source file: /home/buildslave/tahoe/edgy/build/src/allmydata/key_generator.py
file stats: 86 lines, 82 executed: 95.3% covered
1.
2. import os
3. import time
4.
5. import foolscap
6. from zope.interface import implements
7. from twisted.internet import reactor
8. from twisted.application import service
9. from twisted.python import log
10.
11. from pycryptopp.publickey import rsa
12. from allmydata.interfaces import RIKeyGenerator
13.
14. class KeyGenerator(service.MultiService, foolscap.Referenceable):
15. implements(RIKeyGenerator)
16.
17. pool_size = 16 # no. keys to keep on hand in the pool
18. pool_refresh_delay = 6 # no. sec to wait after a fetch before generating new keys
19. verbose = False
20.
21. def __init__(self, default_key_size=2048):
22. service.MultiService.__init__(self)
23. self.keypool = []
24. self.last_fetch = 0
25. self.default_key_size = default_key_size
26.
27. def startService(self):
28. self.timer = reactor.callLater(0, self.maybe_refill_pool)
29. return service.MultiService.startService(self)
30.
31. def stopService(self):
32. if self.timer.active():
33. self.timer.cancel()
34. return service.MultiService.stopService(self)
35.
36. def __repr__(self):
37. return '<KeyGenerator[%s]>' % (len(self.keypool),)
38.
39. def vlog(self, msg):
40. if self.verbose:
41. log.msg(msg)
42.
43. def reset_timer(self):
44. self.last_fetch = time.time()
45. if self.timer.active():
46. self.timer.reset(self.pool_refresh_delay)
47. else:
48. self.timer = reactor.callLater(self.pool_refresh_delay, self.maybe_refill_pool)
49.
50. def maybe_refill_pool(self):
51. now = time.time()
52. if self.last_fetch + self.pool_refresh_delay < now:
53. self.vlog('%s refilling pool' % (self,))
54. while len(self.keypool) < self.pool_size:
55. self.keypool.append(self.gen_key(self.default_key_size))
56. else:
57. self.vlog('%s not refilling pool' % (self,))
58. reactor.callLater(1, self.maybe_refill_pool)
59.
60. def gen_key(self, key_size):
61. self.vlog('%s generating key size %s' % (self, key_size, ))
62. signer = rsa.generate(key_size)
63. verifier = signer.get_verifying_key()
64. return verifier.serialize(), signer.serialize()
65.
66. def remote_get_rsa_key_pair(self, key_size):
67. self.vlog('%s remote_get_key' % (self,))
68. if key_size != self.default_key_size or not self.keypool:
69. key = self.gen_key(key_size)
70. self.reset_timer()
71. return key
72. else:
73. self.reset_timer()
74. return self.keypool.pop()
75.
76. class KeyGeneratorService(service.MultiService):
77. furl_file = 'key_generator.furl'
78.
79. def __init__(self, basedir='.', display_furl=True, default_key_size=2048):
80. service.MultiService.__init__(self)
81. self.basedir = basedir
82. self.tub = foolscap.Tub(certFile=os.path.join(self.basedir, 'key_generator.pem'))
83. self.tub.setServiceParent(self)
84. self.key_generator = KeyGenerator(default_key_size=default_key_size)
85. self.key_generator.setServiceParent(self)
86.
87. portnum = self.get_portnum()
88. self.listener = self.tub.listenOn(portnum or 'tcp:0')
89. d = self.tub.setLocationAutomatically()
90. if portnum is None:
91. d.addCallback(self.save_portnum)
92. d.addCallback(self.tub_ready, display_furl)
93. d.addErrback(log.err)
94.
95. def get_portnum(self):
96. portnumfile = os.path.join(self.basedir, 'portnum')
97. if os.path.exists(portnumfile):
98. return file(portnumfile, 'rb').read().strip()
99.
100. def save_portnum(self, junk):
101. portnum = self.listener.getPortnum()
102. portnumfile = os.path.join(self.basedir, 'portnum')
103. file(portnumfile, 'wb').write('%d\n' % (portnum,))
104.
105. def tub_ready(self, junk, display_furl):
106. kgf = os.path.join(self.basedir, self.furl_file)
107. self.keygen_furl = self.tub.registerReference(self.key_generator, furlFile=kgf)
108. if display_furl:
109. print 'key generator at:', self.keygen_furl