Require CORS Origin header to use https:// and match the entire hostname.

Also require the port number to match if specified in the accepted origins
list.

server/dial_server.c

@@ -491,70 +491,101 @@ static void handle_dial_data(struct mg_connection *conn,
     ds_unlock(ds);
 }
 
-static int ends_with(const char *str, const char *suffix) {
+
-    if (!str || !suffix)
+static int host_matches(const char *origin_host, const char *host) {
+    if (!origin_host || !host)
         return 0;
-    size_t lenstr = strlen(str);
+        
-    size_t lensuffix = strlen(suffix);
+    // If the host contains a port number (indicated by a colon) require an
-    if (lensuffix > lenstr)
+    // exact match.
-        return 0;
+    const char * origin_colon = strrchr(origin_host, ':');
-    return strncmp(str + lenstr - lensuffix, suffix, lensuffix) == 0;
+    const char * host_colon = strrchr(host, ':');
+    if (host_colon != NULL) {
+        // If the host port number is 443, then accept the origin host if it
+        // does not have any port number under the assumption we already
+        // verified https://
+        if (strlen(host_colon) == 4 &&
+	    strncmp(host_colon, ":443", 4) == 0 &&
+	    origin_colon == NULL)
+	{
+	    // Strip off the host port number and require an exact match.
+  	    size_t host_len = host_colon - host;
+	    if (host_len == 0)
+   	        return 0;
+	    return strncmp(origin_host, host, host_len) == 0;
+        }
+        
+        // Other port numbers must match exactly.
+    	if (strlen(origin_host) != strlen(host))
+    	    return 0;
+    	return strncmp(origin_host, host, strlen(host)) == 0;
+    }
+    
+    // Otherwise strip off any port number in the origin host, and require an
+    // exact match.
+    size_t origin_len = (origin_colon == NULL) ? strlen(origin_host) : origin_colon - origin_host;
+    if (origin_len == 0)
+	return 0;
+    if (origin_len != strlen(host))
+	return 0;
+    return strncmp(origin_host, host, origin_len) == 0;
 }
 
-
 // str contains a white space separated list of strings (only supports SPACE characters for now)
-static int ends_with_in_list (const char *str, const char *list) {
+static int is_hostname_in_list(const char *origin_host, const char *list) {
-    if (!str || !list)
+    if (!origin_host || !list)
         return 0;
     
-    const char * scanPointer=list;
+    const char * scanPointer = list;
     const char * spacePointer;
     unsigned int substringSize = 257;
-    char *substring = (char *)malloc(substringSize);
+    char *host = (char *)malloc(substringSize);
-    if (!substring){
+    if (!host) {
         return 0;
     }
-    while ( (spacePointer =strchr(scanPointer, ' ')) != NULL) {
+    while ((spacePointer = strchr(scanPointer, ' ')) != NULL) {
     	int copyLength = spacePointer - scanPointer;      
       
-      // protect against buffer overflow
+      	// protect against buffer overflow
-      if (copyLength>=substringSize){
+      	if (copyLength >= substringSize){
-          substringSize=copyLength+1;
+          	substringSize = copyLength + 1;
-          free(substring);
+	        free(host);
-          substring=(char *)malloc(substringSize);
+    	    host = (char *)malloc(substringSize);
-          if (!substring){
+          	if (!host) {
-              return 0;
+            	return 0;
-          }
+          	}
-      }
+      	}
 
-    	memcpy(substring, scanPointer, copyLength);
+    	memcpy(host, scanPointer, copyLength);
-    	substring[copyLength] = '\0';
+    	host[copyLength] = '\0';
-    	//printf("found %s \n", substring);
+    	//printf("found %s \n", host);
-    	if (ends_with(str, substring)) {
+    	if (host_matches(origin_host, host)) {
-          free(substring); substring = NULL;
+          free(host); host = NULL;
           return 1;
     	}
     	scanPointer = scanPointer + copyLength + 1; // assumption: only 1 character
     }
-    free(substring); substring = NULL;
+    free(host); host = NULL;
-    return ends_with(str, scanPointer);
+    return host_matches(origin_host, scanPointer);
-}
-
-static int should_check_for_origin( char * origin ) {
-    const char * const CHECK_PROTOS[] = { "http:", "https:", "file:" };
-    for (int i = 0; i < 3; ++i) {
-        if (!strncmp(origin, CHECK_PROTOS[i], strlen(CHECK_PROTOS[i]) - 1)) {
-            return 1;
-        }
-    }
-    return 0;
 }
 
 static int is_allowed_origin(DIALServer* ds, char * origin, const char * app_name) {
-    if (!origin || strlen(origin)==0 || !should_check_for_origin(origin)) {
+    const char * const HTTPS_PROTO = "https://";
+    fprintf(stderr, "checking %s for %s\n", origin, app_name);
+
+    if (!origin || strlen(origin)==0) {
         return 1;
     }
     
