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samba-mirror/source3/smbd/chgpasswd.c
Jeremy Allison 2f194322d4 Removed global_myworkgroup, global_myname, global_myscope. Added liberal
dashes of const. This is a rather large check-in, some things may break.
It does compile though :-).
Jeremy.
(This used to be commit f755711df8)
2002-11-12 23:20:50 +00:00

944 lines
22 KiB
C

/*
Unix SMB/CIFS implementation.
Samba utility functions
Copyright (C) Andrew Tridgell 1992-1998
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* 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"
extern struct passdb_ops pdb_ops;
static BOOL check_oem_password(const char *user,
uchar * lmdata, const uchar * lmhash,
const uchar * ntdata, const uchar * nthash,
SAM_ACCOUNT **hnd, char *new_passwd,
int new_passwd_size);
#if ALLOW_CHANGE_PASSWORD
static int findpty(char **slave)
{
int master;
static fstring line;
DIR *dirp;
char *dpname;
#if defined(HAVE_GRANTPT)
/* Try to open /dev/ptmx. If that fails, fall through to old method. */
if ((master = sys_open("/dev/ptmx", O_RDWR, 0)) >= 0)
{
grantpt(master);
unlockpt(master);
*slave = (char *)ptsname(master);
if (*slave == NULL)
{
DEBUG(0,
("findpty: Unable to create master/slave pty pair.\n"));
/* Stop fd leak on error. */
close(master);
return -1;
}
else
{
DEBUG(10,
("findpty: Allocated slave pty %s\n", *slave));
return (master);
}
}
#endif /* HAVE_GRANTPT */
fstrcpy(line, "/dev/ptyXX");
dirp = opendir("/dev");
if (!dirp)
return (-1);
while ((dpname = readdirname(dirp)) != NULL)
{
if (strncmp(dpname, "pty", 3) == 0 && strlen(dpname) == 5)
{
DEBUG(3,
("pty: try to open %s, line was %s\n", dpname,
line));
line[8] = dpname[3];
line[9] = dpname[4];
if ((master = sys_open(line, O_RDWR, 0)) >= 0)
{
DEBUG(3, ("pty: opened %s\n", line));
line[5] = 't';
*slave = line;
closedir(dirp);
return (master);
}
}
}
closedir(dirp);
return (-1);
}
static int dochild(int master, const char *slavedev, const struct passwd *pass,
const char *passwordprogram, BOOL as_root)
{
int slave;
struct termios stermios;
gid_t gid;
uid_t uid;
if (pass == NULL)
{
DEBUG(0,
("dochild: user doesn't exist in the UNIX password database.\n"));
return False;
}
gid = pass->pw_gid;
uid = pass->pw_uid;
gain_root_privilege();
/* 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 = sys_open(slavedev, O_RDWR, 0)) < 0)
{
DEBUG(3, ("More weirdness, could not open %s\n", slavedev));
return (False);
}
#ifdef I_PUSH
ioctl(slave, I_PUSH, "ptem");
ioctl(slave, I_PUSH, "ldterm");
#elif defined(TIOCSCTTY)
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 (sys_dup2(slave, STDIN_FILENO) != STDIN_FILENO)
{
DEBUG(3, ("Could not re-direct stdin\n"));
return (False);
}
if (sys_dup2(slave, STDOUT_FILENO) != STDOUT_FILENO)
{
DEBUG(3, ("Could not re-direct stdout\n"));
return (False);
}
if (sys_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;
#ifdef ONLCR
stermios.c_oflag &= ~(ONLCR);
#endif
if (tcsetattr(0, TCSANOW, &stermios) < 0)
{
DEBUG(3, ("could not set attributes of pty\n"));
return (False);
}
/* make us completely into the right uid */
if (!as_root)
{
become_user_permanently(uid, gid);
}
DEBUG(10,
("Invoking '%s' as password change program.\n",
passwordprogram));
/* 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 *issue, char *expected)
{
pstring buffer;
int attempts, timeout, nread, len;
BOOL match = False;
for (attempts = 0; attempts < 2; attempts++) {
if (!strequal(issue, ".")) {
if (lp_passwd_chat_debug())
DEBUG(100, ("expect: sending [%s]\n", issue));
if ((len = write(master, issue, strlen(issue))) != strlen(issue)) {
DEBUG(2,("expect: (short) write returned %d\n", len ));
return False;
}
}
if (strequal(expected, "."))
