Coverage for ipalib/util : 72%

# Authors: 

#   Jason Gerard DeRose <jderose@redhat.com> 

# 

# Copyright (C) 2008  Red Hat 

# see file 'COPYING' for use and warranty information 

# 

# 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 3 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, see <http://www.gnu.org/licenses/>. 

""" 

Various utility functions. 

""" 

import os 

import imp 

import time 

import socket 

import re 

import decimal 

import netaddr 

from types import NoneType 

from weakref import WeakKeyDictionary 

from dns import resolver, rdatatype 

from dns.exception import DNSException 

from ipalib import errors 

from ipalib.text import _ 

from ipapython.ssh import SSHPublicKey 

from ipapython.dn import DN, RDN 

def json_serialize(obj): 

    if isinstance(obj, (list, tuple)): 

        return [json_serialize(o) for o in obj] 

    if isinstance(obj, dict): 

        return dict((k, json_serialize(v)) for (k, v) in obj.iteritems()) 

    if isinstance(obj, (bool, float, int, long, unicode, NoneType)): 

        return obj 

    if isinstance(obj, str): 

        return obj.decode('utf-8') 

    if isinstance(obj, (decimal.Decimal, DN)): 

        return str(obj) 

    if not callable(getattr(obj, '__json__', None)): 

        # raise TypeError('%r is not JSON serializable') 

        return '' 

    return json_serialize(obj.__json__()) 

def get_current_principal(): 

    try: 

        # krbV isn't necessarily available on client machines, fail gracefully 

        import krbV 

        return unicode(krbV.default_context().default_ccache().principal().name) 

    except ImportError: 

        raise RuntimeError('python-krbV is not available.') 

    except krbV.Krb5Error: 

        #TODO: do a kinit? 

        raise errors.CCacheError() 

# FIXME: This function has no unit test 

def find_modules_in_dir(src_dir): 

    """ 

    Iterate through module names found in ``src_dir``. 

    """ 

    if not (os.path.abspath(src_dir) == src_dir and os.path.isdir(src_dir)): 

        return 

    if os.path.islink(src_dir): 

        return 

    suffix = '.py' 

    for name in sorted(os.listdir(src_dir)): 

        if not name.endswith(suffix): 

            continue 

        pyfile = os.path.join(src_dir, name) 

        if os.path.islink(pyfile) or not os.path.isfile(pyfile): 

            continue 

        module = name[:-len(suffix)] 

        if module == '__init__': 

            continue 

        yield (module, pyfile) 

def validate_host_dns(log, fqdn): 

    """ 

    See if the hostname has a DNS A record. 

    """ 

    try: 

        answers = resolver.query(fqdn, rdatatype.A) 

        log.debug( 

            'IPA: found %d records for %s: %s' % (len(answers), fqdn, 

                ' '.join(str(answer) for answer in answers)) 

        ) 

    except DNSException, e: 

        log.debug( 

            'IPA: DNS A record lookup failed for %s' % fqdn 

        ) 

        raise errors.DNSNotARecordError() 

def isvalid_base64(data): 

    """ 

    Validate the incoming data as valid base64 data or not. 

    The character set must only include of a-z, A-Z, 0-9, + or / and 

    be padded with = to be a length divisible by 4 (so only 0-2 =s are 

    allowed). Its length must be divisible by 4. White space is 

    not significant so it is removed. 

    This doesn't guarantee we have a base64-encoded value, just that it 

    fits the base64 requirements. 

    """ 

    data = ''.join(data.split()) 

    if len(data) % 4 > 0 or \ 

        re.match('^[a-zA-Z0-9\+\/]+\={0,2}$', data) is None: 

        return False 

    else: 

        return True 

def validate_ipaddr(ipaddr): 

    """ 

    Check to see if the given IP address is a valid IPv4 or IPv6 address. 

    Returns True or False 

    """ 

    try: 

        socket.inet_pton(socket.AF_INET, ipaddr) 

    except socket.error: 

        try: 

            socket.inet_pton(socket.AF_INET6, ipaddr) 

        except socket.error: 

            return False 

    return True 

def check_writable_file(filename): 

    """ 

    Determine if the file is writable. If the file doesn't exist then 

    open the file to test writability. 

