BSD 3 development

[unix-history] / usr / src / cmd / su.c

#include <stdio.h>
#include <pwd.h>

struct  passwd *pwd,*getpwnam();
char    *crypt();
char    *getpass();

main(argc,argv)
int     argc;
char    **argv;
{
       char *nptr;
       char *password;
       int badsw = 0;
       char *shell = "/bin/sh";

       if(argc > 1)
               nptr = argv[1];
       else
               nptr = "root";
       if((pwd=getpwnam(nptr)) == NULL) {
               printf("Unknown id: %s\n",nptr);
               exit(1);
       }
       if(pwd->pw_passwd[0] == '\0' || getuid() == 0)
               goto ok;
       password = getpass("Password:");
       if(badsw || (strcmp(pwd->pw_passwd, crypt(password, pwd->pw_passwd)) != 0)) {
bad:
               printf("Sorry\n");
               if(pwd->pw_uid == 0) {
                       FILE *console = fopen("/dev/console", "w");
                       if (console != NULL) {
                               fprintf(console, "BADSU: %s %s\r\n", getlogin(), ttyname(2));
                               fclose(console);
                       }
               }
               exit(2);
       }
       if(pwd->pw_uid == 0 && badroot(getgid(),getuid()))
               goto bad;

ok:
       endpwent();
       if(pwd->pw_uid == 0) {
               FILE *console = fopen("/dev/console", "w");
               if (console != NULL) {
                       fprintf(console, "SU: %s %s\r\n", getlogin(), ttyname(2));
                       fclose(console);
               }
       }
       setgid(pwd->pw_gid);
       setuid(pwd->pw_uid);
       if (pwd->pw_shell && *pwd->pw_shell)
               shell = pwd->pw_shell;
       homeis(pwd->pw_dir);
       shellis(shell);
       execl(shell, "su", 0);
       printf("No shell\n");
       exit(3);
}
badroot(gid,uid)
{
/*
       if(gid!=10 || (uid > 15 && (uid!=40 && uid!=209 && uid!=203
                                   && uid!=54 && uid!=245)))
               return(1);
       else 
*/
               return(0);
}

char    **environ;

homeis(hp)
       char *hp;
{
       register char *cp, *dp;
       register char **ep = environ;
       static char homebuf[128];

       while (dp = *ep++) {
               for (cp = "HOME"; *cp == *dp && *cp; cp++, dp++)
                       continue;
               if (*cp == 0 && (*dp == '=' || *dp == 0)) {
                       strcpy(homebuf, "HOME=");
                       strcat(homebuf, hp);
                       *--ep = homebuf;
                       return;
               }
       }
}

shellis(sp)
       char *sp;
{
       register char *cp, *dp;
       register char **ep = environ;
       static char shellbuf[128];

       while (dp = *ep++) {
               for (cp = "SHELL"; *cp == *dp && *cp; cp++, dp++)
                       continue;
               if (*cp == 0 && (*dp == '=' || *dp == 0)) {
                       strcpy(shellbuf, "SHELL=");
                       strcat(shellbuf, sp);
                       *--ep = shellbuf;
                       return;
               }
       }
}