Add skipIISCustomErrors switch to iisnode

src/config/iisnode_dev_x64.xml

@@ -60,6 +60,7 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="configOverrides" type="string" expanded="true" defaultValue="iisnode.yml"/>
     <attribute name="recycleSignalEnabled" type="bool" defaultValue="false"/>
     <attribute name="idlePageOutTimePeriod" type="uint" defaultValue="0" /> <!-- disabled with default value 0 -->
+    <attribute name="skipIISCustomErrors" type="bool" defaultValue="false" />
     <attribute name="nodeProcessStickySessions" type="bool" defaultValue="false"/>
   </sectionSchema>
 </configSchema>

src/config/iisnode_dev_x86_on_x64.xml

@@ -60,6 +60,7 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="configOverrides" type="string" expanded="true" defaultValue="iisnode.yml"/>
     <attribute name="recycleSignalEnabled" type="bool" defaultValue="false"/>
     <attribute name="idlePageOutTimePeriod" type="uint" defaultValue="0" /> <!-- disabled with default value 0 -->
+    <attribute name="skipIISCustomErrors" type="bool" defaultValue="false" />
     <attribute name="nodeProcessStickySessions" type="bool" defaultValue="false"/>
   </sectionSchema>
 </configSchema>

src/config/iisnode_dev_x86_on_x86.xml

@@ -60,6 +60,7 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="configOverrides" type="string" expanded="true" defaultValue="iisnode.yml"/>
     <attribute name="recycleSignalEnabled" type="bool" defaultValue="false"/>
     <attribute name="idlePageOutTimePeriod" type="uint" defaultValue="0" /> <!-- disabled with default value 0 -->
+    <attribute name="skipIISCustomErrors" type="bool" defaultValue="false" />
     <attribute name="nodeProcessStickySessions" type="bool" defaultValue="false"/>
   </sectionSchema>
 </configSchema>

src/config/iisnode_express_schema.xml

@@ -60,6 +60,7 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="configOverrides" type="string" expanded="true" defaultValue="iisnode.yml"/>
     <attribute name="recycleSignalEnabled" type="bool" defaultValue="false"/>
     <attribute name="idlePageOutTimePeriod" type="uint" defaultValue="0" /> <!-- disabled with default value 0 -->
+    <attribute name="skipIISCustomErrors" type="bool" defaultValue="false" />
     <attribute name="nodeProcessStickySessions" type="bool" defaultValue="false"/>
   </sectionSchema>
 </configSchema>

src/config/iisnode_express_schema_x64.xml

@@ -60,6 +60,7 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="configOverrides" type="string" expanded="true" defaultValue="iisnode.yml"/>
     <attribute name="recycleSignalEnabled" type="bool" defaultValue="false"/>
     <attribute name="idlePageOutTimePeriod" type="uint" defaultValue="0" /> <!-- disabled with default value 0 -->
+    <attribute name="skipIISCustomErrors" type="bool" defaultValue="false" />
     <attribute name="nodeProcessStickySessions" type="bool" defaultValue="false"/>
   </sectionSchema>
 </configSchema>

src/config/iisnode_schema.xml

@@ -60,6 +60,7 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="configOverrides" type="string" expanded="true" defaultValue="iisnode.yml"/>
     <attribute name="recycleSignalEnabled" type="bool" defaultValue="false"/>
     <attribute name="idlePageOutTimePeriod" type="uint" defaultValue="0" /> <!-- disabled with default value 0 -->
+    <attribute name="skipIISCustomErrors" type="bool" defaultValue="false" />
     <attribute name="nodeProcessStickySessions" type="bool" defaultValue="false"/>
   </sectionSchema>
 </configSchema>

src/config/iisnode_schema_x64.xml

@@ -60,6 +60,7 @@ Details at http://learn.iis.net/page.aspx/241/configuration-extensibility/
     <attribute name="configOverrides" type="string" expanded="true" defaultValue="iisnode.yml"/>
     <attribute name="recycleSignalEnabled" type="bool" defaultValue="false"/>
     <attribute name="idlePageOutTimePeriod" type="uint" defaultValue="0" /> <!-- disabled with default value 0 -->
+    <attribute name="skipIISCustomErrors" type="bool" defaultValue="false"/>"
     <attribute name="nodeProcessStickySessions" type="bool" defaultValue="false"/>
   </sectionSchema>
 </configSchema>

src/iisnode/chttpprotocol.cpp

@@ -364,7 +364,20 @@ HRESULT CHttpProtocol::ParseResponseStatusLine(CNodeHttpStoredContext* context)
 	data[newOffset] = 0; // zero-terminate the reason phrase to reuse it without copying
 
