freeipa/ipalib/plugins/cert.py
Jan Cholasta d6fb110b77 Support requests with SAN in cert-request.
For each SAN in a request there must be a matching service entry writable by
the requestor. Users can request certificates with SAN only if they have
"Request Certificate With SubjectAltName" permission.

https://fedorahosted.org/freeipa/ticket/3977

Reviewed-By: Martin Kosek <mkosek@redhat.com>
2014-06-24 12:10:01 +02:00

754 lines
25 KiB
Python

# Authors:
# Andrew Wnuk <awnuk@redhat.com>
# Jason Gerard DeRose <jderose@redhat.com>
# John Dennis <jdennis@redhat.com>
#
# Copyright (C) 2009 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/>.
from ipalib import api, SkipPluginModule
if api.env.enable_ra is not True:
# In this case, abort loading this plugin module...
raise SkipPluginModule(reason='env.enable_ra is not True')
import os
import time
from ipalib import Command, Str, Int, Bytes, Flag, File
from ipalib import errors
from ipalib import pkcs10
from ipalib import x509
from ipalib import util
from ipalib import ngettext
from ipalib.plugable import Registry
from ipalib.plugins.virtual import *
from ipalib.plugins.service import split_principal
import base64
import traceback
from ipalib.text import _
from ipalib.request import context
from ipalib import output
from ipalib.plugins.service import validate_principal
import nss.nss as nss
from nss.error import NSPRError
from pyasn1.error import PyAsn1Error
__doc__ = _("""
IPA certificate operations
Implements a set of commands for managing server SSL certificates.
Certificate requests exist in the form of a Certificate Signing Request (CSR)
in PEM format.
The dogtag CA uses just the CN value of the CSR and forces the rest of the
subject to values configured in the server.
A certificate is stored with a service principal and a service principal
needs a host.
In order to request a certificate:
* The host must exist
* The service must exist (or you use the --add option to automatically add it)
SEARCHING:
Certificates may be searched on by certificate subject, serial number,
revocation reason, validity dates and the issued date.
When searching on dates the _from date does a >= search and the _to date
does a <= search. When combined these are done as an AND.
Dates are treated as GMT to match the dates in the certificates.
The date format is YYYY-mm-dd.
EXAMPLES:
Request a new certificate and add the principal:
ipa cert-request --add --principal=HTTP/lion.example.com example.csr
Retrieve an existing certificate:
ipa cert-show 1032
Revoke a certificate (see RFC 5280 for reason details):
ipa cert-revoke --revocation-reason=6 1032
Remove a certificate from revocation hold status:
ipa cert-remove-hold 1032
Check the status of a signing request:
ipa cert-status 10
Search for certificates by hostname:
ipa cert-find --subject=ipaserver.example.com
Search for revoked certificates by reason:
ipa cert-find --revocation-reason=5
Search for certificates based on issuance date
ipa cert-find --issuedon-from=2013-02-01 --issuedon-to=2013-02-07
IPA currently immediately issues (or declines) all certificate requests so
the status of a request is not normally useful. This is for future use
or the case where a CA does not immediately issue a certificate.
The following revocation reasons are supported:
* 0 - unspecified
* 1 - keyCompromise
* 2 - cACompromise
* 3 - affiliationChanged
* 4 - superseded
* 5 - cessationOfOperation
* 6 - certificateHold
* 8 - removeFromCRL
* 9 - privilegeWithdrawn
* 10 - aACompromise
Note that reason code 7 is not used. See RFC 5280 for more details:
http://www.ietf.org/rfc/rfc5280.txt
""")
register = Registry()
def validate_pkidate(ugettext, value):
"""
A date in the format of %Y-%m-%d
"""
try:
ts = time.strptime(value, '%Y-%m-%d')
except ValueError, e:
return str(e)
return None
def validate_csr(ugettext, csr):
"""
Ensure the CSR is base64-encoded and can be decoded by our PKCS#10
parser.
