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 Provides an extension to encrypt staging directories.
41
42 When this extension is executed, all backed-up files in the configured Cedar
43 Backup staging directory will be encrypted using gpg. Any directory which has
44 already been encrypted (as indicated by the C{cback.encrypt} file) will be
45 ignored.
46
47 This extension requires a new configuration section <encrypt> and is intended
48 to be run immediately after the standard stage action or immediately before the
49 standard store action. Aside from its own configuration, it requires the
50 options and staging configuration sections in the standard Cedar Backup
51 configuration file.
52
53 @author: Kenneth J. Pronovici <pronovic@ieee.org>
54 """
55
56
57
58
59
60
61 import os
62 import logging
63
64
65 from CedarBackup2.filesystem import FilesystemList
66 from CedarBackup2.util import resolveCommand, executeCommand, changeOwnership
67 from CedarBackup2.xmlutil import createInputDom, addContainerNode, addStringNode
68 from CedarBackup2.xmlutil import readFirstChild, readString
69 from CedarBackup2.actions.util import findDailyDirs, writeIndicatorFile, getBackupFiles
70
71
72
73
74
75
76 logger = logging.getLogger("CedarBackup2.log.extend.encrypt")
77
78 GPG_COMMAND = [ "gpg", ]
79 VALID_ENCRYPT_MODES = [ "gpg", ]
80 ENCRYPT_INDICATOR = "cback.encrypt"
81
82
83
84
85
86
88
89 """
90 Class representing encrypt configuration.
91
92 Encrypt configuration is used for encrypting staging directories.
93
94 The following restrictions exist on data in this class:
95
96 - The encrypt mode must be one of the values in L{VALID_ENCRYPT_MODES}
97 - The encrypt target value must be a non-empty string
98
99 @sort: __init__, __repr__, __str__, __cmp__, encryptMode, encryptTarget
100 """
101
102 - def __init__(self, encryptMode=None, encryptTarget=None):
103 """
104 Constructor for the C{EncryptConfig} class.
105
106 @param encryptMode: Encryption mode
107 @param encryptTarget: Encryption target (for instance, GPG recipient)
108
109 @raise ValueError: If one of the values is invalid.
110 """
111 self._encryptMode = None
112 self._encryptTarget = None
113 self.encryptMode = encryptMode
114 self.encryptTarget = encryptTarget
115
117 """
118 Official string representation for class instance.
119 """
120 return "EncryptConfig(%s, %s)" % (self.encryptMode, self.encryptTarget)
121
123 """
124 Informal string representation for class instance.
125 """
126 return self.__repr__()
127
129 """
130 Definition of equals operator for this class.
131 Lists within this class are "unordered" for equality comparisons.
132 @param other: Other object to compare to.
133 @return: -1/0/1 depending on whether self is C{<}, C{=} or C{>} other.
134 """
135 if other is None:
136 return 1
137 if self._encryptMode != other._encryptMode:
138 if self._encryptMode < other._encryptMode:
139 return -1
140 else:
141 return 1
142 if self._encryptTarget != other._encryptTarget:
143 if self._encryptTarget < other._encryptTarget:
144 return -1
145 else:
146 return 1
147 return 0
148
150 """
151 Property target used to set the encrypt mode.
152 If not C{None}, the mode must be one of the values in L{VALID_ENCRYPT_MODES}.
153 @raise ValueError: If the value is not valid.
154 """
155 if value is not None:
156 if value not in VALID_ENCRYPT_MODES:
157 raise ValueError("Encrypt mode must be one of %s." % VALID_ENCRYPT_MODES)
158 self._encryptMode = value
159
161 """
162 Property target used to get the encrypt mode.
163 """
164 return self._encryptMode
165
167 """
168 Property target used to set the encrypt target.
169 """
170 if value is not None:
171 if len(value) < 1:
172 raise ValueError("Encrypt target must be non-empty string.")
173 self._encryptTarget = value
174
176 """
177 Property target used to get the encrypt target.
178 """
179 return self._encryptTarget
180
181 encryptMode = property(_getEncryptMode, _setEncryptMode, None, doc="Encrypt mode.")
182 encryptTarget = property(_getEncryptTarget, _setEncryptTarget, None, doc="Encrypt target (i.e. GPG recipient).")
183
184
185
186
187
188
190
191 """
192 Class representing this extension's configuration document.
193
194 This is not a general-purpose configuration object like the main Cedar
195 Backup configuration object. Instead, it just knows how to parse and emit
196 encrypt-specific configuration values. Third parties who need to read and
197 write configuration related to this extension should access it through the
198 constructor, C{validate} and C{addConfig} methods.
199
200 @note: Lists within this class are "unordered" for equality comparisons.
201
202 @sort: __init__, __repr__, __str__, __cmp__, encrypt, validate, addConfig
203 """
204
205 - def __init__(self, xmlData=None, xmlPath=None, validate=True):
206 """
207 Initializes a configuration object.
208
209 If you initialize the object without passing either C{xmlData} or
210 C{xmlPath} then configuration will be empty and will be invalid until it
211 is filled in properly.
