~bzr-pqm/bzr/bzr.dev

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
# Copyright (C) 2005, 2011 Canonical Ltd
#   Authors: Robert Collins <robert.collins@canonical.com>
#
# 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 2 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""GPG signing and checking logic."""

from __future__ import absolute_import

import os
import sys
from StringIO import StringIO

from bzrlib.lazy_import import lazy_import
lazy_import(globals(), """
import errno
import subprocess

from bzrlib import (
    config,
    errors,
    trace,
    ui,
    )
from bzrlib.i18n import (
    gettext, 
    ngettext,
    )
""")

#verification results
SIGNATURE_VALID = 0
SIGNATURE_KEY_MISSING = 1
SIGNATURE_NOT_VALID = 2
SIGNATURE_NOT_SIGNED = 3
SIGNATURE_EXPIRED = 4


class DisabledGPGStrategy(object):
    """A GPG Strategy that makes everything fail."""

    @staticmethod
    def verify_signatures_available():
        return True

    def __init__(self, ignored):
        """Real strategies take a configuration."""

    def sign(self, content):
        raise errors.SigningFailed('Signing is disabled.')

    def verify(self, content, testament):
        raise errors.SignatureVerificationFailed('Signature verification is \
disabled.')

    def set_acceptable_keys(self, command_line_input):
        pass


class LoopbackGPGStrategy(object):
    """A GPG Strategy that acts like 'cat' - data is just passed through.
    Used in tests.
    """

    @staticmethod
    def verify_signatures_available():
        return True

    def __init__(self, ignored):
        """Real strategies take a configuration."""

    def sign(self, content):
        return ("-----BEGIN PSEUDO-SIGNED CONTENT-----\n" + content +
                "-----END PSEUDO-SIGNED CONTENT-----\n")

    def verify(self, content, testament):
        return SIGNATURE_VALID, None

    def set_acceptable_keys(self, command_line_input):
        if command_line_input is not None:
            patterns = command_line_input.split(",")
            self.acceptable_keys = []
            for pattern in patterns:
                if pattern == "unknown":
                    pass
                else:
                    self.acceptable_keys.append(pattern)

    def do_verifications(self, revisions, repository):
        count = {SIGNATURE_VALID: 0,
                 SIGNATURE_KEY_MISSING: 0,
                 SIGNATURE_NOT_VALID: 0,
                 SIGNATURE_NOT_SIGNED: 0,
                 SIGNATURE_EXPIRED: 0}
        result = []
        all_verifiable = True
        for rev_id in revisions:
            verification_result, uid =\
                repository.verify_revision_signature(rev_id,self)
            result.append([rev_id, verification_result, uid])
            count[verification_result] += 1
            if verification_result != SIGNATURE_VALID:
                all_verifiable = False
        return (count, result, all_verifiable)

    def valid_commits_message(self, count):
        return gettext(u"{0} commits with valid signatures").format(
                                        count[SIGNATURE_VALID])

    def unknown_key_message(self, count):
        return ngettext(u"{0} commit with unknown key",
                             u"{0} commits with unknown keys",
                             count[SIGNATURE_KEY_MISSING]).format(
                                        count[SIGNATURE_KEY_MISSING])

    def commit_not_valid_message(self, count):
        return ngettext(u"{0} commit not valid",
                             u"{0} commits not valid",
                             count[SIGNATURE_NOT_VALID]).format(
                                            count[SIGNATURE_NOT_VALID])

    def commit_not_signed_message(self, count):
        return ngettext(u"{0} commit not signed",
                             u"{0} commits not signed",
                             count[SIGNATURE_NOT_SIGNED]).format(
                                        count[SIGNATURE_NOT_SIGNED])

    def expired_commit_message(self, count):
        return ngettext(u"{0} commit with key now expired",
                        u"{0} commits with key now expired",
                        count[SIGNATURE_EXPIRED]).format(
                                        count[SIGNATURE_EXPIRED])


def _set_gpg_tty():
    tty = os.environ.get('TTY')
    if tty is not None:
        os.environ['GPG_TTY'] = tty
        trace.mutter('setting GPG_TTY=%s', tty)
    else:
        # This is not quite worthy of a warning, because some people
        # don't need GPG_TTY to be set. But it is worthy of a big mark
        # in ~/.bzr.log, so that people can debug it if it happens to them
        trace.mutter('** Env var TTY empty, cannot set GPG_TTY.'
                     '  Is TTY exported?')


