diff options
Diffstat (limited to 'source/smbd/chgpasswd.c')
| -rw-r--r-- | source/smbd/chgpasswd.c | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/source/smbd/chgpasswd.c b/source/smbd/chgpasswd.c new file mode 100644 index 00000000000..dc0514c1ed7 --- /dev/null +++ b/source/smbd/chgpasswd.c @@ -0,0 +1,376 @@ +/* fork a child process to exec passwd and write to its +* tty to change a users password. This is running as the +* user who is attempting to change the password. +*/ + +/* + * This code was copied/borrowed and stolen from various sources. + * The primary source was the poppasswd.c from the authors of POPMail. This software + * was included as a client to change passwords using the 'passwd' program + * on the remote machine. + * + * This routine is called by set_user_password() in password.c only if ALLOW_PASSWORD_CHANGE + * is defined in the compiler directives located in the Makefile. + * + * This code has been hacked by Bob Nance (nance@niehs.nih.gov) and Evan Patterson + * (patters2@niehs.nih.gov) at the National Institute of Environmental Health Sciences + * and rights to modify, distribute or incorporate this change to the CAP suite or + * using it for any other reason are granted, so long as this disclaimer is left intact. + */ + +/* + This code was hacked considerably for inclusion in Samba, primarily + by Andrew.Tridgell@anu.edu.au. The biggest change was the addition + of the "password chat" option, which allows the easy runtime + specification of the expected sequence of events to change a + password. + */ + +#include "includes.h" +#include "loadparm.h" + +extern int DEBUGLEVEL; + +#ifdef ALLOW_CHANGE_PASSWORD + +#define MINPASSWDLENGTH 5 +#define BUFSIZE 512 + +static int findpty(char **slave) +{ + int master; +#ifdef SVR4 + extern char *ptsname(); +#else + static char line[12] = "/dev/ptyXX"; + void *dirp; + char *dpname; +#endif + +#ifdef SVR4 + if ((master = open("/dev/ptmx", O_RDWR)) >= 1) { + grantpt(master); + unlockpt(master); + *slave = ptsname(master); + return (master); + } +#else + dirp = OpenDir("/dev"); + if (!dirp) return(-1); + while ((dpname = ReadDirName(dirp)) != NULL) { + if (strncmp(dpname, "pty", 3) == 0 && strlen(dpname) == 5) { + line[8] = dpname[3]; + line[9] = dpname[4]; + if ((master = open(line, O_RDWR)) >= 0) { + line[5] = 't'; + *slave = line; + CloseDir(dirp); + return (master); + } + } + } + CloseDir(dirp); +#endif + return (-1); +} + +static int dochild(int master,char *slavedev, char *name, char *passwordprogram) +{ + int slave; + struct termios stermios; + struct passwd *pass = Get_Pwnam(name,True); + int gid = pass->pw_gid; + int uid = pass->pw_uid; + +#ifdef USE_SETRES + setresuid(0,0,0); +#else + setuid(0); +#endif + + /* Start new session - gets rid of controlling terminal. */ + if (setsid() < 0) { + DEBUG(3,("Weirdness, couldn't let go of controlling terminal\n")); + return(False); + } + + /* Open slave pty and acquire as new controlling terminal. */ + if ((slave = open(slavedev, O_RDWR)) < 0) { + DEBUG(3,("More weirdness, could not open %s\n", + slavedev)); + return(False); + } +#ifdef SVR4 + ioctl(slave, I_PUSH, "ptem"); + ioctl(slave, I_PUSH, "ldterm"); +#else + if (ioctl(slave,TIOCSCTTY,0) <0) { + DEBUG(3,("Error in ioctl call for slave pty\n")); + /* return(False); */ + } +#endif + + /* Close master. */ + close(master); + + /* Make slave stdin/out/err of child. */ + + if (dup2(slave, STDIN_FILENO) != STDIN_FILENO) { + DEBUG(3,("Could not re-direct stdin\n")); + return(False); + } + if (dup2(slave, STDOUT_FILENO) != STDOUT_FILENO) { + DEBUG(3,("Could not re-direct stdout\n")); + return(False); + } + if (dup2(slave, STDERR_FILENO) != STDERR_FILENO) { + DEBUG(3,("Could not re-direct stderr\n")); + return(False); + } + if (slave > 2) close(slave); + + /* Set proper terminal attributes - no echo, canonical input processing, + no map NL to CR/NL on output. */ + + if (tcgetattr(0, &stermios) < 0) { + DEBUG(3,("could not read default terminal attributes on pty\n")); + return(False); + } + stermios.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL); + stermios.c_lflag |= ICANON; + stermios.c_oflag &= ~(ONLCR); + if (tcsetattr(0, TCSANOW, &stermios) < 0) { + DEBUG(3,("could not set attributes of pty\n")); + return(False); + } + + /* make us completely into the right uid */ +#ifdef USE_SETRES + setresgid(0,0,0); + setresuid(0,0,0); + setresgid(gid,gid,gid); + setresuid(uid,uid,uid); +#else + setuid(0); + seteuid(0); + setgid(gid); + setegid(gid); + setuid(uid); + seteuid(uid); +#endif + + /* execl() password-change application */ + if (execl("/bin/sh","sh","-c",passwordprogram,NULL) < 0) { + DEBUG(3,("Bad status returned from %s\n",passwordprogram)); + return(False); + } + return(True); +} + +static int