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/*
* Unix SMB/Netbios implementation. Version 1.9. smbpasswd module. Copyright
* (C) Jeremy Allison 1995-1997.
*
* 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.
*/
#include "includes.h"
/* Static buffers we will return. */
static struct smb_passwd pw_buf;
static pstring user_name;
static unsigned char smbpwd[16];
static unsigned char smbntpwd[16];
static int gethexpwd(char *p, char *pwd)
{
int i;
unsigned char lonybble, hinybble;
char *hexchars = "0123456789ABCDEF";
char *p1, *p2;
for (i = 0; i < 32; i += 2) {
hinybble = toupper(p[i]);
lonybble = toupper(p[i + 1]);
p1 = strchr(hexchars, hinybble);
p2 = strchr(hexchars, lonybble);
if (!p1 || !p2)
return (False);
hinybble = PTR_DIFF(p1, hexchars);
lonybble = PTR_DIFF(p2, hexchars);
pwd[i / 2] = (hinybble << 4) | lonybble;
}
return (True);
}
struct smb_passwd *
_my_get_smbpwnam(FILE * fp, char *name, BOOL * valid_old_pwd,
BOOL *got_valid_nt_entry, long *pwd_seekpos)
{
char linebuf[256];
unsigned char c;
unsigned char *p;
long uidval;
long linebuf_len;
/*
* Scan the file, a line at a time and check if the name matches.
*/
while (!feof(fp)) {
linebuf[0] = '\0';
*pwd_seekpos = ftell(fp);
fgets(linebuf, 256, fp);
if (ferror(fp))
return NULL;
/*
* Check if the string is terminated with a newline - if not
* then we must keep reading and discard until we get one.
*/
linebuf_len = strlen(linebuf);
if (linebuf[linebuf_len - 1] != '\n') {
c = '\0';
while (!ferror(fp) && !feof(fp)) {
c = fgetc(fp);
if (c == '\n')
break;
}
} else
linebuf[linebuf_len - 1] = '\0';
if ((linebuf[0] == 0) && feof(fp))
break;
/*
* The line we have should be of the form :-
*
* username:uid:[32hex bytes]:....other flags presently
* ignored....
*
* or,
*
* username:uid:[32hex bytes]:[32hex bytes]:....ignored....
*
* if Windows NT compatible passwords are also present.
*/
if (linebuf[0] == '#' || linebuf[0] == '\0')
continue;
p = (unsigned char *) strchr(linebuf, ':');
if (p == NULL)
continue;
/*
* As 256 is shorter than a pstring we don't need to check
* length here - if this ever changes....
*/
strncpy(user_name, linebuf, PTR_DIFF(p, linebuf));
user_name[PTR_DIFF(p, linebuf)] = '\0';
if (!strequal(user_name, name))
continue;
/* User name matches - get uid and password */
p++; /* Go past ':' */
if (!isdigit(*p))
return (False);
uidval = atoi((char *) p);
while (*p && isdigit(*p))
p++;
if (*p != ':')
return (False);
/*
* Now get the password value - this should be 32 hex digits
* which are the ascii representations of a 16 byte string.
* Get two at a time and put them into the password.