 	IHttpResponse* response = context->GetHttpContext()->GetResponse();
-	response->SetStatus(statusCode, data + offset, subStatusCode);
+
+	if (CModuleConfiguration::GetSkipIISCustomErrors(context->GetHttpContext()))
+	{
+		// set fTrySkipCustomErrors so that error responses sent back from the node app through iisnode
+		// are passed through to the client instead of being intercepted by IIS when httpErrors existingResponse="Auto"
+		// this allows a mixed solution where custom error pages can be provided via IIS for errors that occur outside
+		// of iisnode's purview, while also allowing usually-more-helpful error responses from the node application
+		// to be passed through to the client rather than being intercepted by IIS.
+		response->SetStatus(statusCode, data + offset, subStatusCode, S_OK, NULL, TRUE);
+	}
+	else
+	{
+		response->SetStatus(statusCode, data + offset, subStatusCode);
+	}
 
 	// adjust buffers
 

src/iisnode/cmoduleconfiguration.cpp

@@ -898,6 +898,10 @@ HRESULT CModuleConfiguration::ApplyConfigOverrideKeyValue(IHttpContext* context,
     {
         CheckError(GetDWORD(valueStart, &config->idlePageOutTimePeriod));
     }
+    else if(0 == stricmp(keyStart, "skipIISCustomErrors"))
+    {
+        CheckError(GetBOOL(valueStart, &config->skipIISCustomErrors));
+    }
 
     return S_OK;
 Error:
@@ -1258,6 +1262,7 @@ HRESULT CModuleConfiguration::GetConfig(IHttpContext* context, CModuleConfigurat
         CheckError(GetString(section, L"nodeProcessCommandLine", &c->nodeProcessCommandLine));
         CheckError(GetString(section, L"interceptor", &c->interceptor));
         CheckError(GetDWORD(section, L"idlePageOutTimePeriod", &c->idlePageOutTimePeriod));
+        CheckError(GetBOOL(section, L"skipIISCustomErrors", &c->skipIISCustomErrors, FALSE));
 
         // debuggerPathSegment
 
@@ -1504,6 +1509,11 @@ LPWSTR CModuleConfiguration::GetConfigOverrides(IHttpContext* ctx)
     GETCONFIG(configOverrides)
 }
 
+BOOL CModuleConfiguration::GetSkipIISCustomErrors(IHttpContext* ctx)
+{
+    GETCONFIG(skipIISCustomErrors)
+}
+
 HRESULT CModuleConfiguration::GenerateDebuggerConfig(IHttpContext* context, CModuleConfiguration *config)
 {
     HRESULT hr = S_OK;
@@ -1592,12 +1602,12 @@ HRESULT CModuleConfiguration::GetDebuggerFilesPathSegmentHelper(
     DWORD  *pdwDebuggerFilesPathSegmentSize
 )
 {
-    HRESULT         hr = S_OK;
-    HCRYPTPROV      hProv = 0;
+    HRESULT         hr = S_OK;
+    HCRYPTPROV      hProv = 0;
     HCRYPTHASH      hHash = 0;
     CHAR            rgbDigits[] = "0123456789abcdef";
-    BYTE            rgbHash[32]; // sha256 ==> 32 bytes.
-    DWORD           cbHash = 0;
+    BYTE            rgbHash[32]; // sha256 ==> 32 bytes.
+    DWORD           cbHash = 0;
     CHAR            shaHash[MAX_HASH_CHAR + 1]; // we will only use first MAX_HASH_CHAR bytes of the sha256 hash ==> 32 hex chars.
     DWORD           dwSHALength = 0;
     CHAR           *pInput = NULL; 
@@ -1615,27 +1625,27 @@ HRESULT CModuleConfiguration::GetDebuggerFilesPathSegmentHelper(
     ErrorIf(dwInputSize != WideCharToMultiByte(CP_ACP, 0, pszScriptPath, dwScriptPathLen, pInput, dwInputSize, NULL, NULL), E_FAIL);
     pInput[dwInputSize] = '\0';
 
