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
|
# Authors:
# Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2010 Red Hat
# see file 'COPYING' for use and warranty information
#
# 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 3 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, see <http://www.gnu.org/licenses/>.
import os
import sys
import base64
import nss.nss as nss
from pyasn1.type import univ, char, namedtype, tag
from pyasn1.codec.der import decoder
from ipapython import ipautil
from ipalib import api
PEM = 0
DER = 1
SAN_DNSNAME = 'DNS name'
SAN_OTHERNAME_UPN = 'Other Name (OID.1.3.6.1.4.1.311.20.2.3)'
SAN_OTHERNAME_KRB5PRINCIPALNAME = 'Other Name (OID.1.3.6.1.5.2.2)'
def get_subject(csr, datatype=PEM):
"""
Given a CSR return the subject value.
This returns an nss.DN object.
"""
request = load_certificate_request(csr, datatype)
try:
return request.subject
finally:
del request
def get_extensions(csr, datatype=PEM):
"""
Given a CSR return OIDs of certificate extensions.
The return value is a tuple of strings
"""
request = load_certificate_request(csr, datatype)
return tuple(nss.oid_dotted_decimal(ext.oid_tag)[4:]
for ext in request.extensions)
class _PrincipalName(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('name-type', univ.Integer().subtype(
explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))
),
namedtype.NamedType('name-string', univ.SequenceOf(char.GeneralString()).subtype(
explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 1))
),
)
class _KRB5PrincipalName(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('realm', char.GeneralString().subtype(
explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))
),
namedtype.NamedType('principalName', _PrincipalName().subtype(
explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 1))
),
)
def _decode_krb5principalname(data):
principal = decoder.decode(data, asn1Spec=_KRB5PrincipalName())[0]
realm = (str(principal['realm']).replace('\\', '\\\\')
.replace('@', '\\@'))
name = principal['principalName']['name-string']
name = '/'.join(str(n).replace('\\', '\\\\')
.replace('/', '\\/')
.replace('@', '\\@') for n in name)
name = '%s@%s' % (name, realm)
return name
class _AnotherName(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('type-id', univ.ObjectIdentifier()),
namedtype.NamedType('value', univ.Any().subtype(
explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))
),
)
class _GeneralName(univ.Choice):
componentType = namedtype.NamedTypes(
namedtype.NamedType('otherName', _AnotherName().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0))
),
namedtype.NamedType('rfc822Name', char.IA5String().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 1))
),
namedtype.NamedType('dNSName', char.IA5String().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 2))
),
namedtype.NamedType('x400Address', univ.Sequence().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 3))
),
namedtype.NamedType('directoryName', univ.Choice().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 4))
),
namedtype.NamedType('ediPartyName', univ.Sequence().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 5))
),
namedtype.NamedType('uniformResourceIdentifier', char.IA5String().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 6))
),
namedtype.NamedType('iPAddress', univ.OctetString().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 7))
),
namedtype.NamedType('registeredID', univ.ObjectIdentifier().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 8))
),
)
class _SubjectAltName(univ.SequenceOf):
componentType = _GeneralName()
def get_subjectaltname(csr, datatype=PEM):
"""
Given a CSR return the subjectaltname value, if any.
The return value is a tuple of strings or None
"""
request = load_certificate_request(csr, datatype)
for extension in request.extensions:
if extension.oid_tag == nss.SEC_OID_X509_SUBJECT_ALT_NAME:
break
else:
return None
del request
nss_names = nss.x509_alt_name(extension.value, nss.AsObject)
asn1_names = decoder.decode(extension.value.data,
asn1Spec=_SubjectAltName())[0]
names = []
for nss_name, asn1_name in zip(nss_names, asn1_names):
name_type = nss_name.type_string
if name_type == SAN_OTHERNAME_KRB5PRINCIPALNAME:
name = _decode_krb5principalname(asn1_name['otherName']['value'])
else:
name = nss_name.name
names.append((name_type, name))
return tuple(names)
# Unfortunately, NSS can only parse the extension request attribute, so
# we have to parse friendly name ourselves (see RFC 2986)
class _Attribute(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('type', univ.ObjectIdentifier()),
namedtype.NamedType('values', univ.Set()),
)
class _Attributes(univ.SetOf):
componentType = _Attribute()
class _CertificationRequestInfo(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('version', univ.Integer()),
namedtype.NamedType('subject', univ.Sequence()),
namedtype.NamedType('subjectPublicKeyInfo', univ.Sequence()),
namedtype.OptionalNamedType('attributes', _Attributes().subtype(
implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0)))
)
class _CertificationRequest(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('certificationRequestInfo',
_CertificationRequestInfo()),
namedtype.NamedType('signatureAlgorithm', univ.Sequence()),
namedtype.NamedType('signatureValue', univ.BitString()),
)
_FRIENDLYNAME = univ.ObjectIdentifier('1.2.840.113549.1.9.20')
def get_friendlyname(csr, datatype=PEM):
"""
Given a CSR return the value of the friendlyname attribute, if any.
The return value is a string.
"""
if datatype == PEM:
csr = strip_header(csr)
csr = base64.b64decode(csr)
csr = decoder.decode(csr, asn1Spec=_CertificationRequest())[0]
for attribute in csr['certificationRequestInfo']['attributes']:
if attribute['type'] == _FRIENDLYNAME:
return unicode(attribute['values'][0])
return None
def strip_header(csr):
"""
Remove the header and footer from a CSR.
"""
headerlen = 40
s = csr.find("-----BEGIN NEW CERTIFICATE REQUEST-----")
if s == -1:
headerlen = 36
s = csr.find("-----BEGIN CERTIFICATE REQUEST-----")
if s >= 0:
e = csr.find("-----END")
csr = csr[s+headerlen:e]
return csr
def load_certificate_request(csr, datatype=PEM):
"""
Given a base64-encoded certificate request, with or without the
header/footer, return a request object.
"""
if datatype == PEM:
csr = strip_header(csr)
csr = base64.b64decode(csr)
# A fail-safe so we can always read a CSR. python-nss/NSS will segfault
# otherwise
if not nss.nss_is_initialized():
nss.nss_init_nodb()
return nss.CertificateRequest(csr)
if __name__ == '__main__':
nss.nss_init_nodb()
# Read PEM request from stdin and print out its components
csrlines = sys.stdin.readlines()
csr = ''.join(csrlines)
print load_certificate_request(csr)
print get_subject(csr)
print get_subjectaltname(csr)
print get_friendlyname(csr)
|