return True;
timeout = 2000;
nread = 0;
buffer[nread] = 0;
while ((len = read_with_timeout(master, buffer + nread, 1,
sizeof(buffer) - nread - 1,
timeout)) > 0) {
nread += len;
buffer[nread] = 0;
{
/* Eat leading/trailing whitespace before match. */
pstring str;
pstrcpy( str, buffer);
trim_string( str, " ", " ");
if ((match = (unix_wild_match(expected, str) == 0)))
timeout = 200;
}
}
if (lp_passwd_chat_debug())
DEBUG(100, ("expect: expected [%s] received [%s] match %s\n",
expected, buffer, match ? "yes" : "no" ));
if (match)
break;
if (len < 0) {
DEBUG(2, ("expect: %s\n", strerror(errno)));
return False;
}
}
DEBUG(10,("expect: returning %s\n", match ? "True" : "False" ));
return match;
}
static void pwd_sub(char *buf)
{
all_string_sub(buf, "\\n", "\n", 0);
all_string_sub(buf, "\\r", "\r", 0);
all_string_sub(buf, "\\s", " ", 0);
all_string_sub(buf, "\\t", "\t", 0);
}
static int talktochild(int master, const char *seq)
{
int count = 0;
fstring issue, expected;
fstrcpy(issue, ".");
while (next_token(&seq, expected, NULL, sizeof(expected)))
{
pwd_sub(expected);
count++;
if (!expect(master, issue, expected))
{
DEBUG(3, ("Response %d incorrect\n", count));
return False;
}
if (!next_token(&seq, issue, NULL, sizeof(issue)))
fstrcpy(issue, ".");
pwd_sub(issue);
}
if (!strequal(issue, ".")) {
/* we have one final issue to send */
fstrcpy(expected, ".");
if (!expect(master, issue, expected))
return False;
}
return (count > 0);
}
static BOOL chat_with_program(char *passwordprogram, struct passwd *pass,
char *chatsequence, BOOL as_root)
{
char *slavedev;
int master;
pid_t pid, wpid;
int wstat;
BOOL chstat = False;
if (pass == NULL)
{
DEBUG(0,
("chat_with_program: user doesn't exist in the UNIX password database.\n"));
return False;
}
/* allocate a pseudo-terminal device */
if ((master = findpty(&slavedev)) < 0)
{
DEBUG(3,
("Cannot Allocate pty for password change: %s\n",
pass->pw_name));
return (False);
}
/*
* We need to temporarily stop CatchChild from eating
* SIGCLD signals as it also eats the exit status code. JRA.
*/
CatchChildLeaveStatus();
if ((pid = sys_fork()) < 0)
{
DEBUG(3,
("Cannot fork() child for password change: %s\n",
pass->pw_name));
close(master);
CatchChild();
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",
pass->pw_name));
kill(pid, SIGKILL); /* be sure to end this process */
}
while ((wpid = sys_waitpid(pid, &wstat, 0)) < 0)
{
if (errno == EINTR)
{
errno = 0;
continue;
}
break;
}
if (wpid < 0)
{
DEBUG(3, ("The process is no longer waiting!\n\n"));
close(master);
CatchChild();
return (False);
}
/*
* Go back to ignoring children.
*/
CatchChild();
close(master);
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 */
/*
* Lose any oplock capabilities.
*/
oplock_set_capability(False, False);
/* make sure it doesn't freeze */
alarm(20);
if (as_root)
become_root();
DEBUG(3,
("Dochild for user %s (uid=%d,gid=%d)\n", pass->pw_name,
(int)getuid(), (int)getgid()));
chstat =
dochild(master, slavedev, pass, passwordprogram,
as_root);
if (as_root)
unbecome_root();
/*
* The child should never return from dochild() ....