    """ 

    if filename is None: 

        raise errors.FileError(reason=_('Filename is empty')) 

    try: 

        if os.path.exists(filename): 

            if not os.access(filename, os.W_OK): 

                raise errors.FileError(reason=_('Permission denied: %(file)s') % dict(file=filename)) 

        else: 

            fp = open(filename, 'w') 

            fp.close() 

    except (IOError, OSError), e: 

        raise errors.FileError(reason=str(e)) 

def normalize_zonemgr(zonemgr): 

    if not zonemgr: 

        # do not normalize empty or None value 

        return zonemgr 

    if '@' in zonemgr: 

        # local-part needs to be normalized 

        name, at, domain = zonemgr.partition('@') 

        name = name.replace('.', '\\.') 

        zonemgr = u''.join((name, u'.', domain)) 

    if not zonemgr.endswith('.'): 

        zonemgr = zonemgr + u'.' 

    return zonemgr 

def normalize_zone(zone): 

    if zone[-1] != '.': 

        return zone + '.' 

    else: 

        return zone 

def validate_dns_label(dns_label, allow_underscore=False): 

    label_chars = r'a-z0-9' 

    underscore_err_msg = '' 

    if allow_underscore: 

        label_chars += "_" 

        underscore_err_msg = u' _,' 

    label_regex = r'^[%(chars)s]([%(chars)s-]?[%(chars)s])*$' % dict(chars=label_chars) 

    regex = re.compile(label_regex, re.IGNORECASE) 

    if not dns_label: 

        raise ValueError(_('empty DNS label')) 

    if len(dns_label) > 63: 

        raise ValueError(_('DNS label cannot be longer that 63 characters')) 

    if not regex.match(dns_label): 

        raise ValueError(_('only letters, numbers,%(underscore)s and - are allowed. ' \ 

                           'DNS label may not start or end with -') \ 

                           % dict(underscore=underscore_err_msg)) 

def validate_domain_name(domain_name, allow_underscore=False): 

    if domain_name.endswith('.'): 

        domain_name = domain_name[:-1] 

    domain_name = domain_name.split(".") 

    # apply DNS name validator to every name part 

    map(lambda label:validate_dns_label(label,allow_underscore), domain_name) 

    if not domain_name[-1].isalpha(): 

        # see RFC 1123 

        raise ValueError(_('top level domain label must be alphabetic')) 

def validate_zonemgr(zonemgr): 

    """ See RFC 1033, 1035 """ 

    regex_local_part = re.compile(r'^[a-z0-9]([a-z0-9-_]?[a-z0-9])*$', 

                                    re.IGNORECASE) 

    local_part_errmsg = _('mail account may only include letters, numbers, -, _ and a dot. There may not be consecutive -, _ and . characters. Its parts may not start or end with - or _') 

    local_part_sep = '.' 

    local_part = None 

    domain = None 

    if len(zonemgr) > 255: 

        raise ValueError(_('cannot be longer that 255 characters')) 

    if zonemgr.endswith('.'): 

        zonemgr = zonemgr[:-1] 

    if zonemgr.count('@') == 1: 

        local_part, dot, domain = zonemgr.partition('@') 

    elif zonemgr.count('@') > 1: 

        raise ValueError(_('too many \'@\' characters')) 

    else: 

        last_fake_sep = zonemgr.rfind('\\.') 

        if last_fake_sep != -1: # there is a 'fake' local-part/domain separator 

            local_part_sep = '\\.' 

            sep = zonemgr.find('.', last_fake_sep+2) 

            if sep != -1: 

                local_part = zonemgr[:sep] 

                domain = zonemgr[sep+1:] 

        else: 

            local_part, dot, domain = zonemgr.partition('.') 

    if not domain: 

        raise ValueError(_('missing address domain')) 

    validate_domain_name(domain) 

    if not local_part: 

        raise ValueError(_('missing mail account')) 

    if not all(regex_local_part.match(part) for part in \ 

               local_part.split(local_part_sep)): 

        raise ValueError(local_part_errmsg) 

def validate_hostname(hostname, check_fqdn=True, allow_underscore=False): 

