Botan: src/cert/x509cert/x509_ext.cpp Source File

Botan 1.10.16

x509_ext.cpp
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1 /*
2 * X.509 Certificate Extensions
3 * (C) 1999-2010 Jack Lloyd
4 *
5 * Distributed under the terms of the Botan license
6 */
7
8 #include <botan/x509_ext.h>
9 #include <botan/sha160.h>
10 #include <botan/der_enc.h>
11 #include <botan/ber_dec.h>
12 #include <botan/oids.h>
13 #include <botan/internal/bit_ops.h>
14 #include <algorithm>
15 #include <memory>
16
17 namespace Botan {
18
19 /*
20 * List of X.509 Certificate Extensions
21 */
22 Certificate_Extension* Extensions::get_extension(const OID& oid)
23 {
24 #define X509_EXTENSION(NAME, TYPE) \
25 if(OIDS::name_of(oid, NAME)) \
26 return new Cert_Extension::TYPE();
27
28 X509_EXTENSION("X509v3.KeyUsage", Key_Usage);
29 X509_EXTENSION("X509v3.BasicConstraints", Basic_Constraints);
30 X509_EXTENSION("X509v3.SubjectKeyIdentifier", Subject_Key_ID);
31 X509_EXTENSION("X509v3.AuthorityKeyIdentifier", Authority_Key_ID);
32 X509_EXTENSION("X509v3.ExtendedKeyUsage", Extended_Key_Usage);
33 X509_EXTENSION("X509v3.IssuerAlternativeName", Issuer_Alternative_Name);
34 X509_EXTENSION("X509v3.SubjectAlternativeName", Subject_Alternative_Name);
35 X509_EXTENSION("X509v3.CRLNumber", CRL_Number);
36 X509_EXTENSION("X509v3.CertificatePolicies", Certificate_Policies);
37 X509_EXTENSION("X509v3.ReasonCode", CRL_ReasonCode);
38
39 return 0;
40 }
41
42 /*
43 * Extensions Copy Constructor
44 */
45 Extensions::Extensions(const Extensions& extensions) : ASN1_Object()
46 {
47 *this = extensions;
48 }
49
50 /*
51 * Extensions Assignment Operator
52 */
53 Extensions& Extensions::operator=(const Extensions& other)
54 {
55 for(size_t i = 0; i != extensions.size(); ++i)
56 delete extensions[i].first;
57 extensions.clear();
58
59 for(size_t i = 0; i != other.extensions.size(); ++i)
60 extensions.push_back(
61 std::make_pair(other.extensions[i].first->copy(),
62 other.extensions[i].second));
63
64 should_throw = other.should_throw;
65
66 return (*this);
67 }
68
69 /*
70 * Return the OID of this extension
71 */
72 OID Certificate_Extension::oid_of() const
73 {
74 return OIDS::lookup(oid_name());
75 }
76
77 void Extensions::add(Certificate_Extension* extn, bool critical)
78 {
79 extensions.push_back(std::make_pair(extn, critical));
80 }
81
82 /*
83 * Encode an Extensions list
84 */
85 void Extensions::encode_into(DER_Encoder& to_object) const
86 {
87 for(size_t i = 0; i != extensions.size(); ++i)
88 {
89 const Certificate_Extension* ext = extensions[i].first;
90 const bool is_critical = extensions[i].second;
91
92 const bool should_encode = ext->should_encode();
93
94 if(should_encode)
95 {
96 to_object.start_cons(SEQUENCE)
97 .encode(ext->oid_of())
98 .encode_optional(is_critical, false)
99 .encode(ext->encode_inner(), OCTET_STRING)
100 .end_cons();
101 }
102 }
103 }
104
105 /*
106 * Decode a list of Extensions
107 */
108 void Extensions::decode_from(BER_Decoder& from_source)
109 {
110 for(size_t i = 0; i != extensions.size(); ++i)
111 delete extensions[i].first;
112 extensions.clear();
113
114 BER_Decoder sequence = from_source.start_cons(SEQUENCE);
115
116 while(sequence.more_items())
117 {
118 OID oid;
119 MemoryVector<byte> value;
120 bool critical;
121
122 sequence.start_cons(SEQUENCE)
123 .decode(oid)
124 .decode_optional(critical, BOOLEAN, UNIVERSAL, false)
125 .decode(value, OCTET_STRING)
126 .verify_end()
127 .end_cons();
128
129 Certificate_Extension* ext = get_extension(oid);
130
131 if(!ext)
132 {
133 if(!critical || !should_throw)
134 continue;
135
136 throw Decoding_Error("Encountered unknown X.509 extension marked "
137 "as critical; OID = " + oid.as_string());
138 }
139
140 ext->decode_inner(value);
141
142 extensions.push_back(std::make_pair(ext, critical));
143 }
144 sequence.verify_end();
145 }
146
