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06.19.2008 at 05:48PM PDT, ID: 23500987

	[x] Attachment Details

[C server] Login and blank spaces

Asked by roccogalati in C Programming Language, CYGWIN

Tags: C

Hi to all!

I was wondering about the possibility of managing usernames which contain blank spaces.

I use read function to read the commands which the client sends to the server, something like what i posted below.

Each line ends with a "\r\n" sequence, so i try to delete it and to consider just what the client really writes.
The problem is that my code works fine if the username doesn't contain blank spaces, but if it is something like: "user name" my code doesn't work and it crashes.

It's like when you use scanf() and fgets()...

What can I do in order to consider also the blank spaces and continue also to not consider \r\n?
what's the better way in order to avoid security problems, too?

the server works in this way:

server: WHO?
client: HELOusername\r\n
server: PASS
client:password\r\n

but it has also to work fine in this case:

server: WHO?
client: HELOuser name\r\n
server: PASS
client:password\r\n

thanks a lot!
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             while( (n = read(fd, buffer, MAX_LINE)) > 0){
   buffer[n] = '\0';
   char *comando = buffer;
   
   lenght = strlen(comando);
    if(lenght == 0){
            exit(0);
            }
   while (comando) {
  char *next = strstr(comando, "\r\n");
  if (next) {
    *next = '\0';
    next += 2;
  }
      
   if ( strncmp(comando, "HELO", 4) == 0){  
    
   username = strtok((comando+4), "\r\n");
   if (strlen(username) > 16){
   Writeline(fd, alert, strlen(alert));
   }
   Writeline(fd, passw, strlen(passw));
   read(fd, password, MAX_LINE);  
   passwd = strtok(password, "\r\n");
 
   if (verify_login(username, passwd)){
   auth=1;
   Writeline(fd, good, strlen(good));
   } 
   else {
   auth=0;
   Writeline(fd, fail, strlen(fail));
   }
   
   }

           
         

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20080716-EE-VQP-32 / EE_QW_2_20070628

[C server] Login and blank spaces

Asked by roccogalati in C Programming Language, CYGWIN

Tags: C

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