newlib/winsup/cygwin/ldap.cc

717 lines
18 KiB
C++

/* ldap.cc: Helper functions for ldap access to Active Directory.
Copyright 2014, 2015 Red Hat, Inc.
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. */
#include "winsup.h"
#include "ldap.h"
#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "registry.h"
#include "pinfo.h"
#include "lm.h"
#include "dsgetdc.h"
#include "tls_pbuf.h"
#include <sys/param.h>
#define CYG_LDAP_ENUM_PAGESIZE 100 /* entries per page */
static PWCHAR rootdse_attr[] =
{
(PWCHAR) L"defaultNamingContext",
(PWCHAR) L"supportedCapabilities",
NULL
};
static const PCWSTR std_user_attr[] =
{
L"sAMAccountName",
L"objectSid",
L"primaryGroupID",
L"uidNumber",
L"cygwinUnixUid", /* TODO */
/* windows scheme */
L"displayName",
L"homeDrive",
L"homeDirectory",
/* cygwin scheme */
L"cygwinGecos",
L"cygwinHome",
L"cygwinShell",
/* unix scheme */
L"gecos",
L"unixHomeDirectory",
L"loginShell",
/* desc scheme */
L"description"
};
static PWCHAR group_attr[] =
{
(PWCHAR) L"sAMAccountName",
(PWCHAR) L"objectSid",
(PWCHAR) L"gidNumber",
(PWCHAR) L"cygwinUnixGid", /* TODO */
NULL
};
PWCHAR tdom_attr[] =
{
(PWCHAR) L"trustPosixOffset",
NULL
};
PWCHAR sid_attr[] =
{
(PWCHAR) L"objectSid",
NULL
};
PWCHAR rfc2307_uid_attr[] =
{
(PWCHAR) L"uid",
NULL
};
PWCHAR rfc2307_gid_attr[] =
{
(PWCHAR) L"cn",
NULL
};
/* ================================================================= */
/* Helper method of cygheap_pwdgrp class. It sets the user attribs */
/* from the settings in nsswitch.conf. */
/* ================================================================= */
#define user_attr (cygheap->pg.ldap_user_attr)
void
cygheap_pwdgrp::init_ldap_user_attr ()
{
ldap_user_attr = (PWCHAR *)
ccalloc_abort (HEAP_BUF, sizeof (std_user_attr) / sizeof (*std_user_attr)
+ 3 * NSS_SCHEME_MAX + 1, sizeof (PWCHAR));
memcpy (ldap_user_attr, std_user_attr, sizeof (std_user_attr));
uint16_t freeattr_idx = sizeof (std_user_attr) / sizeof (*std_user_attr);
for (uint16_t idx = 0; idx < NSS_SCHEME_MAX; ++idx)
{
if (home_scheme[idx].method == NSS_SCHEME_FREEATTR)
ldap_user_attr[freeattr_idx++] = home_scheme[idx].attrib;
if (shell_scheme[idx].method == NSS_SCHEME_FREEATTR)
ldap_user_attr[freeattr_idx++] = shell_scheme[idx].attrib;
if (gecos_scheme[idx].method == NSS_SCHEME_FREEATTR)
ldap_user_attr[freeattr_idx++] = gecos_scheme[idx].attrib;
}
}
/* ================================================================= */
/* Helper methods. */
/* ================================================================= */
inline int
cyg_ldap::map_ldaperr_to_errno (ULONG lerr)
{
switch (lerr)
{
case LDAP_SUCCESS:
return NO_ERROR;
case LDAP_NO_RESULTS_RETURNED:
/* LdapMapErrorToWin32 maps LDAP_NO_RESULTS_RETURNED to ERROR_MORE_DATA,
which in turn is mapped to EMSGSIZE by geterrno_from_win_error. This
is SO wrong, especially considering that LDAP_MORE_RESULTS_TO_RETURN
is mapped to ERROR_MORE_DATA as well :-P */
return ENMFILE;
default:
break;
}
return geterrno_from_win_error (LdapMapErrorToWin32 (lerr));
}
inline int
cyg_ldap::wait (cygthread *thr)
{
if (!thr)
return EIO;
if (cygwait (*thr, cw_infinite, cw_sig | cw_sig_restart) != WAIT_OBJECT_0)
{
thr->terminate_thread ();
return EIO;
}
thr->detach ();
return 0;
}
/* ================================================================= */