-    // Get handle to the crypto provider
-    ErrorIf(!CryptAcquireContext(&hProv,
-                                 NULL,
-                                 NULL,
-                                 PROV_RSA_AES,
-                                 CRYPT_VERIFYCONTEXT), HRESULT_FROM_WIN32(GetLastError()));
-
+    // Get handle to the crypto provider
+    ErrorIf(!CryptAcquireContext(&hProv,
+                                 NULL,
+                                 NULL,
+                                 PROV_RSA_AES,
+                                 CRYPT_VERIFYCONTEXT), HRESULT_FROM_WIN32(GetLastError()));
+
     ErrorIf(!CryptCreateHash(hProv, CALG_SHA_256, 0, 0, &hHash), HRESULT_FROM_WIN32(GetLastError()));
 
     ErrorIf(!CryptHashData(hHash, (BYTE*) pInput, strnlen_s(pInput, dwInputSize), 0), HRESULT_FROM_WIN32(GetLastError()));
 
     // sha256 ==> 32 bytes.
-    cbHash = 32;
-    ErrorIf(!CryptGetHashParam(hHash, HP_HASHVAL, rgbHash, &cbHash, 0), HRESULT_FROM_WIN32(GetLastError()));
-
-    dwIndex = 0;
-    // convert first (MAX_HASH_CHAR / 2) bytes to hexadecimal form.
-    for (DWORD i = 0; i < (MAX_HASH_CHAR / 2); i++, dwIndex=dwIndex+2)
-    {
-        shaHash[dwIndex] = rgbDigits[rgbHash[i] >> 4];
-        shaHash[dwIndex+1] = rgbDigits[rgbHash[i] & 0xf];
+    cbHash = 32;
+    ErrorIf(!CryptGetHashParam(hHash, HP_HASHVAL, rgbHash, &cbHash, 0), HRESULT_FROM_WIN32(GetLastError()));
+
+    dwIndex = 0;
+    // convert first (MAX_HASH_CHAR / 2) bytes to hexadecimal form.
+    for (DWORD i = 0; i < (MAX_HASH_CHAR / 2); i++, dwIndex=dwIndex+2)
+    {
+        shaHash[dwIndex] = rgbDigits[rgbHash[i] >> 4];
+        shaHash[dwIndex+1] = rgbDigits[rgbHash[i] & 0xf];
     }
 
     shaHash[dwIndex] = '\0';

src/iisnode/cmoduleconfiguration.h

@@ -52,6 +52,7 @@ class CModuleConfiguration : public IHttpStoredContext
     static BOOL invalid;
     SRWLOCK srwlock;
     LPWSTR configOverrides;
+    BOOL skipIISCustomErrors;
     BOOL nodeProcessStickySessions;
 
     static IHttpServer* server;
@@ -130,6 +131,7 @@ class CModuleConfiguration : public IHttpStoredContext
     static BOOL GetEnableXFF(IHttpContext* ctx);
     static HRESULT GetPromoteServerVars(IHttpContext* ctx, char*** vars, int* count);
     static LPWSTR GetConfigOverrides(IHttpContext* ctx);
+    static BOOL GetSkipIISCustomErrors(IHttpContext* ctx);
     static BOOL GetProcessStickySessions(IHttpContext* ctx);
 
     static HRESULT CreateNodeEnvironment(IHttpContext* ctx, DWORD debugPort, PCH namedPipe, PCH signalPipeName, PCH* env);
@@ -139,4 +141,4 @@ class CModuleConfiguration : public IHttpStoredContext
     virtual void CleanupStoredContext();
 };
 
-#endif
+#endif

src/iisnode/cprotocolbridge.cpp

@@ -465,7 +465,11 @@ void CProtocolBridge::SendEmptyResponse(IHttpContext* httpCtx, USHORT status, US
     if (!httpCtx->GetResponseHeadersSent())
     {
         httpCtx->GetResponse()->Clear();
+
+        // Internal iisnode errors should probably not set fTrySkipCustomErrors since these are just empty status responses.
+        // Let IIS capture and replace these responses with more detailed messages depending on the custom error mode.
         httpCtx->GetResponse()->SetStatus(status, reason, subStatus, hresult);
+
         if (disableCache)
         {
             httpCtx->GetResponse()->SetHeader(HttpHeaderCacheControl, "no-cache", 8, TRUE);

src/samples/configuration/iisnode.yml

@@ -141,4 +141,7 @@ enableXFF: false
 # HTTP request headers; for a list of IIS server variables available see
 # http://msdn.microsoft.com/en-us/library/ms524602(v=vs.90).aspx; for example "AUTH_USER,AUTH_TYPE"
 
