3 import hashlib as _hashlib
5 import subprocess as _subprocess
6 import struct as _struct
9 def _get_stdout(args, stdin=None):
12 stdin_pipe = _subprocess.PIPE
13 p = _subprocess.Popen(args, stdin=stdin_pipe, stdout=_subprocess.PIPE)
14 stdout, stderr = p.communicate(stdin)
17 raise RuntimeError(status)
21 class PGPPacket (dict):
22 # http://tools.ietf.org/search/rfc4880
23 _old_format_packet_length_type = { # type: (bytes, struct type)
24 0: (1, 'B'), # 1-byte unsigned integer
25 1: (2, 'H'), # 2-byte unsigned integer
26 2: (4, 'I'), # 4-byte unsigned integer
32 1: 'public-key encrypted session key packet',
33 2: 'signature packet',
34 3: 'symmetric-key encrypted session key packet',
35 4: 'one-pass signature packet',
36 5: 'secret-key packet',
37 6: 'public-key packet',
38 7: 'secret-subkey packet',
39 8: 'compressed data packet',
40 9: 'symmetrically encrypted data packet',
42 11: 'literal data packet',
45 14: 'public-subkey packet',
46 17: 'user attribute packet',
47 18: 'sym. encrypted and integrity protected data packet',
48 19: 'modification detection code packet',
55 _public_key_algorithms = {
56 1: 'rsa (encrypt or sign)',
57 2: 'rsa encrypt-only',
59 16: 'elgamal (encrypt-only)',
60 17: 'dsa (digital signature algorithm)',
61 18: 'reserved for elliptic curve',
62 19: 'reserved for ecdsa',
63 20: 'reserved (formerly elgamal encrypt or sign)',
64 21: 'reserved for diffie-hellman',
78 _symmetric_key_algorithms = {
79 0: 'plaintext or unencrypted data',
86 7: 'aes with 128-bit key',
87 8: 'aes with 192-bit key',
88 9: 'aes with 256-bit key',
103 _cipher_block_size = { # in bits
104 'aes with 128-bit key': 128,
105 'aes with 192-bit key': 128,
106 'aes with 256-bit key': 128,
110 _compression_algorithms = {
153 _string_to_key_types = {
157 3: 'iterated and salted',
172 0x00: 'binary document',
173 0x01: 'canonical text document',
175 0x10: 'generic user id and public-key packet',
176 0x11: 'persona user id and public-key packet',
177 0x12: 'casual user id and public-key packet',
178 0x13: 'postitive user id and public-key packet',
179 0x18: 'subkey binding',
180 0x19: 'primary key binding',
182 0x20: 'key revocation',
183 0x28: 'subkey revocation',
184 0x30: 'certification revocation',
186 0x50: 'third-party confirmation',
189 _signature_subpacket_types = {
192 2: 'signature creation time',
193 3: 'signature expiration time',
194 4: 'exportable certification',
195 5: 'trust signature',
196 6: 'regular expression',
199 9: 'key expiration time',
200 10: 'placeholder for backward compatibility',
201 11: 'preferred symmetric algorithms',
202 12: 'revocation key',
211 21: 'preferred hash algorithms',
212 22: 'preferred compression algorithms',
213 23: 'key server preferences',
214 24: 'preferred key server',
215 25: 'primary user id',
218 28: 'signer user id',
219 29: 'reason for revocation',
221 31: 'signature target',
222 32: 'embedded signature',
236 _clean_type_regex = _re.compile('\W+')
238 def _clean_type(self, type=None):
241 return self._clean_type_regex.sub('_', type)
244 method_name = '_str_{}'.format(self._clean_type())
245 method = getattr(self, method_name, None)
249 return '{}: {}'.format(self['type'], details)
251 def _str_public_key_packet(self):
252 return self._str_generic_key_packet()
254 def _str_public_subkey_packet(self):
255 return self._str_generic_key_packet()
257 def _str_secret_key_packet(self):
258 return self._str_generic_key_packet()
260 def _str_secret_subkey_packet(self):
261 return self._str_generic_key_packet()
263 def _str_generic_key_packet(self):
264 return self['fingerprint'][-8:].upper()
266 def _str_signature_packet(self):
267 lines = [self['signature-type']]
268 if self['unhashed-subpackets']:
269 lines.append(' unhashed subpackets:')
270 for subpacket in self['unhashed-subpackets']:
271 method_name = '_str_{}_signature_subpacket'.format(
272 self._clean_type(type=subpacket['type']))
273 method = getattr(self, method_name, None)
275 lines.append(' {}: {}'.format(
277 method(subpacket=subpacket)))
279 lines.append(' {}'.format(subpacket['type']))
280 return '\n'.join(lines)
282 def _str_issuer_signature_subpacket(self, subpacket):
283 return subpacket['issuer'][-8:].upper()
285 def _str_user_id_packet(self):
288 def from_bytes(self, data):
289 offset = self._parse_header(data=data)
290 packet = data[offset:offset + self['length']]
291 if len(packet) < self['length']:
292 raise ValueError('packet too short ({} < {})'.format(
293 len(packet), self['length']))
294 offset += self['length']
295 method_name = '_parse_{}'.format(self._clean_type())