"""
if api.env.context == 'cli':
# If we are passed in a pointer to a valid file on the client side
# escape and let the load_files() handle things
if csr and os.path.exists(csr):
return
try:
request = pkcs10.load_certificate_request(csr)
except TypeError, e:
raise errors.Base64DecodeError(reason=str(e))
except Exception, e:
raise errors.CertificateOperationError(error=_('Failure decoding Certificate Signing Request: %s') % e)
def normalize_csr(csr):
"""
Strip any leading and trailing cruft around the BEGIN/END block
"""
end_len = 37
s = csr.find('-----BEGIN NEW CERTIFICATE REQUEST-----')
if s == -1:
s = csr.find('-----BEGIN CERTIFICATE REQUEST-----')
e = csr.find('-----END NEW CERTIFICATE REQUEST-----')
if e == -1:
e = csr.find('-----END CERTIFICATE REQUEST-----')
if e != -1:
end_len = 33
if s > -1 and e > -1:
# We're normalizing here, not validating
csr = csr[s:e+end_len]
return csr
def _convert_serial_number(num):
"""
Convert a SN given in decimal or hexadecimal.
Returns the number or None if conversion fails.
"""
# plain decimal or hexa with radix prefix
try:
num = int(num, 0)
except ValueError:
try:
# hexa without prefix
num = int(num, 16)
except ValueError:
num = None
return num
def validate_serial_number(ugettext, num):
if _convert_serial_number(num) == None:
return u"Decimal or hexadecimal number is required for serial number"
return None
def normalize_serial_number(num):
# It's been already validated
return unicode(_convert_serial_number(num))
def get_host_from_principal(principal):
"""
Given a principal with or without a realm return the
host portion.
"""
validate_principal(None, principal)
realm = principal.find('@')
slash = principal.find('/')
if realm == -1:
realm = len(principal)
hostname = principal[slash+1:realm]
return hostname
@register()
class cert_request(VirtualCommand):
__doc__ = _('Submit a certificate signing request.')
takes_args = (
File('csr', validate_csr,
label=_('CSR'),
cli_name='csr_file',
normalizer=normalize_csr,
),
)
operation="request certificate"
takes_options = (
Str('principal',
label=_('Principal'),
doc=_('Service principal for this certificate (e.g. HTTP/test.example.com)'),
),
Str('request_type',
default=u'pkcs10',
autofill=True,
),
Flag('add',
doc=_("automatically add the principal if it doesn't exist"),
default=False,
autofill=True
),
)
has_output_params = (
Str('certificate',
label=_('Certificate'),
),
Str('subject',
label=_('Subject'),
),
Str('issuer',
label=_('Issuer'),
),
Str('valid_not_before',
label=_('Not Before'),
),
Str('valid_not_after',
label=_('Not After'),
),
Str('md5_fingerprint',
label=_('Fingerprint (MD5)'),
),
Str('sha1_fingerprint',
label=_('Fingerprint (SHA1)'),
),
Str('serial_number',
label=_('Serial number'),
),
Str('serial_number_hex',
label=_('Serial number (hex)'),
),
)
has_output = (
output.Output('result',
type=dict,
doc=_('Dictionary mapping variable name to value'),
),
)
_allowed_extensions = {
'2.5.29.14': None, # Subject Key Identifier
'2.5.29.15': None, # Key Usage
'2.5.29.17': 'request certificate with subjectaltname',
'2.5.29.19': None, # Basic Constraints
'2.5.29.37': None, # Extended Key Usage
}
def execute(self, csr, **kw):
ldap = self.api.Backend.ldap2
principal = kw.get('principal')
add = kw.get('add')
request_type = kw.get('request_type')
service = None
"""
Access control is partially handled by the ACI titled
'Hosts can modify service userCertificate'. This is for the case
where a machine binds using a host/ prinicpal. It can only do the
request if the target hostname is in the managedBy attribute which
is managed using the add/del member commands.
Binding with a user principal one needs to be in the request_certs
taskgroup (directly or indirectly via role membership).