/* Helper struct and functions for interruptible LDAP initalization. */
/* ================================================================= */
struct cyg_ldap_init {
cyg_ldap *that;
PCWSTR domain;
bool ssl;
ULONG ret;
};
ULONG
cyg_ldap::connect_ssl (PCWSTR domain)
{
ULONG ret;
if (!(lh = ldap_sslinitW ((PWCHAR) domain, LDAP_SSL_PORT, 1)))
{
debug_printf ("ldap_init(%W) error 0x%02x", domain, LdapGetLastError ());
return LdapGetLastError ();
}
if ((ret = ldap_bind_s (lh, NULL, NULL, LDAP_AUTH_NEGOTIATE)) != LDAP_SUCCESS)
debug_printf ("ldap_bind(%W) 0x%02x", domain, ret);
else if ((ret = ldap_search_sW (lh, NULL, LDAP_SCOPE_BASE,
(PWCHAR) L"(objectclass=*)", rootdse_attr,
0, &msg))
!= LDAP_SUCCESS)
debug_printf ("ldap_search(%W, ROOTDSE) error 0x%02x", domain, ret);
return ret;
}
ULONG
cyg_ldap::connect_non_ssl (PCWSTR domain)
{
ULONG ret;
if (!(lh = ldap_initW ((PWCHAR) domain, LDAP_PORT)))
{
debug_printf ("ldap_init(%W) error 0x%02x", domain, LdapGetLastError ());
return LdapGetLastError ();
}
if ((ret = ldap_set_option (lh, LDAP_OPT_SIGN, LDAP_OPT_ON))
!= LDAP_SUCCESS)
debug_printf ("ldap_set_option(LDAP_OPT_SIGN) error 0x%02x", ret);
if ((ret = ldap_set_option (lh, LDAP_OPT_ENCRYPT, LDAP_OPT_ON))
!= LDAP_SUCCESS)
debug_printf ("ldap_set_option(LDAP_OPT_ENCRYPT) error 0x%02x", ret);
if ((ret = ldap_bind_s (lh, NULL, NULL, LDAP_AUTH_NEGOTIATE)) != LDAP_SUCCESS)
debug_printf ("ldap_bind(%W) 0x%02x", domain, ret);
else if ((ret = ldap_search_sW (lh, NULL, LDAP_SCOPE_BASE,
(PWCHAR) L"(objectclass=*)", rootdse_attr,
0, &msg))
!= LDAP_SUCCESS)
debug_printf ("ldap_search(%W, ROOTDSE) error 0x%02x", domain, ret);
return ret;
}
static DWORD WINAPI
ldap_init_thr (LPVOID param)
{
cyg_ldap_init *cl = (cyg_ldap_init *) param;
cl->ret = cl->ssl ? cl->that->connect_ssl (cl->domain)
: cl->that->connect_non_ssl (cl->domain);
return 0;
}
inline int
cyg_ldap::connect (PCWSTR domain)
{
/* FIXME? connect_ssl can take ages even when failing, so we're trying to
do everything the non-SSL (but still encrypted) way. */
cyg_ldap_init cl = { this, domain, false, NO_ERROR };
cygthread *thr = new cygthread (ldap_init_thr, &cl, "ldap_init");
return wait (thr) ?: map_ldaperr_to_errno (cl.ret);
}
/* ================================================================= */
/* Helper struct and functions for interruptible LDAP search. */
/* ================================================================= */
struct cyg_ldap_search {
cyg_ldap *that;
PWCHAR base;
ULONG scope;
PWCHAR filter;
PWCHAR *attrs;
ULONG ret;
};
ULONG
cyg_ldap::search_s (PWCHAR base, ULONG scope, PWCHAR filter, PWCHAR *attrs)
{
ULONG ret;
if ((ret = ldap_search_sW (lh, base, scope, filter, attrs, 0, &msg))
!= LDAP_SUCCESS)
debug_printf ("ldap_search_sW(%W,%W) error 0x%02x", base, filter, ret);
return ret;
}
static DWORD WINAPI
ldap_search_thr (LPVOID param)
{
cyg_ldap_search *cl = (cyg_ldap_search *) param;
cl->ret = cl->that->search_s (cl->base, cl->scope, cl->filter, cl->attrs);
return 0;
}
inline int
cyg_ldap::search (PWCHAR base, ULONG scope, PWCHAR filter, PWCHAR *attrs)
{
cyg_ldap_search cl = { this, base, scope, filter, attrs, NO_ERROR };
cygthread *thr = new cygthread (ldap_search_thr, &cl, "ldap_search");
return wait (thr) ?: map_ldaperr_to_errno (cl.ret);
}
/* ================================================================= */
