Botan  2.4.0
Crypto and TLS for C++11
ocsp.cpp
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1 /*
2 * OCSP
3 * (C) 2012,2013 Jack Lloyd
4 *
5 * Botan is released under the Simplified BSD License (see license.txt)
6 */
7 
8 #include <botan/ocsp.h>
9 #include <botan/certstor.h>
10 #include <botan/der_enc.h>
11 #include <botan/ber_dec.h>
12 #include <botan/x509_ext.h>
13 #include <botan/oids.h>
14 #include <botan/base64.h>
15 #include <botan/pubkey.h>
16 #include <botan/parsing.h>
17 
18 #if defined(BOTAN_HAS_HTTP_UTIL)
19  #include <botan/http_util.h>
20 #endif
21 
22 namespace Botan {
23 
24 namespace OCSP {
25 
26 namespace {
27 
28 // TODO: should this be in a header somewhere?
29 void decode_optional_list(BER_Decoder& ber,
30  ASN1_Tag tag,
31  std::vector<X509_Certificate>& output)
32  {
33  BER_Object obj = ber.get_next_object();
34 
35  if(obj.type_tag != tag || obj.class_tag != (CONTEXT_SPECIFIC | CONSTRUCTED))
36  {
37  ber.push_back(obj);
38  return;
39  }
40 
41  BER_Decoder list(obj.value);
42 
43  while(list.more_items())
44  {
45  BER_Object certbits = list.get_next_object();
46  X509_Certificate cert(unlock(certbits.value));
47  output.push_back(std::move(cert));
48  }
49  }
50 
51 }
52 
54  const X509_Certificate& subject_cert) :
55  m_issuer(issuer_cert),
56  m_certid(m_issuer, BigInt::decode(subject_cert.serial_number()))
57  {
58  if(subject_cert.issuer_dn() != issuer_cert.subject_dn())
59  throw Invalid_Argument("Invalid cert pair to OCSP::Request (mismatched issuer,subject args?)");
60  }
61 
63  const BigInt& subject_serial) :
64  m_issuer(issuer_cert),
65  m_certid(m_issuer, subject_serial)
66  {
67  }
68 
69 std::vector<uint8_t> Request::BER_encode() const
70  {
73  .start_explicit(0)
74  .encode(static_cast<size_t>(0)) // version #
75  .end_explicit()
78  .encode(m_certid)
79  .end_cons()
80  .end_cons()
81  .end_cons()
83  }
84 
85 std::string Request::base64_encode() const
86  {
88  }
89 
90 Response::Response(const uint8_t response_bits[], size_t response_bits_len) :
91  m_response_bits(response_bits, response_bits + response_bits_len)
92  {
93  BER_Decoder response_outer = BER_Decoder(m_response_bits).start_cons(SEQUENCE);
94 
95  size_t resp_status = 0;
96 
97  response_outer.decode(resp_status, ENUMERATED, UNIVERSAL);
98 
99  if(resp_status != 0)
100  throw Exception("OCSP response status " + std::to_string(resp_status));
101 
102  if(response_outer.more_items())
103  {
104  BER_Decoder response_bytes =
106 
107  response_bytes.decode_and_check(OID("1.3.6.1.5.5.7.48.1.1"),
108  "Unknown response type in OCSP response");
109 
110  BER_Decoder basicresponse =
111  BER_Decoder(response_bytes.get_next_octet_string()).start_cons(SEQUENCE);
112 
113  basicresponse.start_cons(SEQUENCE)
114  .raw_bytes(m_tbs_bits)
115  .end_cons()
116  .decode(m_sig_algo)
117  .decode(m_signature, BIT_STRING);
118  decode_optional_list(basicresponse, ASN1_Tag(0), m_certs);
119 
120  size_t responsedata_version = 0;
121  Extensions extensions;
122 
123  BER_Decoder(m_tbs_bits)
124  .decode_optional(responsedata_version, ASN1_Tag(0),
126 
127  .decode_optional(m_signer_name, ASN1_Tag(1),
129 
130  .decode_optional_string(m_key_hash, OCTET_STRING, 2,
132 
133  .decode(m_produced_at)
134 
135  .decode_list(m_responses)
136 
137  .decode_optional(extensions, ASN1_Tag(1),
139  }
140 
141  response_outer.end_cons();
142  }
143 
145  {
146  try
147  {
148  std::unique_ptr<Public_Key> pub_key(issuer.subject_public_key());
149 
150  const std::vector<std::string> sig_info =
151  split_on(OIDS::lookup(m_sig_algo.get_oid()), '/');
152 
153  if(sig_info.size() != 2 || sig_info[0] != pub_key->algo_name())
