| 1 | #ifndef lint |
| 2 | static char *sccsid = "@(#)su.c 4.4 (Berkeley) 4.4"; |
| 3 | #endif |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <pwd.h> |
| 7 | |
| 8 | struct passwd *pwd,*getpwnam(); |
| 9 | char *crypt(); |
| 10 | char *getpass(); |
| 11 | |
| 12 | main(argc,argv) |
| 13 | int argc; |
| 14 | char **argv; |
| 15 | { |
| 16 | char *nptr = "root"; |
| 17 | char *password; |
| 18 | char *shell = "/bin/sh"; |
| 19 | |
| 20 | if (argc > 1) |
| 21 | nptr = argv[1]; |
| 22 | if ((pwd = getpwnam(nptr)) == NULL) { |
| 23 | printf("Unknown id: %s\n",nptr); |
| 24 | exit(1); |
| 25 | } |
| 26 | if (pwd->pw_passwd[0] == '\0' || getuid() == 0) |
| 27 | goto ok; |
| 28 | password = getpass("Password:"); |
| 29 | if (strcmp(pwd->pw_passwd, crypt(password, pwd->pw_passwd)) != 0) { |
| 30 | printf("Sorry\n"); |
| 31 | if (pwd->pw_uid == 0) { |
| 32 | FILE *console = fopen("/dev/console", "w"); |
| 33 | if (console != NULL) { |
| 34 | fprintf(console, "BADSU: %s %s\r\n", |
| 35 | getlogin(), ttyname(2)); |
| 36 | fclose(console); |
| 37 | } |
| 38 | } |
| 39 | exit(2); |
| 40 | } |
| 41 | ok: |
| 42 | endpwent(); |
| 43 | if (pwd->pw_uid == 0) { |
| 44 | FILE *console = fopen("/dev/console", "w"); |
| 45 | if (console != NULL) { |
| 46 | fprintf(console, "SU: %s %s\r\n", |
| 47 | getlogin(), ttyname(2)); |
| 48 | fclose(console); |
| 49 | } |
| 50 | } |
| 51 | if (setgid(pwd->pw_gid) < 0) { |
| 52 | perror("su: setgid"); |
| 53 | exit(3); |
| 54 | } |
| 55 | if (initgroups(nptr, pwd->pw_gid)) { |
| 56 | fprintf(stderr, "su: initgroups failed\n"); |
| 57 | exit(4); |
| 58 | } |
| 59 | if (setuid(pwd->pw_uid) < 0) { |
| 60 | perror("su: setuid"); |
| 61 | exit(5); |
| 62 | } |
| 63 | if (pwd->pw_shell && *pwd->pw_shell) |
| 64 | shell = pwd->pw_shell; |
| 65 | homeis(pwd->pw_dir); |
| 66 | shellis(shell); |
| 67 | execl(shell, "su", 0); |
| 68 | printf("No shell\n"); |
| 69 | exit(3); |
| 70 | } |
| 71 | |
| 72 | char **environ; |
| 73 | |
| 74 | homeis(hp) |
| 75 | char *hp; |
| 76 | { |
| 77 | register char *cp, *dp; |
| 78 | register char **ep = environ; |
| 79 | static char homebuf[128]; |
| 80 | |
| 81 | while (dp = *ep++) { |
| 82 | for (cp = "HOME"; *cp == *dp && *cp; cp++, dp++) |
| 83 | continue; |
| 84 | if (*cp == 0 && (*dp == '=' || *dp == 0)) { |
| 85 | strcpy(homebuf, "HOME="); |
| 86 | strcat(homebuf, hp); |
| 87 | *--ep = homebuf; |
| 88 | return; |
| 89 | } |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | shellis(sp) |
| 94 | char *sp; |
| 95 | { |
| 96 | register char *cp, *dp; |
| 97 | register char **ep = environ; |
| 98 | static char shellbuf[128]; |
| 99 | |
| 100 | while (dp = *ep++) { |
| 101 | for (cp = "SHELL"; *cp == *dp && *cp; cp++, dp++) |
| 102 | continue; |
| 103 | if (*cp == 0 && (*dp == '=' || *dp == 0)) { |
| 104 | strcpy(shellbuf, "SHELL="); |
| 105 | strcat(shellbuf, sp); |
| 106 | *--ep = shellbuf; |
| 107 | return; |
| 108 | } |
| 109 | } |
| 110 | } |