*/
DEBUG(0,
("chat_with_program: Error: dochild() returned %d\n",
chstat));
exit(1);
}
if (chstat)
DEBUG(3,
("Password change %ssuccessful for user %s\n",
(chstat ? "" : "un"), pass->pw_name));
return (chstat);
}
BOOL chgpasswd(const char *name, const char *oldpass, const char *newpass, BOOL as_root)
{
pstring passwordprogram;
pstring chatsequence;
size_t i;
size_t len;
struct passwd *pass;
if (!name) {
DEBUG(1, ("NULL username specfied to chgpasswd()!\n"));
}
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) < lp_min_passwd_length()) {
/* too short, must be at least MINPASSWDLENGTH */
DEBUG(0, ("Password Change: user %s, New password is shorter than minimum password length = %d\n",
name, lp_min_passwd_length()));
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 */
}
/*
* Check the old and new passwords don't contain any control
* characters.
*/
len = strlen(oldpass);
for (i = 0; i < len; i++) {
if (iscntrl((int)oldpass[i])) {
DEBUG(0,
("chat_with_program: oldpass contains control characters (disallowed).\n"));
return False;
}
}
len = strlen(newpass);
for (i = 0; i < len; i++) {
if (iscntrl((int)newpass[i])) {
DEBUG(0,
("chat_with_program: newpass contains control characters (disallowed).\n"));
return False;
}
}
pass = Get_Pwnam(name);
#ifdef WITH_PAM
if (lp_pam_password_change()) {
BOOL ret;
if (as_root)
become_root();
if (pass) {
ret = smb_pam_passchange(pass->pw_name, oldpass, newpass);
} else {
ret = smb_pam_passchange(name, oldpass, newpass);
}
if (as_root)
unbecome_root();
return ret;
}
#endif
/* A non-PAM password change just doen't make sense without a valid local user */
if (pass == NULL)
{
DEBUG(0,
("chgpasswd: user %s doesn't exist in the UNIX password database.\n",
name));
return False;
}
pstrcpy(passwordprogram, lp_passwd_program());
pstrcpy(chatsequence, lp_passwd_chat());
if (!*chatsequence) {
DEBUG(2, ("chgpasswd: Null chat sequence - no password changing\n"));
return (False);
}
if (!*passwordprogram) {
DEBUG(2, ("chgpasswd: Null password program - no password changing\n"));
return (False);
}
if (as_root) {
/* The password program *must* contain the user name to work. Fail if not. */
if (strstr(passwordprogram, "%u") == NULL) {
DEBUG(0,("chgpasswd: Running as root the 'passwd program' parameter *MUST* contain \
the string %%u, and the given string %s does not.\n", passwordprogram ));
return False;
}
}
pstring_sub(passwordprogram, "%u", name);
/* note that we do NOT substitute the %o and %n in the password program
as this would open up a security hole where the user could use
a new password containing shell escape characters */
pstring_sub(chatsequence, "%u", name);
all_string_sub(chatsequence, "%o", oldpass, sizeof(pstring));
all_string_sub(chatsequence, "%n", newpass, sizeof(pstring));
return (chat_with_program
(passwordprogram, pass, chatsequence, as_root));
}
#else /* ALLOW_CHANGE_PASSWORD */
BOOL chgpasswd(const char *name, const char *oldpass, const char *newpass, BOOL as_root)
{
DEBUG(0, ("Password changing not compiled in (user=%s)\n", name));
return (False);
}
#endif /* ALLOW_CHANGE_PASSWORD */
/***********************************************************
Code to check the lanman hashed password.
************************************************************/
BOOL check_lanman_password(char *user, uchar * pass1,
uchar * pass2, SAM_ACCOUNT **hnd)
{
uchar unenc_new_pw[16];
uchar unenc_old_pw[16];
SAM_ACCOUNT *sampass = NULL;
uint16 acct_ctrl;
const uint8 *lanman_pw;
BOOL ret;
become_root();
ret = pdb_getsampwnam(sampass, user);
unbecome_root();
if (ret == False) {
DEBUG(0,("check_lanman_password: getsampwnam returned NULL\n"));
pdb_free_sam(&sampass);
return False;
}
acct_ctrl = pdb_get_acct_ctrl (sampass);
lanman_pw = pdb_get_lanman_passwd (sampass);
if (acct_ctrl & ACB_DISABLED) {
DEBUG(0,("check_lanman_password: account %s disabled.\n", user));
pdb_free_sam(&sampass);
return False;
}
if (lanman_pw == NULL) {
if (acct_ctrl & ACB_PWNOTREQ) {
/* this saves the pointer for the caller */
*hnd = sampass;
return True;
} else {
DEBUG(0, ("check_lanman_password: no lanman password !\n"));
pdb_free_sam(&sampass);
return False;
}
}
/* Get the new lanman hash. */
D_P16(lanman_pw, pass2, unenc_new_pw);
/* Use this to get the old lanman hash. */
D_P16(unenc_new_pw, pass1, unenc_old_pw);
/* Check that the two old passwords match. */
if (memcmp(lanman_pw, unenc_old_pw, 16)) {
DEBUG(0,("check_lanman_password: old password doesn't match.\n"));
pdb_free_sam(&sampass);
return False;
}
/* this saves the pointer for the caller */
*hnd = sampass;
return True;
}
/***********************************************************
Code to change the lanman hashed password.
