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
|
'''This module manages ssh key files for bcfg2'''
__revision__ = '$Revision$'
import binascii
import os
import socket
import shutil
import sys
import tempfile
from subprocess import Popen, PIPE
import Bcfg2.Server.Plugin
class SSHbase(Bcfg2.Server.Plugin.Plugin,
Bcfg2.Server.Plugin.Generator,
Bcfg2.Server.Plugin.DirectoryBacked,
Bcfg2.Server.Plugin.PullTarget):
"""
The sshbase generator manages ssh host keys (both v1 and v2)
for hosts. It also manages the ssh_known_hosts file. It can
integrate host keys from other management domains and similarly
export its keys. The repository contains files in the following
formats:
ssh_host_key.H_(hostname) -> the v1 host private key for
(hostname)
ssh_host_key.pub.H_(hostname) -> the v1 host public key
for (hostname)
ssh_host_(dr)sa_key.H_(hostname) -> the v2 ssh host
private key for (hostname)
ssh_host_(dr)sa_key.pub.H_(hostname) -> the v2 ssh host
public key for (hostname)
ssh_known_hosts -> the current known hosts file. this
is regenerated each time a new key is generated.
"""
name = 'SSHbase'
__version__ = '$Id$'
__author__ = 'bcfg-dev@mcs.anl.gov'
pubkeys = ["ssh_host_dsa_key.pub.H_%s",
"ssh_host_rsa_key.pub.H_%s",
"ssh_host_key.pub.H_%s"]
hostkeys = ["ssh_host_dsa_key.H_%s",
"ssh_host_rsa_key.H_%s",
"ssh_host_key.H_%s"]
keypatterns = ["ssh_host_dsa_key",
"ssh_host_rsa_key",
"ssh_host_key",
"ssh_host_dsa_key.pub",
"ssh_host_rsa_key.pub",
"ssh_host_key.pub"]
def __init__(self, core, datastore):
Bcfg2.Server.Plugin.Plugin.__init__(self, core, datastore)
Bcfg2.Server.Plugin.Generator.__init__(self)
Bcfg2.Server.Plugin.PullTarget.__init__(self)
try:
Bcfg2.Server.Plugin.DirectoryBacked.__init__(self, self.data,
self.core.fam)
except OSError:
ioerr = sys.exc_info()[1]
self.logger.error("Failed to load SSHbase repository from %s" \
% (self.data))
self.logger.error(ioerr)
raise Bcfg2.Server.Plugin.PluginInitError
self.Entries = {'Path':
{'/etc/ssh/ssh_known_hosts': self.build_skn,
'/etc/ssh/ssh_host_dsa_key': self.build_hk,
'/etc/ssh/ssh_host_rsa_key': self.build_hk,
'/etc/ssh/ssh_host_dsa_key.pub': self.build_hk,
'/etc/ssh/ssh_host_rsa_key.pub': self.build_hk,
'/etc/ssh/ssh_host_key': self.build_hk,
'/etc/ssh/ssh_host_key.pub': self.build_hk}}
self.ipcache = {}
self.namecache = {}
self.__skn = False
def get_skn(self):
"""Build memory cache of the ssh known hosts file."""
if not self.__skn:
self.__skn = "\n".join([value.data.decode() for key, value in \
list(self.entries.items()) if \
key.endswith('.static')])
names = dict()
# if no metadata is registered yet, defer
if len(self.core.metadata.query.all()) == 0:
self.__skn = False
return self.__skn
for cmeta in self.core.metadata.query.all():
names[cmeta.hostname] = set([cmeta.hostname])
names[cmeta.hostname].update(cmeta.aliases)
newnames = set()
newips = set()
for name in names[cmeta.hostname]:
newnames.add(name.split('.')[0])
try:
newips.add(self.get_ipcache_entry(name)[0])
except:
continue
names[cmeta.hostname].update(newnames)
names[cmeta.hostname].update(cmeta.addresses)
names[cmeta.hostname].update(newips)
# TODO: Only perform reverse lookups on IPs if an option is set.
if True:
for ip in newips:
try:
names[cmeta.hostname].update(self.get_namecache_entry(ip))
except:
continue
names[cmeta.hostname] = sorted(names[cmeta.hostname])
# now we have our name cache
pubkeys = [pubk for pubk in list(self.entries.keys()) \
if pubk.find('.pub.H_') != -1]
pubkeys.sort()
badnames = set()
for pubkey in pubkeys:
hostname = pubkey.split('H_')[1]
if hostname not in names:
if hostname not in badnames:
badnames.add(hostname)
self.logger.error("SSHbase: Unknown host %s; ignoring public keys" % hostname)
continue
self.__skn += "%s %s" % (','.join(names[hostname]),
self.entries[pubkey].data.decode())
return self.__skn
def set_skn(self, value):
"""Set backing data for skn."""
self.__skn = value
skn = property(get_skn, set_skn)
def HandleEvent(self, event=None):
"""Local event handler that does skn regen on pubkey change."""