expect(int master,char *expected,char *buf) +{ + int n, m; + + n = 0; + buf[0] = 0; + while (1) { + if (n >= BUFSIZE-1) { + return False; + } + + /* allow 4 seconds for some output to appear */ + m = read_with_timeout(master, buf+n, 1, BUFSIZE-1-n, 4000, True); + if (m < 0) + return False; + + n += m; + buf[n] = 0; + + { + pstring s1,s2; + strcpy(s1,buf); + strcpy(s2,expected); + if (do_match(s1, s2, False)) + return(True); + } + } +} + +static void pwd_sub(char *buf) +{ + string_sub(buf,"\\n","\n"); + string_sub(buf,"\\r","\r"); + string_sub(buf,"\\s"," "); + string_sub(buf,"\\t","\t"); +} + +static void writestring(int fd,char *s) +{ + int l; + + l = strlen (s); + write (fd, s, l); +} + + +static int talktochild(int master, char *chatsequence) +{ + char buf[BUFSIZE]; + int count=0; + char *ptr=chatsequence; + fstring chatbuf; + + *buf = 0; + sleep(1); + + while (next_token(&ptr,chatbuf,NULL)) { + BOOL ok=True; + count++; + pwd_sub(chatbuf); + if (!strequal(chatbuf,".")) + ok = expect(master,chatbuf,buf); + +#if DEBUG_PASSWORD + DEBUG(100,("chatbuf=[%s] responsebuf=[%s]\n",chatbuf,buf)); +#endif + + if (!ok) { + DEBUG(3,("response %d incorrect\n",count)); + return(False); + } + + if (!next_token(&ptr,chatbuf,NULL)) break; + pwd_sub(chatbuf); + if (!strequal(chatbuf,".")) + writestring(master,chatbuf); + +#if DEBUG_PASSWORD + DEBUG(100,("sendbuf=[%s]\n",chatbuf)); +#endif + } + + if (count<1) return(False); + + return (True); +} + + +BOOL chat_with_program(char *passwordprogram,char *name,char *chatsequence) +{ + char *slavedev; + int master; + pid_t pid, wpid; + int wstat; + BOOL chstat; + + /* allocate a pseudo-terminal device */ + if ((master = findpty (&slavedev)) < 0) { + DEBUG(3,("Cannot Allocate pty for password change: %s",name)); + return(False); + } + + if ((pid = fork()) < 0) { + DEBUG(3,("Cannot fork() child for password change: %s",name)); + return(False); + } + + /* we now have a pty */ + if (pid > 0){ /* This is the parent process */ + if ((chstat = talktochild(master, chatsequence)) == False) { + DEBUG(3,("Child failed to change password: %s\n",name)); + kill(pid, SIGKILL); /* be sure to end this process */ + return(False); + } + if ((wpid = waitpid(pid, &wstat, 0)) < 0) { + DEBUG(3,("The process is no longer waiting!\n\n")); + return(False); + } + if (pid != wpid) { + DEBUG(3,("We were waiting for the wrong process ID\n")); + return(False); + } + if (WIFEXITED(wstat) == 0) { + DEBUG(3,("The process exited while we were waiting\n")); + return(False); + } + if (WEXITSTATUS(wstat) != 0) { + DEBUG(3,("The status of the process exiting was %d\n", wstat)); + return(False); + } + + } else { + /* CHILD */ + + /* make sure it doesn't freeze */ + alarm(20); + + DEBUG(3,("Dochild for user %s (uid=%d,gid=%d)\n",name,getuid(),getgid())); + chstat = dochild(master, slavedev, name, passwordprogram); + } + DEBUG(3,("Password change %ssuccessful for user %s\n", (chstat?"":"un"), name)); + return (chstat); +} + + +BOOL chgpasswd(char *name,char *oldpass,char *newpass) +{ + pstring passwordprogram; + pstring chatsequence; + + strlower(name); + DEBUG(3,("Password change for user: %s\n",name)); + +#if DEBUG_PASSWORD + DEBUG(100,("Passwords: old=%s new=%s\n",oldpass,newpass)); +#endif + + /* Take the passed information and test it for minimum criteria */ + /* Minimum password length */ + if (strlen(newpass) < MINPASSWDLENGTH) /* too short, must be at least MINPASSWDLENGTH */ + { + DEBUG(2,("Password Change: %s, New password is shorter than MINPASSWDLENGTH\n",name)); + return (False); /* inform the user */ + } + + /* Password is same as old password */ + if (strcmp(oldpass,newpass) == 0) /* don't allow same password */ + { + DEBUG(2,("Password Change: %s, New password is same as old\n",name)); /* log the attempt */ + return (False); /* inform the user */ + } + +#if (defined(PASSWD_PROGRAM) && defined(PASSWD_CHAT)) + strcpy(passwordprogram,PASSWD_PROGRAM); + strcpy(chatsequence,PASSWD_CHAT); +#else + strcpy(passwordprogram,lp_passwd_program()); + strcpy(chatsequence,lp_passwd_chat()); +#endif + + if (!*chatsequence) { + DEBUG(2,("Null chat sequence - no password changing\n")); + return(False); + } + + if (!*passwordprogram) { + DEBUG(2,("Null password program - no password changing\n")); + return(False); + } + + string_sub(passwordprogram,"%u",name); + string_sub(passwordprogram,"%o",oldpass); + string_sub(passwordprogram,"%n",newpass); + + string_sub(chatsequence,"%u",name); + string_sub(chatsequence,"%o",oldpass); + string_sub(chatsequence,"%n",newpass); + return(chat_with_program(passwordprogram,name,chatsequence)); +} + +#else +BOOL chgpasswd(char *name,char *oldpass,char *newpass) +{ + DEBUG(0,("Password changing not compiled in (user=%s)\n",name)); + return(False); +} +#endif |