It nulls out the NT hashed password as it will
no longer be valid.
************************************************************/
BOOL change_lanman_password(SAM_ACCOUNT *sampass, uchar * pass1,
uchar * pass2)
{
static uchar null_pw[16];
uchar unenc_new_pw[16];
BOOL ret;
uint16 acct_ctrl;
const uint8 *pwd;
if (sampass == NULL) {
DEBUG(0,("change_lanman_password: no smb password entry.\n"));
return False;
}
acct_ctrl = pdb_get_acct_ctrl(sampass);
pwd = pdb_get_lanman_passwd(sampass);
if (acct_ctrl & ACB_DISABLED) {
DEBUG(0,("change_lanman_password: account %s disabled.\n",
pdb_get_username(sampass)));
return False;
}
if (pwd == NULL) {
if (acct_ctrl & ACB_PWNOTREQ) {
uchar no_pw[14];
memset(no_pw, '\0', 14);
E_P16(no_pw, null_pw);
/* Get the new lanman hash. */
D_P16(null_pw, pass2, unenc_new_pw);
} else {
DEBUG(0,("change_lanman_password: no lanman password !\n"));
return False;
}
} else {
/* Get the new lanman hash. */
D_P16(pwd, pass2, unenc_new_pw);
}
if (!pdb_set_lanman_passwd(sampass, unenc_new_pw, PDB_CHANGED)) {
return False;
}
if (!pdb_set_nt_passwd (sampass, NULL, PDB_CHANGED)) {
return False; /* We lose the NT hash. Sorry. */
}
if (!pdb_set_pass_changed_now (sampass)) {
pdb_free_sam(&sampass);
/* Not quite sure what this one qualifies as, but this will do */
return False;
}
/* Now flush the sam_passwd struct to persistent storage */
become_root();
ret = pdb_update_sam_account (sampass);
unbecome_root();
return ret;
}
/***********************************************************
Code to check and change the OEM hashed password.
************************************************************/
BOOL pass_oem_change(char *user,
uchar * lmdata, uchar * lmhash,
uchar * ntdata, uchar * nthash)
{
fstring new_passwd;
const char *unix_user;
SAM_ACCOUNT *sampass = NULL;
BOOL ret = check_oem_password(user, lmdata, lmhash, ntdata, nthash,
&sampass, new_passwd, sizeof(new_passwd));
/*
* At this point we have the new case-sensitive plaintext
* password in the fstring new_passwd. If we wanted to synchronise
* with UNIX passwords we would call a UNIX password changing
* function here. However it would have to be done as root
* as the plaintext of the old users password is not
* available. JRA.
*/
unix_user = pdb_get_username(sampass);
if ((ret) && (unix_user) && (*unix_user) && lp_unix_password_sync())
ret = chgpasswd(unix_user, "", new_passwd, True);
if (ret)
ret = change_oem_password(sampass, new_passwd);
memset(new_passwd, 0, sizeof(new_passwd));
pdb_free_sam(&sampass);
return ret;
}
/***********************************************************
Code to check the OEM hashed password.
this function ignores the 516 byte nt OEM hashed password
but does use the lm OEM password to check the nt hashed-hash.
