def verify_fqdn(host_name, no_host_dns=False, local_hostname=True):
"""
Run fqdn checks for given host:
- test hostname format
- test that hostname is fully qualified
- test forward and reverse hostname DNS lookup
Raises `BadHostError` or derived Exceptions if there is an error
:param host_name: The host name to verify.
:param no_host_dns: If true, skip DNS resolution tests of the host name.
:param local_hostname: If true, run additional checks for local hostnames
"""
if len(host_name.split(".")) < 2 or host_name == "localhost.localdomain":
raise BadHostError("Invalid hostname '%s', must be fully-qualified." % host_name)
if host_name != host_name.lower():
raise BadHostError("Invalid hostname '%s', must be lower-case." % host_name)
if ipautil.valid_ip(host_name):
raise BadHostError("IP address not allowed as a hostname")
try:
# make sure that the host name meets the requirements in ipalib
validate_hostname(host_name)
except ValueError, e:
raise BadHostError("Invalid hostname '%s', %s" % (host_name, unicode(e)))
def verify_fqdn(host_name, no_host_dns=False, local_hostname=True):
"""
Run fqdn checks for given host:
- test hostname format
- test that hostname is fully qualified
- test forward and reverse hostname DNS lookup
Raises `BadHostError` or derived Exceptions if there is an error
:param host_name: The host name to verify.
:param no_host_dns: If true, skip DNS resolution tests of the host name.
:param local_hostname: If true, run additional checks for local hostnames
"""
if len(host_name.split(".")) < 2 or host_name == "localhost.localdomain":
raise BadHostError("Invalid hostname '%s', must be fully-qualified." %
host_name)
if host_name != host_name.lower():
raise BadHostError("Invalid hostname '%s', must be lower-case." %
host_name)
if ipautil.valid_ip(host_name):
raise BadHostError("IP address not allowed as a hostname")
try:
# make sure that the host name meets the requirements in ipalib
validate_hostname(host_name)
except ValueError, e:
raise BadHostError("Invalid hostname '%s', %s" %
(host_name, unicode(e)))
def search(self,
domain="",
servers="",
realm=None,
hostname=None,
ca_cert_path=None):
"""
Use DNS discovery to identify valid IPA servers.
servers may contain an optional list of servers which will be used
instead of discovering available LDAP SRV records.
Returns a constant representing the overall search result.
"""
root_logger.debug("[IPA Discovery]")
root_logger.debug(
'Starting IPA discovery with domain=%s, servers=%s, hostname=%s',
domain, servers, hostname)
self.server = None
autodiscovered = False
if not servers:
if not domain: #domain not provided do full DNS discovery
# get the local host name
if not hostname:
hostname = socket.getfqdn()
root_logger.debug('Hostname: %s', hostname)
if not hostname:
return BAD_HOST_CONFIG
if valid_ip(hostname):
return NOT_FQDN
# first, check for an LDAP server for the local domain
p = hostname.find(".")
if p == -1: #no domain name
return NOT_FQDN
domain = hostname[p + 1:]
