newlib/winsup/utils/mkpasswd.c
Corinna Vinschen 526107a753 mkgroup/mkpasswd: Fix potential buffer overwrite in corner case
Fixes Coverity CIDs 60076, 60077 and 60081

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2016-10-23 17:04:55 +02:00

721 lines
20 KiB
C

/* mkpasswd.c:
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#define _WIN32_WINNT 0x0a00
#include <errno.h>
#include <ctype.h>
#include <stdlib.h>
#include <wchar.h>
#include <wctype.h>
#include <locale.h>
#include <stdio.h>
#include <unistd.h>
#include <inttypes.h>
#include <getopt.h>
#include <io.h>
#include <pwd.h>
#include <sys/fcntl.h>
#include <sys/cygwin.h>
#include <cygwin/version.h>
#include <windows.h>
#include <lm.h>
#include <iptypes.h>
#include <wininet.h>
#include <ntsecapi.h>
#include <dsgetdc.h>
#include <ntdef.h>
#define print_win_error(x) _print_win_error(x, __LINE__)
SID_IDENTIFIER_AUTHORITY sid_world_auth = {SECURITY_WORLD_SID_AUTHORITY};
SID_IDENTIFIER_AUTHORITY sid_nt_auth = {SECURITY_NT_AUTHORITY};
#ifndef min
#define min(a,b) (((a)<(b))?(a):(b))
#endif
typedef struct
{
char *str;
BOOL domain;
BOOL with_dom;
} domlist_t;
static void
_print_win_error(DWORD code, int line)
{
char buf[4096];
if (FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM
| FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
code,
MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) buf, sizeof (buf), NULL))
fprintf (stderr, "mkpasswd (%d): [%" PRIu32 "] %s",
line, (unsigned int) code, buf);
else
fprintf (stderr, "mkpasswd (%d): error %" PRIu32,
line, (unsigned int) code);
}
static char *
put_sid (PSID sid)
{
static char s[512];
char t[32];
DWORD i;
strcpy (s, "S-1-");
sprintf(t, "%u", GetSidIdentifierAuthority (sid)->Value[5]);
strcat (s, t);
for (i = 0; i < *GetSidSubAuthorityCount (sid); ++i)
{
sprintf(t, "-%" PRIu32, (unsigned int) *GetSidSubAuthority (sid, i));
strcat (s, t);
}
return s;
}
static void
uni2ansi (LPWSTR wcs, char *mbs, int size)
{
if (wcs)
wcstombs (mbs, wcs, size);
else
*mbs = '\0';
}
typedef struct {
PSID psid;
int buffer[10];
} sidbuf;
static sidbuf curr_user;
static sidbuf curr_pgrp;
static BOOL got_curr_user = FALSE;
static void
fetch_current_user_sid ()
{
DWORD len;
HANDLE ptok;
if (!OpenProcessToken (GetCurrentProcess (), TOKEN_QUERY, &ptok)
|| !GetTokenInformation (ptok, TokenUser, &curr_user, sizeof curr_user,
&len)
|| !GetTokenInformation (ptok, TokenPrimaryGroup, &curr_pgrp,
sizeof curr_pgrp, &len)
|| !CloseHandle (ptok))
{
print_win_error (GetLastError ());
return;
}
}
static void
enum_unix_users (domlist_t *mach, const char *sep, DWORD id_offset,
char *unix_user_list)
{
WCHAR machine[INTERNET_MAX_HOST_NAME_LENGTH + 1];
SID_IDENTIFIER_AUTHORITY auth = { { 0, 0, 0, 0, 0, 22 } };
char *ustr, *user_list;
WCHAR user[UNLEN + sizeof ("Unix User\\") + 1];