************************************************************/
static BOOL check_oem_password(const char *user,
uchar * lmdata, const uchar * lmhash,
const uchar * ntdata, const uchar * nthash,
SAM_ACCOUNT **hnd, char *new_passwd,
int new_passwd_size)
{
static uchar null_pw[16];
static uchar null_ntpw[16];
SAM_ACCOUNT *sampass = NULL;
const uint8 *lanman_pw, *nt_pw;
uint16 acct_ctrl;
int new_pw_len;
uchar new_ntp16[16];
uchar unenc_old_ntpw[16];
uchar new_p16[16];
uchar unenc_old_pw[16];
char no_pw[2];
BOOL ret;
BOOL nt_pass_set = (ntdata != NULL && nthash != NULL);
pdb_init_sam(&sampass);
become_root();
ret = pdb_getsampwnam(sampass, user);
unbecome_root();
if (ret == False) {
DEBUG(0, ("check_oem_password: getsmbpwnam returned NULL\n"));
return False;
}
*hnd = sampass;
acct_ctrl = pdb_get_acct_ctrl(sampass);
if (acct_ctrl & ACB_DISABLED) {
DEBUG(0,("check_lanman_password: account %s disabled.\n", user));
return False;
}
/* construct a null password (in case one is needed */
no_pw[0] = 0;
no_pw[1] = 0;
nt_lm_owf_gen(no_pw, null_ntpw, null_pw);
/* save pointers to passwords so we don't have to keep looking them up */
lanman_pw = pdb_get_lanman_passwd(sampass);
nt_pw = pdb_get_nt_passwd (sampass);
/* check for null passwords */
if (lanman_pw == NULL) {
if (!(acct_ctrl & ACB_PWNOTREQ)) {
DEBUG(0,("check_oem_password: no lanman password !\n"));
return False;
}
}
if (pdb_get_nt_passwd(sampass) == NULL && nt_pass_set) {
if (!(acct_ctrl & ACB_PWNOTREQ)) {
DEBUG(0,("check_oem_password: no ntlm password !\n"));
return False;
}
}
/*
* Call the hash function to get the new password.
*/
SamOEMhash( lmdata, lanman_pw, 516);
/*
* The length of the new password is in the last 4 bytes of
* the data buffer.
*/
new_pw_len = IVAL(lmdata, 512);
if (new_pw_len < 0 || new_pw_len > new_passwd_size - 1) {
DEBUG(0,("check_oem_password: incorrect password length (%d).\n", new_pw_len));
return False;
}
if (nt_pass_set) {
/*
* nt passwords are in unicode
*/
pull_ucs2(NULL, new_passwd,
(const smb_ucs2_t *)&lmdata[512 - new_pw_len],
new_passwd_size, new_pw_len, 0);
} else {
memcpy(new_passwd, &lmdata[512 - new_pw_len], new_pw_len);
new_passwd[new_pw_len] = 0;
}
/*
* To ensure we got the correct new password, hash it and
* use it as a key to test the passed old password.
*/
nt_lm_owf_gen(new_passwd, new_ntp16, new_p16);
if (!nt_pass_set)
{
/*
* Now use new_p16 as the key to see if the old
* password matches.
*/
D_P16(new_p16, lmhash, unenc_old_pw);
if (memcmp(lanman_pw, unenc_old_pw, 16))
{
DEBUG(0,("check_oem_password: old lm password doesn't match.\n"));
return False;
}
#ifdef DEBUG_PASSWORD
DEBUG(100,
("check_oem_password: password %s ok\n", new_passwd));
#endif
return True;
}
/*
* Now use new_p16 as the key to see if the old
* password matches.
*/
D_P16(new_ntp16, lmhash, unenc_old_pw);
D_P16(new_ntp16, nthash, unenc_old_ntpw);
if (memcmp(lanman_pw, unenc_old_pw, 16))
{
DEBUG(0,("check_oem_password: old lm password doesn't match.\n"));
return False;
}
if (memcmp(nt_pw, unenc_old_ntpw, 16))
{
DEBUG(0,("check_oem_password: old nt password doesn't match.\n"));
return False;
}
#ifdef DEBUG_PASSWORD
DEBUG(100, ("check_oem_password: password %s ok\n", new_passwd));
#endif
return True;
}
/***********************************************************
Code to change the oem password. Changes both the lanman
and NT hashes.
************************************************************/
BOOL change_oem_password(SAM_ACCOUNT *hnd, char *new_passwd)
{
BOOL ret;
if (!pdb_set_plaintext_passwd (hnd, new_passwd)) {
return False;
}
/* Now write it into the file. */
become_root();
ret = pdb_update_sam_account (hnd);
unbecome_root();
return ret;
}