# Get the list of domains from /etc/resolv.conf, we'll search
# them all. We search the domain of our hostname first though.
# This is to avoid the situation where domain isn't set in
# /etc/resolv.conf and the search list has the hostname domain
# not first. We could end up with the wrong SRV record.
domains = self.__get_resolver_domains()
domains = [(domain, 'domain of the hostname')] + domains
tried = set()
for domain, reason in domains:
servers, domain = self.check_domain(domain, tried, reason)
if servers:
autodiscovered = True
self.domain = domain
self.server_source = self.domain_source = (
'Discovered LDAP SRV records from %s (%s)' %
(domain, reason))
break
if not self.domain: #no ldap server found
root_logger.debug('No LDAP server found')
return NO_LDAP_SERVER
else:
root_logger.debug("Search for LDAP SRV record in %s", domain)
servers = self.ipadns_search_srv(domain,
'_ldap._tcp',
389,
break_on_first=False)
if servers:
autodiscovered = True
self.domain = domain
self.server_source = self.domain_source = (
'Discovered LDAP SRV records from %s' % domain)
else:
self.server = None
root_logger.debug('No LDAP server found')
return NO_LDAP_SERVER
else:
root_logger.debug("Server and domain forced")
self.domain = domain
self.domain_source = self.server_source = 'Forced'
#search for kerberos
root_logger.debug("[Kerberos realm search]")
if realm:
root_logger.debug("Kerberos realm forced")
self.realm = realm
self.realm_source = 'Forced'
else:
realm = self.ipadnssearchkrbrealm()
self.realm = realm
self.realm_source = ('Discovered Kerberos DNS records from %s' %
self.domain)
if not servers and not realm:
return REALM_NOT_FOUND
self.kdc = self.ipadnssearchkrbkdc()
self.kdc_source = ('Discovered Kerberos DNS records from %s' %
self.domain)
# We may have received multiple servers corresponding to the domain
# Iterate through all of those to check if it is IPA LDAP server
ldapret = [NOT_IPA_SERVER]
ldapaccess = True
root_logger.debug("[LDAP server check]")
valid_servers = []
for server in servers:
root_logger.debug('Verifying that %s (realm %s) is an IPA server',
server, self.realm)
# check ldap now
ldapret = self.ipacheckldap(server,
self.realm,
ca_cert_path=ca_cert_path)
if ldapret[0] == 0:
self.server = ldapret[1]
self.realm = ldapret[2]
self.server_source = self.realm_source = (
'Discovered from LDAP DNS records in %s' % self.server)
valid_servers.append(server)
# verified, we actually talked to the remote server and it
# is definetely an IPA server
if autodiscovered:
# No need to keep verifying servers if we discovered them
# via DNS
break
elif ldapret[0] == NO_ACCESS_TO_LDAP or ldapret[0] == NO_TLS_LDAP:
ldapaccess = False
valid_servers.append(server)
# we may set verified_servers below, we don't have it yet
if autodiscovered:
# No need to keep verifying servers if we discovered them
# via DNS
break
elif ldapret[0] == NOT_IPA_SERVER:
root_logger.warn('Skip %s: not an IPA server', server)
elif ldapret[0] == NO_LDAP_SERVER:
root_logger.warn(
'Skip %s: LDAP server is not responding, unable to verify if '
'this is an IPA server', server)
else:
root_logger.warn(
'Skip %s: cannot verify if this is an IPA server', server)
# If one of LDAP servers checked rejects access (maybe anonymous
# bind is disabled), assume realm and basedn generated off domain.
# Note that in case ldapret[0] == 0 and ldapaccess == False (one of
# servers didn't provide access but another one succeeded), self.realm
# will be set already to a proper value above, self.basdn will be
# initialized during the LDAP check itself and we'll skip these two checks.
if not ldapaccess and self.realm is None:
# Assume realm is the same as domain.upper()
self.realm = self.domain.upper()
self.realm_source = 'Assumed same as domain'
root_logger.debug("Assuming realm is the same as domain: %s",
self.realm)
if not ldapaccess and self.basedn is None:
# Generate suffix from realm
self.basedn = realm_to_suffix(self.realm)
self.basedn_source = 'Generated from Kerberos realm'
root_logger.debug("Generated basedn from realm: %s" % self.basedn)
root_logger.debug(
"Discovery result: %s; server=%s, domain=%s, kdc=%s, basedn=%s",
error_names.get(ldapret[0], ldapret[0]), self.server, self.domain,
self.kdc, self.basedn)
root_logger.debug("Validated servers: %s" % ','.join(valid_servers))
self.servers = valid_servers
# If we have any servers left then override the last return value
# to indicate success.
if valid_servers:
self.server = servers[0]
ldapret[0] = 0
return ldapret[0]
def search(self, domain="", servers="", realm=None, hostname=None, ca_cert_path=None):
"""
Use DNS discovery to identify valid IPA servers.
servers may contain an optional list of servers which will be used
instead of discovering available LDAP SRV records.
Returns a constant representing the overall search result.