155 
156  std::string padding = sig_info[1];
157  Signature_Format format = (pub_key->message_parts() >= 2) ? DER_SEQUENCE : IEEE_1363;
158 
159  PK_Verifier verifier(*pub_key, padding, format);
160 
161  if(verifier.verify_message(ASN1::put_in_sequence(m_tbs_bits), m_signature))
163  else
165  }
166  catch(Exception&)
167  {
169  }
170  }
171 
172 Certificate_Status_Code Response::check_signature(const std::vector<Certificate_Store*>& trusted_roots,
173  const std::vector<std::shared_ptr<const X509_Certificate>>& ee_cert_path) const
174  {
175  std::shared_ptr<const X509_Certificate> signing_cert;
176 
177  for(size_t i = 0; i != trusted_roots.size(); ++i)
178  {
179  if(m_signer_name.empty() && m_key_hash.empty())
181 
182  if(!m_signer_name.empty())
183  {
184  signing_cert = trusted_roots[i]->find_cert(m_signer_name, std::vector<uint8_t>());
185  if(signing_cert)
186  {
187  break;
188  }
189  }
190 
191  if(m_key_hash.size() > 0)
192  {
193  signing_cert = trusted_roots[i]->find_cert_by_pubkey_sha1(m_key_hash);
194  if(signing_cert)
195  {
196  break;
197  }
198  }
199  }
200 
201  if(!signing_cert && ee_cert_path.size() > 1)
202  {
203  // End entity cert is not allowed to sign their own OCSP request :)
204  for(size_t i = 1; i < ee_cert_path.size(); ++i)
205  {
206  // Check all CA certificates in the (assumed validated) EE cert path
207  if(!m_signer_name.empty() && ee_cert_path[i]->subject_dn() == m_signer_name)
208  {
209  signing_cert = ee_cert_path[i];
210  break;
211  }
212 
213  if(m_key_hash.size() > 0 && ee_cert_path[i]->subject_public_key_bitstring_sha1() == m_key_hash)
214  {
215  signing_cert = ee_cert_path[i];
216  break;
217  }
218  }
219  }
220 
221  if(!signing_cert && m_certs.size() > 0)
222  {
223  for(size_t i = 0; i < m_certs.size(); ++i)
224  {
225  // Check all CA certificates in the (assumed validated) EE cert path
226  if(!m_signer_name.empty() && m_certs[i].subject_dn() == m_signer_name)
227  {
228  signing_cert = std::make_shared<const X509_Certificate>(m_certs[i]);
229  break;
230  }
231 
232  if(m_key_hash.size() > 0 && m_certs[i].subject_public_key_bitstring_sha1() == m_key_hash)
233  {
234  signing_cert = std::make_shared<const X509_Certificate>(m_certs[i]);
235  break;
236  }
237  }
238  }
239 
240  if(!signing_cert)
242 
243  if(!signing_cert->allowed_usage(CRL_SIGN) &&
244  !signing_cert->allowed_extended_usage("PKIX.OCSPSigning"))
245  {
247  }
248 
249  return this->verify_signature(*signing_cert);
250  }
251 
253  const X509_Certificate& subject,
254  std::chrono::system_clock::time_point ref_time) const
255  {
256  for(const auto& response : m_responses)
257  {
258  if(response.certid().is_id_for(issuer, subject))
259  {
260  X509_Time x509_ref_time(ref_time);
261 
262  if(response.cert_status() == 1)
264 
265  if(response.this_update() > x509_ref_time)
267 
268  if(response.next_update().time_is_set() && x509_ref_time > response.next_update())
270 
271  if(response.cert_status() == 0)
273  else
275  }
276  }
277 
279  }
280 
281 #if defined(BOTAN_HAS_HTTP_UTIL)
282 
283 Response online_check(const X509_Certificate& issuer,
284  const BigInt& subject_serial,
285  const std::string& ocsp_responder,
286  Certificate_Store* trusted_roots,
287  std::chrono::milliseconds timeout)
288  {
289  if(ocsp_responder.empty())
290  throw Invalid_Argument("No OCSP responder specified");
291 
292  OCSP::Request req(issuer, subject_serial);
293 
294  auto http = HTTP::POST_sync(ocsp_responder,
295  "application/ocsp-request",
296  req.BER_encode(),
297  1,
298  timeout);
299 
300  http.throw_unless_ok();
301 
302  // Check the MIME type?
