Andrew Boyson / web

Common stuff for all my devices' web server pages: css, login, log, ipv4, ipv6, firmware update, clock, reset info etc.

Dependents:   oldheating gps motorhome heating

Security

A password has to be set whenever there has been a software reset. Resets following faults or power on do not require a new password as the hash is restored from the RTC GPREG register.

The password is not saved on the device; instead a 32 bit hash of the password is saved. It would take 2^31 attempts to brute force the password: this could be done in under a month if an attempt were possible every millisecond. To prevent this a 200 ms delay is introduced in the reply to the login form, that gives a more reasonable 13 years to brute force the password.

Once the password is accepted a random session id is created. This is 36 bit to give six base 64 characters but without an extra delay. If an attempt could be made every ms then this would still take over a year to brute force.

The most likely attack would to use a dictionary with, say, 10 million entries against the password which would still take 20 days to do.

Diff: web.c

Revision:
112:f29bb9b99059
Parent:
111:aaa858678e34
Child:
122:cd3f391ac8aa
--- a/web.c	Wed May 01 07:15:11 2019 +0000
+++ b/web.c	Wed May 01 10:04:31 2019 +0000
@@ -1,6 +1,6 @@
 #include "http.h"
 #include "web-server-base.h"
-#include "web-server-derived.h"
+#include "web-server-this.h"
 #include "web.h"
 #include "web-pages-base.h"
 #include "mstimer.h"
@@ -14,8 +14,8 @@
     if (HttpSameStr(pPath, "/login")) return DO_LOGIN;
     
     int todo;
-    todo = WebServerBaseDecideWhatToDo   (pPath, pLastModified); if (todo != DO_NOT_FOUND) return todo;
-    todo = WebServerDerivedDecideWhatToDo(pPath, pLastModified); if (todo != DO_NOT_FOUND) return todo;
+    todo = WebServerBaseDecideWhatToDo(pPath, pLastModified); if (todo != DO_NOT_FOUND) return todo;
+    todo = WebServerThisDecideWhatToDo(pPath, pLastModified); if (todo != DO_NOT_FOUND) return todo;
     return DO_NOT_FOUND;
 }
 static void handleQuery(int todo, char* pQuery)
@@ -24,13 +24,13 @@
     {
         case DO_LOGIN:         WebLoginQuery   (pQuery); return;
     }
-    if (WebServerBaseHandleQuery   (todo, pQuery)) return;
-    if (WebServerDerivedHandleQuery(todo, pQuery)) return;
+    if (WebServerBaseHandleQuery(todo, pQuery)) return;
+    if (WebServerThisHandleQuery(todo, pQuery)) return;
 }
 static void handlePost(int todo, int contentLength, int contentStart, int size, char* pRequestStream, uint32_t positionInRequestStream, bool* pComplete)
 {
-    if (WebServerBasePost   (todo, contentLength, contentStart, size, pRequestStream, positionInRequestStream, pComplete)) return;
-    if (WebServerDerivedPost(todo, contentLength, contentStart, size, pRequestStream, positionInRequestStream, pComplete)) return;
+    if (WebServerBasePost(todo, contentLength, contentStart, size, pRequestStream, positionInRequestStream, pComplete)) return;
+    if (WebServerThisPost(todo, contentLength, contentStart, size, pRequestStream, positionInRequestStream, pComplete)) return;
     *pComplete = true;
 }
 
@@ -45,8 +45,8 @@
     }
     
     //If not called then call the derived (child) module
-    if (WebServerBaseReply   (todo)) return;
-    if (WebServerDerivedReply(todo)) return;
+    if (WebServerBaseReply(todo)) return;
+    if (WebServerThisReply(todo)) return;
 }
 
 static void handleRequest(int size, char* pRequestStream, uint32_t positionInRequestStream, int* pToDo, bool* pPostComplete, uint32_t* pDelayUntil)