it's enough to modify the source code of multircon.c.
The instruction which reads the passwords from the wordlist is that one at line 358 so if you want to set a minimum of 3 chars and a maximum of 8 it's enough to add the following instruction at line 359:
Code:
if((strlen(bpwd) < 3) || (strlen(bpwd) > 8)) continue;
so that part of the code will looks like
Code:
while(mybrute_word(brutex, fd) && !bfound) {
if((strlen(bpwd) < 3) || (strlen(bpwd) > 8)) continue;
rconbrute(sd, buff, bpwd);
printf("%-79s\r", bpwd);
usleep(bdelay);
}
you could also place an automatic limitation of the passwords just in the tool, so for example if you have a password of 100 chars it will be truncated to how much you desire (truncated instead of being skipped).
It's enough to substituite the 64 at line 334 with the number you desire (like 8 and so on).