147 /*
148 * Write the extensions to an info store
149 */
150 void Extensions::contents_to(Data_Store& subject_info,
151 Data_Store& issuer_info) const
152 {
153 for(size_t i = 0; i != extensions.size(); ++i)
154 extensions[i].first->contents_to(subject_info, issuer_info);
155 }
156
157 /*
158 * Delete an Extensions list
159 */
160 Extensions::~Extensions()
161 {
162 for(size_t i = 0; i != extensions.size(); ++i)
163 delete extensions[i].first;
164 }
165
166 namespace Cert_Extension {
167
168 /*
169 * Checked accessor for the path_limit member
170 */
171 size_t Basic_Constraints::get_path_limit() const
172 {
173 if(!is_ca)
174 throw Invalid_State("Basic_Constraints::get_path_limit: Not a CA");
175 return path_limit;
176 }
177
178 /*
179 * Encode the extension
180 */
181 MemoryVector<byte> Basic_Constraints::encode_inner() const
182 {
183 return DER_Encoder()
184 .start_cons(SEQUENCE)
185 .encode_if(is_ca,
186 DER_Encoder()
187 .encode(is_ca)
188 .encode_optional(path_limit, NO_CERT_PATH_LIMIT)
189 )
190 .end_cons()
191 .get_contents();
192 }
193
194 /*
195 * Decode the extension
196 */
197 void Basic_Constraints::decode_inner(const MemoryRegion<byte>& in)
198 {
199 BER_Decoder(in)
200 .start_cons(SEQUENCE)
201 .decode_optional(is_ca, BOOLEAN, UNIVERSAL, false)
202 .decode_optional(path_limit, INTEGER, UNIVERSAL, NO_CERT_PATH_LIMIT)
203 .verify_end()
204 .end_cons();
205
206 if(is_ca == false)
207 path_limit = 0;
208 }
209
210 /*
211 * Return a textual representation
212 */
213 void Basic_Constraints::contents_to(Data_Store& subject, Data_Store&) const
214 {
215 subject.add("X509v3.BasicConstraints.is_ca", (is_ca ? 1 : 0));
216 subject.add("X509v3.BasicConstraints.path_constraint", path_limit);
217 }
218
219 /*
220 * Encode the extension
221 */
222 MemoryVector<byte> Key_Usage::encode_inner() const
223 {
224 if(constraints == NO_CONSTRAINTS)
225 throw Encoding_Error("Cannot encode zero usage constraints");
226
227 const size_t unused_bits = low_bit(constraints) - 1;
228
229 MemoryVector<byte> der;
230 der.push_back(BIT_STRING);
231 der.push_back(2 + ((unused_bits < 8) ? 1 : 0));
232 der.push_back(unused_bits % 8);
233 der.push_back((constraints >> 8) & 0xFF);
234 if(constraints & 0xFF)
235 der.push_back(constraints & 0xFF);
236
237 return der;
238 }
239
240 /*
241 * Decode the extension
242 */
243 void Key_Usage::decode_inner(const MemoryRegion<byte>& in)
244 {
245 BER_Decoder ber(in);
246
247 BER_Object obj = ber.get_next_object();
248
249 if(obj.type_tag != BIT_STRING || obj.class_tag != UNIVERSAL)
250 throw BER_Bad_Tag("Bad tag for usage constraint",
251 obj.type_tag, obj.class_tag);
252
253 if(obj.value.size() != 2 && obj.value.size() != 3)
254 throw BER_Decoding_Error("Bad size for BITSTRING in usage constraint");
255
256 if(obj.value[0] >= 8)
257 throw BER_Decoding_Error("Invalid unused bits in usage constraint");
258
259 obj.value[obj.value.size()-1] &= (0xFF << obj.value[0]);
260
261 u16bit usage = 0;
262 for(size_t i = 1; i != obj.value.size(); ++i)
263 usage = (obj.value[i] << 8) | usage;
264
265 constraints = Key_Constraints(usage);
266 }
267
268 /*
269 * Return a textual representation
270 */
271 void Key_Usage::contents_to(Data_Store& subject, Data_Store&) const
272 {
273 subject.add("X509v3.KeyUsage", constraints);
274 }
275
276 /*
277 * Encode the extension
278 */
279 MemoryVector<byte> Subject_Key_ID::encode_inner() const
280 {
281 return DER_Encoder().encode(key_id, OCTET_STRING).get_contents();
282 }
283
284 /*
285 * Decode the extension
286 */
287 void Subject_Key_ID::decode_inner(const MemoryRegion<byte>& in)
288 {
289 BER_Decoder(in).decode(key_id, OCTET_STRING).verify_end();
290 }
291
292 /*
293 * Return a textual representation
294 */
295 void Subject_Key_ID::contents_to(Data_Store& subject, Data_Store&) const
296 {
297 subject.add("X509v3.SubjectKeyIdentifier", key_id);