WCHAR dom[MAX_DOMAIN_NAME_LEN + 1];
DWORD ulen, dlen, sidlen;
PSID psid;
PSID numeric_psid;
char psid_buffer[SECURITY_MAX_SID_SIZE];
SID_NAME_USE acc_type;
int ret = mbstowcs (machine, mach->str, INTERNET_MAX_HOST_NAME_LENGTH + 1);
if (ret < 1 || ret >= INTERNET_MAX_HOST_NAME_LENGTH + 1)
{
fprintf (stderr, "%s: Invalid machine name '%s'. Skipping...\n",
program_invocation_short_name, mach->str);
return;
}
if (!AllocateAndInitializeSid (&auth, 2, 1, 0, 0, 0, 0, 0, 0, 0,
&numeric_psid))
return;
if (!(user_list = strdup (unix_user_list)))
{
FreeSid (numeric_psid);
return;
}
for (ustr = strtok (user_list, ","); ustr; ustr = strtok (NULL, ","))
{
if (!isdigit ((unsigned char) ustr[0]) && ustr[0] != '-')
{
PWCHAR p = wcpcpy (user, L"Unix User\\");
ret = mbstowcs (p, ustr, UNLEN + 1);
if (ret < 1 || ret >= UNLEN + 1)
{
fprintf (stderr, "%s: Invalid user name '%s'. Skipping...\n",
program_invocation_short_name, ustr);
continue;
}
psid = (PSID) psid_buffer;
sidlen = SECURITY_MAX_SID_SIZE;
dlen = MAX_DOMAIN_NAME_LEN + 1;
if (LookupAccountNameW (machine, user, psid, &sidlen,
dom, &dlen, &acc_type))
printf ("%s%s%ls:*:%" PRIu32 ":99999:,%s::\n",
"Unix_User",
sep,
user + 10,
(unsigned int) (id_offset +
*GetSidSubAuthority (psid,
*GetSidSubAuthorityCount(psid) - 1)),
put_sid (psid));
}
else
{
DWORD start, stop;
char *p = ustr;
if (*p == '-')
start = 0;
else
start = strtol (p, &p, 10);
if (!*p)
stop = start;
else if (*p++ != '-' || !isdigit ((unsigned char) *p)
|| (stop = strtol (p, &p, 10)) < start || *p)
{
fprintf (stderr, "%s: Malformed unix user list entry '%s'. "
"Skipping...\n",
program_invocation_short_name, ustr);
continue;
}
for (; start <= stop; ++ start)
{
psid = numeric_psid;
*GetSidSubAuthority (psid, *GetSidSubAuthorityCount(psid) - 1)
= start;
ulen = GNLEN + 1;
dlen = MAX_DOMAIN_NAME_LEN + 1;
if (LookupAccountSidW (machine, psid, user, &ulen,
dom, &dlen, &acc_type)
&& !iswdigit (user[0]))
printf ("%s%s%ls:*:%" PRIu32 ":99999:,%s::\n",
"Unix_User",
sep,
user,
(unsigned int) (id_offset + start),
put_sid (psid));
}
}
}
free (user_list);
FreeSid (numeric_psid);
}
static int
enum_users (domlist_t *mach, const char *sep, const char *passed_home_path,
DWORD id_offset, char *disp_username, int print_current)
{
WCHAR machine[INTERNET_MAX_HOST_NAME_LENGTH + 1];
USER_INFO_3 *buffer;
DWORD entriesread = 0;
DWORD totalentries = 0;
DWORD resume_handle = 0;
DWORD rc;
WCHAR uni_name[UNLEN + 1];
int ret = mbstowcs (machine, mach->str, INTERNET_MAX_HOST_NAME_LENGTH + 1);
if (ret < 1 || ret >= INTERNET_MAX_HOST_NAME_LENGTH + 1)
{
fprintf (stderr, "%s: Invalid machine name '%s'. Skipping...\n",
program_invocation_short_name, mach->str);
return 1;
}
do
{
DWORD i;
if (disp_username != NULL)
{
mbstowcs (uni_name, disp_username, UNLEN + 1);
rc = NetUserGetInfo (machine, (LPWSTR) &uni_name, 3,
(void *) &buffer);
