--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/VirtualMailManager/password.py Thu Jun 28 19:26:50 2012 +0000
@@ -0,0 +1,459 @@
+# -*- coding: UTF-8 -*-
+# Copyright (c) 2010 - 2012, Pascal Volk
+# See COPYING for distribution information.
+"""
+ VirtualMailManager.password
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+ VirtualMailManager's password module to generate password hashes from
+ passwords or random passwords. This module provides following
+ functions:
+
+ hashed_password = pwhash(password[, scheme][, user])
+ random_password = randompw()
+ scheme, encoding = verify_scheme(scheme)
+ schemes, encodings = list_schemes()
+"""
+
+from crypt import crypt
+from random import SystemRandom
+from subprocess import Popen, PIPE
+
+try:
+ import hashlib
+except ImportError:
+ from VirtualMailManager.pycompat import hashlib
+
+from VirtualMailManager import ENCODING
+from VirtualMailManager.emailaddress import EmailAddress
+from VirtualMailManager.common import get_unicode, version_str
+from VirtualMailManager.constants import VMM_ERROR
+from VirtualMailManager.errors import VMMError
+
+COMPAT = hasattr(hashlib, 'compat')
+SALTCHARS = './0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
+PASSWDCHARS = '._-+#*23456789abcdefghikmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ'
+DEFAULT_B64 = (None, 'B64', 'BASE64')
+DEFAULT_HEX = (None, 'HEX')
+CRYPT_ID_MD5 = 1
+CRYPT_ID_BLF = '2a'
+CRYPT_ID_SHA256 = 5
+CRYPT_ID_SHA512 = 6
+CRYPT_SALT_LEN = 2
+CRYPT_BLF_ROUNDS_MIN = 4
+CRYPT_BLF_ROUNDS_MAX = 31
+CRYPT_BLF_SALT_LEN = 22
+CRYPT_MD5_SALT_LEN = 8
+CRYPT_SHA2_ROUNDS_DEFAULT = 5000
+CRYPT_SHA2_ROUNDS_MIN = 1000
+CRYPT_SHA2_ROUNDS_MAX = 999999999
+CRYPT_SHA2_SALT_LEN = 16
+SALTED_ALGO_SALT_LEN = 4
+
+
+_ = lambda msg: msg
+cfg_dget = lambda option: None
+_sys_rand = SystemRandom()
+_choice = _sys_rand.choice
+_get_salt = lambda s_len: ''.join(_choice(SALTCHARS) for x in xrange(s_len))
+
+
+def _dovecotpw(password, scheme, encoding):
+ """Communicates with dovecotpw (Dovecot 2.0: `doveadm pw`) and returns
+ the hashed password: {scheme[.encoding]}hash
+ """
+ if encoding:
+ scheme = '.'.join((scheme, encoding))
+ cmd_args = [cfg_dget('bin.dovecotpw'), '-s', scheme, '-p',
+ get_unicode(password)]
+ if cfg_dget('misc.dovecot_version') >= 0x20000a01:
+ cmd_args.insert(1, 'pw')
+ process = Popen(cmd_args, stdout=PIPE, stderr=PIPE)
+ stdout, stderr = process.communicate()
+ if process.returncode:
+ raise VMMError(stderr.strip(), VMM_ERROR)
+ hashed = stdout.strip()
+ if not hashed.startswith('{%s}' % scheme):
+ raise VMMError('Unexpected result from %s: %s' %
+ (cfg_dget('bin.dovecotpw'), hashed), VMM_ERROR)
+ return hashed
+
+
+def _md4_new():
+ """Returns an new MD4-hash object if supported by the hashlib or
+ provided by PyCrypto - other `None`.
+ """
+ try:
+ return hashlib.new('md4')
+ except ValueError, err:
+ if str(err) == 'unsupported hash type':
+ if not COMPAT:
+ try:
+ from Crypto.Hash import MD4
+ return MD4.new()
+ except ImportError:
+ return None
+ else:
+ raise
+
+
+def _sha256_new(data=''):
+ """Returns a new sha256 object from the hashlib.
+
+ Returns `None` if the PyCrypto in pycompat.hashlib is too old."""
