citadel/chkpw.c

   1 /*
   2  *
   3  */
   4
   5 #include <errno.h>
   6 #include <stdlib.h>
   7 #include <unistd.h>
   8 #include <stdio.h>
   9 #include <fcntl.h>
  10 #include <signal.h>
  11 #include <pwd.h>
  12 #include <ctype.h>
  13 #include <sys/types.h>
  14 #include <sys/wait.h>
  15 #include <sys/stat.h>
  16 #include <unistd.h>
  17 #include <string.h>
  18 #include <limits.h>
  19 #include <dirent.h>
  20
  21
  22 #include "citadel.h"
  23 #include "sysdep.h"
  24 #include "citadel_dirs.h"
  25 /* These pipes are used to talk to the chkpwd daemon, which is forked during startup */
  26 int chkpwd_write_pipe[2];
  27 int chkpwd_read_pipe[2];
  28
  29 /*
  30  * Validate a password on the host unix system by talking to the chkpwd daemon
  31  */
  32 static int validpw(uid_t uid, const char *pass)
  33 {
  34         char buf[256];
  35
  36         write(chkpwd_write_pipe[1], &uid, sizeof(uid_t));
  37         write(chkpwd_write_pipe[1], pass, 256);
  38         read(chkpwd_read_pipe[0], buf, 4);
  39
  40         if (!strncmp(buf, "PASS", 4)) {
  41                 printf("pass\n");
  42                 return(1);
  43         }
  44
  45         printf("fail\n");
  46         return 0;
  47 }
  48
  49 /*
  50  * Start up the chkpwd daemon so validpw() has something to talk to
  51  */
  52 void start_chkpwd_daemon(void) {
  53         pid_t chkpwd_pid;
  54         struct stat filestats;
  55         int i;
  56
  57         printf("Starting chkpwd daemon for host authentication mode\n");
  58
  59         if ((stat(file_chkpwd, &filestats)==-1) ||
  60             (filestats.st_size==0)){
  61                 printf("didn't find chkpwd daemon in %s: %s\n", file_chkpwd, strerror(errno));
  62                 abort();
  63         }
  64         if (pipe(chkpwd_write_pipe) != 0) {
  65                 printf("Unable to create pipe for chkpwd daemon: %s\n", strerror(errno));
  66                 abort();
  67         }
  68         if (pipe(chkpwd_read_pipe) != 0) {
  69                 printf("Unable to create pipe for chkpwd daemon: %s\n", strerror(errno));
  70                 abort();
  71         }
  72
  73         chkpwd_pid = fork();
  74         if (chkpwd_pid < 0) {
  75                 printf("Unable to fork chkpwd daemon: %s\n", strerror(errno));
  76                 abort();
  77         }
  78         if (chkpwd_pid == 0) {
  79                 dup2(chkpwd_write_pipe[0], 0);
  80                 dup2(chkpwd_read_pipe[1], 1);
  81                 for (i=2; i<256; ++i) close(i);
  82                 execl(file_chkpwd, file_chkpwd, NULL);
  83                 printf("Unable to exec chkpwd daemon: %s\n", strerror(errno));
  84                 abort();
  85                 exit(errno);
  86         }
  87 }
  88
  89
  90
  91 int main(int argc, char **argv) {
  92         char buf[256];
  93         struct passwd *p;
  94         int uid;
  95         char ctdldir[PATH_MAX]=CTDLDIR;
  96
  97         calc_dirs_n_files(0,0,"", ctdldir, 0);
  98
  99         printf("\n\n ** host auth mode test utility **\n\n");
 100         start_chkpwd_daemon();
 101
 102         if (getuid() != 0){
 103                 printf("\n\nERROR: you need to be root to run this!\n\n");
 104                 return(1);
 105         }
 106         while(1) {
 107                 printf("\n\nUsername: ");
 108                 fgets(buf, sizeof buf, stdin);
 109                 buf[strlen(buf)-1] = 0;
 110                 p = getpwnam(buf);
 111                 if (p == NULL) {
 112                         printf("Not found\n");
 113                 }
 114                 else {
 115                         uid = p->pw_uid;
 116                         printf("     uid: %d\n", uid);
 117                         printf("Password: ");
 118                         fgets(buf, sizeof buf, stdin);
 119                         buf[strlen(buf)-1] = 0;
 120                         validpw(uid, buf);
 121                 }
 122         }
 123
 124         return(0);
 125 }