python/samba/__init__.py

   1 # Unix SMB/CIFS implementation.
   2 # Copyright (C) Jelmer Vernooij <jelmer@samba.org> 2007-2008
   3 #
   4 # Based on the original in EJS:
   5 # Copyright (C) Andrew Tridgell <tridge@samba.org> 2005
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 3 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 #
  20
  21 """Samba 4."""
  22
  23 __docformat__ = "restructuredText"
  24
  25 import os
  26 import time
  27 import ldb
  28 import samba.param
  29 import re
  30 from samba import _glue
  31 from samba._ldb import Ldb as _Ldb
  32
  33
  34 def source_tree_topdir():
  35     """Return the top level source directory."""
  36     paths = ["../../..", "../../../.."]
  37     for p in paths:
  38         topdir = os.path.normpath(os.path.join(os.path.dirname(__file__), p))
  39         if os.path.exists(os.path.join(topdir, 'source4')):
  40             return topdir
  41     raise RuntimeError("unable to find top level source directory")
  42
  43
  44 def in_source_tree():
  45     """Return True if we are running from within the samba source tree"""
  46     try:
  47         topdir = source_tree_topdir()
  48     except RuntimeError:
  49         return False
  50     return True
  51
  52
  53 class Ldb(_Ldb):
  54     """Simple Samba-specific LDB subclass that takes care
  55     of setting up the modules dir, credentials pointers, etc.
  56
  57     Please note that this is intended to be for all Samba LDB files,
  58     not necessarily the Sam database. For Sam-specific helper
  59     functions see samdb.py.
  60     """
  61
  62     def __init__(self, url=None, lp=None, modules_dir=None, session_info=None,
  63                  credentials=None, flags=0, options=None):
  64         """Opens a Samba Ldb file.
  65
  66         :param url: Optional LDB URL to open
  67         :param lp: Optional loadparm object
  68         :param modules_dir: Optional modules directory
  69         :param session_info: Optional session information
  70         :param credentials: Optional credentials, defaults to anonymous.
  71         :param flags: Optional LDB flags
  72         :param options: Additional options (optional)
  73
  74         This is different from a regular Ldb file in that the Samba-specific
  75         modules-dir is used by default and that credentials and session_info
  76         can be passed through (required by some modules).
  77         """
  78
  79         if modules_dir is not None:
  80             self.set_modules_dir(modules_dir)
  81         else:
  82             self.set_modules_dir(os.path.join(samba.param.modules_dir(), "ldb"))
  83
  84         if session_info is not None:
  85             self.set_session_info(session_info)
  86
  87         if credentials is not None:
  88             self.set_credentials(credentials)
  89
  90         if lp is not None:
  91             self.set_loadparm(lp)
  92
  93         # This must be done before we load the schema, as these handlers for
  94         # objectSid and objectGUID etc must take precedence over the 'binary
  95         # attribute' declaration in the schema
  96         self.register_samba_handlers()
  97
  98         # TODO set debug
  99         def msg(l, text):
 100             print(text)
 101         # self.set_debug(msg)
 102
 103         self.set_utf8_casefold()
 104
 105         # Allow admins to force non-sync ldb for all databases
 106         if lp is not None:
 107             nosync_p = lp.get("ldb:nosync")
 108             if nosync_p is not None and nosync_p:
 109                 flags |= ldb.FLG_NOSYNC
 110
 111         self.set_create_perms(0o600)
 112
 113         if url is not None:
 114             self.connect(url, flags, options)
 115
 116     def searchone(self, attribute, basedn=None, expression=None,
 117                   scope=ldb.SCOPE_BASE):
 118         """Search for one attribute as a string.
 119
 120         :param basedn: BaseDN for the search.
 121         :param attribute: Name of the attribute
 122         :param expression: Optional search expression.
 123         :param scope: Search scope (defaults to base).
 124         :return: Value of attribute as a string or None if it wasn't found.