Bcfg2.Server.Plugin.DirectoryBacked.HandleEvent(self, event)
if event and '_key.pub.H_' in event.filename:
self.skn = False
if event and event.filename.endswith('.static'):
self.skn = False
if not self.__skn:
if (len(list(self.entries.keys()))) >= (len(os.listdir(self.data)) - 1):
_ = self.skn
def HandlesEntry(self, entry, _):
"""Handle key entries dynamically."""
return entry.tag == 'Path' and \
([fpat for fpat in self.keypatterns
if entry.get('name').endswith(fpat)]
or entry.get('name').endswith('ssh_known_hosts'))
def HandleEntry(self, entry, metadata):
"""Bind data."""
if entry.get('name').endswith('ssh_known_hosts'):
return self.build_skn(entry, metadata)
else:
return self.build_hk(entry, metadata)
def get_ipcache_entry(self, client):
"""Build a cache of dns results."""
if client in self.ipcache:
if self.ipcache[client]:
return self.ipcache[client]
else:
raise socket.gaierror
else:
# need to add entry
try:
ipaddr = socket.gethostbyname(client)
self.ipcache[client] = (ipaddr, client)
return (ipaddr, client)
except socket.gaierror:
cmd = "getent hosts %s" % client
ipaddr = Popen(cmd, shell=True, \
stdout=PIPE).stdout.read().strip().split()
if ipaddr:
self.ipcache[client] = (ipaddr, client)
return (ipaddr, client)
self.ipcache[client] = False
self.logger.error("Failed to find IP address for %s" % client)
raise socket.gaierror
def get_namecache_entry(self, cip):
"""Build a cache of name lookups from client IP addresses."""
if cip in self.namecache:
# lookup cached name from IP
if self.namecache[cip]:
return self.namecache[cip]
else:
raise socket.gaierror
else:
# add an entry that has not been cached
try:
rvlookup = socket.gethostbyaddr(cip)
if rvlookup[0]:
self.namecache[cip] = [rvlookup[0]]
else:
self.namecache[cip] = []
self.namecache[cip].extend(rvlookup[1])
return self.namecache[cip]
except socket.gaierror:
self.namecache[cip] = False
self.logger.error("Failed to find any names associated with IP address %s" % cip)
raise
def build_skn(self, entry, metadata):
"""This function builds builds a host specific known_hosts file."""
client = metadata.hostname
entry.text = self.skn
hostkeys = [keytmpl % client for keytmpl in self.pubkeys \
if (keytmpl % client) in self.entries]
hostkeys.sort()
for hostkey in hostkeys:
entry.text += "localhost,localhost.localdomain,127.0.0.1 %s" % (
self.entries[hostkey].data.decode())
permdata = {'owner': 'root',
'group': 'root',
'type': 'file',
'perms': '0644'}
[entry.attrib.__setitem__(key, permdata[key]) for key in permdata]
def build_hk(self, entry, metadata):
"""This binds host key data into entries."""
client = metadata.hostname
filename = "%s.H_%s" % (entry.get('name').split('/')[-1], client)
if filename not in list(self.entries.keys()):
self.GenerateHostKeys(client)
if not filename in self.entries:
self.logger.error("%s still not registered" % filename)
raise Bcfg2.Server.Plugin.PluginExecutionError
keydata = self.entries[filename].data
permdata = {'owner': 'root',
'group': 'root',
'type': 'file'}
if entry.get('name')[-4:] == '.pub':
permdata['perms'] = '0644'
else:
permdata['perms'] = '0600'
permdata['sensitive'] = 'true'
[entry.attrib.__setitem__(key, permdata[key]) for key in permdata]
if "ssh_host_key.H_" == filename[:15]:
entry.attrib['encoding'] = 'base64'
entry.text = binascii.b2a_base64(keydata)
else:
entry.text = keydata
def GenerateHostKeys(self, client):
"""Generate new host keys for client."""
keylist = [keytmpl % client for keytmpl in self.hostkeys]
for hostkey in keylist:
if 'ssh_host_rsa_key.H_' == hostkey[:19]:
keytype = 'rsa'
elif 'ssh_host_dsa_key.H_' == hostkey[:19]:
keytype = 'dsa'
else:
keytype = 'rsa1'
if hostkey not in list(self.entries.keys()):
fileloc = "%s/%s" % (self.data, hostkey)
publoc = self.data + '/' + ".".join([hostkey.split('.')[0],
'pub',
"H_%s" % client])
tempdir = tempfile.mkdtemp()
temploc = "%s/%s" % (tempdir, hostkey)
cmd = 'ssh-keygen -q -f %s -N "" -t %s -C root@%s < /dev/null'
os.system(cmd % (temploc, keytype, client))
shutil.copy(temploc, fileloc)
shutil.copy("%s.pub" % temploc, publoc)
self.AddEntry(hostkey)
self.AddEntry(".".join([hostkey.split('.')[0]] + ['pub', "H_%s" \
% client]))
try:
os.unlink(temploc)
os.unlink("%s.pub" % temploc)
os.rmdir(tempdir)
except OSError:
self.logger.error("Failed to unlink temporary ssh keys")
def AcceptChoices(self, _, metadata):
return [Bcfg2.Server.Plugin.Specificity(hostname=metadata.hostname)]
def AcceptPullData(self, specific, entry, log):
"""Per-plugin bcfg2-admin pull support."""
# specific will always be host specific
filename = "%s/%s.H_%s" % (self.data, entry['name'].split('/')[-1],
specific.hostname)
try:
open(filename, 'w').write(entry['text'])
if log:
print("Wrote file %s" % filename)
except KeyError:
self.logger.error("Failed to pull %s. This file does not currently "
"exist on the client" % entry.get('name'))
|