entriesread = 1;
/* Avoid annoying error messages just because the user hasn't been
found. */
if (rc == NERR_UserNotFound)
return 0;
}
else
rc = NetUserEnum (machine, 3, FILTER_NORMAL_ACCOUNT,
(void *) &buffer, MAX_PREFERRED_LENGTH,
&entriesread, &totalentries, &resume_handle);
switch (rc)
{
case ERROR_ACCESS_DENIED:
print_win_error(rc);
return 1;
case ERROR_MORE_DATA:
case ERROR_SUCCESS:
break;
default:
print_win_error(rc);
return 1;
}
for (i = 0; i < entriesread; i++)
{
char homedir_psx[PATH_MAX];
WCHAR domain_name[MAX_DOMAIN_NAME_LEN + 1];
DWORD domname_len = MAX_DOMAIN_NAME_LEN + 1;
char psid_buffer[SECURITY_MAX_SID_SIZE];
PSID psid = (PSID) psid_buffer;
DWORD sid_length = SECURITY_MAX_SID_SIZE;
SID_NAME_USE acc_type;
int uid = buffer[i].usri3_user_id;
int gid = buffer[i].usri3_primary_group_id;
homedir_psx[0] = '\0';
if (passed_home_path[0] == '\0')
{
if (buffer[i].usri3_home_dir[0] != L'\0')
cygwin_conv_path (CCP_WIN_W_TO_POSIX | CCP_ABSOLUTE,
buffer[i].usri3_home_dir, homedir_psx,
PATH_MAX);
else
uni2ansi (buffer[i].usri3_name,
stpcpy (homedir_psx, "/home/"), PATH_MAX - 6);
}
else
uni2ansi (buffer[i].usri3_name,
stpcpy (homedir_psx, passed_home_path),
PATH_MAX - strlen (passed_home_path));
if (!LookupAccountNameW (machine, buffer[i].usri3_name,
psid, &sid_length, domain_name,
&domname_len, &acc_type))
{
print_win_error(GetLastError ());
fprintf(stderr, " (%ls)\n", buffer[i].usri3_name);
continue;
}
else if (acc_type == SidTypeDomain)
{
WCHAR domname[MAX_DOMAIN_NAME_LEN + UNLEN + 2];
PWCHAR p;
p = wcpcpy (domname, machine);
p = wcpcpy (p, L"\\");
p = wcpncpy (p, buffer[i].usri3_name, UNLEN);
*p = L'\0';
sid_length = SECURITY_MAX_SID_SIZE;
domname_len = sizeof (domname);
if (!LookupAccountNameW (machine, domname, psid,
&sid_length, domain_name,
&domname_len, &acc_type))
{
print_win_error(GetLastError ());
fprintf(stderr, " (%ls)\n", domname);
continue;
}
}
if (!print_current)
/* fall through */;
else if (EqualSid (curr_user.psid, psid))
got_curr_user = TRUE;
printf ("%ls%s%ls:*:%" PRIu32 ":%" PRIu32
":%ls%sU-%ls\\%ls,%s:%s:/bin/bash\n",
mach->with_dom ? domain_name : L"",
mach->with_dom ? sep : "",
buffer[i].usri3_name,
(unsigned int) (id_offset + uid),
(unsigned int) (id_offset + gid),
buffer[i].usri3_full_name ?: L"",
buffer[i].usri3_full_name
&& buffer[i].usri3_full_name[0] ? "," : "",
domain_name,
buffer[i].usri3_name,
put_sid (psid),
homedir_psx);
}
NetApiBufferFree (buffer);
}
while (rc == ERROR_MORE_DATA);
return 0;
}
static int
usage (FILE * stream)
{
fprintf (stream,
"Usage: %s [OPTIONS]...\n"
"\n"
"Write /etc/passwd-like output to stdout\n"
"\n"
"Don't use this command to generate a local /etc/passwd file, unless you\n"
"really need one. See the Cygwin User's Guide for more information.\n"
"\n"
"Options:\n"
"\n"