 125         """
 126         res = self.search(basedn, scope, expression, [attribute])
 127         if len(res) != 1 or res[0][attribute] is None:
 128             return None
 129         values = set(res[0][attribute])
 130         assert len(values) == 1
 131         return self.schema_format_value(attribute, values.pop())
 132
 133     def erase_users_computers(self, dn):
 134         """Erases user and computer objects from our AD.
 135
 136         This is needed since the 'samldb' module denies the deletion of primary
 137         groups. Therefore all groups shouldn't be primary somewhere anymore.
 138         """
 139
 140         try:
 141             res = self.search(base=dn, scope=ldb.SCOPE_SUBTREE, attrs=[],
 142                               expression="(|(objectclass=user)(objectclass=computer))")
 143         except ldb.LdbError as error:
 144             (errno, estr) = error.args
 145             if errno == ldb.ERR_NO_SUCH_OBJECT:
 146                 # Ignore no such object errors
 147                 return
 148             else:
 149                 raise
 150
 151         try:
 152             for msg in res:
 153                 self.delete(msg.dn, ["relax:0"])
 154         except ldb.LdbError as error:
 155             (errno, estr) = error.args
 156             if errno != ldb.ERR_NO_SUCH_OBJECT:
 157                 # Ignore no such object errors
 158                 raise
 159
 160     def erase_except_schema_controlled(self):
 161         """Erase this ldb.
 162
 163         :note: Removes all records, except those that are controlled by
 164             Samba4's schema.
 165         """
 166
 167         basedn = ""
 168
 169         # Try to delete user/computer accounts to allow deletion of groups
 170         self.erase_users_computers(basedn)
 171
 172         # Delete the 'visible' records, and the invisible 'deleted' records (if
 173         # this DB supports it)
 174         for msg in self.search(basedn, ldb.SCOPE_SUBTREE,
 175                                "(&(|(objectclass=*)(distinguishedName=*))(!(distinguishedName=@BASEINFO)))",
 176                                [], controls=["show_deleted:0", "show_recycled:0"]):
 177             try:
 178                 self.delete(msg.dn, ["relax:0"])
 179             except ldb.LdbError as error:
 180                 (errno, estr) = error.args
 181                 if errno != ldb.ERR_NO_SUCH_OBJECT:
 182                     # Ignore no such object errors
 183                     raise
 184
 185         res = self.search(basedn, ldb.SCOPE_SUBTREE,
 186                           "(&(|(objectclass=*)(distinguishedName=*))(!(distinguishedName=@BASEINFO)))",
 187                           [], controls=["show_deleted:0", "show_recycled:0"])
 188         assert len(res) == 0
 189
 190         # delete the specials
 191         for attr in ["@SUBCLASSES", "@MODULES",
 192                      "@OPTIONS", "@PARTITION", "@KLUDGEACL"]:
 193             try:
 194                 self.delete(attr, ["relax:0"])
 195             except ldb.LdbError as error:
 196                 (errno, estr) = error.args
 197                 if errno != ldb.ERR_NO_SUCH_OBJECT:
 198                     # Ignore missing dn errors
 199                     raise
 200
 201     def erase(self):
 202         """Erase this ldb, removing all records."""
 203         self.erase_except_schema_controlled()
 204
 205         # delete the specials
 206         for attr in ["@INDEXLIST", "@ATTRIBUTES"]:
 207             try:
 208                 self.delete(attr, ["relax:0"])
 209             except ldb.LdbError as error:
 210                 (errno, estr) = error.args
 211                 if errno != ldb.ERR_NO_SUCH_OBJECT:
 212                     # Ignore missing dn errors
 213                     raise
 214
 215     def load_ldif_file_add(self, ldif_path):
 216         """Load a LDIF file.
 217
 218         :param ldif_path: Path to LDIF file.
 219         """
 220         with open(ldif_path, 'r') as ldif_file:
 221             self.add_ldif(ldif_file.read())
 222
 223     def add_ldif(self, ldif, controls=None):
 224         """Add data based on a LDIF string.
 225
 226         :param ldif: LDIF text.
