
+      // Answers resolved from the resolvers appear to come directly
       // from the HNS root zone.
       this.ns.signRRSet(replacementRes.answer, type);
 

lib/sia.js

@@ -0,0 +1,147 @@
+'use strict';
+
+const axios = require('axios').default;
+const { Zone } = require('bns');
+const LRU = require('blru');
+
+class Sia {
+  constructor({ logger, portal }) {
+    this.logger = logger;
+    this.cache = new SiaCache();
+
+    const match = portal.match(/(?:https?\:\/\/)?([\w\.\-_]+)\/?/i);
+    if (match) this.portal = match[1];
+    else this.logger.error('Invalid portal.');
+  }
+
+  async resolveDnsFromSkylink(name, type, ns, node) {
+    this.logger.debug('Resolving', name, type, ns);
+    if (!node) node = name;
+
+    const labels = ns.split('.');
+
+    if (labels.length !== 3) return null;
+    if (labels[1] !== '_sia') return null;
+
+    const skylink = labels[0];
+    if (skylink.length !== 46) return null;
+
+    const skylinkContent = await this.getSkylinkContent(skylink);
+    return this.resolveDnsFromZone(skylinkContent, name, type);
+  }
+
+  async resolveDnsFromRegistry(name, type, ns, node) {
+    this.logger.debug('Resolving from Registry: ', name, type, ns);
+    if (!node) node = name;
+
+    const labels = ns.split('.');
+
+    if (labels.length !== 7) return null;
+    if (labels[5] !== '_siaregistry') return null;
+
+    // Pubkey and datakey are split into 2 labels of 32 bytes each because of max label length
+    const algo = labels[0];
+    const pubKey = labels[1] + labels[2];
+    const dataKey = labels[3] + labels[4];
+    if (algo.length <= 0 || pubKey.length !== 64 || dataKey.length !== 64)
+      return null;
+
+    const registryData = await this.getRegistryEntry(algo, pubKey, dataKey);
+    const skylinkContent = await this.getSkylinkContent(registryData);
+    return this.resolveDnsFromZone(skylinkContent, name, type);
+  }
+
+  async getSkylinkContent(skylink) {
+    const item = this.cache.get(skylink);
+    if (item) return item;
+
+    const skylinkContent = await this._getSkylinkContent(skylink);
+    this.cache.set(skylink, skylinkContent);
+    return skylinkContent;
+  }
+
+  async _getSkylinkContent(skylink) {
+    this.logger.debug('Fetching skylink...', skylink);
+    const content = await axios({
+      url: `https://${this.portal}/${skylink}`,
+      responseType: 'text',
+      transformResponse: [
+        (data) => {
+          return data;
+        },
+      ], // force text response: https://github.com/axios/axios/issues/907
+      maxBodyLength: 20000, // in bytes
+    });
+    this.logger.spam(content.data);
+    return content.data;
+  }
+
+  async getRegistryEntry(algo, pubKey, dataKey) {
+    const key = `${pubKey};${dataKey}`;
+    const item = this.cache.get(key);
+    if (item) return item;
+
+    const registryEntry = await this._getRegistryEntry(algo, pubKey, dataKey);
+    this.cache.set(key, registryEntry);
+    return registryEntry;
+  }
+
+  async _getRegistryEntry(algo, pubKey, dataKey) {
+    this.logger.debug('Fetching sia registry...', algo, pubKey, dataKey);
+    const content = await axios({
+      url: `https://${this.portal}/skynet/registry?publickey=${algo}:${pubKey}&datakey=${dataKey}`,
+      maxBodyLength: 20000, // in bytes
+    });
+    this.logger.spam(content.data);
+    return Buffer.from(content.data.data, 'hex').toString();
+  }
+
+  async resolveDnsFromZone(zoneContent, name, type) {
+    const zone = new Zone();
+
+    try {
+      zone.fromString(zoneContent);
+    } catch (error) {
+      if (error.type !== 'ParseError') this.logger.error(error);
+      return null;
+    }
+
+    this.logger.spam(zone);
+    const records = zone.get(name, type).map((rec) => rec.toRaw());
+    if (!records.length) return null;
+
+    return Buffer.concat(records);
+  }
+}
+
+class SiaCache {
+  constructor(size = 3000) {
+    this.cache = new LRU(size);
+    this.CACHE_TTL = 30 * 60 * 1000;
+  }
+
+  set(key, data) {
+    this.cache.set(key, {
+      time: Date.now(),
+      data,
+    });
+
+    return this;
+  }
+
+  get(key) {
+    const item = this.cache.get(key);
+
+    if (!item) return null;
+
+    if (Date.now() > item.time + this.CACHE_TTL) return null;
+
+    return item.data;
+  }
+
+  reset() {
+    this.cache.reset();
+  }
+}
+
+module.exports = Sia;

package.json

@@ -26,6 +26,8 @@
   },
   "homepage": "https://github.com/imperviousinc/handover#readme",
   "dependencies": {
+    "axios": "^0.21.1",
+    "blru": "^0.1.6",
     "bufio": "^1.0.7",
     "ethers": "^5.0.31"
   },