+ if not COMPAT:
+ return hashlib.sha256(data)
+ try:
+ return hashlib.new('sha256', data)
+ except ValueError, err:
+ if str(err) == 'unsupported hash type':
+ return None
+ else:
+ raise
+
+
+def _format_digest(digest, scheme, encoding):
+ """Formats the arguments to a string: {scheme[.encoding]}digest."""
+ if not encoding:
+ return '{%s}%s' % (scheme, digest)
+ return '{%s.%s}%s' % (scheme, encoding, digest)
+
+
+def _clear_hash(password, scheme, encoding):
+ """Generates a (encoded) CLEARTEXT/PLAIN 'hash'."""
+ if encoding:
+ if encoding == 'HEX':
+ password = password.encode('hex')
+ else:
+ password = password.encode('base64').replace('\n', '')
+ return _format_digest(password, scheme, encoding)
+ return get_unicode('{%s}%s' % (scheme, password))
+
+
+def _get_crypt_blowfish_salt():
+ """Generates a salt for Blowfish crypt."""
+ rounds = cfg_dget('misc.crypt_blowfish_rounds')
+ if rounds < CRYPT_BLF_ROUNDS_MIN:
+ rounds = CRYPT_BLF_ROUNDS_MIN
+ elif rounds > CRYPT_BLF_ROUNDS_MAX:
+ rounds = CRYPT_BLF_ROUNDS_MAX
+ return '$%s$%02d$%s' % (CRYPT_ID_BLF, rounds,
+ _get_salt(CRYPT_BLF_SALT_LEN))
+
+
+def _get_crypt_sha2_salt(crypt_id):
+ """Generates a salt for crypt using the SHA-256 or SHA-512 encryption
+ method.
+ *crypt_id* must be either `5` (SHA-256) or `6` (SHA-512).
+ """
+ assert crypt_id in (CRYPT_ID_SHA256, CRYPT_ID_SHA512), 'invalid crypt ' \
+ 'id: %r' % crypt_id
+ if crypt_id is CRYPT_ID_SHA512:
+ rounds = cfg_dget('misc.crypt_sha512_rounds')
+ else:
+ rounds = cfg_dget('misc.crypt_sha256_rounds')
+ if rounds < CRYPT_SHA2_ROUNDS_MIN:
+ rounds = CRYPT_SHA2_ROUNDS_MIN
+ elif rounds > CRYPT_SHA2_ROUNDS_MAX:
+ rounds = CRYPT_SHA2_ROUNDS_MAX
+ if rounds == CRYPT_SHA2_ROUNDS_DEFAULT:
+ return '$%d$%s' % (crypt_id, _get_salt(CRYPT_SHA2_SALT_LEN))
+ return '$%d$rounds=%d$%s' % (crypt_id, rounds,
+ _get_salt(CRYPT_SHA2_SALT_LEN))
+
+
+def _crypt_hash(password, scheme, encoding):
+ """Generates (encoded) CRYPT/MD5/{BLF,MD5,SHA{256,512}}-CRYPT hashes."""
+ if scheme == 'CRYPT':
+ salt = _get_salt(CRYPT_SALT_LEN)
+ elif scheme == 'BLF-CRYPT':
+ salt = _get_crypt_blowfish_salt()
+ elif scheme in ('MD5-CRYPT', 'MD5'):
+ salt = '$%d$%s' % (CRYPT_ID_MD5, _get_salt(CRYPT_MD5_SALT_LEN))
+ elif scheme == 'SHA256-CRYPT':
+ salt = _get_crypt_sha2_salt(CRYPT_ID_SHA256)
+ else:
+ salt = _get_crypt_sha2_salt(CRYPT_ID_SHA512)
+ encrypted = crypt(password, salt)
+ if encoding:
+ if encoding == 'HEX':
+ encrypted = encrypted.encode('hex')
+ else:
+ encrypted = encrypted.encode('base64').replace('\n', '')
+ if scheme in ('BLF-CRYPT', 'SHA256-CRYPT', 'SHA512-CRYPT') and \
+ cfg_dget('misc.dovecot_version') < 0x20000b06:
+ scheme = 'CRYPT'
+ return _format_digest(encrypted, scheme, encoding)
+
+
+def _md4_hash(password, scheme, encoding):
+ """Generates encoded PLAIN-MD4 hashes."""
