feat: add hostname for checkAddress (#525)

src/HttpAgent.ts

@@ -6,7 +6,7 @@ import {
   buildConnector,
 } from 'undici';
 
-export type CheckAddressFunction = (ip: string, family: number | string) => boolean;
+export type CheckAddressFunction = (ip: string, family: number | string, hostname: string) => boolean;
 
 export type HttpAgentOptions = {
   lookup?: LookupFunction;
@@ -46,13 +46,13 @@ export class HttpAgent extends Agent {
         if (options.checkAddress) {
           // dnsOptions.all set to default on Node.js >= 20, dns.lookup will return address array object
           if (typeof address === 'string') {
-            if (!options.checkAddress(address, family)) {
+            if (!options.checkAddress(address, family, hostname)) {
               err = new IllegalAddressError(hostname, address, family);
             }
           } else if (Array.isArray(address)) {
             const addresses = address as { address: string, family: number }[];
             for (const addr of addresses) {
-              if (!options.checkAddress(addr.address, addr.family)) {
+              if (!options.checkAddress(addr.address, addr.family, hostname)) {
                 err = new IllegalAddressError(hostname, addr.address, addr.family);
                 break;
               }
@@ -79,7 +79,7 @@ export class HttpAgent extends Agent {
       const family = isIP(hostname);
       if (family === 4 || family === 6) {
         // if request hostname is ip, custom lookup won't execute
-        if (!this.#checkAddress(hostname, family)) {
+        if (!this.#checkAddress(hostname, family, hostname)) {
           throw new IllegalAddressError(hostname, hostname, family);
         }
       }

test/HttpClient.test.ts

@@ -313,5 +313,32 @@ describe('HttpClient.test.ts', () => {
         return true;
       });
     });
+
+    it('should allow hostname check', async () => {
+      let hostname: string;
+      const httpclient = new HttpClient({
+        checkAddress(ip, family, aHostname) {
+          hostname = aHostname;
+          return true;
+        },
+        lookup(hostname, options, callback) {
+          if (
+            process.version.startsWith('v18')
+            || process.version.startsWith('v16')
+            || process.version.startsWith('v14')
+          ) {
+            return callback(null, '127.0.0.1', 4);
+          }
+          return callback(null, [{
+            address: '127.0.0.1',
+            family: 4,
+          }]);
+        },
+      });
+
+      const response = await httpclient.request(_url.replace('localhost', 'check-host-ssrf.com'));
+      assert.equal(hostname, 'check-host-ssrf.com');
+      assert.equal(response.status, 200);
+    });
   });
 });