212
213 No reference to the original XML data or original path is saved off by
214 this class. Once the data has been parsed (successfully or not) this
215 original information is discarded.
216
217 Unless the C{validate} argument is C{False}, the L{LocalConfig.validate}
218 method will be called (with its default arguments) against configuration
219 after successfully parsing any passed-in XML. Keep in mind that even if
220 C{validate} is C{False}, it might not be possible to parse the passed-in
221 XML document if lower-level validations fail.
222
223 @note: It is strongly suggested that the C{validate} option always be set
224 to C{True} (the default) unless there is a specific need to read in
225 invalid configuration from disk.
226
227 @param xmlData: XML data representing configuration.
228 @type xmlData: String data.
229
230 @param xmlPath: Path to an XML file on disk.
231 @type xmlPath: Absolute path to a file on disk.
232
233 @param validate: Validate the document after parsing it.
234 @type validate: Boolean true/false.
235
236 @raise ValueError: If both C{xmlData} and C{xmlPath} are passed-in.
237 @raise ValueError: If the XML data in C{xmlData} or C{xmlPath} cannot be parsed.
238 @raise ValueError: If the parsed configuration document is not valid.
239 """
240 self._encrypt = None
241 self.encrypt = None
242 if xmlData is not None and xmlPath is not None:
243 raise ValueError("Use either xmlData or xmlPath, but not both.")
244 if xmlData is not None:
245 self._parseXmlData(xmlData)
246 if validate:
247 self.validate()
248 elif xmlPath is not None:
249 xmlData = open(xmlPath).read()
250 self._parseXmlData(xmlData)
251 if validate:
252 self.validate()
253
255 """
256 Official string representation for class instance.
257 """
258 return "LocalConfig(%s)" % (self.encrypt)
259
261 """
262 Informal string representation for class instance.
263 """
264 return self.__repr__()
265
267 """
268 Definition of equals operator for this class.
269 Lists within this class are "unordered" for equality comparisons.
270 @param other: Other object to compare to.
271 @return: -1/0/1 depending on whether self is C{<}, C{=} or C{>} other.
272 """
273 if other is None:
274 return 1
275 if self._encrypt != other._encrypt:
276 if self._encrypt < other._encrypt:
277 return -1
278 else:
279 return 1
280 return 0
281
283 """
284 Property target used to set the encrypt configuration value.
285 If not C{None}, the value must be a C{EncryptConfig} object.
286 @raise ValueError: If the value is not a C{EncryptConfig}
287 """
288 if value is None:
289 self._encrypt = None
290 else:
291 if not isinstance(value, EncryptConfig):
292 raise ValueError("Value must be a C{EncryptConfig} object.")
293 self._encrypt = value
294
296 """
297 Property target used to get the encrypt configuration value.
298 """
299 return self._encrypt
300
301 encrypt = property(_getEncrypt, _setEncrypt, None, "Encrypt configuration in terms of a C{EncryptConfig} object.")
302
304 """
305 Validates configuration represented by the object.
306
307 Encrypt configuration must be filled in. Within that, both the encrypt
308 mode and encrypt target must be filled in.
309
310 @raise ValueError: If one of the validations fails.
311 """
312 if self.encrypt is None:
313 raise ValueError("Encrypt section is required.")
314 if self.encrypt.encryptMode is None:
315 raise ValueError("Encrypt mode must be set.")
316 if self.encrypt.encryptTarget is None:
317 raise ValueError("Encrypt target must be set.")
318
320 """
321 Adds an <encrypt> configuration section as the next child of a parent.
322
323 Third parties should use this function to write configuration related to
324 this extension.
325
326 We add the following fields to the document::
327
328 encryptMode //cb_config/encrypt/encrypt_mode
329 encryptTarget //cb_config/encrypt/encrypt_target
330
331 @param xmlDom: DOM tree as from C{impl.createDocument()}.
332 @param parentNode: Parent that the section should be appended to.
333 """
334 if self.encrypt is not None:
335 sectionNode = addContainerNode(xmlDom, parentNode, "encrypt")
336 addStringNode(xmlDom, sectionNode, "encrypt_mode", self.encrypt.encryptMode)
337 addStringNode(xmlDom, sectionNode, "encrypt_target", self.encrypt.encryptTarget)
338
340 """
341 Internal method to parse an XML string into the object.
342
343 This method parses the XML document into a DOM tree (C{xmlDom}) and then
344 calls a static method to parse the encrypt configuration section.
345
346 @param xmlData: XML data to be parsed
347 @type xmlData: String data
348
349 @raise ValueError: If the XML cannot be successfully parsed.
350 """
351 (xmlDom, parentNode) = createInputDom(xmlData)
352 self._encrypt = LocalConfig._parseEncrypt(parentNode)
353
355 """
356 Parses an encrypt configuration section.
357
358 We read the following individual fields::
359
360 encryptMode //cb_config/encrypt/encrypt_mode
361 encryptTarget //cb_config/encrypt/encrypt_target
362
363 @param parent: Parent node to search beneath.
364
365 @return: C{EncryptConfig} object or C{None} if the section does not exist.