" -l,--local [machine] Print local user accounts of \"machine\",\n"
" from local machine if no machine specified.\n"
" Automatically adding machine prefix for local\n"
" machine depends on settings in /etc/nsswitch.conf.\n"
" -L,--Local machine Ditto, but generate username with machine prefix.\n"
" -d,--domain [domain] Print domain accounts,\n"
" from current domain if no domain specified.\n"
" -c,--current Print current user.\n"
" -S,--separator char For -L use character char as domain\\user\n"
" separator in username instead of the default '%s'.\n"
" -o,--id-offset offset Change the default offset (0x10000) added to uids\n"
" of foreign local machine accounts. Use with -l/-L.\n"
" -u,--username username Only return information for the specified user.\n"
" One of -l, -d must be specified, too\n"
" -b,--no-builtin Don't print BUILTIN users.\n"
" -p,--path-to-home path Use specified path instead of user account home dir\n"
" or /home prefix.\n"
" -U,--unix userlist Print UNIX users when using -l on a UNIX Samba\n"
" server. Userlist is a comma-separated list of\n"
" usernames or uid ranges (root,-25,50-100).\n"
" Enumerating large ranges can take a long time!\n"
" -h,--help Displays this message.\n"
" -V,--version Version information and exit.\n"
"\n"
"Default is to print local accounts on stand-alone machines, domain accounts\n"
"on domain controllers and domain member machines.\n"
"\n", program_invocation_short_name,
(const char *) cygwin_internal (CW_GETNSSSEP));
return 1;
}
static struct option longopts[] = {
{"no-builtin", no_argument, NULL, 'b'},
{"current", no_argument, NULL, 'c'},
{"Current", no_argument, NULL, 'C'},
{"domain", optional_argument, NULL, 'd'},
{"Domain", optional_argument, NULL, 'D'},
{"local-groups", no_argument, NULL, 'g'},
{"help", no_argument, NULL, 'h'},
{"local", optional_argument, NULL, 'l'},
{"Local", optional_argument, NULL, 'L'},
{"no-mount", no_argument, NULL, 'm'},
{"id-offset", required_argument, NULL, 'o'},
{"path-to-home", required_argument, NULL, 'p'},
{"no-sids", no_argument, NULL, 's'},
{"separator", required_argument, NULL, 'S'},
{"username", required_argument, NULL, 'u'},
{"unix", required_argument, NULL, 'U'},
{"version", no_argument, NULL, 'V'},
{0, no_argument, NULL, 0}
};
static char opts[] = "bcCd::D::ghl::L::mo:sS:p:u:U:V";
static void
print_version ()
{
printf ("mkpasswd (cygwin) %d.%d.%d\n"
"Passwd File Generator\n"
"Copyright (C) 1997 - %s Cygwin Authors\n"
"This is free software; see the source for copying conditions. There is NO\n"
"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n",
CYGWIN_VERSION_DLL_MAJOR / 1000,
CYGWIN_VERSION_DLL_MAJOR % 1000,
CYGWIN_VERSION_DLL_MINOR,
strrchr (__DATE__, ' ') + 1);
}
int
main (int argc, char **argv)
{
int print_domlist = 0;
domlist_t domlist[32];
char cname[1024];
char *opt, *p, *ep;
int print_current = 0;
