Added product header check (#112180)

* Added product header check

* Added suggestions from code review

src/plugins/interactive_setup/server/elasticsearch_service.test.ts

@@ -57,6 +57,13 @@ describe('ElasticsearchService', () => {
             return mockConnectionStatusClient;
         }
       });
+      mockPingClient.asInternalUser.transport.request.mockResolvedValue(
+        interactiveSetupMock.createApiResponse({
+          statusCode: 200,
+          body: {},
+          headers: { 'x-elastic-product': 'Elasticsearch' },
+        })
+      );
 
       setupContract = service.setup({
         elasticsearch: mockElasticsearchPreboot,
@@ -537,6 +544,19 @@ some weird+ca/with
         );
       });
 
+      it('fails if host is not Elasticsearch', async () => {
+        mockPingClient.asInternalUser.ping.mockResolvedValue(
+          interactiveSetupMock.createApiResponse({ statusCode: 200, body: true })
+        );
+        mockPingClient.asInternalUser.transport.request.mockResolvedValue(
+          interactiveSetupMock.createApiResponse({ statusCode: 200, body: {}, headers: {} })
+        );
+
+        await expect(setupContract.ping('http://localhost:9200')).rejects.toMatchInlineSnapshot(
+          `[Error: Host did not respond with valid Elastic product header.]`
+        );
+      });
+
       it('succeeds if host does not require authentication', async () => {
         mockPingClient.asInternalUser.ping.mockResolvedValue(
           interactiveSetupMock.createApiResponse({ statusCode: 200, body: true })

src/plugins/interactive_setup/server/elasticsearch_service.ts

@@ -290,6 +290,7 @@ export class ElasticsearchService {
       ssl: { verificationMode: 'none' },
     });
 
+    this.logger.debug(`Connecting to host "${host}"`);
     let authRequired = false;
     try {
       await client.asInternalUser.ping();
@@ -304,10 +305,9 @@ export class ElasticsearchService {
       }
 
       authRequired = getErrorStatusCode(error) === 401;
-    } finally {
-      await client.close();
     }
 
+    this.logger.debug(`Fetching certificate chain from host "${host}"`);
     let certificateChain: Certificate[] | undefined;
     const { protocol, hostname, port } = new URL(host);
     if (protocol === 'https:') {
@@ -320,10 +320,32 @@ export class ElasticsearchService {
         this.logger.error(
           `Failed to fetch peer certificate from host "${host}": ${getDetailedErrorMessage(error)}`
         );
+        await client.close();
         throw error;
       }
     }
 
+    // This check is a security requirement - Do not remove it!
+    this.logger.debug(`Verifying that host "${host}" responds with Elastic product header`);
+
+    try {
+      const response = await client.asInternalUser.transport.request({
+        method: 'OPTIONS',
+        path: '/',
+      });
+      if (response.headers?.['x-elastic-product'] !== 'Elasticsearch') {
+        throw new Error('Host did not respond with valid Elastic product header.');
+      }
+    } catch (error) {
+      this.logger.error(
+        `Host "${host}" is not a valid Elasticsearch cluster: ${getDetailedErrorMessage(error)}`
+      );
+      await client.close();
+      throw error;
+    }
+
+    await client.close();
+
     return {
       authRequired,
       certificateChain,