+    // Make sure the origin begins with HTTPS.
+    if (strncmp(origin, HTTPS_PROTO, strlen(HTTPS_PROTO)) != 0) {
+    	return 0;
+    }
+    
+    // For the rest of the check, we only care about the hostname and optional
+    // port number.
+    const char *origin_host = origin + strlen(HTTPS_PROTO);
+
     if (!ds_lock(ds)) {
         // If we can't check, fail in favor of safety.
         return 0;
@@ -564,7 +595,7 @@ static int is_allowed_origin(DIALServer* ds, char * origin, const char * app_nam
     for (app = ds->apps; app != NULL; app = app->next) {
     	if (!strcmp(app->name, app_name)) {
             if (!app->corsAllowedOrigin[0] ||
-                ends_with_in_list(origin, app->corsAllowedOrigin)) {
+                is_hostname_in_list(origin_host, app->corsAllowedOrigin)) {
                 result = 1;
                 break;
             }

server/main.c

@@ -288,8 +288,8 @@ void runDial(void)
     struct DIALAppCallbacks cb_yt = {youtube_start, youtube_hide, youtube_stop, youtube_status};
     struct DIALAppCallbacks cb_system = {system_start, system_hide, NULL, system_status};
 
-    if (DIAL_register_app(ds, "Netflix", &cb_nf, NULL, 1, ".netflix.com") == -1 ||
+    if (DIAL_register_app(ds, "Netflix", &cb_nf, NULL, 1, "netflix.com www.netflix.com port.netflix.com:123") == -1 ||
-        DIAL_register_app(ds, "YouTube", &cb_yt, NULL, 1, ".youtube.com") == -1 ||
+        DIAL_register_app(ds, "YouTube", &cb_yt, NULL, 1, "youtube.com www.youtube.com port.youtube.com:123") == -1 ||
         DIAL_register_app(ds, "system", &cb_system, NULL, 1, "") == -1)
     {
         printf("Unable to register DIAL applications.\n");

server/tests/test_cors.html

@@ -17,7 +17,7 @@ and open the template in the editor.
               console.log("make dial post...");
               var ip = $("#ipAddress").val();
               var port = $("#dialPort").val();
-              var urlStr = "http://"+ip+":"+port+"/apps/"+app;
+              var urlStr = "https://"+ip+":"+port+"/apps/"+app;
               console.log(urlStr);
               $("#status").text("posted to "+urlStr);
               $.ajax({

server/tests/test_cors.sh

@@ -9,7 +9,7 @@ ip_address=$1
 port=$2
 
 #Testing all the positive cases
-origins="http://www4.netflix.com http://1.netflix.com https://www.netflix.com https://www4.netflix.com ftp://this.is.fine"
+origins="https://www.netflix.com https://netflix.com https://port.netflix.com:123 https://www.netflix.com:80 https://www.netflix.com:123"
 for origin in $origins; do
 curl --fail --silent --header "Origin:$origin" --data "v=QH2-TGUlwu4"  http://$ip_address:$port/apps/Netflix || echo "failed: $origin should be accepted"
 curl --fail --silent --header "Origin:$origin" -X OPTIONS  http://$ip_address:$port/apps/Netflix || echo "failed: $origin should be accepted"
@@ -21,7 +21,7 @@ then
 fi
 done
 
-origins="http://www4.youtube.com http://1.youtube.com https://www.youtube.com https://www4.youtube.com ftp://this.is.fine"
+origins="https://www.youtube.com https://youtube.com https://port.youtube.com:123 https://www.youtube.com:80 https://www.youtube.com:123"
 for origin in $origins; do
 curl --fail --silent --header "Origin:$origin" --data "v=QH2-TGUlwu4"  http://$ip_address:$port/apps/YouTube || echo "failed: $origin should be accepted"
 curl --fail --silent --header "Origin:$origin" -X OPTIONS  http://$ip_address:$port/apps/YouTube || echo "failed: $origin should be accepted"
@@ -34,7 +34,7 @@ fi
 done
 
 #Testing all the negative cases
-origins="http://www.netflix-a.com http://www.netflix.com4 http://a-netflix.com https://ww.netflix-a.com https://www.netflix.com4 https://a-netflix.com http://netflix.com http://www.attack.com https://www.attack.com file://www.attack.com"
+origins="http://www.netflix-a.com http://www.netflix.com4 http://a-netflix.com http://www4.netflix.com https://port.netflix.com:1234 http://1.netflix.com https://www4.netflix.com https://ww.netflix-a.com https://www.netflix.com4 https://a-netflix.com http://netflix.com http://www.attack.com https://www.attack.com file://www.attack.com ftp://this.is.not.fine"
 for origin in $origins; do
 curl --fail --silent --header "Origin:$origin" --data "v=QH2-TGUlwu4"  http://$ip_address:$port/apps/Netflix && echo "failed: $origin should be rejected"
 curl --fail --silent --header "Origin:$origin" -X OPTIONS  http://$ip_address:$port/apps/Netflix && echo "failed: $origin should be rejected"
@@ -46,7 +46,7 @@ then
 fi
 done
 
-origins="http://www.youtube-a.com http://www.youtube.com4 http://a-youtube.com https://ww.youtube-a.com https://www.youtube.com4 https://a-youtube.com http://youtube.com https://youtube.com http://www.attack.com https://www.attack.com file://www.attack.com"
+origins="http://www.youtube-a.com http://www.youtube.com4 http://a-youtube.com https://ww.youtube-a.com http://www4.youtube.com https://port.youtube.com:1234 http://1.youtube.com https://www4.youtube.com https://www.youtube.com4 https://a-youtube.com http://youtube.com http://www.attack.com https://www.attack.com file://www.attack.com ftp://this.is.not.fine"
 for origin in $origins; do
 curl --fail --silent --header "Origin:$origin" --data "v=QH2-TGUlwu4"  http://$ip_address:$port/apps/YouTube && echo "failed: $origin should be rejected"
 curl --fail --silent --header "Origin:$origin" -X OPTIONS  http://$ip_address:$port/apps/YouTube && echo "failed: $origin should be rejected"