*/
p++;
*pwd_seekpos += PTR_DIFF(p, linebuf); /* Save exact position
* of passwd in file -
* this is used by
* smbpasswd.c */
if (*p == '*' || *p == 'X') {
/* Password deliberately invalid - end here. */
*valid_old_pwd = False;
*got_valid_nt_entry = False;
pw_buf.smb_nt_passwd = NULL; /* No NT password (yet)*/
/* Now check if the NT compatible password is
available. */
p += 33; /* Move to the first character of the line after
the lanman password. */
if ((linebuf_len >= (PTR_DIFF(p, linebuf) + 33)) && (p[32] == ':')) {
/* NT Entry was valid - even if 'X' or '*', can be overwritten */
*got_valid_nt_entry = True;
if (*p != '*' && *p != 'X') {
if (gethexpwd((char *)p,(char *)smbntpwd))
pw_buf.smb_nt_passwd = smbntpwd;
}
}
pw_buf.smb_name = user_name;
pw_buf.smb_userid = uidval;
pw_buf.smb_passwd = NULL; /* No password */
return (&pw_buf);
}
if (linebuf_len < (PTR_DIFF(p, linebuf) + 33))
return (False);
if (p[32] != ':')
return (False);
if (!strncasecmp((char *)p, "NO PASSWORD", 11)) {
pw_buf.smb_passwd = NULL; /* No password */
} else {
if(!gethexpwd((char *)p,(char *)smbpwd))
return False;
pw_buf.smb_passwd = smbpwd;
}
pw_buf.smb_name = user_name;
pw_buf.smb_userid = uidval;
pw_buf.smb_nt_passwd = NULL;
*got_valid_nt_entry = False;
*valid_old_pwd = True;
/* Now check if the NT compatible password is
available. */
p += 33; /* Move to the first character of the line after
the lanman password. */
if ((linebuf_len >= (PTR_DIFF(p, linebuf) + 33)) && (p[32] == ':')) {
/* NT Entry was valid - even if 'X' or '*', can be overwritten */
*got_valid_nt_entry = True;
if (*p != '*' && *p != 'X') {
if (gethexpwd((char *)p,(char *)smbntpwd))
pw_buf.smb_nt_passwd = smbntpwd;
}
}
return &pw_buf;
}
return NULL;
}
/*
* Print command usage on stderr and die.
*/
static void usage(char *name)
{
fprintf(stderr, "Usage is : %s [-add] [username] [password]\n", name);
exit(1);
}
int main(int argc, char **argv)
{
int real_uid;
struct passwd *pwd;
fstring old_passwd;
uchar old_p16[16];
uchar old_nt_p16[16];
fstring new_passwd;
uchar new_p16[16];
uchar new_nt_p16[16];
char *p;
struct smb_passwd *smb_pwent;
FILE *fp;
BOOL valid_old_pwd = False;
BOOL got_valid_nt_entry = False;
BOOL add_user = False;
int add_pass = 0;
long seekpos;
int pwfd;
char ascii_p16[66];
char c;
int ret, i, err, writelen;
int lockfd = -1;
char *pfile = SMB_PASSWD_FILE;
char readbuf[16 * 1024];
TimeInit();
setup_logging(argv[0],True);
charset_initialise();
#ifndef DEBUG_PASSWORD
/* Check the effective uid */
if (geteuid() != 0) {
fprintf(stderr, "%s: Must be setuid root.\n", argv[0]);
exit(1);
}
#endif
/* Get the real uid */
real_uid = getuid();
/* Deal with usage problems */
if (real_uid == 0)
{
/* As root we can change anothers password and add a user. */
if (argc > 4 )
usage(argv[0]);
}
else if (argc == 2 || argc > 3)
{
fprintf(stderr, "%s: Only root can set anothers password.\n", argv[0]);
usage(argv[0]);
}
if (real_uid == 0 && (argc > 1))
{
/* We are root - check if we should add the user */
if ((argv[1][0] == '-') && (argv[1][1] == 'a'))
add_user = True;
if(add_user && (argc <= 2 || argc > 4))
usage(argv[0]);
/* root can specify password on command-line */
if (argc == (add_user ? 4 : 3))
{
/* -a argument (add_user): new password is 3rd argument. */
/* no -a argument (add_user): new password is 2nd argument */
