| 1 | /* su - become super-user Author: Patrick van Kleef */
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| 2 |
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| 3 | #include <sys/types.h>
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| 4 | #include <pwd.h>
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| 5 | #include <grp.h>
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| 6 | #include <stdio.h>
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| 7 | #include <stdlib.h>
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| 8 | #include <string.h>
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| 9 | #include <unistd.h>
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| 10 | #include <limits.h>
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| 11 | #include <fcntl.h>
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| 12 | #include <time.h>
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| 13 | #if __minix_vmd
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| 14 | #include <sys/syslog.h>
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| 15 | #endif
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| 16 | #include <minix/minlib.h>
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| 17 |
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| 18 | _PROTOTYPE(int main, (int argc, char **argv));
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| 19 |
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| 20 | int main(argc, argv)
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| 21 | int argc;
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| 22 | char *argv[];
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| 23 | {
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| 24 | register char *name, *password;
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| 25 | char *shell, sh0[100];
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| 26 | char from_user[8+1], from_shell[100];
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| 27 | register struct passwd *pwd;
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| 28 | char USER[20], LOGNAME[25], HOME[100], SHELL[100];
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| 29 | char *envv[20], **envp;
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| 30 | int smallenv;
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| 31 | char *p;
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| 32 | int super;
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| 33 | int loginshell;
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| 34 | #if __minix_vmd
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| 35 | gid_t groups[NGROUPS_MAX];
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| 36 | int ngroups;
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| 37 | int g;
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| 38 | #endif
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| 39 |
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| 40 | smallenv = 0;
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| 41 | loginshell = 0;
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| 42 | if (argc > 1 && (strcmp(argv[1], "-") == 0 || strcmp(argv[1], "-e") == 0)) {
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| 43 | if (argv[1][1] == 0)
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| 44 | loginshell= 1; /* 'su -' reads .profile */
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| 45 | argv[1] = argv[0];
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| 46 | argv++;
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| 47 | argc--;
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| 48 | smallenv = 1; /* Use small environment. */
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| 49 | }
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| 50 | if (argc > 1) {
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| 51 | if (argv[1][0] == '-') {
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| 52 | fprintf(stderr,
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| 53 | "Usage: su [-[e]] [user [shell-arguments ...]]\n");
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| 54 | exit(1);
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| 55 | }
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| 56 | name = argv[1];
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| 57 | argv[1] = argv[0];
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| 58 | argv++;
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| 59 | } else {
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| 60 | name = "root";
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| 61 | }
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| 62 |
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| 63 | if ((pwd = getpwuid(getuid())) == 0) {
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| 64 | fprintf(stderr, "You do not exist\n");
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| 65 | exit(1);
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| 66 | }
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| 67 | strncpy(from_user, pwd->pw_name, 8);
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| 68 | from_user[8]= 0;
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| 69 | strncpy(from_shell, pwd->pw_shell[0] == '\0' ? "/bin/sh" : pwd->pw_shell,
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| 70 | sizeof(from_shell)-1);
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| 71 | from_shell[sizeof(from_shell)-1]= 0;
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| 72 |
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| 73 | if ((pwd = getpwnam(name)) == 0) {
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| 74 | fprintf(stderr, "Unknown id: %s\n", name);
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| 75 | exit(1);
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| 76 | }
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| 77 | super = 0;
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| 78 | if (getgid() == 0) super = 1;
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| 79 | #if __minix_vmd
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| 80 | ngroups = getgroups(NGROUPS_MAX, groups);
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| 81 | for (g = 0; g < ngroups; g++) if (groups[g] == 0) super = 1;
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| 82 | #endif
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| 83 |
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| 84 | if (!super && strcmp(pwd->pw_passwd, crypt("", pwd->pw_passwd)) != 0) {
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| 85 | #if __minix_vmd
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| 86 | openlog("su", 0, LOG_AUTH);
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| 87 | #endif
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| 88 | password = getpass("Password:");
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| 89 | if (password == 0
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| 90 | || strcmp(pwd->pw_passwd, crypt(password, pwd->pw_passwd)) != 0) {
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| 91 | if (password != 0 && *password != 0) {
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| 92 | #if __minix_vmd
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| 93 | syslog(LOG_WARNING, "su %s failed for %s",
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| 94 | name, from_user);
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| 95 | #endif
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| 96 | }
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| 97 | fprintf(stderr, "Sorry\n");
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| 98 | exit(2);
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| 99 | }
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| 100 | #if __minix_vmd
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| 101 | syslog(LOG_NOTICE, "su %s succeeded for %s", name, from_user);
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| 102 | closelog();
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| 103 | #endif
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| 104 | }
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| 105 |
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| 106 | #if __minix_vmd
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| 107 | initgroups(pwd->pw_name, pwd->pw_gid);
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| 108 | #endif
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| 109 | setgid(pwd->pw_gid);
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| 110 | setuid(pwd->pw_uid);
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| 111 | if (loginshell) {
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| 112 | shell = pwd->pw_shell[0] == '\0' ? "/bin/sh" : pwd->pw_shell;
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| 113 | } else {
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| 114 | if ((shell = getenv("SHELL")) == NULL) shell = from_shell;
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| 115 | }
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| 116 | if ((p= strrchr(shell, '/')) == 0) p= shell; else p++;
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| 117 | sh0[0]= '-';
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| 118 | strcpy(loginshell ? sh0+1 : sh0, p);
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| 119 | argv[0]= sh0;
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| 120 |
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| 121 | if (smallenv) {
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| 122 | envp = envv;
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| 123 | *envp++ = "PATH=:/bin:/usr/bin",
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| 124 | strcpy(USER, "USER=");
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| 125 | strcpy(USER + 5, name);
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| 126 | *envp++ = USER;
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| 127 | strcpy(LOGNAME, "LOGNAME=");
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| 128 | strcpy(LOGNAME + 8, name);
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| 129 | *envp++ = LOGNAME;
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| 130 | strcpy(SHELL, "SHELL=");
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| 131 | strcpy(SHELL + 6, shell);
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| 132 | *envp++ = SHELL;
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| 133 | strcpy(HOME, "HOME=");
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| 134 | strcpy(HOME + 5, pwd->pw_dir);
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| 135 | *envp++ = HOME;
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| 136 | if ((p = getenv("TERM")) != NULL) {
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| 137 | *envp++ = p - 5;
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| 138 | }
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| 139 | if ((p = getenv("TERMCAP")) != NULL) {
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| 140 | *envp++ = p - 8;
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| 141 | }
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| 142 | if ((p = getenv("TZ")) != NULL) {
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| 143 | *envp++ = p - 3;
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| 144 | }
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| 145 | *envp = NULL;
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| 146 | (void) chdir(pwd->pw_dir);
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| 147 | execve(shell, argv, envv);
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| 148 | perror(shell);
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| 149 | } else {
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| 150 | execv(shell, argv);
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| 151 | perror(shell);
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| 152 | }
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| 153 | fprintf(stderr, "No shell\n");
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| 154 | return(3);
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| 155 | }
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