summaryrefslogtreecommitdiffstats
path: root/ipapython/certmonger.py
blob: 03f4b23738197905f6891c0bfe842328723afd5a (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
# Authors: Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2010  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/>.
#

# Some certmonger functions, mostly around updating the request file.
# This is used so we can add tracking to the Apache and 389-ds
# server certificates created during the IPA server installation.

import os
import sys
import re
import time
from ipapython import ipautil
from ipapython import dogtag

REQUEST_DIR='/var/lib/certmonger/requests/'
CA_DIR='/var/lib/certmonger/cas/'

# Normalizer types for critera in get_request_id()
NPATH = 1

def find_request_value(filename, directive):
    """
    Return a value from a certmonger request file for the requested directive

    It tries to do this a number of times because sometimes there is a delay
    when ipa-getcert returns and the file is fully updated, particularly
    when doing a request. Generating a CSR is fast but not instantaneous.
    """
    tries = 1
    value = None
    found = False
    while value is None and tries <= 5:
        tries=tries + 1
        time.sleep(1)
        fp = open(filename, 'r')
        lines = fp.readlines()
        fp.close()

        for line in lines:
            if found:
                # A value can span multiple lines. If it does then it has a
                # leading space.
                if not line.startswith(' '):
                    # We hit the next directive, return now
                    return value
                else:
                    value = value + line[1:]
            else:
                if line.startswith(directive + '='):
                    found = True
                    value = line[len(directive)+1:]

    return value

def get_request_value(request_id, directive):
    """
    There is no guarantee that the request_id will match the filename
    in the certmonger requests directory, so open each one to find the
    request_id.
    """
    fileList=os.listdir(REQUEST_DIR)
    for file in fileList:
        value = find_request_value('%s/%s' % (REQUEST_DIR, file), 'id')
        if value is not None and value.rstrip() == request_id:
            return find_request_value('%s/%s' % (REQUEST_DIR, file), directive)

    return None

def get_request_id(criteria):
    """
    If you don't know the certmonger request_id then try to find it by looking
    through all the request files. An alternative would be to parse the
    ipa-getcert list output but this seems cleaner.

    criteria is a tuple of key/value/type to search for. The more specific
    the better. An error is raised if multiple request_ids are returned for
    the same criteria.

    None is returned if none of the criteria match.
    """
    assert type(criteria) is tuple

    reqid=None
    fileList=os.listdir(REQUEST_DIR)
    for file in fileList:
        match = True
        for (key, value, valtype) in criteria:
            rv = find_request_value('%s/%s' % (REQUEST_DIR, file), key)
            if rv and valtype == NPATH:
                rv = os.path.abspath(rv)
            if rv is None or rv.rstrip() != value:
                match = False
                break
        if match and reqid is not None:
            raise RuntimeError('multiple certmonger requests match the criteria')
        if match:
            reqid = find_request_value('%s/%s' % (REQUEST_DIR, file), 'id').rstrip()

    return reqid

def get_requests_for_dir(dir):
    """
    Return a list containing the request ids for a given NSS database
    directory.
    """
    reqid=[]
    fileList=os.listdir(REQUEST_DIR)
    for file in fileList:
        rv = find_request_value(os.path.join(REQUEST_DIR, file),
                                'cert_storage_location')
        if rv is None:
            continue
        rv = os.path.abspath(rv).rstrip()
        if rv != dir:
            continue
        id = find_request_value(os.path.join(REQUEST_DIR, file), 'id')
        if id is not None:
            reqid.append(id.rstrip())

    return reqid

def add_request_value(request_id, directive, value):
    """
    Add a new directive to a certmonger request file.

    The certmonger service MUST be stopped in order for this to work.
    """
    fileList=os.listdir(REQUEST_DIR)
    for file in fileList:
        id = find_request_value('%s/%s' % (REQUEST_DIR, file), 'id')
        if id is not None and id.rstrip() == request_id:
            current_value = find_request_value('%s/%s' % (REQUEST_DIR, file), directive)
            if not current_value:
                fp = open('%s/%s' % (REQUEST_DIR, file), 'a')
                fp.write('%s=%s\n' % (directive, value))
                fp.close()

    return

def add_principal(request_id, principal):
    """
    In order for a certmonger request to be renewable it needs a principal.

