103 lines
3.7 KiB
Org Mode
103 lines
3.7 KiB
Org Mode
* Beroot
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Beroot is just another privilege escalation tool. I made Beroot for two reasons:
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- I wanted to learn (I discovered a lot of new functions in the standard
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library)
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- Sudo is bloated, and wanted to do something smaller - but usable - than doas.
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** Usage
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Beroot is just two files: ~main.c~ the source of beroot, ~config,h~ the
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configurations of the tool. Beroot doesn't have any ~.conf~ files that need to be
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parsed or something similar, all the changes are made to the ~config.h~ file.
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First, you'll need to build the program:
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#+begin_src bash
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make
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#+end_src
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Now, you'll need to login as root to execute the following commands:
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#+begin_src bash
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make install
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#+end_src
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That command will copy ~./bin/beroot~ to ~/usr/bin~ and set the appropriate permissions to it.
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** Configuration
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The only thing you need to modify is the ~permissions~ variable in ~config.h~. This
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file contains the following structure:
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#+begin_src C
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struct user_permissions
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{
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const char name[16384];
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const char target_user[16384];
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unsigned char permissions;
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};
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#+end_src
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It only has three fields:
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- ~name~: The name of the user you expect can use beroot (like the ones that
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belong to the ~wheel~ group)
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- ~target_user~: In case you want a user not to be root, but rather a different
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user that exists on the machine, you can specify their name using this
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variable.
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- ~permissions~: Here you can set some of the following permission bits:
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- ~PERM_ROOT~: If this is set, the user will execute commands as root,
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~target_user~ will be ignored in this case.
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- ~PERM_USER~: If this bit is present, the user will execute commands as
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~target_user~ instead of root. If both ~PERM_ROOT~ and ~PERM_USER~ are present,
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the last one is ignored as ~PERM_ROOT~ is checked first in the code.
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- ~PERM_PASSWD~: If this is set, beroot will ask for the target user password
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every time that the command is ran.
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- ~PERM_NOPASSWD~: If this bit is present, beroot won't ask for the target user
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password, it will just execute the specified command. Notice that either
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~PERM_PASSWD~ or ~PERM_NOPASSWD~ must be present, if none of them are, beroot
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will display an error.
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For example, if we have a user called ~lain~ and we want this user to execute
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commands as root, and not ask for a password, we'd add the following to the
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~permissions~ variable in ~config.h~:
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#+begin_src C
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const static struct user_permissions permissions[] = {
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{ .name = "lain",
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.target_user = "\0",
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.permissions = PERM_ROOT | PERM_NOPASSWD }
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};
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#+end_src
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In that case, we are setting the user ~lain~ with the permissions of ~PERM_ROOT~
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(execute commands as root) and ~PERM_NOPASSWD~ (don't ask for a password).
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If we want to have multiple rules, we can just separate them by a comma (,):
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#+begin_src C
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const static struct user_permissions permissions[]
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= { { .name = "lain",
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.target_user = "\0",
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.permissions = PERM_ROOT | PERM_NOPASSWD },
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{ .name = "alyssa",
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.target_user = "dbuser",
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.permissions = PERM_USER | PERM_PASSWD } };
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#+end_src
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In that code now we have two users: ~lain~ with the settings we mentioned before,
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and a new user ~alyssa~ that will execute commands as ~dbuser~ and ~PERM_PASSWD~ will
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make that she has to enter her password every time she runs ~beroot~.
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** TODO
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I don't want to make this a big program, I want to keep everything as simple as
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possible, but there are some things that I want to do:
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- Optimise the code, I wrote this in like 1 hour just to test things in the
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standard library.
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- Some kind of persistency (there can be a ~PERM_PERSIST~ flag) so the password
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doesn't need to be entered every time.
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- Hide the password while it's being typed.
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Those are the only things I have planned adding to beroot.
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