"""
root_logger.debug("[IPA Discovery]")
root_logger.debug(
'Starting IPA discovery with domain=%s, servers=%s, hostname=%s',
domain, servers, hostname)
self.server = None
autodiscovered = False
if not servers:
if not domain: #domain not provided do full DNS discovery
# get the local host name
if not hostname:
hostname = socket.getfqdn()
root_logger.debug('Hostname: %s', hostname)
if not hostname:
return BAD_HOST_CONFIG
if valid_ip(hostname):
return NOT_FQDN
# first, check for an LDAP server for the local domain
p = hostname.find(".")
if p == -1: #no domain name
return NOT_FQDN
domain = hostname[p+1:]
# Get the list of domains from /etc/resolv.conf, we'll search
# them all. We search the domain of our hostname first though.
# This is to avoid the situation where domain isn't set in
# /etc/resolv.conf and the search list has the hostname domain
# not first. We could end up with the wrong SRV record.
domains = self.__get_resolver_domains()
domains = [(domain, 'domain of the hostname')] + domains
tried = set()
for domain, reason in domains:
servers, domain = self.check_domain(domain, tried, reason)
if servers:
autodiscovered = True
self.domain = domain
self.server_source = self.domain_source = (
'Discovered LDAP SRV records from %s (%s)' %
(domain, reason))
break
if not self.domain: #no ldap server found
root_logger.debug('No LDAP server found')
return NO_LDAP_SERVER
else:
root_logger.debug("Search for LDAP SRV record in %s", domain)
servers = self.ipadns_search_srv(domain, '_ldap._tcp', 389,
break_on_first=False)
if servers:
autodiscovered = True
self.domain = domain
self.server_source = self.domain_source = (
'Discovered LDAP SRV records from %s' % domain)
else:
self.server = None
root_logger.debug('No LDAP server found')
return NO_LDAP_SERVER
else:
root_logger.debug("Server and domain forced")
self.domain = domain
self.domain_source = self.server_source = 'Forced'
#search for kerberos
root_logger.debug("[Kerberos realm search]")
if realm:
root_logger.debug("Kerberos realm forced")
self.realm = realm
self.realm_source = 'Forced'
else:
realm = self.ipadnssearchkrbrealm()
self.realm = realm
self.realm_source = (
'Discovered Kerberos DNS records from %s' % self.domain)
if not servers and not realm:
return REALM_NOT_FOUND
if autodiscovered:
self.kdc = self.ipadnssearchkrbkdc()
self.kdc_source = (
'Discovered Kerberos DNS records from %s' % self.domain)
else:
self.kdc = ', '.join(servers)
self.kdc_source = "Kerberos DNS record discovery bypassed"
# We may have received multiple servers corresponding to the domain
# Iterate through all of those to check if it is IPA LDAP server
ldapret = [NOT_IPA_SERVER]
ldapaccess = True
root_logger.debug("[LDAP server check]")
valid_servers = []
for server in servers:
root_logger.debug('Verifying that %s (realm %s) is an IPA server',
server, self.realm)
# check ldap now
ldapret = self.ipacheckldap(server, self.realm, ca_cert_path=ca_cert_path)
if ldapret[0] == 0:
self.server = ldapret[1]
self.realm = ldapret[2]
self.server_source = self.realm_source = (
'Discovered from LDAP DNS records in %s' % self.server)
valid_servers.append(server)
# verified, we actually talked to the remote server and it
# is definetely an IPA server
if autodiscovered:
# No need to keep verifying servers if we discovered them
# via DNS
break
elif ldapret[0] == NO_ACCESS_TO_LDAP or ldapret[0] == NO_TLS_LDAP:
ldapaccess = False
valid_servers.append(server)
# we may set verified_servers below, we don't have it yet
if autodiscovered:
# No need to keep verifying servers if we discovered them
# via DNS
break
elif ldapret[0] == NOT_IPA_SERVER:
root_logger.warning(
'Skip %s: not an IPA server', server)
elif ldapret[0] == NO_LDAP_SERVER:
root_logger.warning(
'Skip %s: LDAP server is not responding, unable to verify if '
'this is an IPA server', server)
else:
root_logger.warning(
'Skip %s: cannot verify if this is an IPA server', server)
