(feat) user rate-limiting support for all SOGo requests

Documentation/SOGoInstallationGuide.asciidoc

@@ -715,6 +715,21 @@ Default value is `0`, or disabled.
 |Number of seconds, default to `300` (or 5 minutes). Note that
 _SOGoCacheCleanupInterval_ must be set to a value equal or higher than
 _SOGoFailedLoginBlockInterval_.
+
+|S |SOGoMaximumRequestCount
+|Parameter used to control the number of requests a user can send to the SOGo
+server in _SOGoMaximumRequestInterval_ seconds or more. If conditions are met
+or exceeded, the user will not be able to perform requests on the SOGo server
+for _SOGoRequestBlockInterval_ seconds and will receive 429 HTTP responses for
+any requests being made. Default value is 0, or disabled
+
+|S |SOGoMaximumRequestInterval
+|Number of seconds, defaults to `30`.
+
+|S |SOGoRequestBlockInterval
+|Number of seconds, defaults to 300 (or 5 minutes). Note that _SOGoCacheCleanupInterval_
+must be set to a value equal or higher than _SOGoRequestBlockInterval_.
+
 |=======================================================================
 
 Authentication using LDAP

Main/SOGo.m

@@ -476,6 +476,8 @@ static BOOL debugLeaks;
   static BOOL debugOn = NO;
   WOResponse *resp;
   NSDate *startDate;
+  NSString *path;
+
   NSTimeInterval timeDelta;
 
   if (debugRequests)
@@ -499,6 +501,62 @@ static BOOL debugLeaks;
     }
 #endif
 
+  // We check for rate-limiting settings - ignore anything actually
+  // sent to /SOGo/ (so unauthenticated requests).
+  path = [_request requestHandlerPath];
+  if ([path length])
+    {
+      NSDictionary *requestCount;
+      NSString *username;
+      NSRange r;
+
+      r = [path rangeOfString: @"/"];
+      username = [path substringWithRange: NSMakeRange(0, r.location)];
+      requestCount = [cache requestCountForLogin: username];
+
+      if (requestCount)
+        {
+          SOGoSystemDefaults *sd;
+
+          unsigned int  current_time, start_time, delta, block_time, request_count;
+
+          sd = [SOGoSystemDefaults sharedSystemDefaults];
+
+          current_time = [[NSCalendarDate date] timeIntervalSince1970];
+          start_time = [[requestCount objectForKey: @"InitialDate"] unsignedIntValue];
+          delta = current_time - start_time;
+
+          block_time = [sd requestBlockInterval];
+          request_count = [[requestCount objectForKey: @"RequestCount"] intValue];
+
+          if ( request_count >= [sd maximumRequestCount] &&
+               delta < [sd maximumRequestInterval] &&
+               delta <= block_time )
+            {
+              resp = [WOResponse responseWithRequest: _request];
+              [resp setStatus: 429];
+              return resp;
+            }
+
+          if (delta > block_time)
+            {
+              [cache setRequestCount: 1
+                            forLogin: username
+                            interval: current_time];
+            }
+          else
+            [cache setRequestCount: (request_count+1)
+                          forLogin: username
+                          interval: start_time];
+        }
+      else
+        {
+          [cache setRequestCount: 1
+                        forLogin: username
+                        interval: 0];
+        }
+    }
+
   resp = [super dispatchRequest: _request];
   [cache killCache];
 

SoObjects/SOGo/SOGoCache.h

@@ -141,6 +141,15 @@
 	 forPath: (NSString *) thePath;
 - (NSMutableDictionary *) aclsForPath: (NSString *) thePath;
 
+//
+// SOGo rate-limiting
+//
+- (void) setRequestCount: (int) theCount
+                forLogin: (NSString *) theLogin
+                interval: (unsigned int) theInterval;
+
+- (NSDictionary *) requestCountForLogin: (NSString *) theLogin;
+
 @end
 
 #endif /* SOGOCACHE_H */

SoObjects/SOGo/SOGoCache.m

@@ -727,5 +727,58 @@ static memcached_st *handle = NULL;
 }
 
 
+//
+// SOGo request count for rate-limiting
+//
+- (void) setRequestCount: (int) theCount
+                forLogin: (NSString *) theLogin
+                interval: (unsigned int) theInterval
+{
+  NSMutableDictionary *d;
+  NSNumber *count;
+
+  if (theCount)
+    {
+      count = [NSNumber numberWithInt: theCount];
+
+      d = [NSMutableDictionary dictionaryWithDictionary: [self requestCountForLogin: theLogin]];
+
+      if (![d objectForKey: @"InitialDate"] || theInterval == 0)
+        [d setObject: [NSNumber numberWithUnsignedInt: [[NSCalendarDate date] timeIntervalSince1970]] forKey: @"InitialDate"];
+      else
+        [d setObject: [NSNumber numberWithUnsignedInt: theInterval] forKey: @"InitialDate"];
+
+      [d setObject: count  forKey: @"RequestCount"];
+      [self _cacheValues: [d jsonRepresentation]
+                  ofType:  @"requestcount"
+                  forKey: theLogin];
+    }
+  else
+    {
+      [self removeValueForKey: [NSString stringWithFormat: @"%@+failedlogins", theLogin]];
+    }
+}
+
+//
+// Returns a dictionary with two keys/values
+//
+// RequestCount ->
+// InitialDate ->
+//
+- (NSDictionary *) requestCountForLogin: (NSString *) theLogin
+{
+  NSDictionary *d;
+  NSString *s;
+
+  s = [self _valuesOfType: @"requestcount" forKey: theLogin];
+  d = nil;
+
+  if (s)
+    {
+      d = [s objectFromJSONString];
+    }
+
+  return d;
+}
 
 @end

SoObjects/SOGo/SOGoSystemDefaults.h

@@ -97,6 +97,11 @@
 - (int) maximumSubmissionInterval;
 - (int) messageSubmissionBlockInterval;
 
+- (int) maximumRequestCount;
+- (int) maximumRequestInterval;
+- (int) requestBlockInterval;
+
+
 - (int) maximumPingInterval;
 - (int) maximumSyncInterval;
 - (int) internalSyncInterval;

SoObjects/SOGo/SOGoSystemDefaults.m

@@ -598,6 +598,42 @@ _injectConfigurationFromFile (NSMutableDictionary *defaultsDict,
   return v;
 }
 
+//
+// SOGo rate-limiting
+//
+- (int) maximumRequestCount
+{
+  return [self integerForKey: @"SOGoMaximumRequestCount"];
+}
+
+- (int) maximumRequestInterval
+{
+  int v;
+
+  v = [self integerForKey: @"SOGoMaximumRequestInterval"];
+
+  if (!v)
+    v = 30;
+
+  return v;
+}
+
+- (int) requestBlockInterval
+{
+  int v;
+
+  v = [self integerForKey: @"SOGoRequestBlockInterval"];
+
+  if (!v)
+    v = 300;
+
+  return v;
+}
+
+
+//
+// SOGo EAS settings
+//
 - (int) maximumPingInterval
 {
   int v;