296 method = getattr(self, method_name, None)
298 raise NotImplementedError(
299 'cannot parse packet type {!r}'.format(self['type']))
303 def _parse_header(self, data):
306 always_one = packet_tag & 1 << 7
308 raise ValueError('most significant packet tag bit not set')
309 self['new-format'] = packet_tag & 1 << 6
310 if self['new-format']:
311 type_code = packet_tag & 0b111111
312 raise NotImplementedError('new-format packet length')
314 type_code = packet_tag >> 2 & 0b1111
315 self['length-type'] = packet_tag & 0b11
316 length_bytes, length_type = self._old_format_packet_length_type[
319 raise NotImplementedError(
320 'old-format packet of indeterminate length')
321 length_format = '>{}'.format(length_type)
322 length_data = data[offset: offset + length_bytes]
323 offset += length_bytes
324 self['length'] = _struct.unpack(length_format, length_data)[0]
325 self['type'] = self._packet_types[type_code]
329 def _parse_multiprecision_integer(data):
330 r"""Parse RFC 4880's multiprecision integers
332 >>> PGPPacket._parse_multiprecision_integer(b'\x00\x01\x01')
334 >>> PGPPacket._parse_multiprecision_integer(b'\x00\x09\x01\xff')
337 bits = _struct.unpack('>H', data[:2])[0]
339 length = (bits + 7) // 8
341 for i in range(length):
342 value += data[offset + i] * 1 << (8 * (length - i - 1))
344 return (offset, value)
346 def _parse_string_to_key_specifier(self, data):
347 self['string-to-key-type'] = self._string_to_key_types[data[0]]
349 if self['string-to-key-type'] == 'simple':
350 self['string-to-key-hash-algorithm'] = self._hash_algorithms[
353 elif self['string-to-key-type'] == 'salted':
354 self['string-to-key-hash-algorithm'] = self._hash_algorithms[
357 self['string-to-key-salt'] = data[offset: offset + 8]
359 elif self['string-to-key-type'] == 'iterated and salted':
360 self['string-to-key-hash-algorithm'] = self._hash_algorithms[
363 self['string-to-key-salt'] = data[offset: offset + 8]
365 self['string-to-key-coded-count'] = data[offset]
368 raise NotImplementedError(
369 'string-to-key type {}'.format(self['string-to-key-type']))
372 def _parse_public_key_packet(self, data):
373 self._parse_generic_public_key_packet(data=data)
375 def _parse_public_subkey_packet(self, data):
376 self._parse_generic_public_key_packet(data=data)
378 def _parse_generic_public_key_packet(self, data):
379 self['key-version'] = data[0]
381 if self['key-version'] != 4:
382 raise NotImplementedError(
383 'public (sub)key packet version {}'.format(
384 self['key-version']))
386 self['creation-time'], algorithm = _struct.unpack(
387 '>IB', data[offset: offset + length])
389 self['public-key-algorithm'] = self._public_key_algorithms[algorithm]
390 if self['public-key-algorithm'].startswith('rsa '):
391 o, self['public-modulus'] = self._parse_multiprecision_integer(
394 o, self['public-exponent'] = self._parse_multiprecision_integer(
397 elif self['public-key-algorithm'].startswith('dsa '):
398 o, self['prime'] = self._parse_multiprecision_integer(
401 o, self['group-order'] = self._parse_multiprecision_integer(
404 o, self['group-generator'] = self._parse_multiprecision_integer(
407 o, self['public-key'] = self._parse_multiprecision_integer(
410 elif self['public-key-algorithm'].startswith('elgamal '):
411 o, self['prime'] = self._parse_multiprecision_integer(
414 o, self['group-generator'] = self._parse_multiprecision_integer(
417 o, self['public-key'] = self._parse_multiprecision_integer(
421 raise NotImplementedError(
422 'algorithm-specific key fields for {}'.format(
423 self['public-key-algorithm']))
424 fingerprint = _hashlib.sha1()
425 fingerprint.update(b'\x99')
426 fingerprint.update(_struct.pack('>H', len(data)))
427 fingerprint.update(data)
428 self['fingerprint'] = fingerprint.hexdigest()
431 def _parse_secret_key_packet(self, data):
432 self._parse_generic_secret_key_packet(data=data)
434 def _parse_secret_subkey_packet(self, data):
435 self._parse_generic_secret_key_packet(data=data)
437 def _parse_generic_secret_key_packet(self, data):
438 offset = self._parse_generic_public_key_packet(data=data)
439 string_to_key_usage = data[offset]
441 if string_to_key_usage in [255, 254]:
442 self['symmetric-encryption-algorithm'] = (
443 self._symmetric_key_algorithms[data[offset]])
445 offset += self._parse_string_to_key_specifier(data=data[offset:])
447 self['symmetric-encryption-algorithm'] = (
448 self._symmetric_key_algorithms[string_to_key_usage])
449 if string_to_key_usage:
450 block_size_bits = self._cipher_block_size.get(
451 self['symmetric-encryption-algorithm'], None)