-promoteServerVars:     
+promoteServerVars:     
+
+# skipIISCustomErrors - controls whether iisnode will try to skip IIS <httpErrors> custom error handling when existingResponse="Auto"
+skipIISCustomErrors: false

src/samples/configuration/readme.htm

@@ -145,6 +145,8 @@ <h2>
             maxRequestBufferSize: 8192 # increasing from the default
             # maxConcurrentRequestsPerProcess: 512 - commented out setting
 
+    * skipIISCustomErrors - controls whether iisnode will try to skip IIS &gt;httpErrors&lt; custom error handling when existingResponse="Auto"
+
     --&gt;
 
     &lt;iisnode      
@@ -175,6 +177,7 @@ <h2>
       enableXFF="false"
       promoteServerVars=""
       configOverrides="node.conf"
+      skipIISCustomErrors="false"
      /&gt;
 
     &lt;!--     
@@ -335,6 +338,10 @@ <h2>
 # HTTP request headers; for a list of IIS server variables available see
 # http://msdn.microsoft.com/en-us/library/ms524602(v=vs.90).aspx; for example "AUTH_USER,AUTH_TYPE"
 
-promoteServerVars:</pre>
+promoteServerVars:
+
+# skipIISCustomErrors - controls whether iisnode will try to skip IIS &gt;httpErrors&lt; custom error handling when existingResponse="Auto"
+skipIISCustomErrors: false
+</pre>
 </body>
 </html>

src/samples/configuration/web.config

@@ -109,6 +109,8 @@
             nodeProcessCountPerApplication: 2
             maxRequestBufferSize: 8192 # increasing from the default
             # maxConcurrentRequestsPerProcess: 512 - commented out setting
+
+    * skipIISCustomErrors - controls whether iisnode will try to skip IIS <httpErrors> custom error handling when existingResponse="Auto"
 
     -->
 
@@ -140,6 +142,7 @@
       enableXFF="false"
       promoteServerVars=""
       configOverrides="iisnode.yml"
+      skipIISCustomErrors="false"
      />
 
     <!--     

test/functional/tests/144_skip_iis_custom_errors.js

@@ -0,0 +1,18 @@
+var iisnodeassert = require("iisnodeassert");
+
+iisnodeassert.sequence([
+    // when skipIISCustomErrors="true", error responses returned by the node application should pass through to the client
+    // when skipIISCustomErrors="false", IIS can intercept error responses from the node application with custom error handling based on the error code
+    // this option only comes into play when httpErrors existingResponse="Auto".
+    // existingResponse="PassThrough" and existingResponse="Replace" will always pass error messages from the node app through to the client or replace them, respectively
+    iisnodeassert.get(10000, "/143_skip_iis_custom_errors/on/create_error.js", 400, 'App created error. Gets replaced by IIS Custom error if skipIISCustomErrors="false"'),
+    iisnodeassert.get(10000, "/143_skip_iis_custom_errors/off/create_error.js", 400, 'Bad Request'),
+
+    // iisnode skipIISCustomErrors option should not affect custom error routing for errors outside of iisnode's purview
+    iisnodeassert.get(10000, "/143_skip_iis_custom_errors/on/access_denied.js", 401, 'IIS Custom Error page still gets served for non iisnode error responses'),
+    iisnodeassert.get(10000, "/143_skip_iis_custom_errors/off/access_denied.js", 401, 'IIS Custom Error page still gets served for non iisnode error responses'),
+
+    // internal iisnode errors should still get extra handling by IIS depending on error mode
+    iisnodeassert.get(10000, "/143_skip_iis_custom_errors/on/malformed.js", 500, 'The page cannot be displayed because an internal server error has occurred.'),
+    iisnodeassert.get(10000, "/143_skip_iis_custom_errors/off/malformed.js", 500, 'The page cannot be displayed because an internal server error has occurred.'),    
+]);