class GPGStrategy(object):
    """GPG Signing and checking facilities."""

    acceptable_keys = None

    def __init__(self, config_stack):
        self._config_stack = config_stack
        try:
            import gpgme
            self.context = gpgme.Context()
        except ImportError, error:
            pass # can't use verify()

    @staticmethod
    def verify_signatures_available():
        """
        check if this strategy can verify signatures

        :return: boolean if this strategy can verify signatures
        """
        try:
            import gpgme
            return True
        except ImportError, error:
            return False

    def _command_line(self):
        key = self._config_stack.get('gpg_signing_key')
        if key is None or key == 'default':
            # 'default' or not setting gpg_signing_key at all means we should
            # use the user email address
            key = config.extract_email_address(self._config_stack.get('email'))
        return [self._config_stack.get('gpg_signing_command'), '--clearsign',
                '-u', key]

    def sign(self, content):
        if isinstance(content, unicode):
            raise errors.BzrBadParameterUnicode('content')
        ui.ui_factory.clear_term()

        preexec_fn = _set_gpg_tty
        if sys.platform == 'win32':
            # Win32 doesn't support preexec_fn, but wouldn't support TTY anyway.
            preexec_fn = None
        try:
            process = subprocess.Popen(self._command_line(),
                                       stdin=subprocess.PIPE,
                                       stdout=subprocess.PIPE,
                                       preexec_fn=preexec_fn)
            try:
                result = process.communicate(content)[0]
                if process.returncode is None:
                    process.wait()
                if process.returncode != 0:
                    raise errors.SigningFailed(self._command_line())
                return result
            except OSError, e:
                if e.errno == errno.EPIPE:
                    raise errors.SigningFailed(self._command_line())
                else:
                    raise
        except ValueError:
            # bad subprocess parameters, should never happen.
            raise
        except OSError, e:
            if e.errno == errno.ENOENT:
                # gpg is not installed
                raise errors.SigningFailed(self._command_line())
            else:
                raise

    def verify(self, content, testament):
        """Check content has a valid signature.
        
        :param content: the commit signature
        :param testament: the valid testament string for the commit
        
        :return: SIGNATURE_VALID or a failed SIGNATURE_ value, key uid if valid
        """
        try:
            import gpgme
        except ImportError, error:
            raise errors.GpgmeNotInstalled(error)

        signature = StringIO(content)
        plain_output = StringIO()
        try:
            result = self.context.verify(signature, None, plain_output)
        except gpgme.GpgmeError,error:
            raise errors.SignatureVerificationFailed(error[2])