+ md4 = _md4_new()
+ if md4:
+ md4.update(password)
+ if encoding in DEFAULT_HEX:
+ digest = md4.hexdigest()
+ else:
+ digest = md4.digest().encode('base64').rstrip()
+ return _format_digest(digest, scheme, encoding)
+ return _dovecotpw(password, scheme, encoding)
+
+
+def _md5_hash(password, scheme, encoding, user=None):
+ """Generates DIGEST-MD5 aka PLAIN-MD5 and LDAP-MD5 hashes."""
+ md5 = hashlib.md5()
+ if scheme == 'DIGEST-MD5':
+ # Prior to Dovecot v1.1.12/v1.2.beta2 there was a problem with a
+ # empty auth_realms setting in dovecot.conf and user@domain.tld
+ # usernames. So we have to generate different hashes for different
+ # versions. See also:
+ # http://dovecot.org/list/dovecot-news/2009-March/000103.html
+ # http://hg.dovecot.org/dovecot-1.1/rev/2b0043ba89ae
+ if cfg_dget('misc.dovecot_version') >= 0x1010cf00:
+ md5.update('%s:%s:' % (user.localpart, user.domainname))
+ else:
+ md5.update('%s::' % user)
+ md5.update(password)
+ if (scheme in ('PLAIN-MD5', 'DIGEST-MD5') and encoding in DEFAULT_HEX) or \
+ (scheme == 'LDAP-MD5' and encoding == 'HEX'):
+ digest = md5.hexdigest()
+ else:
+ digest = md5.digest().encode('base64').rstrip()
+ return _format_digest(digest, scheme, encoding)
+
+
+def _ntlm_hash(password, scheme, encoding):
+ """Generates NTLM hashes."""
+ md4 = _md4_new()
+ if md4:
+ password = ''.join('%s\x00' % c for c in password)
+ md4.update(password)
+ if encoding in DEFAULT_HEX:
+ digest = md4.hexdigest()
+ else:
+ digest = md4.digest().encode('base64').rstrip()
+ return _format_digest(digest, scheme, encoding)
+ return _dovecotpw(password, scheme, encoding)
+
+
+def _sha1_hash(password, scheme, encoding):
+ """Generates SHA1 aka SHA hashes."""
+ sha1 = hashlib.sha1(password)
+ if encoding in DEFAULT_B64:
+ digest = sha1.digest().encode('base64').rstrip()
+ else:
+ digest = sha1.hexdigest()
+ return _format_digest(digest, scheme, encoding)
+
+
+def _sha256_hash(password, scheme, encoding):
+ """Generates SHA256 hashes."""
+ sha256 = _sha256_new(password)
+ if sha256:
+ if encoding in DEFAULT_B64:
+ digest = sha256.digest().encode('base64').rstrip()
+ else:
+ digest = sha256.hexdigest()
+ return _format_digest(digest, scheme, encoding)
+ return _dovecotpw(password, scheme, encoding)
+
+
+def _sha512_hash(password, scheme, encoding):
+ """Generates SHA512 hashes."""
+ if not COMPAT:
+ sha512 = hashlib.sha512(password)
+ if encoding in DEFAULT_B64:
+ digest = sha512.digest().encode('base64').replace('\n', '')
+ else:
+ digest = sha512.hexdigest()
+ return _format_digest(digest, scheme, encoding)
+ return _dovecotpw(password, scheme, encoding)
+
+
+def _smd5_hash(password, scheme, encoding):
+ """Generates SMD5 (salted PLAIN-MD5) hashes."""
+ md5 = hashlib.md5(password)
+ salt = _get_salt(SALTED_ALGO_SALT_LEN)
+ md5.update(salt)
+ if encoding in DEFAULT_B64:
+ digest = (md5.digest() + salt).encode('base64').rstrip()
+ else:
+ digest = md5.hexdigest() + salt.encode('hex')
+ return _format_digest(digest, scheme, encoding)
+
+
+def _ssha1_hash(password, scheme, encoding):
+ """Generates SSHA (salted SHA/SHA1) hashes."""
