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

Dependents:   heating gps

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.

Revision:
110:8ab752842d25
Parent:
109:3e82f62c7e1f
Child:
111:aaa858678e34
--- a/web.c	Mon Apr 29 14:45:30 2019 +0000
+++ b/web.c	Tue Apr 30 12:45:08 2019 +0000
@@ -1,10 +1,53 @@
 #include "http.h"
 #include "web-server-base.h"
-#include "web-base.h"
+#include "web-server-derived.h"
+#include "web.h"
+#include "web-pages-base.h"
 #include "mstimer.h"
 
 #define LOGIN_DELAY_MS 200
 
+#define DO_LOGIN DO_SERVER + 0
+
+static int decideWhatToDo(char *pPath, char* pLastModified)
+{
+    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;
+    return DO_NOT_FOUND;
+}
+static void handleQuery(int todo, char* pQuery)
+{
+    switch (todo)
+    {
+        case DO_LOGIN:         WebLoginQuery   (pQuery); return;
+    }
+    if (WebServerBaseHandleQuery   (todo, pQuery)) return;
+    if (WebServerDerivedHandleQuery(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;
+}
+
+static void reply(int todo)
+{
+    //Try all the base modules
+    switch (todo)
+    {
+        case DO_LOGIN:           WebLoginHtml     (); return;
+        case DO_NOT_FOUND:       HttpNotFound     (); return;
+        case DO_NOT_MODIFIED:    HttpNotModified  (); return;
+    }
+    
+    //If not called then call the derived (child) module
+    if (WebServerBaseReply   (todo)) return;
+    if (WebServerDerivedReply(todo)) return;
+}
+
 static void handleRequest(int size, char* pRequestStream, uint32_t positionInRequestStream, int* pToDo, bool* pPostComplete, uint32_t* pDelayUntil)
 {
     //Handle request for the first packet of data received but leave todo the same after that.
@@ -21,7 +64,7 @@
         contentStart = HttpRequestRead(pRequestStream, size, &pMethod, &pPath, &pQuery, &pLastModified, &pCookies, &contentLength);
         
         //Ask the web server what to do
-        *pToDo = WebServerBaseDecideWhatToDo(pPath, pLastModified);
+        *pToDo = decideWhatToDo(pPath, pLastModified);
         
         //If what to do is NOTHING, NOT_FOUND or NOT_MODIFIED then no query or post will be valid so stop now
         if (*pToDo < DO_LOGIN) { *pPostComplete = true; return; }
@@ -29,7 +72,7 @@
         //If what to do is LOGIN then the user has just returned the login form
         if (*pToDo == DO_LOGIN)
         {
-            WebServerBaseHandleQuery(*pToDo, pQuery);                  //Read the password and the original location
+            handleQuery(*pToDo, pQuery);                  //Read the password and the original location
             if (WebLoginQueryPasswordOk)
             {
                 if (!WebLoginSessionIdIsSet())           //If there isn't a session id already
@@ -54,11 +97,11 @@
         }
         
         //Handle the query
-        WebServerBaseHandleQuery(*pToDo, pQuery);
+        handleQuery(*pToDo, pQuery);
     }
     
     //Do the upload of anything that needs it. Todos it doesn't understand are ignored.
-    if (!*pPostComplete) *pPostComplete = WebServerBaseHandlePost(*pToDo, contentLength, contentStart, size, pRequestStream, positionInRequestStream);
+    if (!*pPostComplete) handlePost(*pToDo, contentLength, contentStart, size, pRequestStream, positionInRequestStream, pPostComplete);
 }
 
 static void sendReply(int todo)
@@ -78,7 +121,7 @@
         HttpOkCookieMaxAge = -1;
     }
     
-    WebServerBaseReply(todo);
+    reply(todo);
 }
 
 int WebInit()