test/functional/www/143_skip_iis_custom_errors/error.html

@@ -0,0 +1 @@
+IIS Custom Error page still gets served for non iisnode error responses

test/functional/www/143_skip_iis_custom_errors/off/access_denied.js

@@ -0,0 +1,6 @@
+var http = require('http');
+
+http.createServer(function (req, res) {
+    res.writeHead(200, {'Content-Type': 'text/html'});
+    res.end('Hello, world!');
+}).listen(process.env.PORT);  

test/functional/www/143_skip_iis_custom_errors/off/create_error.js

@@ -0,0 +1,6 @@
+var http = require('http');
+
+http.createServer(function (req, res) {
+    res.writeHead(400, {'Content-Type': 'text/html'});
+    res.end('Created error');
+}).listen(process.env.PORT);  

test/functional/www/143_skip_iis_custom_errors/off/malformed.js

@@ -0,0 +1 @@
+invalid js file

test/functional/www/143_skip_iis_custom_errors/off/web.config

@@ -0,0 +1,5 @@
+<configuration>
+  <system.webServer>
+    <iisnode skipIISCustomErrors="false" />
+  </system.webServer>
+</configuration>

test/functional/www/143_skip_iis_custom_errors/on/access_denied.js

@@ -0,0 +1,6 @@
+var http = require('http');
+
+http.createServer(function (req, res) {
+    res.writeHead(200, {'Content-Type': 'text/html'});
+    res.end('Hello, world!');
+}).listen(process.env.PORT);  

test/functional/www/143_skip_iis_custom_errors/on/create_error.js

@@ -0,0 +1,6 @@
+var http = require('http');
+
+http.createServer(function (req, res) {
+    res.writeHead(400, {'Content-Type': 'text/html'});
+    res.end('App created error. Gets replaced by IIS Custom error if skipIISCustomErrors="false"');
+}).listen(process.env.PORT);  

test/functional/www/143_skip_iis_custom_errors/on/malformed.js

@@ -0,0 +1 @@
+invalid js file

test/functional/www/143_skip_iis_custom_errors/on/web.config

@@ -0,0 +1,5 @@
+<configuration>
+  <system.webServer>
+    <iisnode skipIISCustomErrors="true" />
+  </system.webServer>
+</configuration>

test/functional/www/143_skip_iis_custom_errors/web.config

@@ -0,0 +1,60 @@
+<configuration>
+  <system.webServer>
+    <!-- 
+    errorMode="Custom" to prevent IIS from helpfully serving a more detailed error .aspx page when run locally
+    Default error mode is DetailedLocalOnly, which serves custom errors to remote users and more detailed error pages
+    to local users.
+    -->
+    <httpErrors existingResponse="Auto" errorMode="Custom">
+      <clear />
+      <remove statusCode="401" />
+      <error statusCode="401" path="error.html" responseMode="File" />
+    </httpErrors>
+    <handlers>
+      <add name="iisnode" path="*/*.js" verb="*" modules="iisnode" />
+    </handlers>
+    <iisnode devErrorsEnabled="false" />
+  </system.webServer>
+
+  <!--
+   Cause requests to hello.js to fail authentication before hitting iisnode. 
+   In this scenario, we may want to re-route to a custom error page via IIS
+   since we won't be able to handle the request in the node application.
+   -->
+  <location path="off/access_denied.js">
+    <system.webServer>
+      <security>
+        <authorization>
+          <clear />
+          <add accessType="Deny" users="*" />
+        </authorization>
+      </security>
+    </system.webServer>
+  </location>
+  <location path="on/access_denied.js">
+    <system.webServer>
+      <security>
+        <authorization>
+          <clear />
+          <add accessType="Deny" users="*" />
+        </authorization>
+      </security>
+    </system.webServer>
+  </location>
+
+  <!-- 
+  Need to allow users access to error.html. 
+  NOTE: Seprately, you will need to give IUSR account read access to custom error page so that IIS can access and serve the file.
+  -->
+  <location path="error.html">
+    <system.webServer>
+      <security>
+        <authorization>
+          <clear />
+          <add accessType="Allow" users="*" />
+        </authorization>
+      </security>
+    </system.webServer>
+  </location>
+
+</configuration>