    When an existing certificate is added via start-tracking it won't have
    a principal.
    """
    return add_request_value(request_id, 'template_principal', principal)

def add_subject(request_id, subject):
    """
    In order for a certmonger request to be renwable it needs the subject
    set in the request file.

    When an existing certificate is added via start-tracking it won't have
    a subject_template set.
    """
    return add_request_value(request_id, 'template_subject', subject)

def request_cert(nssdb, nickname, subject, principal, passwd_fname=None):
    """
    Execute certmonger to request a server certificate
    """
    args = ['/usr/bin/ipa-getcert',
            'request',
            '-d', nssdb,
            '-n', nickname,
            '-N', subject,
            '-K', principal,
    ]
    if passwd_fname:
        args.append('-p')
        args.append(os.path.abspath(passwd_fname))
    (stdout, stderr, returncode) = ipautil.run(args)
    # FIXME: should be some error handling around this
    m = re.match('New signing request "(\d+)" added', stdout)
    request_id = m.group(1)
    return request_id

def cert_exists(nickname, secdir):
    """
    See if a nickname exists in an NSS database.

    Returns True/False

    This isn't very sophisticated in that it doesn't differentiate between
    a database that doesn't exist and a nickname that doesn't exist within
    the database.
    """
    args = ["/usr/bin/certutil", "-L",
           "-d", os.path.abspath(secdir),
           "-n", nickname
          ]
    (stdout, stderr, rc) = ipautil.run(args, raiseonerr=False)
    if rc == 0:
        return True
    else:
        return False

def start_tracking(nickname, secdir, password_file=None, command=None):
    """
    Tell certmonger to track the given certificate nickname in NSS
    database in secdir protected by optional password file password_file.

    command is an optional parameter which specifies a command for
    certmonger to run when it renews a certificate. This command must
    reside in /usr/lib/ipa/certmonger to work with SELinux.

    Returns the stdout, stderr and returncode from running ipa-getcert

    This assumes that certmonger is already running.
    """
    if not cert_exists(nickname, os.path.abspath(secdir)):
        raise RuntimeError('Nickname "%s" doesn\'t exist in NSS database "%s"' % (nickname, secdir))
    args = ["/usr/bin/ipa-getcert", "start-tracking",
            "-d", os.path.abspath(secdir),
            "-n", nickname]
    if password_file:
        args.append("-p")
        args.append(os.path.abspath(password_file))
    if command:
        args.append("-C")
        args.append(command)

    (stdout, stderr, returncode) = ipautil.run(args)

    return (stdout, stderr, returncode)

def stop_tracking(secdir, request_id=None, nickname=None):
    """
    Stop tracking the current request using either the request_id or nickname.

    This assumes that the certmonger service is running.
    """
    if request_id is None and nickname is None:
        raise RuntimeError('Both request_id and nickname are missing.')
    if nickname:
        # Using the nickname find the certmonger request_id
        criteria = (('cert_storage_location', os.path.abspath(secdir), NPATH),('cert_nickname', nickname, None))
        try:
            request_id = get_request_id(criteria)
            if request_id is None:
                return ('', '', 0)
        except RuntimeError:
            # This means that multiple requests matched, skip it for now
            # Fall back to trying to stop tracking using nickname
            pass

    args = ['/usr/bin/getcert',
            'stop-tracking',
    ]
    if request_id:
        args.append('-i')
        args.append(request_id)
    else:
        args.append('-n')
        args.append(nickname)
        args.append('-d')
        args.append(os.path.abspath(secdir))

    (stdout, stderr, returncode) = ipautil.run(args)

    return (stdout, stderr, returncode)

def _find_IPA_ca():
    """
    Look through all the certmonger CA files to find the one that
    has id=IPA

    We can use find_request_value because the ca files have the
    same file format.
    """
    fileList=os.listdir(CA_DIR)
    for file in fileList:
        value = find_request_value('%s/%s' % (CA_DIR, file), 'id')
        if value is not None and value.strip() == 'IPA':
            return '%s/%s' % (CA_DIR, file)

    return None

def add_principal_to_cas(principal):
    """
    If the hostname we were passed to use in ipa-client-install doesn't
    match the value of gethostname() then we need to append
    -k host/HOSTNAME@REALM to the ca helper defined for
    /usr/libexec/certmonger/ipa-submit.

    We also need to restore this on uninstall.

