summaryrefslogtreecommitdiffstats
path: root/ipalib/plugins/cert.py
blob: 643e1cdd2ae6c26f0148074dfe02f1f68290ebd6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
# 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/>.

"""
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.

If using the selfsign back end then the subject in the CSR needs to match
the subject configured in the server. The dogtag CA uses just the CN
value of the CSR and forces the rest of the subject.

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)

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

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

"""

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')
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.plugins.virtual import *
from ipalib.plugins.service import split_principal
import base64
import logging
import traceback
from ipalib.text import _
from ipalib.request import context
from ipalib.output import Output
from ipalib.plugins.service import validate_principal
import nss.nss as nss
from nss.error import NSPRError

def get_csr_hostname(csr):
    """
    Return the value of CN in the subject of the request or None
    """
    try:
        request = pkcs10.load_certificate_request(csr)
        subject = pkcs10.get_subject(request)
        return subject.common_name
    except NSPRError, nsprerr:
        raise errors.CertificateOperationError(error=_('Failure decoding Certificate Signing Request:'))

def get_subjectaltname(csr):
    """
    Return the first value of the subject alt name, if any
    """
    try:
        request = pkcs10.load_certificate_request(csr)
        for extension in request.extensions:
            if extension.oid_tag == nss.SEC_OID_X509_SUBJECT_ALT_NAME:
                return nss.x509_alt_name(extension.value)[0]
        return None
    except NSPRError, nsprerr:
        raise errors.CertificateOperationError(error=_('Failure decoding Certificate Signing Request'))

def validate_csr(ugettext, csr):
    """
    Ensure the CSR is base64-encoded and can be decoded by our PKCS#10
    parser.
    """
    try:
        request = pkcs10.load_certificate_request(csr)
    except TypeError, e:
        raise errors.Base64DecodeError(reason=str(e))
    except NSPRError:
        raise errors.CertificateOperationError(error=_('Failure decoding Certificate Signing Request'))
    except Exception, e:
        raise errors.CertificateOperationError(error=_('Failure decoding Certificate Signing Request: %s') % str(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

class cert_request(VirtualCommand):
    """
    Submit a certificate signing request.
    """

    takes_args = (
        File('csr', validate_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'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
        Str('subject?',
            label=_('Subject'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
        Str('issuer?',
            label=_('Issuer'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
        Str('valid_not_before?',
            label=_('Not Before'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
        Str('valid_not_after?',
            label=_('Not After'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
        Str('md5_fingerprint?',
            label=_('Fingerprint (MD5)'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
        Str('sha1_fingerprint?',
            label=_('Fingerprint (SHA1)'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
        Str('serial_number?',
            label=_('Serial number'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
    )

    has_output = (
        Output('result',
            type=dict,
            doc=_('Dictionary mapping variable name to value'),
        ),
    )

    def execute(self, csr, **kw):
        ldap = self.api.Backend.ldap2
        principal = kw.get('principal')
        add = kw.get('add')
        del kw['principal']
        del kw['add']
        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()

        # FIXME: add support for subject alt name

        # Ensure that the hostname in the CSR matches the principal
        subject_host = get_csr_hostname(csr)
        (servicename, hostname, realm) = split_principal(principal)
        if subject_host.lower() != hostname.lower():
            raise errors.ACIError(info="hostname in subject of request '%s' does not match principal hostname '%s'" % (subject_host, hostname))

        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 not principal.startswith('host/'):
                service = api.Command['service_show'](principal, all=True, raw=True)['result']
                dn = service['dn']
            else:
                hostname = get_host_from_principal(principal)
                service = api.Command['host_show'](hostname, all=True, raw=True)['result']
                dn = service['dn']
        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})['result']
                dn = service['dn']
            except errors.ACIError:
                raise errors.ACIError(info='You need to be a member of the serviceadmin role to add services')

        # 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
        request = pkcs10.load_certificate_request(csr)
        subjectaltname = pkcs10.get_subjectaltname(request)
        if subjectaltname is not None:
            for name in subjectaltname:
                try:
                    hostentry = api.Command['host_show'](name, all=True, raw=True)['result']
                    hostdn = hostentry['dn']
                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='no host record for subject alt name %s in certificate request' % name)
                authprincipal = getattr(context, 'principal')
                if authprincipal.startswith("host/"):
                    if not hostdn in service.get('managedby', []):
                        raise errors.ACIError(info="Insufficient privilege to create a certificate with subject alt name '%s'." % name)

        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, **kw)
        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
        )

api.register(cert_request)


class cert_status(VirtualCommand):
    """
    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)
        )

api.register(cert_status)


_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,
)

class cert_show(VirtualCommand):
    """
    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'),
        ),
    )

    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)


api.register(cert_show)


class cert_revoke(VirtualCommand):
    """
    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,
        ),
    )

    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
        if kw['revocation_reason'] == 7:
            raise errors.CertificateOperationError(error=_('7 is not a valid revocation reason'))
        return dict(
            result=self.Backend.ra.revoke_certificate(serial_number, **kw)
        )

api.register(cert_revoke)


class cert_remove_hold(VirtualCommand):
    """
    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)
        )

api.register(cert_remove_hold)