"""
bind_principal = getattr(context, 'principal')
# Can this user request certs?
if not bind_principal.startswith('host/'):
self.check_access()
try:
subject = pkcs10.get_subject(csr)
extensions = pkcs10.get_extensions(csr)
subjectaltname = pkcs10.get_subjectaltname(csr) or ()
except (NSPRError, PyAsn1Error), e:
raise errors.CertificateOperationError(
error=_("Failure decoding Certificate Signing Request: %s") % e)
if not bind_principal.startswith('host/'):
for ext in extensions:
operation = self._allowed_extensions.get(ext)
if operation:
self.check_access(operation)
# Ensure that the hostname in the CSR matches the principal
subject_host = subject.common_name #pylint: disable=E1101
if not subject_host:
raise errors.ValidationError(name='csr',
error=_("No hostname was found in subject of request."))
(servicename, hostname, realm) = split_principal(principal)
if subject_host.lower() != hostname.lower():
raise errors.ACIError(
info=_("hostname in subject of request '%(subject_host)s' "
"does not match principal hostname '%(hostname)s'") % dict(
subject_host=subject_host, hostname=hostname))
for ext in extensions:
if ext not in self._allowed_extensions:
raise errors.ValidationError(
name='csr', error=_("extension %s is forbidden") % ext)
for name_type, name in subjectaltname:
if name_type not in (pkcs10.SAN_DNSNAME,
pkcs10.SAN_OTHERNAME_KRB5PRINCIPALNAME,
pkcs10.SAN_OTHERNAME_UPN):
raise errors.ValidationError(
name='csr',
error=_("subject alt name type %s is forbidden") %
name_type)
dn = None
service = None
# See if the service exists and punt if it doesn't and we aren't
# going to add it
try:
if servicename != 'host':
service = api.Command['service_show'](principal, all=True)
else:
service = api.Command['host_show'](hostname, all=True)
except errors.NotFound, e:
if not add:
raise errors.NotFound(reason=_("The service principal for "
"this request doesn't exist."))
try:
service = api.Command['service_add'](principal, force=True)
except errors.ACIError:
raise errors.ACIError(info=_('You need to be a member of '
'the serviceadmin role to add services'))
service = service['result']
dn = service['dn']
# We got this far so the service entry exists, can we write it?
if not ldap.can_write(dn, "usercertificate"):
raise errors.ACIError(info=_("Insufficient 'write' privilege "
"to the 'userCertificate' attribute of entry '%s'.") % dn)
# Validate the subject alt name, if any
for name_type, name in subjectaltname:
if name_type == pkcs10.SAN_DNSNAME:
name = unicode(name)
try:
if servicename == 'host':
altservice = api.Command['host_show'](name, all=True)
else:
altprincipal = '%s/%s@%s' % (servicename, name, realm)
altservice = api.Command['service_show'](
altprincipal, all=True)
except errors.NotFound:
# We don't want to issue any certificates referencing
# machines we don't know about. Nothing is stored in this
# host record related to this certificate.
raise errors.NotFound(reason=_('The service principal for '
'subject alt name %s in certificate request does not '
'exist') % name)
altdn = altservice['result']['dn']
if not ldap.can_write(altdn, "usercertificate"):
raise errors.ACIError(info=_(
"Insufficient privilege to create a certificate with "
"subject alt name '%s'.") % name)
elif name_type in (pkcs10.SAN_OTHERNAME_KRB5PRINCIPALNAME,
pkcs10.SAN_OTHERNAME_UPN):
if name != principal:
raise errors.ACIError(
info=_("Principal '%s' in subject alt name does not "
"match requested service principal") % name)
else:
raise errors.ACIError(
info=_("Subject alt name type %s is forbidden") %
name_type)
if 'usercertificate' in service:
serial = x509.get_serial_number(service['usercertificate'][0], datatype=x509.DER)