# If one of LDAP servers checked rejects access (maybe anonymous
# bind is disabled), assume realm and basedn generated off domain.
# Note that in case ldapret[0] == 0 and ldapaccess == False (one of
# servers didn't provide access but another one succeeded), self.realm
# will be set already to a proper value above, self.basdn will be
# initialized during the LDAP check itself and we'll skip these two checks.
if not ldapaccess and self.realm is None:
# Assume realm is the same as domain.upper()
self.realm = self.domain.upper()
self.realm_source = 'Assumed same as domain'
root_logger.debug(
"Assuming realm is the same as domain: %s", self.realm)
if not ldapaccess and self.basedn is None:
# Generate suffix from realm
self.basedn = realm_to_suffix(self.realm)
self.basedn_source = 'Generated from Kerberos realm'
root_logger.debug("Generated basedn from realm: %s" % self.basedn)
root_logger.debug(
"Discovery result: %s; server=%s, domain=%s, kdc=%s, basedn=%s",
error_names.get(ldapret[0], ldapret[0]),
self.server, self.domain, self.kdc, self.basedn)
root_logger.debug("Validated servers: %s" % ','.join(valid_servers))
self.servers = valid_servers
# If we have any servers left then override the last return value
# to indicate success.
if valid_servers:
self.server = servers[0]
ldapret[0] = 0
return ldapret[0]
def verify_fqdn(host_name, no_host_dns=False, local_hostname=True):
"""
Run fqdn checks for given host:
- test hostname format
- test that hostname is fully qualified
- test forward and reverse hostname DNS lookup
Raises `BadHostError` or derived Exceptions if there is an error
:param host_name: The host name to verify.
:param no_host_dns: If true, skip DNS resolution tests of the host name.
:param local_hostname: If true, run additional checks for local hostnames
"""
if len(host_name.split(".")) < 2 or host_name == "localhost.localdomain":
raise BadHostError("Invalid hostname '%s', must be fully-qualified." % host_name)
if host_name != host_name.lower():
raise BadHostError("Invalid hostname '%s', must be lower-case." % host_name)
if ipautil.valid_ip(host_name):
raise BadHostError("IP address not allowed as a hostname")
try:
# make sure that the host name meets the requirements in ipalib
validate_hostname(host_name)
except ValueError as e:
raise BadHostError("Invalid hostname '%s', %s" % (host_name, unicode(e)))
if local_hostname:
try:
logger.debug('Check if %s is a primary hostname for localhost',
host_name)
ex_name = socket.gethostbyaddr(host_name)
logger.debug('Primary hostname for localhost: %s', ex_name[0])
if host_name != ex_name[0]:
raise HostLookupError("The host name %s does not match the primary host name %s. "\
"Please check /etc/hosts or DNS name resolution" % (host_name, ex_name[0]))
except socket.gaierror:
pass
except socket.error as e:
logger.debug(
'socket.gethostbyaddr() error: %d: %s',
e.errno, e.strerror) # pylint: disable=no-member
if no_host_dns:
print("Warning: skipping DNS resolution of host", host_name)
return
try:
logger.debug('Search DNS for %s', host_name)
hostaddr = socket.getaddrinfo(host_name, None)
except Exception as e:
logger.debug('Search failed: %s', e)
raise HostForwardLookupError("Unable to resolve host name, check /etc/hosts or DNS name resolution")
if len(hostaddr) == 0:
raise HostForwardLookupError("Unable to resolve host name, check /etc/hosts or DNS name resolution")
# Verify this is NOT a CNAME
try:
logger.debug('Check if %s is not a CNAME', host_name)
resolver.query(host_name, rdatatype.CNAME)
raise HostReverseLookupError("The IPA Server Hostname cannot be a CNAME, only A and AAAA names are allowed.")