/* Helper struct and functions for interruptible LDAP page search. */
/* ================================================================= */
struct cyg_ldap_next_page {
cyg_ldap *that;
ULONG ret;
};
ULONG
cyg_ldap::next_page_s ()
{
ULONG total;
ULONG ret;
do
{
ret = ldap_get_next_page_s (lh, srch_id, NULL, CYG_LDAP_ENUM_PAGESIZE,
&total, &msg);
}
while (ret == LDAP_SUCCESS && ldap_count_entries (lh, msg) == 0);
if (ret && ret != LDAP_NO_RESULTS_RETURNED)
debug_printf ("ldap_result() error 0x%02x", ret);
return ret;
}
static DWORD WINAPI
ldap_next_page_thr (LPVOID param)
{
cyg_ldap_next_page *cl = (cyg_ldap_next_page *) param;
cl->ret = cl->that->next_page_s ();
return 0;
}
inline int
cyg_ldap::next_page ()
{
cyg_ldap_next_page cl = { this, NO_ERROR };
cygthread *thr = new cygthread (ldap_next_page_thr, &cl, "ldap_next_page");
return wait (thr) ?: map_ldaperr_to_errno (cl.ret);
}
/* ================================================================= */
/* Public methods. */
/* ================================================================= */
int
cyg_ldap::open (PCWSTR domain)
{
int ret = NO_ERROR;
/* Already open? */
if (lh)
return NO_ERROR;
if ((ret = connect (domain)) != NO_ERROR)
goto err;
/* Prime `ret' and fetch ROOTDSE search result. */
ret = EIO;
if (!(entry = ldap_first_entry (lh, msg)))
{
debug_printf ("No ROOTDSE entry for %W", domain);
goto err;
}
if (!(val = ldap_get_valuesW (lh, entry, rootdse_attr[0])))
{
debug_printf ("No %W value for %W", rootdse_attr[0], domain);
goto err;
}
if (!(def_context = wcsdup (val[0])))
{
debug_printf ("wcsdup(%W, %W) %d", domain, rootdse_attr[0],
get_errno ());
goto err;
}
ldap_value_freeW (val);
if ((val = ldap_get_valuesW (lh, entry, rootdse_attr[1])))
{
for (ULONG idx = 0; idx < ldap_count_valuesW (val); ++idx)
if (!wcscmp (val[idx], LDAP_CAP_ACTIVE_DIRECTORY_OID_W))
{
isAD = true;
break;
}
}
ldap_value_freeW (val);
val = NULL;
ldap_msgfree (msg);
msg = entry = NULL;
return NO_ERROR;
err:
close ();
return ret;
}
void
cyg_ldap::close ()
{
if (srch_id != NULL)
ldap_search_abandon_page (lh, srch_id);
if (lh)
ldap_unbind (lh);
if (msg)
ldap_msgfree (msg);
if (val)
ldap_value_freeW (val);
if (def_context)
free (def_context);
lh = NULL;
msg = entry = NULL;
val = NULL;
def_context = NULL;
srch_id = NULL;
last_fetched_sid = NO_SID;
}
PWCHAR
cyg_ldap::get_string_attribute (PCWSTR name)
{
if (val)
ldap_value_freeW (val);
val = ldap_get_valuesW (lh, entry, (PWCHAR) name);
if (val)
return val[0];
return NULL;
}
uint32_t
cyg_ldap::get_num_attribute (PCWSTR name)
{
PWCHAR ret = get_string_attribute (name);
if (ret)
return (uint32_t) wcstoul (ret, NULL, 10);
return (uint32_t) -1;
}
#define ACCOUNT_FILTER_START L"(&(|(&(objectCategory=Person)" \
"(objectClass=User))" \
"(objectClass=Group))" \
"(objectSid="
#define ACCOUNT_FILTER_END L"))"
bool
cyg_ldap::fetch_ad_account (PSID sid, bool group, PCWSTR domain)
{
WCHAR filter[sizeof (ACCOUNT_FILTER_START) + sizeof (ACCOUNT_FILTER_END)
+ 3 * SECURITY_MAX_SID_SIZE + 1];
PWCHAR f, base = NULL;
LONG len = (LONG) RtlLengthSid (sid);
PBYTE s = (PBYTE) sid;
static WCHAR hex_wchars[] = L"0123456789abcdef";
tmp_pathbuf tp;
if (last_fetched_sid == sid)
return true;
if (open (NULL) != NO_ERROR)
return false;
if (msg)
{
ldap_msgfree (msg);
msg = entry = NULL;
}
if (val)
{
ldap_value_freeW (val);