# revoke the certificate and remove it from the service
# entry before proceeding. First we retrieve the certificate to
# see if it is already revoked, if not then we revoke it.
try:
result = api.Command['cert_show'](unicode(serial))['result']
if 'revocation_reason' not in result:
try:
api.Command['cert_revoke'](unicode(serial), revocation_reason=4)
except errors.NotImplementedError:
# some CA's might not implement revoke
pass
except errors.NotImplementedError:
# some CA's might not implement get
pass
if not principal.startswith('host/'):
api.Command['service_mod'](principal, usercertificate=None)
else:
hostname = get_host_from_principal(principal)
api.Command['host_mod'](hostname, usercertificate=None)
# Request the certificate
result = self.Backend.ra.request_certificate(
csr, request_type=request_type)
cert = x509.load_certificate(result['certificate'])
result['issuer'] = unicode(cert.issuer)
result['valid_not_before'] = unicode(cert.valid_not_before_str)
result['valid_not_after'] = unicode(cert.valid_not_after_str)
result['md5_fingerprint'] = unicode(nss.data_to_hex(nss.md5_digest(cert.der_data), 64)[0])
result['sha1_fingerprint'] = unicode(nss.data_to_hex(nss.sha1_digest(cert.der_data), 64)[0])
# Success? Then add it to the service entry.
if 'certificate' in result:
if not principal.startswith('host/'):
skw = {"usercertificate": str(result.get('certificate'))}
api.Command['service_mod'](principal, **skw)
else:
hostname = get_host_from_principal(principal)
skw = {"usercertificate": str(result.get('certificate'))}
api.Command['host_mod'](hostname, **skw)
return dict(
result=result
)
@register()
class cert_status(VirtualCommand):
__doc__ = _('Check the status of a certificate signing request.')
takes_args = (
Str('request_id',
label=_('Request id'),
flags=['no_create', 'no_update', 'no_search'],
),
)
has_output_params = (
Str('cert_request_status',
label=_('Request status'),
),
)
operation = "certificate status"
def execute(self, request_id, **kw):
self.check_access()
return dict(
result=self.Backend.ra.check_request_status(request_id)
)
_serial_number = Str('serial_number',
validate_serial_number,
label=_('Serial number'),
doc=_('Serial number in decimal or if prefixed with 0x in hexadecimal'),
normalizer=normalize_serial_number,
)
@register()
class cert_show(VirtualCommand):
__doc__ = _('Retrieve an existing certificate.')
takes_args = _serial_number
has_output_params = (
Str('certificate',
label=_('Certificate'),
),
Str('subject',
label=_('Subject'),
),
Str('issuer',
label=_('Issuer'),
),
Str('valid_not_before',
label=_('Not Before'),
),
Str('valid_not_after',
label=_('Not After'),
),
Str('md5_fingerprint',
label=_('Fingerprint (MD5)'),
),
Str('sha1_fingerprint',
label=_('Fingerprint (SHA1)'),
),
Str('revocation_reason',
label=_('Revocation reason'),
),
Str('serial_number_hex',
label=_('Serial number (hex)'),
),
)
takes_options = (
Str('out?',
label=_('Output filename'),
doc=_('File to store the certificate in.'),
exclude='webui',
),
)
operation="retrieve certificate"
def execute(self, serial_number, **options):
hostname = None
try:
self.check_access()
except errors.ACIError, acierr:
self.debug("Not granted by ACI to retrieve certificate, looking at principal")
bind_principal = getattr(context, 'principal')
if not bind_principal.startswith('host/'):
raise acierr
hostname = get_host_from_principal(bind_principal)
result=self.Backend.ra.get_certificate(serial_number)
cert = x509.load_certificate(result['certificate'])
result['subject'] = unicode(cert.subject)
result['issuer'] = unicode(cert.issuer)
result['valid_not_before'] = unicode(cert.valid_not_before_str)
result['valid_not_after'] = unicode(cert.valid_not_after_str)
result['md5_fingerprint'] = unicode(nss.data_to_hex(nss.md5_digest(cert.der_data), 64)[0])
result['sha1_fingerprint'] = unicode(nss.data_to_hex(nss.sha1_digest(cert.der_data), 64)[0])
if hostname:
# If we have a hostname we want to verify that the subject
# of the certificate matches it, otherwise raise an error
if hostname != cert.subject.common_name: #pylint: disable=E1101
raise acierr
return dict(result=result)
def forward(self, *keys, **options):
if 'out' in options:
util.check_writable_file(options['out'])
result = super(cert_show, self).forward(*keys, **options)
if 'certificate' in result['result']:
x509.write_certificate(result['result']['certificate'], options['out'])
return result
else:
raise errors.NoCertificateError(entry=keys[-1])
else:
return super(cert_show, self).forward(*keys, **options)
@register()
class cert_revoke(VirtualCommand):