+ sha1 = hashlib.sha1(password)
+ salt = _get_salt(SALTED_ALGO_SALT_LEN)
+ sha1.update(salt)
+ if encoding in DEFAULT_B64:
+ digest = (sha1.digest() + salt).encode('base64').rstrip()
+ else:
+ digest = sha1.hexdigest() + salt.encode('hex')
+ return _format_digest(digest, scheme, encoding)
+
+
+def _ssha256_hash(password, scheme, encoding):
+ """Generates SSHA256 (salted SHA256) hashes."""
+ sha256 = _sha256_new(password)
+ if sha256:
+ salt = _get_salt(SALTED_ALGO_SALT_LEN)
+ sha256.update(salt)
+ if encoding in DEFAULT_B64:
+ digest = (sha256.digest() + salt).encode('base64').rstrip()
+ else:
+ digest = sha256.hexdigest() + salt.encode('hex')
+ return _format_digest(digest, scheme, encoding)
+ return _dovecotpw(password, scheme, encoding)
+
+
+def _ssha512_hash(password, scheme, encoding):
+ """Generates SSHA512 (salted SHA512) hashes."""
+ if not COMPAT:
+ salt = _get_salt(SALTED_ALGO_SALT_LEN)
+ sha512 = hashlib.sha512(password + salt)
+ if encoding in DEFAULT_B64:
+ digest = (sha512.digest() + salt).encode('base64').replace('\n',
+ '')
+ else:
+ digest = sha512.hexdigest() + salt.encode('hex')
+ return _format_digest(digest, scheme, encoding)
+ return _dovecotpw(password, scheme, encoding)
+
+_scheme_info = {
+ 'CLEARTEXT': (_clear_hash, 0x10000f00),
+ 'CRAM-MD5': (_dovecotpw, 0x10000f00),
+ 'CRYPT': (_crypt_hash, 0x10000f00),
+ 'DIGEST-MD5': (_md5_hash, 0x10000f00),
+ 'HMAC-MD5': (_dovecotpw, 0x10000f00),
+ 'LANMAN': (_dovecotpw, 0x10000f00),
+ 'LDAP-MD5': (_md5_hash, 0x10000f00),
+ 'MD5': (_crypt_hash, 0x10000f00),
+ 'MD5-CRYPT': (_crypt_hash, 0x10000f00),
+ 'NTLM': (_ntlm_hash, 0x10000f00),
+ 'OTP': (_dovecotpw, 0x10100a01),
+ 'PLAIN': (_clear_hash, 0x10000f00),
+ 'PLAIN-MD4': (_md4_hash, 0x10000f00),
+ 'PLAIN-MD5': (_md5_hash, 0x10000f00),
+ 'RPA': (_dovecotpw, 0x10000f00),
+ 'SHA': (_sha1_hash, 0x10000f00),
+ 'SHA1': (_sha1_hash, 0x10000f00),
+ 'SHA256': (_sha256_hash, 0x10100a01),
+ 'SHA512': (_sha512_hash, 0x20000b03),
+ 'SKEY': (_dovecotpw, 0x10100a01),
+ 'SMD5': (_smd5_hash, 0x10000f00),
+ 'SSHA': (_ssha1_hash, 0x10000f00),
+ 'SSHA256': (_ssha256_hash, 0x10200a04),
+ 'SSHA512': (_ssha512_hash, 0x20000b03),
+}
+
+
+def list_schemes():
+ """Returns the tuple (schemes, encodings).
+
+ `schemes` is an iterator for all supported password schemes (depends on
+ the used Dovecot version and features of the libc).
+ `encodings` is a tuple with all usable encoding suffixes. The tuple may
+ be empty.
+ """
+ dcv = cfg_dget('misc.dovecot_version')
+ schemes = (k for (k, v) in _scheme_info.iteritems() if v[1] <= dcv)
+ if dcv >= 0x10100a01:
+ encodings = ('.B64', '.BASE64', '.HEX')
+ else:
+ encodings = ()
+ return schemes, encodings
+
+
+def verify_scheme(scheme):
+ """Checks if the password scheme *scheme* is known and supported by the
+ configured `misc.dovecot_version`.
+
+ The *scheme* maybe a password scheme's name (e.g.: 'PLAIN') or a scheme
+ name with a encoding suffix (e.g. 'PLAIN.BASE64'). If the scheme is
+ known and supported by the used Dovecot version,
+ a tuple ``(scheme, encoding)`` will be returned.
+ The `encoding` in the tuple may be `None`.