add_pass = add_user ? 3 : 2;
}
/* If we are root we can change another's password. */
strncpy(user_name, add_user ? argv[2] : argv[1], sizeof(user_name) - 1);
user_name[sizeof(user_name) - 1] = '\0';
pwd = getpwnam(user_name);
}
else
{
/* non-root can specify old pass / new pass on command-line */
if (argc == 3)
{
/* non-root specifies new password as 2nd argument */
add_pass = 2;
}
pwd = getpwuid(real_uid);
}
if (pwd == 0) {
fprintf(stderr, "%s: Unable to get UNIX password entry for user.\n", argv[0]);
exit(1);
}
/* If we are root we don't ask for the old password. */
old_passwd[0] = '\0';
if (real_uid != 0)
{
if (add_pass)
{
/* old password, as non-root, is 1st argument */
strncpy(old_passwd, argv[1], sizeof(fstring));
}
else
{
p = getpass("Old SMB password:");
strncpy(old_passwd, p, sizeof(fstring));
}
old_passwd[sizeof(fstring)-1] = '\0';
}
if (add_pass)
{
/* new password is specified on the command line */
strncpy(new_passwd, argv[add_user ? 3 : 2], sizeof(new_passwd) - 1);
new_passwd[sizeof(new_passwd) - 1] = '\0';
}
else
{
new_passwd[0] = '\0';
p = getpass("New SMB password:");
strncpy(new_passwd, p, sizeof(fstring));
new_passwd[sizeof(fstring)-1] = '\0';
p = getpass("Retype new SMB password:");
if (strncmp(p, new_passwd, sizeof(fstring)-1))
{
fprintf(stderr, "%s: Mismatch - password unchanged.\n", argv[0]);
exit(1);
}
}
if (new_passwd[0] == '\0')
{
printf("Password not set\n");
exit(0);
}
/* Calculate the MD4 hash (NT compatible) of the old and new passwords */
memset(old_nt_p16, '\0', 16);
E_md4hash((uchar *)old_passwd, old_nt_p16);
memset(new_nt_p16, '\0', 16);
E_md4hash((uchar *) new_passwd, new_nt_p16);
/* Mangle the passwords into Lanman format */
old_passwd[14] = '\0';
strupper(old_passwd);
new_passwd[14] = '\0';
strupper(new_passwd);
/*
* Calculate the SMB (lanman) hash functions of both old and new passwords.
*/
memset(old_p16, '\0', 16);
E_P16((uchar *) old_passwd, old_p16);
memset(new_p16, '\0', 16);
E_P16((uchar *) new_passwd, new_p16);
/*
* Open the smbpaswd file XXXX - we need to parse smb.conf to get the
* filename
*/
if ((fp = fopen(pfile, "a+")) == NULL) {
err = errno;
fprintf(stderr, "%s: Failed to open password file %s.\n",
argv[0], pfile);
errno = err;
perror(argv[0]);
exit(err);
}
/* position at the start of the file */
fseek(fp, 0, SEEK_SET);
/* Set read buffer to 16k for effiecient reads */
setvbuf(fp, readbuf, _IOFBF, sizeof(readbuf));
/* make sure it is only rw by the owner */
chmod(pfile, 0600);
/* Lock the smbpasswd file for write. */
if ((lockfd = pw_file_lock(pfile, F_WRLCK, 5)) < 0) {
err = errno;
fprintf(stderr, "%s: Failed to lock password file %s.\n",
argv[0], pfile);
fclose(fp);
errno = err;
perror(argv[0]);
exit(err);
}
/* Get the smb passwd entry for this user */
smb_pwent = _my_get_smbpwnam(fp, pwd->pw_name, &valid_old_pwd,
&got_valid_nt_entry, &seekpos);
if (smb_pwent == NULL) {
if(add_user == False) {
fprintf(stderr, "%s: Failed to find entry for user %s in file %s.\n",
argv[0], pwd->pw_name, pfile);
fclose(fp);
pw_file_unlock(lockfd);
exit(1);
}
/* Create a new smb passwd entry and set it to the given password. */
{
int fd;
int new_entry_length;
char *new_entry;
long offpos;
/* The add user write needs to be atomic - so get the fd from
the fp and do a raw write() call.