val = NULL;
}
f = wcpcpy (filter, ACCOUNT_FILTER_START);
while (len-- > 0)
{
*f++ = L'\\';
*f++ = hex_wchars[*s >> 4];
*f++ = hex_wchars[*s++ & 0xf];
}
wcpcpy (f, ACCOUNT_FILTER_END);
if (domain)
{
/* FIXME: This is a hack. The most correct solution is probably to
open a connection to the DC of the trusted domain. But this always
takes extra time, so we're trying to avoid it. If this results in
problems, we know what to do. */
base = tp.w_get ();
PWCHAR b = base;
for (PWCHAR dotp = (PWCHAR) domain; dotp && *dotp; domain = dotp)
{
dotp = wcschr (domain, L'.');
if (dotp)
*dotp++ = L'\0';
if (b > base)
*b++ = L',';
b = wcpcpy (b, L"DC=");
b = wcpcpy (b, domain);
}
}
else
{
/* def_context is only valid after open. */
base = def_context;
}
if (!user_attr)
cygheap->pg.init_ldap_user_attr ();
attr = group ? group_attr : user_attr;
if (search (base, LDAP_SCOPE_SUBTREE, filter, attr) != 0)
return false;
if (!(entry = ldap_first_entry (lh, msg)))
{
debug_printf ("No entry for %W in base %W", filter, base);
return false;
}
last_fetched_sid = sid;
return true;
}
int
cyg_ldap::enumerate_ad_accounts (PCWSTR domain, bool group)
{
int ret;
tmp_pathbuf tp;
PCWSTR filter;
close ();
if ((ret = open (domain)) != NO_ERROR)
return ret;
if (!group)
filter = L"(&(objectCategory=Person)"
"(objectClass=User)"
/* 512 == ADS_UF_NORMAL_ACCOUNT
Without checking this flag we'd enumerate undesired accounts
like, e.g., interdomain trusts. */
"(userAccountControl:" LDAP_MATCHING_RULE_BIT_AND ":=512)"
"(objectSid=*))";
else if (!domain)
/* From the local domain, we fetch well-known groups. */
filter = L"(&(objectClass=Group)"
"(objectSid=*))";
else
/* From foreign domains, we don't. */
filter = L"(&(objectClass=Group)"
/* 1 == BUILTIN_LOCAL_GROUP */
"(!(groupType:" LDAP_MATCHING_RULE_BIT_AND ":=1))"
"(objectSid=*))";
if (!user_attr)
cygheap->pg.init_ldap_user_attr ();
attr = group ? group_attr : user_attr;
srch_id = ldap_search_init_pageW (lh, def_context, LDAP_SCOPE_SUBTREE,
(PWCHAR) filter, attr, 0, NULL, NULL,
INFINITE, CYG_LDAP_ENUM_PAGESIZE, NULL);
if (srch_id == NULL)
{
debug_printf ("ldap_search_init_pageW(%W,%W) error 0x%02x",
def_context, filter, LdapGetLastError ());
return map_ldaperr_to_errno (LdapGetLastError ());
}
return NO_ERROR;
}
int
cyg_ldap::next_account (cygsid &sid)
{
ULONG ret;
PLDAP_BERVAL *bval;
if (entry)
{
if ((entry = ldap_next_entry (lh, entry))
&& (bval = ldap_get_values_lenW (lh, entry, (PWCHAR) L"objectSid")))
{
last_fetched_sid = sid = (PSID) bval[0]->bv_val;
ldap_value_free_len (bval);
return NO_ERROR;
}
ldap_msgfree (msg);
msg = entry = NULL;
}
ret = next_page ();
if (ret == NO_ERROR)
{
if ((entry = ldap_first_entry (lh, msg))
&& (bval = ldap_get_values_lenW (lh, entry, (PWCHAR) L"objectSid")))
{
last_fetched_sid = sid = (PSID) bval[0]->bv_val;
ldap_value_free_len (bval);
return NO_ERROR;
}
ret = EIO;
}
ldap_search_abandon_page (lh, srch_id);
srch_id = NULL;
return ret;
}
#define SYSTEM_CONTAINER L"CN=System,"
#define PSX_OFFSET_FILTER L"(&(objectClass=trustedDomain)(name=%W))"
#define PSX_OFFSET_FILTER_FLAT L"(&(objectClass=trustedDomain)(flatName=%W))"
/* Return UINT32_MAX on error to allow differing between not being able
to fetch a value and a real 0 offset. */
uint32_t
cyg_ldap::fetch_posix_offset_for_domain (PCWSTR domain)
{