    """ See RFC 952, 1123 

    :param hostname Checked value 

    :param check_fqdn Check if hostname is fully qualified 

    """ 

    if len(hostname) > 255: 

        raise ValueError(_('cannot be longer that 255 characters')) 

    if hostname.endswith('.'): 

        hostname = hostname[:-1] 

    if '..' in hostname: 

        raise ValueError(_('hostname contains empty label (consecutive dots)')) 

    if '.' not in hostname: 

        if check_fqdn: 

            raise ValueError(_('not fully qualified')) 

        validate_dns_label(hostname,allow_underscore) 

    else: 

        validate_domain_name(hostname,allow_underscore) 

def normalize_sshpubkey(value): 

    return SSHPublicKey(value).openssh() 

def validate_sshpubkey(ugettext, value): 

    try: 

        SSHPublicKey(value) 

    except ValueError, UnicodeDecodeError: 

        return _('invalid SSH public key') 

def validate_sshpubkey_no_options(ugettext, value): 

    try: 

        pubkey = SSHPublicKey(value) 

    except ValueError, UnicodeDecodeError: 

        return _('invalid SSH public key') 

    if pubkey.has_options(): 

        return _('options are not allowed') 

def convert_sshpubkey_post(ldap, dn, entry_attrs): 

    if 'ipasshpubkey' in entry_attrs: 

        pubkeys = entry_attrs.pop('ipasshpubkey') 

    else: 

        old_entry_attrs = ldap.get_entry(dn, ['ipasshpubkey']) 

        pubkeys = old_entry_attrs[1].get('ipasshpubkey') 

    if not pubkeys: 

        return 

    newpubkeys = [] 

    fingerprints = [] 

    for pubkey in pubkeys: 

        try: 

            pubkey = SSHPublicKey(pubkey) 

        except ValueError, UnicodeDecodeError: 

            continue 

        fp = pubkey.fingerprint_hex_md5() 

        comment = pubkey.comment() 

        if comment: 

            fp = u'%s %s' % (fp, comment) 

        fp = u'%s (%s)' % (fp, pubkey.keytype()) 

        newpubkeys.append(pubkey.openssh()) 

        fingerprints.append(fp) 

    if newpubkeys: 

        entry_attrs['ipasshpubkey'] = newpubkeys 

    if fingerprints: 

        entry_attrs['sshpubkeyfp'] = fingerprints 

class cachedproperty(object): 

    """ 

    A property-like attribute that caches the return value of a method call. 

    When the attribute is first read, the method is called and its return 

    value is saved and returned. On subsequent reads, the saved value is 

    returned. 

    Typical usage: 

    class C(object): 

        @cachedproperty 

        def attr(self): 

            return 'value' 

    """ 

    __slots__ = ('getter', 'store') 

    def __init__(self, getter): 

        self.getter = getter 

        self.store = WeakKeyDictionary() 

    def __get__(self, obj, cls): 

        if obj is None: 

            return None 

        if obj not in self.store: 

            self.store[obj] = self.getter(obj) 

        return self.store[obj] 

    def __set__(self, obj, value): 

        raise AttributeError("can't set attribute") 

    def __delete__(self, obj): 

        raise AttributeError("can't delete attribute") 

# regexp matching signed floating point number (group 1) followed by 

# optional whitespace followed by time unit, e.g. day, hour (group 7) 

time_duration_re = re.compile(r'([-+]?((\d+)|(\d+\.\d+)|(\.\d+)|(\d+\.)))\s*([a-z]+)', re.IGNORECASE) 

# number of seconds in a time unit 

time_duration_units = { 

    'year'    : 365*24*60*60, 

    'years'   : 365*24*60*60, 

    'y'       : 365*24*60*60, 

    'month'   : 30*24*60*60, 

    'months'  : 30*24*60*60, 

    'week'    : 7*24*60*60, 

    'weeks'   : 7*24*60*60, 

    'w'       : 7*24*60*60, 

    'day'     : 24*60*60, 

    'days'    : 24*60*60, 

    'd'       : 24*60*60, 

    'hour'    : 60*60, 

    'hours'   : 60*60, 

    'h'       : 60*60, 

    'minute'  : 60, 

    'minutes' : 60, 

    'min'     : 60, 

    'second'  : 1, 

    'seconds' : 1, 

    'sec'     : 1, 

    's'       : 1, 

} 

def parse_time_duration(value): 

    ''' 

    Given a time duration string, parse it and return the total number 

    of seconds represented as a floating point value. Negative values 

    are permitted. 

    The string should be composed of one or more numbers followed by a 

    time unit. Whitespace and punctuation is optional. The numbers may 

    be optionally signed.  The time units are case insenstive except 

    for the single character 'M' or 'm' which means month and minute 

    respectively. 

