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
|
#!/usr/bin/python
#
from pyasn1.codec.der import decoder, encoder
from pyasn1_modules import rfc2560, rfc2459, pem
from pyasn1.type import univ
import sys, hashlib
try:
import urllib2
except ImportError:
import urllib.request as urllib2
sha1oid = univ.ObjectIdentifier((1, 3, 14, 3, 2, 26))
class ValueOnlyBitStringEncoder(encoder.encoder.BitStringEncoder):
# These methods just do not encode tag and length fields of TLV
def encodeTag(self, *args): return ''
def encodeLength(self, *args): return ''
def encodeValue(*args):
substrate, isConstructed = encoder.encoder.BitStringEncoder.encodeValue(*args)
# OCSP-specific hack follows: cut off the "unused bit count"
# encoded bit-string value.
return substrate[1:], isConstructed
def __call__(self, bitStringValue):
return self.encode(None, bitStringValue, defMode=1, maxChunkSize=0)
valueOnlyBitStringEncoder = ValueOnlyBitStringEncoder()
def mkOcspRequest(issuerCert, userCert):
issuerTbsCertificate = issuerCert.getComponentByName('tbsCertificate')
issuerSubject = issuerTbsCertificate.getComponentByName('subject')
userTbsCertificate = userCert.getComponentByName('tbsCertificate')
userIssuer = userTbsCertificate.getComponentByName('issuer')
assert issuerSubject == userIssuer, '%s\n%s' % (
issuerSubject.prettyPrint(), userIssuer.prettyPrint()
)
userIssuerHash = hashlib.sha1(
encoder.encode(userIssuer)
).digest()
issuerSubjectPublicKey = issuerTbsCertificate.getComponentByName('subjectPublicKeyInfo').getComponentByName('subjectPublicKey')
issuerKeyHash = hashlib.sha1(
valueOnlyBitStringEncoder(issuerSubjectPublicKey)
).digest()
userSerialNumber = userTbsCertificate.getComponentByName('serialNumber')
# Build request object
request = rfc2560.Request()
reqCert = request.setComponentByName('reqCert').getComponentByName('reqCert')
hashAlgorithm = reqCert.setComponentByName('hashAlgorithm').getComponentByName('hashAlgorithm')
hashAlgorithm.setComponentByName('algorithm', sha1oid)
reqCert.setComponentByName('issuerNameHash', userIssuerHash)
reqCert.setComponentByName('issuerKeyHash', issuerKeyHash)
reqCert.setComponentByName('serialNumber', userSerialNumber)
ocspRequest = rfc2560.OCSPRequest()
tbsRequest = ocspRequest.setComponentByName('tbsRequest').getComponentByName('tbsRequest')
tbsRequest.setComponentByName('version', 'v1')
requestList = tbsRequest.setComponentByName('requestList').getComponentByName('requestList')
requestList.setComponentByPosition(0, request)
return ocspRequest
def parseOcspRequest(ocspRequest):
tbsRequest = ocspRequest['responseStatus']
assert responseStatus == rfc2560.OCSPResponseStatus('successful'), responseStatus.prettyPrint()
responseBytes = ocspResponse.getComponentByName('responseBytes')
responseType = responseBytes.getComponentByName('responseType')
assert responseType == id_pkix_ocsp_basic, responseType.prettyPrint()
response = responseBytes.getComponentByName('response')
basicOCSPResponse, _ = decoder.decode(
response, asn1Spec=rfc2560.BasicOCSPResponse()
)
tbsResponseData = basicOCSPResponse.getComponentByName('tbsResponseData')
response0 = tbsResponseData.getComponentByName('responses').getComponentByPosition(0)
return (
tbsResponseData.getComponentByName('producedAt'),
response0.getComponentByName('certID'),
response0.getComponentByName('certStatus').getName(),
response0.getComponentByName('thisUpdate')
)
if len(sys.argv) != 2:
print("""Usage:
$ cat CACertificate.pem userCertificate.pem | %s <ocsp-responder-url>""" % sys.argv[0])
sys.exit(-1)
else:
ocspUrl = sys.argv[1]
# Parse CA and user certificates
issuerCert, _ = decoder.decode(
pem.readPemFromFile(sys.stdin)[1],
asn1Spec=rfc2459.Certificate()
)
userCert, _ = decoder.decode(
pem.readPemFromFile(sys.stdin)[1],
asn1Spec=rfc2459.Certificate()
)
# Build OCSP request
ocspReq = mkOcspRequest(issuerCert, userCert)
# Use HTTP POST to get response (see Appendix A of RFC 2560)
# In case you need proxies, set the http_proxy env variable
httpReq = urllib2.Request(
ocspUrl,
encoder.encode(ocspReq),
{ 'Content-Type': 'application/ocsp-request' }
)
httpRsp = urllib2.urlopen(httpReq).read()
# Process OCSP response
ocspRsp, _ = decoder.decode(httpRsp, asn1Spec=rfc2560.OCSPResponse())
producedAt, certId, certStatus, thisUpdate = parseOcspResponse(ocspRsp)
print('Certificate ID %s is %s at %s till %s\n' % (
certId.getComponentByName('serialNumber'),
certStatus,
producedAt,
thisUpdate
))
|