int print_builtin = 1;
char *print_unix = NULL;
const char *nss_sep = (const char *) cygwin_internal (CW_GETNSSSEP);
const char *sep_char = nss_sep;
DWORD id_offset = 0x10000, off;
int c, i;
char *disp_username = NULL;
char passed_home_path[PATH_MAX];
int optional_args = 0;
uintptr_t nss_src = cygwin_internal (CW_GETNSS_PWD_SRC);
passed_home_path[0] = '\0';
if (!isatty (1))
setmode (1, O_BINARY);
/* Use locale from environment. If not set or set to "C", use UTF-8. */
setlocale (LC_CTYPE, "");
if (!strcmp (setlocale (LC_CTYPE, NULL), "C"))
setlocale (LC_CTYPE, "en_US.UTF-8");
fetch_current_user_sid ();
if (argc == 1)
{
int enums = ENUM_PRIMARY | ENUM_LOCAL | ENUM_BUILTIN;
uintptr_t ticket = cygwin_internal (CW_SETENT, FALSE, enums, NULL);
if (ticket)
{
struct passwd *pwd;
while ((pwd = (struct passwd *) cygwin_internal (CW_GETENT, FALSE,
ticket)))
printf ("%s:%s:%u:%u:%s:%s:%s\n", pwd->pw_name, pwd->pw_passwd,
pwd->pw_uid, pwd->pw_gid, pwd->pw_gecos, pwd->pw_dir,
pwd->pw_shell);
cygwin_internal (CW_ENDENT, FALSE, ticket);
}
return 0;
}
unsetenv ("POSIXLY_CORRECT"); /* To get optional arg processing right. */
while ((c = getopt_long (argc, argv, opts, longopts, NULL)) != EOF)
switch (c)
{
case 'd':
case 'D':
case 'l':
case 'L':
if (print_domlist >= 32)
{
fprintf (stderr, "%s: Can not enumerate from more than 32 "
"domains and machines.\n",
program_invocation_short_name);
return 1;
}
domlist[print_domlist].domain = (c == 'd' || c == 'D');
opt = optarg ?:
argv[optind] && argv[optind][0] != '-' ? argv[optind] : NULL;
if (argv[optind] && opt == argv[optind])
++optional_args;
for (i = 0; i < print_domlist; ++i)
if (domlist[i].domain == domlist[print_domlist].domain
&& ((!domlist[i].str && !opt)
|| (domlist[i].str && opt
&& (off = strlen (domlist[i].str))
&& !strncmp (domlist[i].str, opt, off)
&& (!opt[off] || opt[off] == ','))))
{
fprintf (stderr, "%s: Duplicate %s '%s'. Skipping...\n",
program_invocation_short_name,
domlist[i].domain ? "domain" : "machine",
domlist[i].str);
break;
}
domlist[print_domlist].str = opt;
if (opt && (p = strchr (opt, ',')))
{
if (p == opt)
{
fprintf (stderr, "%s: Malformed domain string '%s'. "
"Skipping...\n", program_invocation_short_name, opt);
break;
}
*p = '\0';
}
if (c == 'l' || c == 'L')
{
DWORD csize = sizeof cname;
domlist[print_domlist].with_dom = (c == 'L');
if (!opt)
{
/* If the system uses /etc/passwd exclusively as account DB,
create local group names the old fashioned way. */
if (nss_src == NSS_SRC_FILES)
{
GetComputerNameExA (ComputerNameNetBIOS, cname, &csize);
domlist[print_domlist].str = cname;
}
}
else if (nss_src != NSS_SRC_FILES)
{
/* If the system uses Windows account DBs, check if machine
name is local machine. If so, remove the domain name to
enforce system naming convention. */
if (GetComputerNameExA (strchr (opt, '.')