 227         """
 228         for changetype, msg in self.parse_ldif(ldif):
 229             assert changetype == ldb.CHANGETYPE_NONE
 230             self.add(msg, controls)
 231
 232     def modify_ldif(self, ldif, controls=None):
 233         """Modify database based on a LDIF string.
 234
 235         :param ldif: LDIF text.
 236         """
 237         for changetype, msg in self.parse_ldif(ldif):
 238             if changetype == ldb.CHANGETYPE_NONE:
 239                 changetype = ldb.CHANGETYPE_MODIFY
 240
 241             if changetype == ldb.CHANGETYPE_ADD:
 242                 self.add(msg, controls)
 243             elif changetype == ldb.CHANGETYPE_MODIFY:
 244                 self.modify(msg, controls)
 245             elif changetype == ldb.CHANGETYPE_DELETE:
 246                 deldn = msg
 247                 self.delete(deldn, controls)
 248             elif changetype == ldb.CHANGETYPE_MODRDN:
 249                 olddn = msg["olddn"]
 250                 deleteoldrdn = msg["deleteoldrdn"]
 251                 newdn = msg["newdn"]
 252                 if deleteoldrdn is False:
 253                     raise ValueError("Invalid ldb.CHANGETYPE_MODRDN with deleteoldrdn=False")
 254                 self.rename(olddn, newdn, controls)
 255             else:
 256                 raise ValueError("Invalid ldb.CHANGETYPE_%u: %s" % (changetype, msg))
 257
 258
 259 def substitute_var(text, values):
 260     """Substitute strings of the form ${NAME} in str, replacing
 261     with substitutions from values.
 262
 263     :param text: Text in which to substitute.
 264     :param values: Dictionary with keys and values.
 265     """
 266
 267     for (name, value) in values.items():
 268         assert isinstance(name, str), "%r is not a string" % name
 269         assert isinstance(value, str), "Value %r for %s is not a string" % (value, name)
 270         text = text.replace("${%s}" % name, value)
 271
 272     return text
 273
 274
 275 def check_all_substituted(text):
 276     """Check that all substitution variables in a string have been replaced.
 277
 278     If not, raise an exception.
 279
 280     :param text: The text to search for substitution variables
 281     """
 282     if "${" not in text:
 283         return
 284
 285     var_start = text.find("${")
 286     var_end = text.find("}", var_start)
 287
 288     raise Exception("Not all variables substituted: %s" %
 289                     text[var_start:var_end + 1])
 290
 291
 292 def read_and_sub_file(file_name, subst_vars):
 293     """Read a file and sub in variables found in it
 294
 295     :param file_name: File to be read (typically from setup directory)
 296     :param subst_vars: Optional variables to substitute in the file.
 297     """
 298     with open(file_name, 'r', encoding="utf-8") as data_file:
 299         data = data_file.read()
 300         if subst_vars is not None:
 301             data = substitute_var(data, subst_vars)
 302             check_all_substituted(data)
 303     return data
 304
 305
 306 def setup_file(template, fname, subst_vars=None):
 307     """Setup a file in the private dir.
 308
 309     :param template: Path of the template file.
 310     :param fname: Path of the file to create.
 311     :param subst_vars: Substitution variables.
 312     """
 313     if os.path.exists(fname):
 314         os.unlink(fname)
 315
 316     data = read_and_sub_file(template, subst_vars)
 317     f = open(fname, 'w')
 318     try:
 319         f.write(data)
 320     finally:
 321         f.close()
 322
 323
 324 MAX_NETBIOS_NAME_LEN = 15
 325
 326
 327 def is_valid_netbios_char(c):
 328     return (c.isalnum() or c in " !#$%&'()-.@^_{}~")
 329
 330
 331 def valid_netbios_name(name):
 332     """Check whether a name is valid as a NetBIOS name. """
 333     # See crh's book (1.4.1.1)
 334     if len(name) > MAX_NETBIOS_NAME_LEN:
 335         return False
 336     for x in name:
 337         if not is_valid_netbios_char(x):
 338             return False
 339     return True
 340
 341
 342 def dn_from_dns_name(dnsdomain):
 343     """return a DN from a DNS name domain/forest root"""
 344     return "DC=" + ",DC=".join(dnsdomain.split("."))