        # No result if input is invalid.
        # test_verify_invalid()
        if len(result) == 0:
            return SIGNATURE_NOT_VALID, None
        # User has specified a list of acceptable keys, check our result is in
        # it.  test_verify_unacceptable_key()
        fingerprint = result[0].fpr
        if self.acceptable_keys is not None:
            if not fingerprint in self.acceptable_keys:
                return SIGNATURE_KEY_MISSING, fingerprint[-8:]
        # Check the signature actually matches the testament.
        # test_verify_bad_testament()
        if testament != plain_output.getvalue():
            return SIGNATURE_NOT_VALID, None
        # Yay gpgme set the valid bit.
        # Can't write a test for this one as you can't set a key to be
        # trusted using gpgme.
        if result[0].summary & gpgme.SIGSUM_VALID:
            key = self.context.get_key(fingerprint)
            name = key.uids[0].name
            email = key.uids[0].email
            return SIGNATURE_VALID, name + " <" + email + ">"
        # Sigsum_red indicates a problem, unfortunatly I have not been able
        # to write any tests which actually set this.
        if result[0].summary & gpgme.SIGSUM_RED:
            return SIGNATURE_NOT_VALID, None
        # GPG does not know this key.
        # test_verify_unknown_key()
        if result[0].summary & gpgme.SIGSUM_KEY_MISSING:
            return SIGNATURE_KEY_MISSING, fingerprint[-8:]
        # Summary isn't set if sig is valid but key is untrusted but if user
        # has explicity set the key as acceptable we can validate it.
        if result[0].summary == 0 and self.acceptable_keys is not None:
            if fingerprint in self.acceptable_keys:
                # test_verify_untrusted_but_accepted()
                return SIGNATURE_VALID, None
        # test_verify_valid_but_untrusted()
        if result[0].summary == 0 and self.acceptable_keys is None:
            return SIGNATURE_NOT_VALID, None
        if result[0].summary & gpgme.SIGSUM_KEY_EXPIRED:
            expires = self.context.get_key(result[0].fpr).subkeys[0].expires
            if expires > result[0].timestamp:
                # The expired key was not expired at time of signing.
                # test_verify_expired_but_valid()
                return SIGNATURE_EXPIRED, fingerprint[-8:]
            else:
                # I can't work out how to create a test where the signature
                # was expired at the time of signing.
                return SIGNATURE_NOT_VALID, None
        # A signature from a revoked key gets this.
        # test_verify_revoked_signature()
        if result[0].summary & gpgme.SIGSUM_SYS_ERROR:
            return SIGNATURE_NOT_VALID, None
        # Other error types such as revoked keys should (I think) be caught by
        # SIGSUM_RED so anything else means something is buggy.
        raise errors.SignatureVerificationFailed("Unknown GnuPG key "\
                                                 "verification result")

    def set_acceptable_keys(self, command_line_input):
        """Set the acceptable keys for verifying with this GPGStrategy.
        
        :param command_line_input: comma separated list of patterns from
                                command line
        :return: nothing
        """
        key_patterns = None
        acceptable_keys_config = self._config_stack.get('acceptable_keys')
        try:
            if isinstance(acceptable_keys_config, unicode):
                acceptable_keys_config = str(acceptable_keys_config)
        except UnicodeEncodeError:
            # gpg Context.keylist(pattern) does not like unicode
            raise errors.BzrCommandError(
                gettext('Only ASCII permitted in option names'))

        if acceptable_keys_config is not None:
            key_patterns = acceptable_keys_config
        if command_line_input is not None: # command line overrides config
            key_patterns = command_line_input
        if key_patterns is not None:
            patterns = key_patterns.split(",")

            self.acceptable_keys = []
            for pattern in patterns:
                result = self.context.keylist(pattern)
                found_key = False
                for key in result:
                    found_key = True
                    self.acceptable_keys.append(key.subkeys[0].fpr)
                    trace.mutter("Added acceptable key: " + key.subkeys[0].fpr)
                if not found_key:
                    trace.note(gettext(
                            "No GnuPG key results for pattern: {0}"
                                ).format(pattern))

    def do_verifications(self, revisions, repository,
                            process_events_callback=None):
        """do verifications on a set of revisions
        
        :param revisions: list of revision ids to verify
        :param repository: repository object
        :param process_events_callback: method to call for GUI frontends that
                                                want to keep their UI refreshed
        
        :return: count dictionary of results of each type,
                 result list for each revision,
                 boolean True if all results are verified successfully
        """
        count = {SIGNATURE_VALID: 0,
                 SIGNATURE_KEY_MISSING: 0,
                 SIGNATURE_NOT_VALID: 0,
                 SIGNATURE_NOT_SIGNED: 0,
                 SIGNATURE_EXPIRED: 0}
        result = []
        all_verifiable = True
        for rev_id in revisions:
            verification_result, uid =\
                repository.verify_revision_signature(rev_id, self)
            result.append([rev_id, verification_result, uid])
            count[verification_result] += 1
            if verification_result != SIGNATURE_VALID:
                all_verifiable = False
            if process_events_callback is not None:
                process_events_callback()
        return (count, result, all_verifiable)