366 @raise ValueError: If some filled-in value is invalid.
367 """
368 encrypt = None
369 section = readFirstChild(parent, "encrypt")
370 if section is not None:
371 encrypt = EncryptConfig()
372 encrypt.encryptMode = readString(section, "encrypt_mode")
373 encrypt.encryptTarget = readString(section, "encrypt_target")
374 return encrypt
375 _parseEncrypt = staticmethod(_parseEncrypt)
376
377
378
379
380
381
382
383
384
385
416
417
418
419
420
421
422 -def _encryptDailyDir(dailyDir, encryptMode, encryptTarget, backupUser, backupGroup):
423 """
424 Encrypts the contents of a daily staging directory.
425
426 Indicator files are ignored. All other files are encrypted. The only valid
427 encrypt mode is C{"gpg"}.
428
429 @param dailyDir: Daily directory to encrypt
430 @param encryptMode: Encryption mode (only "gpg" is allowed)
431 @param encryptTarget: Encryption target (GPG recipient for "gpg" mode)
432 @param backupUser: User that target files should be owned by
433 @param backupGroup: Group that target files should be owned by
434
435 @raise ValueError: If the encrypt mode is not supported.
436 @raise ValueError: If the daily staging directory does not exist.
437 """
438 logger.debug("Begin encrypting contents of [%s]." % dailyDir)
439 fileList = getBackupFiles(dailyDir)
440 for path in fileList:
441 _encryptFile(path, encryptMode, encryptTarget, backupUser, backupGroup, removeSource=True)
442 logger.debug("Completed encrypting contents of [%s]." % dailyDir)
443
444
445
446
447
448
449 -def _encryptFile(sourcePath, encryptMode, encryptTarget, backupUser, backupGroup, removeSource=False):
450 """
451 Encrypts the source file using the indicated mode.
452
453 The encrypted file will be owned by the indicated backup user and group. If
454 C{removeSource} is C{True}, then the source file will be removed after it is
455 successfully encrypted.
456
457 Currently, only the C{"gpg"} encrypt mode is supported.
458
459 @param sourcePath: Absolute path of the source file to encrypt
460 @param encryptMode: Encryption mode (only "gpg" is allowed)
461 @param encryptTarget: Encryption target (GPG recipient)
462 @param backupUser: User that target files should be owned by
463 @param backupGroup: Group that target files should be owned by
464 @param removeSource: Indicates whether to remove the source file
465
466 @return: Path to the newly-created encrypted file.
467
468 @raise ValueError: If an invalid encrypt mode is passed in.
469 @raise IOError: If there is a problem accessing, encrypting or removing the source file.
470 """
471 if not os.path.exists(sourcePath):
472 raise ValueError("Source path [%s] does not exist." % sourcePath);
473 if encryptMode == 'gpg':
474 encryptedPath = _encryptFileWithGpg(sourcePath, recipient=encryptTarget)
475 else:
476 raise ValueError("Unknown encrypt mode [%s]" % encryptMode);
477 changeOwnership(encryptedPath, backupUser, backupGroup)
478 if removeSource:
479 if os.path.exists(sourcePath):
480 try:
481 os.remove(sourcePath)
482 logger.debug("Completed removing old file [%s]." % sourcePath)
483 except:
484 raise IOError("Failed to remove file [%s] after encrypting it." % (sourcePath))
485 return encryptedPath
486
487
488
489
490
491
493 """
494 Encrypts the indicated source file using GPG.
495
496 The encrypted file will be in GPG's binary output format and will have the
497 same name as the source file plus a C{".gpg"} extension. The source file
498 will not be modified or removed by this function call.
499
500 @param sourcePath: Absolute path of file to be encrypted.
501 @param recipient: Recipient name to be passed to GPG's C{"-r"} option
502
503 @return: Path to the newly-created encrypted file.
504
505 @raise IOError: If there is a problem encrypting the file.
506 """
507 encryptedPath = "%s.gpg" % sourcePath
508 command = resolveCommand(GPG_COMMAND)
509 args = [ "--batch", "--yes", "-e", "-r", recipient, "-o", encryptedPath, sourcePath, ]
510 result = executeCommand(command, args)[0]
511 if result != 0:
512 raise IOError("Error [%d] calling gpg to encrypt [%s]." % (result, sourcePath))
513 if not os.path.exists(encryptedPath):
514 raise IOError("After call to [%s], encrypted file [%s] does not exist." % (command, encryptedPath))
515 logger.debug("Completed encrypting file [%s] to [%s]." % (sourcePath, encryptedPath))
516 return encryptedPath
517
518
519
520
521
522
524 """
525 Confirms that a recipient's public key is known to GPG.
526 Throws an exception if there is a problem, or returns normally otherwise.
527 @param recipient: Recipient name
528 @raise IOError: If the recipient's public key is not known to GPG.
529 """
530 command = resolveCommand(GPG_COMMAND)
531 args = [ "--batch", "-k", recipient, ]
532 result = executeCommand(command, args)[0]
533 if result != 0:
534 raise IOError("GPG unable to find public key for [%s]." % recipient)
535