 345
 346
 347 def current_unix_time():
 348     return int(time.time())
 349
 350
 351 def arcfour_encrypt(key, data):
 352     from samba.crypto import arcfour_crypt_blob
 353     return arcfour_crypt_blob(data, key)
 354
 355
 356 def aead_aes_256_cbc_hmac_sha512(plaintext, cek, key_salt, mac_salt, iv):
 357     from samba.crypto import aead_aes_256_cbc_hmac_sha512_blob
 358     return aead_aes_256_cbc_hmac_sha512_blob(
 359         plaintext,
 360         cek,
 361         key_salt,
 362         mac_salt,
 363         iv
 364     )
 365
 366
 367 GUID_RE = re.compile(
 368     "[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}")
 369
 370 GUID_MIXCASE_RE = re.compile(
 371     "[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}",
 372     flags = re.IGNORECASE)
 373
 374
 375 def string_is_guid(string, lower_case_only=False):
 376     """Is the string an ordinary undecorated string GUID?
 377
 378     That is, like 12345678-abcd-1234-FEED-1234567890ab, and not like
 379     variants which have surrounding curly brackets or lack hyphens.
 380
 381     If lower case_only is true, only lowercase hex characters are
 382     accepted. This is tighter than we ever require, but matches what
 383     we usually emit.
 384     """
 385     # Note: it is rightly tempting to use misc.GUID() here and catch
 386     # the error, but misc.GUID is more forgiving than we want,
 387     # allowing all kinds of weird variants.
 388     if lower_case_only:
 389         m = GUID_RE.fullmatch(string)
 390     else:
 391         m = GUID_MIXCASE_RE.fullmatch(string)
 392
 393     if m is None:
 394         return False
 395     return True
 396
 397
 398 def enable_net_export_keytab():
 399     """This function modifies the samba.net.Net class to contain
 400     an export_keytab() method."""
 401     # This looks very strange because it is.
 402     #
 403     # The dckeytab modules contains nothing, but the act of importing
 404     # it pushes a method into samba.net.Net. It ended up this way
 405     # because Net.export_keytab() only works on AD DC builds, and
 406     # people sometimes want to compile Samba without the AD DC while
 407     # still having a working samba-tool.
 408     #
 409     # There is probably a better way to do this than a magic module
 410     # import (yes, that's a FIXME if you can be bothered).
 411     from samba import net
 412     from samba import dckeytab
 413
 414
 415 version = _glue.version
 416 interface_ips = _glue.interface_ips
 417 fault_setup = _glue.fault_setup
 418 set_debug_level = _glue.set_debug_level
 419 get_debug_level = _glue.get_debug_level
 420 float2nttime = _glue.float2nttime
 421 nttime2float = _glue.nttime2float
 422 nttime2string = _glue.nttime2string
 423 nttime2unix = _glue.nttime2unix
 424 unix2nttime = _glue.unix2nttime
 425 generate_random_password = _glue.generate_random_password
 426 generate_random_machine_password = _glue.generate_random_machine_password
 427 check_password_quality = _glue.check_password_quality
 428 generate_random_bytes = _glue.generate_random_bytes
 429 strcasecmp_m = _glue.strcasecmp_m
 430 strstr_m = _glue.strstr_m
 431 is_ntvfs_fileserver_built = _glue.is_ntvfs_fileserver_built
 432 is_heimdal_built = _glue.is_heimdal_built
 433 is_ad_dc_built = _glue.is_ad_dc_built
 434 is_selftest_enabled = _glue.is_selftest_enabled
 435 is_rust_built = _glue.is_rust_built
 436
 437 NTSTATUSError = _glue.NTSTATUSError
 438 HRESULTError = _glue.HRESULTError
 439 WERRORError = _glue.WERRORError
 440 DsExtendedError = _glue.DsExtendedError