*/
fd = fileno(fp);
if((offpos = lseek(fd, 0, SEEK_END)) == -1) {
fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
fclose(fp);
pw_file_unlock(lockfd);
exit(1);
}
new_entry_length = strlen(pwd->pw_name) + 1 + 15 + 1 +
32 + 1 + 32 + 1 + strlen(pwd->pw_gecos) +
1 + strlen(pwd->pw_dir) + 1 +
strlen(pwd->pw_shell) + 1;
if((new_entry = (char *)malloc( new_entry_length )) == 0) {
fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
fclose(fp);
pw_file_unlock(lockfd);
exit(1);
}
sprintf(new_entry, "%s:%u:", pwd->pw_name, pwd->pw_uid);
p = &new_entry[strlen(new_entry)];
for( i = 0; i < 16; i++)
sprintf(&p[i*2], "%02X", new_p16[i]);
p += 32;
*p++ = ':';
for( i = 0; i < 16; i++)
sprintf(&p[i*2], "%02X", new_nt_p16[i]);
p += 32;
*p++ = ':';
sprintf(p, "%s:%s:%s\n", pwd->pw_gecos,
pwd->pw_dir, pwd->pw_shell);
if(write(fd, new_entry, strlen(new_entry)) != strlen(new_entry)) {
fprintf(stderr, "%s: Failed to add entry for user %s to file %s. \
Error was %s\n", argv[0], pwd->pw_name, pfile, strerror(errno));
/* Remove the entry we just wrote. */
if(ftruncate(fd, offpos) == -1) {
fprintf(stderr, "%s: ERROR failed to ftruncate file %s. \
Error was %s. Password file may be corrupt ! Please examine by hand !\n",
argv[0], pwd->pw_name, strerror(errno));
}
fclose(fp);
pw_file_unlock(lockfd);
exit(1);
}
fclose(fp);
pw_file_unlock(lockfd);
exit(0);
}
}
/* If we are root or the password is 'NO PASSWORD' then
we don't need to check the old password. */
if (real_uid != 0) {
if (valid_old_pwd == False) {
fprintf(stderr, "%s: User %s has no old SMB password.\n", argv[0], pwd->pw_name);
}
/* Check the old Lanman password - NULL means 'NO PASSWORD' */
if (smb_pwent->smb_passwd != NULL) {
if (memcmp(old_p16, smb_pwent->smb_passwd, 16)) {
fprintf(stderr, "%s: Couldn't change password.\n", argv[0]);
fclose(fp);
pw_file_unlock(lockfd);
exit(1);
}
}
/* Check the NT password if it exists */
if (smb_pwent->smb_nt_passwd != NULL) {
if (memcmp(old_nt_p16, smb_pwent->smb_nt_passwd, 16)) {
fprintf(stderr, "%s: Couldn't change password.\n", argv[0]);
fclose(fp);
pw_file_unlock(lockfd);
exit(1);
}
}
}
/*
* If we get here either we were root or the old password checked out
* ok.
*/
/* Create the 32 byte representation of the new p16 */
for (i = 0; i < 16; i++) {
sprintf(&ascii_p16[i * 2], "%02X", (uchar) new_p16[i]);
}
if(got_valid_nt_entry) {
/* Add on the NT md4 hash */
ascii_p16[32] = ':';
for (i = 0; i < 16; i++) {
sprintf(&ascii_p16[(i * 2)+33], "%02X", (uchar) new_nt_p16[i]);
}
}
/*
* Do an atomic write into the file at the position defined by
* seekpos.
*/
pwfd = fileno(fp);
ret = lseek(pwfd, seekpos - 1, SEEK_SET);
if (ret != seekpos - 1) {
err = errno;
fprintf(stderr, "%s: seek fail on file %s.\n",
argv[0], pfile);
fclose(fp);
errno = err;
perror(argv[0]);
pw_file_unlock(lockfd);
exit(1);
}
/* Sanity check - ensure the character is a ':' */
if (read(pwfd, &c, 1) != 1) {
err = errno;
fprintf(stderr, "%s: read fail on file %s.\n",
argv[0], pfile);
fclose(fp);
errno = err;
perror(argv[0]);
pw_file_unlock(lockfd);
exit(1);
}
if (c != ':') {
fprintf(stderr, "%s: sanity check on passwd file %s failed.\n",
argv[0], pfile);
fclose(fp);
pw_file_unlock(lockfd);
exit(1);
}
writelen = (got_valid_nt_entry) ? 65 : 32;
if (write(pwfd, ascii_p16, writelen) != writelen) {
err = errno;
fprintf(stderr, "%s: write fail in file %s.\n",
argv[0], pfile);
fclose(fp);
errno = err;
perror(argv[0]);
pw_file_unlock(lockfd);
exit(err);
}
fclose(fp);
pw_file_unlock(lockfd);
printf("Password changed\n");
return 0;
}
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