    def verbose_valid_message(self, result):
        """takes a verify result and returns list of signed commits strings"""
        signers = {}
        for rev_id, validity, uid in result:
            if validity == SIGNATURE_VALID:
                signers.setdefault(uid, 0)
                signers[uid] += 1
        result = []
        for uid, number in signers.items():
             result.append( ngettext(u"{0} signed {1} commit",
                             u"{0} signed {1} commits",
                             number).format(uid, number) )
        return result


    def verbose_not_valid_message(self, result, repo):
        """takes a verify result and returns list of not valid commit info"""
        signers = {}
        for rev_id, validity, empty in result:
            if validity == SIGNATURE_NOT_VALID:
                revision = repo.get_revision(rev_id)
                authors = ', '.join(revision.get_apparent_authors())
                signers.setdefault(authors, 0)
                signers[authors] += 1
        result = []
        for authors, number in signers.items():
            result.append( ngettext(u"{0} commit by author {1}",
                                 u"{0} commits by author {1}",
                                 number).format(number, authors) )
        return result

    def verbose_not_signed_message(self, result, repo):
        """takes a verify result and returns list of not signed commit info"""
        signers = {}
        for rev_id, validity, empty in result:
            if validity == SIGNATURE_NOT_SIGNED:
                revision = repo.get_revision(rev_id)
                authors = ', '.join(revision.get_apparent_authors())
                signers.setdefault(authors, 0)
                signers[authors] += 1
        result = []
        for authors, number in signers.items():
            result.append( ngettext(u"{0} commit by author {1}",
                                 u"{0} commits by author {1}",
                                 number).format(number, authors) )
        return result

    def verbose_missing_key_message(self, result):
        """takes a verify result and returns list of missing key info"""
        signers = {}
        for rev_id, validity, fingerprint in result:
            if validity == SIGNATURE_KEY_MISSING:
                signers.setdefault(fingerprint, 0)
                signers[fingerprint] += 1
        result = []
        for fingerprint, number in signers.items():
            result.append( ngettext(u"Unknown key {0} signed {1} commit",
                                 u"Unknown key {0} signed {1} commits",
                                 number).format(fingerprint, number) )
        return result

    def verbose_expired_key_message(self, result, repo):
        """takes a verify result and returns list of expired key info"""
        signers = {}
        fingerprint_to_authors = {}
        for rev_id, validity, fingerprint in result:
            if validity == SIGNATURE_EXPIRED:
                revision = repo.get_revision(rev_id)
                authors = ', '.join(revision.get_apparent_authors())
                signers.setdefault(fingerprint, 0)
                signers[fingerprint] += 1
                fingerprint_to_authors[fingerprint] = authors
        result = []
        for fingerprint, number in signers.items():
            result.append(
                ngettext(u"{0} commit by author {1} with key {2} now expired",
                         u"{0} commits by author {1} with key {2} now expired",
                         number).format(
                    number, fingerprint_to_authors[fingerprint], fingerprint) )
        return result

    def valid_commits_message(self, count):
        """returns message for number of commits"""
        return gettext(u"{0} commits with valid signatures").format(
                                        count[SIGNATURE_VALID])

    def unknown_key_message(self, count):
        """returns message for number of commits"""
        return ngettext(u"{0} commit with unknown key",
                        u"{0} commits with unknown keys",
                        count[SIGNATURE_KEY_MISSING]).format(
                                        count[SIGNATURE_KEY_MISSING])

    def commit_not_valid_message(self, count):
        """returns message for number of commits"""
        return ngettext(u"{0} commit not valid",
                        u"{0} commits not valid",
                        count[SIGNATURE_NOT_VALID]).format(
                                            count[SIGNATURE_NOT_VALID])

    def commit_not_signed_message(self, count):
        """returns message for number of commits"""
        return ngettext(u"{0} commit not signed",
                        u"{0} commits not signed",
                        count[SIGNATURE_NOT_SIGNED]).format(
                                        count[SIGNATURE_NOT_SIGNED])

    def expired_commit_message(self, count):
        """returns message for number of commits"""
        return ngettext(u"{0} commit with key now expired",
                        u"{0} commits with key now expired",
                        count[SIGNATURE_EXPIRED]).format(
                                    count[SIGNATURE_EXPIRED])