WCHAR base[wcslen (def_context) + sizeof (SYSTEM_CONTAINER) / sizeof (WCHAR)];
WCHAR filter[sizeof (PSX_OFFSET_FILTER_FLAT) + wcslen (domain) + 1];
if (msg)
{
ldap_msgfree (msg);
msg = entry = NULL;
}
if (val)
{
ldap_value_freeW (val);
val = NULL;
}
/* As base, use system container within default naming context to restrict
the search to this container only. */
wcpcpy (wcpcpy (base, SYSTEM_CONTAINER), def_context);
/* If domain name has no dot, it's a Netbios name. In that case, filter
by flatName rather than by name. */
__small_swprintf (filter, wcschr (domain, L'.') ? PSX_OFFSET_FILTER
: PSX_OFFSET_FILTER_FLAT,
domain);
if (search (base, LDAP_SCOPE_ONELEVEL, filter, attr = tdom_attr) != 0)
return UINT32_MAX;
if (!(entry = ldap_first_entry (lh, msg)))
{
debug_printf ("No entry for %W in def_context %W", filter, def_context);
return UINT32_MAX;
}
return get_num_attribute (tdom_attr[0]);
}
#define UXID_FILTER_GRP L"(&(objectClass=Group)" \
"(gidNumber=%u))"
#define UXID_FILTER_USR L"(&(objectCategory=Person)" \
"(objectClass=User)" \
"(uidNumber=%u))"
bool
cyg_ldap::fetch_unix_sid_from_ad (uint32_t id, cygsid &sid, bool group)
{
WCHAR filter[MAX (sizeof (UXID_FILTER_GRP), sizeof (UXID_FILTER_USR)) + 16];
PLDAP_BERVAL *bval;
if (msg)
{
ldap_msgfree (msg);
msg = entry = NULL;
}
__small_swprintf (filter, group ? UXID_FILTER_GRP : UXID_FILTER_USR, id);
if (search (def_context, LDAP_SCOPE_SUBTREE, filter, sid_attr) != 0)
return false;
if ((entry = ldap_first_entry (lh, msg))
&& (bval = ldap_get_values_lenW (lh, entry, (PWCHAR) L"objectSid")))
{
sid = (PSID) bval[0]->bv_val;
ldap_value_free_len (bval);
return true;
}
return false;
}
#define PSXID_FILTER_GRP L"(&(objectClass=posixGroup)" \
"(gidNumber=%u))"
#define PSXID_FILTER_USR L"(&(objectClass=posixAccount)" \
"(uidNumber=%u))"
PWCHAR
cyg_ldap::fetch_unix_name_from_rfc2307 (uint32_t id, bool group)
{
WCHAR filter[MAX (sizeof (PSXID_FILTER_GRP), sizeof (PSXID_FILTER_USR)) + 16];
if (msg)
{
ldap_msgfree (msg);
msg = entry = NULL;
}
if (val)
{
ldap_value_freeW (val);
val = NULL;
}
attr = group ? rfc2307_gid_attr : rfc2307_uid_attr;
__small_swprintf (filter, group ? PSXID_FILTER_GRP : PSXID_FILTER_USR, id);
if (search (def_context, LDAP_SCOPE_SUBTREE, filter, attr) != 0)
return NULL;
if (!(entry = ldap_first_entry (lh, msg)))
{
debug_printf ("No entry for %W in def_context %W", filter, def_context);
return NULL;
}
return get_string_attribute (attr[0]);
}
uid_t
cyg_ldap::remap_uid (uid_t uid)
{
cygsid user (NO_SID);
PWCHAR name;
struct passwd *pw;
if (isAD)
{
if (fetch_unix_sid_from_ad (uid, user, false)
&& user != NO_SID
&& (pw = internal_getpwsid (user, this)))
return pw->pw_uid;
}
else if ((name = fetch_unix_name_from_rfc2307 (uid, false)))
{
char *mbname = NULL;
sys_wcstombs_alloc (&mbname, HEAP_NOTHEAP, name);
if ((pw = internal_getpwnam (mbname)))
return pw->pw_uid;
}
return ILLEGAL_UID;
}
gid_t
cyg_ldap::remap_gid (gid_t gid)
{
cygsid group (NO_SID);
PWCHAR name;
struct group *gr;
if (isAD)
{
if (fetch_unix_sid_from_ad (gid, group, true)
&& group != NO_SID
&& (gr = internal_getgrsid (group, this)))
return gr->gr_gid;
}
else if ((name = fetch_unix_name_from_rfc2307 (gid, true)))
{
char *mbname = NULL;
sys_wcstombs_alloc (&mbname, HEAP_NOTHEAP, name);
if ((gr = internal_getgrnam (mbname)))
return gr->gr_gid;
}
return ILLEGAL_GID;
}