+
+ Raises a `VMMError` if the password scheme:
+ * is unknown
+ * depends on a newer Dovecot version
+ * has a unknown encoding suffix
+ """
+ assert isinstance(scheme, basestring), 'Not a str/unicode: %r' % scheme
+ scheme_encoding = scheme.upper().split('.')
+ scheme = scheme_encoding[0]
+ if scheme not in _scheme_info:
+ raise VMMError(_(u"Unsupported password scheme: '%s'") % scheme,
+ VMM_ERROR)
+ if cfg_dget('misc.dovecot_version') < _scheme_info[scheme][1]:
+ raise VMMError(_(u"The password scheme '%(scheme)s' requires Dovecot "
+ u">= v%(version)s.") % {'scheme': scheme,
+ 'version': version_str(_scheme_info[scheme][1])},
+ VMM_ERROR)
+ if len(scheme_encoding) > 1:
+ if cfg_dget('misc.dovecot_version') < 0x10100a01:
+ raise VMMError(_(u'Encoding suffixes for password schemes require '
+ u'Dovecot >= v1.1.alpha1.'), VMM_ERROR)
+ if scheme_encoding[1] not in ('B64', 'BASE64', 'HEX'):
+ raise VMMError(_(u"Unsupported password encoding: '%s'") %
+ scheme_encoding[1], VMM_ERROR)
+ encoding = scheme_encoding[1]
+ else:
+ encoding = None
+ return scheme, encoding
+
+
+def pwhash(password, scheme=None, user=None):
+ """Generates a password hash from the plain text *password* string.
+
+ If no *scheme* is given the password scheme from the configuration will
+ be used for the hash generation. When 'DIGEST-MD5' is used as scheme,
+ also an EmailAddress instance must be given as *user* argument.
+ """
+ if not isinstance(password, basestring):
+ raise TypeError('Password is not a string: %r' % password)
+ if isinstance(password, unicode):
+ password = password.encode(ENCODING)
+ password = password.strip()
+ if not password:
+ raise ValueError("Could not accept empty password.")
+ if scheme is None:
+ scheme = cfg_dget('misc.password_scheme')
+ scheme, encoding = verify_scheme(scheme)
+ if scheme == 'DIGEST-MD5':
+ assert isinstance(user, EmailAddress)
+ return _md5_hash(password, scheme, encoding, user)
+ return _scheme_info[scheme][0](password, scheme, encoding)
+
+
+def randompw():
+ """Generates a plain text random password.
+
+ The length of the password can be configured in the ``vmm.cfg``
+ (account.password_length).
+ """
+ pw_len = cfg_dget('account.password_length')
+ if pw_len < 8:
+ pw_len = 8
+ return ''.join(_sys_rand.sample(PASSWDCHARS, pw_len))
+
+
+def _test_crypt_algorithms():
+ """Check for Blowfish/SHA-256/SHA-512 support in crypt.crypt()."""
+ _blowfish = '$2a$04$0123456789abcdefABCDE.N.drYX5yIAL1LkTaaZotW3yI0hQhZru'
+ _sha256 = '$5$rounds=1000$0123456789abcdef$K/DksR0DT01hGc8g/kt9McEgrbFMKi\
+9qrb1jehe7hn4'
+ _sha512 = '$6$rounds=1000$0123456789abcdef$ZIAd5WqfyLkpvsVCVUU1GrvqaZTqvh\
+JoouxdSqJO71l9Ld3tVrfOatEjarhghvEYADkq//LpDnTeO90tcbtHR1'
+
+ if crypt('08/15!test~4711', '$2a$04$0123456789abcdefABCDEF$') == _blowfish:
+ _scheme_info['BLF-CRYPT'] = (_crypt_hash, 0x10000f00)
+ if crypt('08/15!test~4711', '$5$rounds=1000$0123456789abcdef$') == _sha256:
+ _scheme_info['SHA256-CRYPT'] = (_crypt_hash, 0x10000f00)
+ if crypt('08/15!test~4711', '$6$rounds=1000$0123456789abcdef$') == _sha512:
+ _scheme_info['SHA512-CRYPT'] = (_crypt_hash, 0x10000f00)
+
+_test_crypt_algorithms()
+del _, cfg_dget, _test_crypt_algorithms