    Recognized time units are: 

        * year, years, y 

        * month, months, M 

        * week, weeks, w 

        * day, days, d 

        * hour, hours, h 

        * minute, minutes, min, m 

        * second, seconds, sec, s 

    Examples: 

        "1h"                    # 1 hour 

        "2 HOURS, 30 Minutes"   # 2.5 hours 

        "1week -1 day"          # 6 days 

        ".5day"                 # 12 hours 

        "2M"                    # 2 months 

        "1h:15m"                # 1.25 hours 

        "1h, -15min"            # 45 minutes 

        "30 seconds"            # .5 minute 

    Note: Despite the appearance you can perform arithmetic the 

    parsing is much simpler, the parser searches for signed values and 

    adds the signed value to a running total. Only + and - are permitted 

    and must appear prior to a digit. 

    :parameters: 

        value : string 

            A time duration string in the specified format 

    :returns: 

        total number of seconds as float (may be negative) 

    ''' 

    matches = 0 

    duration = 0.0 

    for match in time_duration_re.finditer(value): 

        matches += 1 

        magnitude = match.group(1) 

        unit = match.group(7) 

        # Get the unit, only M and m are case sensitive 

        if unit == 'M':         # month 

            seconds_per_unit = 30*24*60*60 

        elif unit == 'm':       # minute 

            seconds_per_unit = 60 

        else: 

            unit = unit.lower() 

            seconds_per_unit = time_duration_units.get(unit) 

            if seconds_per_unit is None: 

                raise ValueError('unknown time duration unit "%s"' % unit) 

        magnitude = float(magnitude) 

        seconds = magnitude * seconds_per_unit 

        duration += seconds 

    if matches == 0: 

        raise ValueError('no time duration found in "%s"' % value) 

    return duration 

def get_dns_forward_zone_update_policy(realm, rrtypes=('A', 'AAAA', 'SSHFP')): 

    """ 

    Generate update policy for a forward DNS zone (idnsUpdatePolicy 

    attribute). Bind uses this policy to grant/reject access for client 

    machines trying to dynamically update their records. 

    :param realm: A realm of the of the client 

    :param rrtypes: A list of resource records types that client shall be 

                    allowed to update 

    """ 

    policy_element = "grant %(realm)s krb5-self * %(rrtype)s" 

    policies = [ policy_element % dict(realm=realm, rrtype=rrtype) \ 

               for rrtype in rrtypes ] 

    policy = "; ".join(policies) 

    policy += ";" 

    return policy 

def get_dns_reverse_zone_update_policy(realm, reverse_zone, rrtypes=('PTR',)): 

    """ 

    Generate update policy for a reverse DNS zone (idnsUpdatePolicy 

    attribute). Bind uses this policy to grant/reject access for client 

    machines trying to dynamically update their records. 

    :param realm: A realm of the of the client 

    :param reverse_zone: Name of the actual zone. All clients with IPs in this 

                         sub-domain will be allowed to perform changes 

    :param rrtypes: A list of resource records types that client shall be 

                    allowed to update 

    """ 

    policy_element = "grant %(realm)s krb5-subdomain %(zone)s %(rrtype)s" 

    policies = [ policy_element \ 

                    % dict(realm=realm, zone=reverse_zone, rrtype=rrtype) \ 

                 for rrtype in rrtypes ] 

    policy = "; ".join(policies) 

    policy += ";" 

    return policy 

# dictionary of valid reverse zone -> number of address components 

REVERSE_DNS_ZONES = { 

    '.in-addr.arpa.' : 4, 

    '.ip6.arpa.' : 32, 

} 

def zone_is_reverse(zone_name): 

    zone_name = normalize_zone(zone_name) 

    if any(zone_name.endswith(name) for name in REVERSE_DNS_ZONES): 

        return True 

    return False 

def get_reverse_zone_default(ip_address): 

    ip = netaddr.IPAddress(ip_address) 

    items = ip.reverse_dns.split('.') 

    if ip.version == 4: 

        items = items[1:]   # /24 for IPv4 

    elif ip.version == 6: 

        items = items[16:]  # /64 for IPv6 

    return normalize_zone('.'.join(items)) 

def validate_rdn_param(ugettext, value): 

    try: 

        rdn = RDN(value) 

    except Exception, e: 

        return str(e) 

    return None