__doc__ = _('Revoke a certificate.')
takes_args = _serial_number
has_output_params = (
Flag('revoked',
label=_('Revoked'),
),
)
operation = "revoke certificate"
# FIXME: The default is 0. Is this really an Int param?
takes_options = (
Int('revocation_reason',
label=_('Reason'),
doc=_('Reason for revoking the certificate (0-10)'),
minvalue=0,
maxvalue=10,
default=0,
autofill=True
),
)
def execute(self, serial_number, **kw):
hostname = None
try:
self.check_access()
except errors.ACIError, acierr:
self.debug("Not granted by ACI to revoke certificate, looking at principal")
try:
# Let cert_show() handle verifying that the subject of the
# cert we're dealing with matches the hostname in the principal
result = api.Command['cert_show'](unicode(serial_number))['result']
except errors.NotImplementedError:
pass
revocation_reason = kw['revocation_reason']
if revocation_reason == 7:
raise errors.CertificateOperationError(error=_('7 is not a valid revocation reason'))
return dict(
result=self.Backend.ra.revoke_certificate(
serial_number, revocation_reason=revocation_reason)
)
@register()
class cert_remove_hold(VirtualCommand):
__doc__ = _('Take a revoked certificate off hold.')
takes_args = _serial_number
has_output_params = (
Flag('unrevoked',
label=_('Unrevoked'),
),
Str('error_string',
label=_('Error'),
),
)
operation = "certificate remove hold"
def execute(self, serial_number, **kw):
self.check_access()
return dict(
result=self.Backend.ra.take_certificate_off_hold(serial_number)
)
@register()
class cert_find(Command):
__doc__ = _('Search for existing certificates.')
takes_options = (
Str('subject?',
label=_('Subject'),
doc=_('Subject'),
autofill=False,
),
Int('revocation_reason?',
label=_('Reason'),
doc=_('Reason for revoking the certificate (0-10)'),
minvalue=0,
maxvalue=10,
autofill=False,
),
Int('min_serial_number?',
doc=_("minimum serial number"),
autofill=False,
minvalue=0,
maxvalue=2147483647,
),
Int('max_serial_number?',
doc=_("maximum serial number"),
autofill=False,
minvalue=0,
maxvalue=2147483647,
),
Flag('exactly?',
doc=_('match the common name exactly'),
autofill=False,
),
Str('validnotafter_from?', validate_pkidate,
doc=_('Valid not after from this date (YYYY-mm-dd)'),
autofill=False,
),
Str('validnotafter_to?', validate_pkidate,
doc=_('Valid not after to this date (YYYY-mm-dd)'),
autofill=False,
),
Str('validnotbefore_from?', validate_pkidate,
doc=_('Valid not before from this date (YYYY-mm-dd)'),
autofill=False,
),
Str('validnotbefore_to?', validate_pkidate,
doc=_('Valid not before to this date (YYYY-mm-dd)'),
autofill=False,
),
Str('issuedon_from?', validate_pkidate,
doc=_('Issued on from this date (YYYY-mm-dd)'),
autofill=False,
),
Str('issuedon_to?', validate_pkidate,
doc=_('Issued on to this date (YYYY-mm-dd)'),
autofill=False,
),
Str('revokedon_from?', validate_pkidate,
doc=_('Revoked on from this date (YYYY-mm-dd)'),
autofill=False,
),
Str('revokedon_to?', validate_pkidate,
doc=_('Revoked on to this date (YYYY-mm-dd)'),
autofill=False,
),
Int('sizelimit?',
label=_('Size Limit'),
doc=_('Maximum number of certs returned'),
flags=['no_display'],
minvalue=0,
default=100,
),
)
has_output = output.standard_list_of_entries
has_output_params = (
Str('serial_number_hex',
label=_('Serial number (hex)'),
),
Str('serial_number',
label=_('Serial number'),
),
Str('status',
label=_('Status'),
),
)
msg_summary = ngettext(
'%(count)d certificate matched', '%(count)d certificates matched', 0
)
def execute(self, **options):
ret = dict(
result=self.Backend.ra.find(options)
)
ret['count'] = len(ret['result'])
ret['truncated'] = False
return ret