452 if block_size_bits % 8:
453 raise NotImplementedError(
454 ('{}-bit block size for {} is not an integer number of bytes'
456 block_size_bits, self['symmetric-encryption-algorithm']))
457 block_size = block_size_bits // 8
459 raise NotImplementedError(
460 'unknown block size for {}'.format(
461 self['symmetric-encryption-algorithm']))
462 self['initial-vector'] = data[offset: offset + block_size]
464 if string_to_key_usage in [0, 255]:
468 self['secret-key'] = data[offset:key_end]
470 self['secret-key-checksum'] = data[key_end:]
472 def _parse_signature_subpackets(self, data):
474 while offset < len(data):
475 o, subpacket = self._parse_signature_subpacket(data=data[offset:])
479 def _parse_signature_subpacket(self, data):
485 elif first >= 192 and first < 255:
486 second = data[offset]
488 length = ((first - 192) << 8) + second + 192
490 length = _struct.unpack(
491 '>I', data[offset: offset + 4])[0]
493 subpacket['type'] = self._signature_subpacket_types[data[offset]]
495 subpacket_data = data[offset: offset + length - 1]
496 offset += len(subpacket_data)
497 method_name = '_parse_{}_signature_subpacket'.format(
498 self._clean_type(type=subpacket['type']))
499 method = getattr(self, method_name, None)
501 raise NotImplementedError(
502 'cannot parse signature subpacket type {!r}'.format(
504 method(data=subpacket_data, subpacket=subpacket)
505 return (offset, subpacket)
507 def _parse_signature_packet(self, data):
508 self['signature-version'] = data[0]
510 if self['signature-version'] != 4:
511 raise NotImplementedError(
512 'signature packet version {}'.format(
513 self['signature-version']))
514 self['signature-type'] = self._signature_types[data[offset]]
516 self['public-key-algorithm'] = self._public_key_algorithms[
519 self['hash-algorithm'] = self._hash_algorithms[data[offset]]
521 hashed_count = _struct.unpack('>H', data[offset: offset + 2])[0]
523 self['hashed-subpackets'] = data[offset: offset + hashed_count]
524 offset += hashed_count
525 unhashed_count = _struct.unpack('>H', data[offset: offset + 2])[0]
527 self['unhashed-subpackets'] = list(self._parse_signature_subpackets(
528 data=data[offset: offset + unhashed_count]))
529 offset += unhashed_count
530 self['signed-hash-word'] = data[offset: offset + 2]
532 self['signature'] = data[offset:]
534 def _parse_issuer_signature_subpacket(self, data, subpacket):
535 subpacket['issuer'] = ''.join('{:02x}'.format(byte) for byte in data)
537 def _parse_user_id_packet(self, data):
538 self['user'] = str(data, 'utf-8')
544 def packets_from_bytes(data):
546 while offset < len(data):
548 offset += packet.from_bytes(data=data[offset:])
552 class PGPKey (object):
553 def __init__(self, fingerprint):
554 self.fingerprint = fingerprint
555 self.public_packets = None
556 self.secret_packets = None
559 lines = ['key: {}'.format(self.fingerprint)]
560 if self.public_packets:
561 lines.append(' public:')
562 for packet in self.public_packets:
563 lines.extend(self._str_packet(packet=packet, prefix=' '))
564 if self.secret_packets:
565 lines.append(' secret:')
566 for packet in self.secret_packets:
567 lines.extend(self._str_packet(packet=packet, prefix=' '))
568 return '\n'.join(lines)
570 def _str_packet(self, packet, prefix):
571 lines = str(packet).split('\n')
572 return [prefix + line for line in lines]
574 def import_from_gpg(self):
575 key_export = _get_stdout(
576 ['gpg', '--export', self.fingerprint])
577 self.public_packets = list(
578 packets_from_bytes(data=key_export))
579 if self.public_packets[0]['type'] != 'public-key packet':
581 '{} does not start with a public-key packet'.format(
583 key_secret_export = _get_stdout(
584 ['gpg', '--export-secret-keys', self.fingerprint])
585 self.secret_packets = list(
586 packets_from_bytes(data=key_secret_export))
588 def export_to_gpg(self):
589 raise NotImplemetedError('export to gpg')
591 def import_from_key(self, key):
592 """Migrate the (sub)keys into this key"""
596 def migrate(old_key, new_key):
597 """Add the old key and sub-keys to the new key
599 For example, to upgrade your master key, while preserving old
600 signatures you'd made. You will lose signature *on* your old key
601 though, since sub-keys can't be signed (I don't think).
603 old_key = PGPKey(fingerprint=old_key)
604 old_key.import_from_gpg()
605 new_key = PGPKey(fingerprint=new_key)
606 new_key.import_from_gpg()
607 new_key.import_from_key(key=old_key)
613 if __name__ == '__main__':
616 old_key, new_key = _sys.argv[1:3]
617 migrate(old_key=old_key, new_key=new_key)