int channel_droppriv(char *user, char **shell) {
struct passwd *pw;
char *name;
pw = getpwnam(user);
if (!pw) return 0;
if (isatty(0)) {
name = ttyname(0);
if (!name) return 0;
if (!newenv_env("SSH_TTY", name)) return 0;
if (!setowner(name, pw)) return 0;
}
/* drop privileges */
if (!dropuidgid(pw->pw_uid, pw->pw_gid)) return 0;
if (chdir(pw->pw_dir) == -1) return 0;
if (!newenv_env("HOME", pw->pw_dir)) return 0;
if (!newenv_env("USER", pw->pw_name)) return 0;
if (!newenv_env("LOGNAME", pw->pw_name)) return 0;
if (!newenv_env("LOGIN", pw->pw_name)) return 0;
if (!newenv_env("SHELL", pw->pw_shell)) return 0;
*shell = pw->pw_shell;
return 1;
}
static void droproot(void) {
uid_t uid;
uid = geteuid();
if (uid == 0) {
pw = getpwnam("nobody");
if (!pw) fail("getpwnam() failure")
if (!dropuidgid(pw->pw_name, pw->pw_uid, pw->pw_gid)) fail("dropuidgid() failure");
}