    The certmonger service MUST be stopped in order for this to work.
    """
    cafile = _find_IPA_ca()
    if cafile is None:
        return

    update = False
    fp = open(cafile, 'r')
    lines = fp.readlines()
    fp.close()

    for i in xrange(len(lines)):
        if lines[i].startswith('ca_external_helper') and \
            lines[i].find('-k') == -1:
            lines[i] = '%s -k %s\n' % (lines[i].strip(), principal)
            update = True

    if update:
        fp = open(cafile, 'w')
        for line in lines:
            fp.write(line)
        fp.close()

def remove_principal_from_cas():
    """
    Remove any -k principal options from the ipa_submit helper.

    The certmonger service MUST be stopped in order for this to work.
    """
    cafile = _find_IPA_ca()
    if cafile is None:
        return

    update = False
    fp = open(cafile, 'r')
    lines = fp.readlines()
    fp.close()

    for i in xrange(len(lines)):
        if lines[i].startswith('ca_external_helper') and \
            lines[i].find('-k') > 0:
            lines[i] = lines[i].strip().split(' ')[0] + '\n'
            update = True

    if update:
        fp = open(cafile, 'w')
        for line in lines:
            fp.write(line)
        fp.close()

# Routines specific to renewing dogtag CA certificates
def get_pin(token, dogtag_constants=None):
    """
    Dogtag stores its NSS pin in a file formatted as token:PIN.

    The caller is expected to handle any exceptions raised.
    """
    if dogtag_constants is None:
        dogtag_constants = dogtag.configured_constants()
    with open(dogtag_constants.PASSWORD_CONF_PATH, 'r') as f:
        for line in f:
            (tok, pin) = line.split('=', 1)
            if token == tok:
                return pin.strip()
    return None

def dogtag_start_tracking(ca, nickname, pin, pinfile, secdir, pre_command,
                          post_command):
    """
    Tell certmonger to start tracking a dogtag CA certificate. These
    are handled differently because their renewal must be done directly
    and not through IPA.

    This uses the generic certmonger command getcert so we can specify
    a different helper.

    pre_command is the script to execute before a renewal is done.
    post_command is the script to execute after a renewal is done.

    Both commands can be None.

    Returns the stdout, stderr and returncode from running ipa-getcert

    This assumes that certmonger is already running.
    """
    if not cert_exists(nickname, os.path.abspath(secdir)):
        raise RuntimeError('Nickname "%s" doesn\'t exist in NSS database "%s"' % (nickname, secdir))

    args = ["/usr/bin/getcert", "start-tracking",
            "-d", os.path.abspath(secdir),
            "-n", nickname,
            "-c", ca,
           ]

    if pre_command is not None:
        if not os.path.isabs(pre_command):
            if sys.maxsize > 2**32L:
                libpath = 'lib64'
            else:
                libpath = 'lib'
            pre_command = '/usr/%s/ipa/certmonger/%s' % (libpath, pre_command)
        args.append("-B")
        args.append(pre_command)

    if post_command is not None:
        if not os.path.isabs(post_command):
            if sys.maxsize > 2**32L:
                libpath = 'lib64'
            else:
                libpath = 'lib'
            post_command = '/usr/%s/ipa/certmonger/%s' % (libpath, post_command)
        args.append("-C")
        args.append(post_command)

    if pinfile:
        args.append("-p")
        args.append(pinfile)
    else:
        args.append("-P")
        args.append(pin)

    if ca == 'dogtag-ipa-retrieve-agent-submit':
        # We cheat and pass in the nickname as the profile when
        # renewing on a clone. The submit otherwise doesn't pass in the
        # nickname and we need some way to find the right entry in LDAP.
        args.append("-T")
        args.append(nickname)

    (stdout, stderr, returncode) = ipautil.run(args, nolog=[pin])

def check_state(dirs):
    """
    Given a set of directories and nicknames verify that we are no longer
    tracking certificates.

    dirs is a list of directories to test for. We will return a tuple
    of nicknames for any tracked certificates found.

    This can only check for NSS-based certificates.
    """
    reqids = []
    for dir in dirs:
        reqids.extend(get_requests_for_dir(dir))

    return reqids

if __name__ == '__main__':
    request_id = request_cert("/etc/httpd/alias", "Test", "cn=tiger.example.com,O=IPA", "HTTP/tiger.example.com@EXAMPLE.COM")
    csr = get_request_value(request_id, 'csr')
    print csr
    stop_tracking(request_id)