? ComputerNameDnsFullyQualified
: ComputerNameNetBIOS,
cname, &csize)
&& strcasecmp (opt, cname) == 0)
domlist[print_domlist].str = NULL;
}
}
++print_domlist;
break;
case 'S':
sep_char = optarg;
if (strlen (sep_char) > 1)
{
fprintf (stderr, "%s: Only one ASCII character allowed as "
"domain\\user separator character.\n",
program_invocation_short_name);
return 1;
}
if (*sep_char == ':')
{
fprintf (stderr, "%s: Colon not allowed as domain\\user separator "
"character.\n", program_invocation_short_name);
return 1;
}
break;
case 'U':
print_unix = optarg;
break;
case 'c':
case 'C':
print_current = 1;
break;
case 'o':
id_offset = strtoul (optarg, &ep, 10);
break;
case 'b':
print_builtin = 0;
break;
case 'p':
if (optarg[0] != '/')
{
fprintf (stderr, "%s: '%s' is not a fully qualified path.\n",
program_invocation_short_name, optarg);
return 1;
}
strcpy (passed_home_path, optarg);
if (optarg[strlen (optarg)-1] != '/')
strcat (passed_home_path, "/");
break;
case 'u':
disp_username = optarg;
break;
case 'h':
usage (stdout);
return 0;
case 'V':
print_version ();
return 0;
case 'g': /* deprecated */
case 's': /* deprecated */
case 'm': /* deprecated */
break;
default:
fprintf (stderr, "Try `%s --help' for more information.\n",
program_invocation_short_name);
return 1;
}
optind += optional_args;
if (argv[optind])
{
fprintf (stderr,
"mkpasswd: non-option command line argument `%s' is not allowed.\n"
"Try `mkpasswd --help' for more information.\n", argv[optind]);
exit (1);
}
struct passwd *ppwd = NULL;
const char *ppwd_sid = NULL;
if (print_current)
{
ppwd = (struct passwd *) cygwin_internal (CW_GETPWSID, TRUE,
curr_user.psid);
if (ppwd)
ppwd_sid = strrchr (ppwd->pw_gecos, ',');
}
int enums = ENUM_NONE;
WCHAR tdoms[print_domlist * 258];
PWCHAR t = tdoms;
if (!disp_username && print_builtin && print_domlist)
enums |= ENUM_BUILTIN;
for (i = 0; i < print_domlist; ++i)
{
if (domlist[i].domain)
{
if (domlist[i].str)
{
enums |= ENUM_TDOMS;
t += mbstowcs (t, domlist[i].str, 257);
*t++ = L'\0';
}
else
enums |= ENUM_PRIMARY;
}
else if (!domlist[i].str)
enums |= ENUM_LOCAL;
}
if (t > tdoms)
*t++ = L'\0';
if (enums)
{
uintptr_t ticket = cygwin_internal (CW_SETENT, FALSE, enums,
t > tdoms ? tdoms : NULL);
if (ticket)
{
struct passwd *pwd;
while ((pwd = (struct passwd *)
cygwin_internal (CW_GETENT, FALSE, ticket)))
{
p = NULL;
if (disp_username
&& strcasecmp (disp_username, pwd->pw_name) != 0
&& (!(p = strchr (pwd->pw_name, nss_sep[0]))
|| strcasecmp (disp_username, p + 1) != 0))
continue;
printf ("%s:%s:%u:%u:%s:%s%s:%s\n", pwd->pw_name, pwd->pw_passwd,
pwd->pw_uid, pwd->pw_gid, pwd->pw_gecos,
passed_home_path[0] ? passed_home_path : "",
passed_home_path[0] ? (p ? p + 1 : pwd->pw_name)
: pwd->pw_dir,
pwd->pw_shell);
const char *pwd_sid = strrchr (pwd->pw_gecos, ',');
if (ppwd && ppwd_sid && pwd_sid && !strcmp (pwd_sid, ppwd_sid))
got_curr_user = TRUE;
}
cygwin_internal (CW_ENDENT, FALSE, ticket);
}
}
if (print_current && !got_curr_user)
{
p = strchr (ppwd->pw_name, nss_sep[0]);
printf ("%s:%s:%u:%u:%s:%s%s:%s\n", ppwd->pw_name, ppwd->pw_passwd,
ppwd->pw_uid, ppwd->pw_gid, ppwd->pw_gecos,
passed_home_path[0] ? passed_home_path : "",
passed_home_path[0] ? (p ? p + 1 : ppwd->pw_name) : ppwd->pw_dir,
ppwd->pw_shell);
}
off = 0xfd000000;
for (i = 0; i < print_domlist; ++i)
{
if (domlist[i].domain || !domlist[i].str)
continue;
enum_users (domlist + i, sep_char, passed_home_path,
(nss_src == NSS_SRC_FILES) ? 0x30000 : off,
disp_username, print_current);
if (!domlist[i].domain && domlist[i].str && print_unix)
enum_unix_users (domlist + i, sep_char, 0xff000000, print_unix);
off += id_offset;
}
return 0;
}