303 
304  OCSP::Response response(http.body());
305 
306  std::vector<Certificate_Store*> trusted_roots_vec;
307  trusted_roots_vec.push_back(trusted_roots);
308 
309  if(trusted_roots)
310  response.check_signature(trusted_roots_vec);
311 
312  return response;
313  }
314 
315 
316 Response online_check(const X509_Certificate& issuer,
317  const X509_Certificate& subject,
318  Certificate_Store* trusted_roots,
319  std::chrono::milliseconds timeout)
320  {
321  if(subject.issuer_dn() != issuer.subject_dn())
322  throw Invalid_Argument("Invalid cert pair to OCSP::online_check (mismatched issuer,subject args?)");
323 
324  return online_check(issuer,
325  BigInt::decode(subject.serial_number()),
326  subject.ocsp_responder(),
327  trusted_roots,
328  timeout);
329  }
330 
331 #endif
332 
333 }
334 
335 }
std::vector< uint8_t > get_contents_unlocked()
Definition: der_enc.h:27
bool verify_message(const uint8_t msg[], size_t msg_length, const uint8_t sig[], size_t sig_length)
Definition: pubkey.cpp:281
bool empty() const
Definition: x509_dn.h:56
std::vector< std::string > split_on(const std::string &str, char delim)
Definition: parsing.cpp:142
Response POST_sync(const std::string &url, const std::string &content_type, const std::vector< uint8_t > &body, size_t allowable_redirects, std::chrono::milliseconds timeout)
Definition: http_util.cpp:242
BER_Decoder & decode_optional_string(std::vector< uint8_t, Alloc > &out, ASN1_Tag real_type, uint16_t type_no, ASN1_Tag class_tag=CONTEXT_SPECIFIC)
Definition: ber_dec.h:179
BER_Decoder & decode_and_check(const T &expected, const std::string &error_msg)
Definition: ber_dec.h:163
Signature_Format
Definition: pubkey.h:27
Public_Key * subject_public_key() const
Definition: x509cert.h:49
BER_Decoder & decode(bool &v)
Definition: ber_dec.cpp:355
DER_Encoder & end_explicit()
Definition: der_enc.cpp:173
std::string to_string(const BER_Object &obj)
Definition: asn1_obj.cpp:108
ASN1_Tag
Definition: asn1_obj.h:22
BER_Decoder & raw_bytes(std::vector< uint8_t, Alloc > &out)
Definition: ber_dec.h:73
DER_Encoder & end_cons()
Definition: der_enc.cpp:146
std::string ocsp_responder() const
Definition: x509cert.cpp:543
DER_Encoder & encode(bool b)
Definition: der_enc.cpp:202
BER_Decoder & decode_optional(T &out, ASN1_Tag type_tag, ASN1_Tag class_tag, const T &default_value=T())
Definition: ber_dec.h:230
std::string base64_encode() const
Definition: ocsp.cpp:85
Certificate_Status_Code status_for(const X509_Certificate &issuer, const X509_Certificate &subject, std::chrono::system_clock::time_point ref_time=std::chrono::system_clock::now()) const
Definition: ocsp.cpp:252
const X509_DN & subject_dn() const
Definition: x509cert.cpp:415
size_t base64_encode(char out[], const uint8_t in[], size_t input_length, size_t &input_consumed, bool final_inputs)
Definition: base64.cpp:35
BER_Decoder & end_cons()
Definition: ber_dec.cpp:265
Certificate_Status_Code verify_signature(const X509_Certificate &issuer) const
Definition: ocsp.cpp:144
secure_vector< uint8_t > decode(DataSource &source, std::string &label)
Definition: pem.cpp:68
const X509_DN & issuer_dn() const
Definition: x509cert.cpp:410
BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
Definition: ber_dec.cpp:251
Definition: alg_id.cpp:13
std::vector< uint8_t > put_in_sequence(const std::vector< uint8_t > &contents)
Definition: asn1_obj.cpp:96
Request(const X509_Certificate &issuer_cert, const X509_Certificate &subject_cert)
Definition: ocsp.cpp:53
std::vector< T > unlock(const secure_vector< T > &in)
Definition: secmem.h:95
const OID & get_oid() const
Definition: alg_id.h:37
std::vector< uint8_t > BER_encode() const
Definition: ocsp.cpp:69
DER_Encoder & start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag=UNIVERSAL)
Definition: der_enc.cpp:136
BER_Decoder & decode_list(std::vector< T > &out, ASN1_Tag type_tag=SEQUENCE, ASN1_Tag class_tag=UNIVERSAL)
Definition: ber_dec.h:289
const std::vector< uint8_t > & serial_number() const
Definition: x509cert.cpp:399
Certificate_Status_Code
Definition: cert_status.h:18
std::vector< uint8_t > get_next_octet_string()
Definition: ber_dec.cpp:384
bool more_items() const
Definition: ber_dec.cpp:166
std::string lookup(const OID &oid)
Definition: oids.cpp:18
static BigInt decode(const uint8_t buf[], size_t length, Base base=Binary)
Definition: big_code.cpp:114
DER_Encoder & start_explicit(uint16_t type_tag)
Definition: der_enc.cpp:160
Certificate_Status_Code check_signature(const std::vector< Certificate_Store *> &trust_roots, const std::vector< std::shared_ptr< const X509_Certificate >> &cert_path={}) const
Definition: ocsp.cpp:172