except DNSException:
pass
# list of verified addresses to prevent multiple searches for the same address
verified = set()
for a in hostaddr:
address = a[4][0]
if address in verified:
continue
if address in ('127.0.0.1', '::1'):
raise HostForwardLookupError("The IPA Server hostname must not resolve to localhost (%s). A routable IP address must be used. Check /etc/hosts to see if %s is an alias for %s" % (address, host_name, address))
try:
logger.debug('Check reverse address of %s', address)
revname = socket.gethostbyaddr(address)[0]
except Exception as e:
logger.debug('Check failed: %s', e)
logger.error(
"Unable to resolve the IP address %s to a host name, "
"check /etc/hosts and DNS name resolution", address)
else:
logger.debug('Found reverse name: %s', revname)
if revname != host_name:
logger.error(
"The host name %s does not match the value %s obtained "
"by reverse lookup on IP address %s", host_name, revname,
address)
verified.add(address)
def verify_fqdn(host_name, no_host_dns=False, local_hostname=True):
"""
Run fqdn checks for given host:
- test hostname format
- test that hostname is fully qualified
- test forward and reverse hostname DNS lookup
Raises `BadHostError` or derived Exceptions if there is an error
:param host_name: The host name to verify.
:param no_host_dns: If true, skip DNS resolution tests of the host name.
:param local_hostname: If true, run additional checks for local hostnames
"""
if len(host_name.split(".")) < 2 or host_name == "localhost.localdomain":
raise BadHostError("Invalid hostname '%s', must be fully-qualified." % host_name)
if host_name != host_name.lower():
raise BadHostError("Invalid hostname '%s', must be lower-case." % host_name)
if ipautil.valid_ip(host_name):
raise BadHostError("IP address not allowed as a hostname")
try:
# make sure that the host name meets the requirements in ipalib
validate_hostname(host_name)
except ValueError as e:
raise BadHostError("Invalid hostname '%s', %s" % (host_name, unicode(e)))
if local_hostname:
try:
root_logger.debug('Check if %s is a primary hostname for localhost', host_name)
ex_name = socket.gethostbyaddr(host_name)
root_logger.debug('Primary hostname for localhost: %s', ex_name[0])
if host_name != ex_name[0]:
raise HostLookupError("The host name %s does not match the primary host name %s. "\
"Please check /etc/hosts or DNS name resolution" % (host_name, ex_name[0]))
except socket.gaierror:
pass
except socket.error as e:
root_logger.debug(
'socket.gethostbyaddr() error: %d: %s',
e.errno, e.strerror) # pylint: disable=no-member
if no_host_dns:
print("Warning: skipping DNS resolution of host", host_name)
return
try:
root_logger.debug('Search DNS for %s', host_name)
hostaddr = socket.getaddrinfo(host_name, None)
except Exception as e:
root_logger.debug('Search failed: %s', e)
raise HostForwardLookupError("Unable to resolve host name, check /etc/hosts or DNS name resolution")
if len(hostaddr) == 0:
raise HostForwardLookupError("Unable to resolve host name, check /etc/hosts or DNS name resolution")
# Verify this is NOT a CNAME
try:
root_logger.debug('Check if %s is not a CNAME', host_name)
resolver.query(host_name, rdatatype.CNAME)
raise HostReverseLookupError("The IPA Server Hostname cannot be a CNAME, only A and AAAA names are allowed.")
except DNSException:
pass
# list of verified addresses to prevent multiple searches for the same address
verified = set()
for a in hostaddr:
address = a[4][0]
if address in verified:
continue
if address == '127.0.0.1' or address == '::1':
raise HostForwardLookupError("The IPA Server hostname must not resolve to localhost (%s). A routable IP address must be used. Check /etc/hosts to see if %s is an alias for %s" % (address, host_name, address))
try:
root_logger.debug('Check reverse address of %s', address)
revname = socket.gethostbyaddr(address)[0]
except Exception as e:
root_logger.debug('Check failed: %s', e)
root_logger.error(
"Unable to resolve the IP address %s to a host name, "
"check /etc/hosts and DNS name resolution", address)
else:
root_logger.debug('Found reverse name: %s', revname)
if revname != host_name:
root_logger.error(
"The host name %s does not match the value %s obtained "
"by reverse lookup on IP address %s", host_name, revname,
address)
verified.add(address)