298 }
299
300 /*
301 * Subject_Key_ID Constructor
302 */
303 Subject_Key_ID::Subject_Key_ID(const MemoryRegion<byte>& pub_key)
304 {
305 SHA_160 hash;
306 key_id = hash.process(pub_key);
307 }
308
309 /*
310 * Encode the extension
311 */
312 MemoryVector<byte> Authority_Key_ID::encode_inner() const
313 {
314 return DER_Encoder()
315 .start_cons(SEQUENCE)
316 .encode(key_id, OCTET_STRING, ASN1_Tag(0), CONTEXT_SPECIFIC)
317 .end_cons()
318 .get_contents();
319 }
320
321 /*
322 * Decode the extension
323 */
324 void Authority_Key_ID::decode_inner(const MemoryRegion<byte>& in)
325 {
326 BER_Decoder(in)
327 .start_cons(SEQUENCE)
328 .decode_optional_string(key_id, OCTET_STRING, 0);
329 }
330
331 /*
332 * Return a textual representation
333 */
334 void Authority_Key_ID::contents_to(Data_Store&, Data_Store& issuer) const
335 {
336 if(key_id.size())
337 issuer.add("X509v3.AuthorityKeyIdentifier", key_id);
338 }
339
340 /*
341 * Encode the extension
342 */
343 MemoryVector<byte> Alternative_Name::encode_inner() const
344 {
345 return DER_Encoder().encode(alt_name).get_contents();
346 }
347
348 /*
349 * Decode the extension
350 */
351 void Alternative_Name::decode_inner(const MemoryRegion<byte>& in)
352 {
353 BER_Decoder(in).decode(alt_name);
354 }
355
356 /*
357 * Return a textual representation
358 */
359 void Alternative_Name::contents_to(Data_Store& subject_info,
360 Data_Store& issuer_info) const
361 {
362 std::multimap<std::string, std::string> contents =
363 get_alt_name().contents();
364
365 if(oid_name_str == "X509v3.SubjectAlternativeName")
366 subject_info.add(contents);
367 else if(oid_name_str == "X509v3.IssuerAlternativeName")
368 issuer_info.add(contents);
369 else
370 throw Internal_Error("In Alternative_Name, unknown type " +
371 oid_name_str);
372 }
373
374 /*
375 * Alternative_Name Constructor
376 */
377 Alternative_Name::Alternative_Name(const AlternativeName& alt_name,
378 const std::string& oid_name_str,
379 const std::string& config_name_str)
380 {
381 this->alt_name = alt_name;
382 this->oid_name_str = oid_name_str;
383 this->config_name_str = config_name_str;
384 }
385
386 /*
387 * Subject_Alternative_Name Constructor
388 */
389 Subject_Alternative_Name::Subject_Alternative_Name(
390 const AlternativeName& name) :
391
392 Alternative_Name(name, "X509v3.SubjectAlternativeName",
393 "subject_alternative_name")
394 {
395 }
396
397 /*
398 * Issuer_Alternative_Name Constructor
399 */
400 Issuer_Alternative_Name::Issuer_Alternative_Name(const AlternativeName& name) :
401 Alternative_Name(name, "X509v3.IssuerAlternativeName",
402 "issuer_alternative_name")
403 {
404 }
405
406 /*
407 * Encode the extension
408 */
409 MemoryVector<byte> Extended_Key_Usage::encode_inner() const
410 {
411 return DER_Encoder()
412 .start_cons(SEQUENCE)
413 .encode_list(oids)
414 .end_cons()
415 .get_contents();
416 }
417
418 /*
419 * Decode the extension
420 */
421 void Extended_Key_Usage::decode_inner(const MemoryRegion<byte>& in)
422 {
423 BER_Decoder(in)
424 .start_cons(SEQUENCE)
425 .decode_list(oids)
426 .end_cons();
427 }
428
429 /*
430 * Return a textual representation
431 */
432 void Extended_Key_Usage::contents_to(Data_Store& subject, Data_Store&) const
433 {
434 for(size_t i = 0; i != oids.size(); ++i)
435 subject.add("X509v3.ExtendedKeyUsage", oids[i].as_string());
436 }
437
438 namespace {
439
440 /*
441 * A policy specifier
442 */
443 class Policy_Information : public ASN1_Object
444 {
445 public:
446 OID oid;
447
448 Policy_Information() {}
449 Policy_Information(const OID& oid) : oid(oid) {}
450
451 void encode_into(DER_Encoder& codec) const
452 {
453 codec.start_cons(SEQUENCE)
454 .encode(oid)
455 .end_cons();
456 }
457
458 void decode_from(BER_Decoder& codec)
459 {
460 codec.start_cons(SEQUENCE)
461 .decode(oid)
462 .discard_remaining()
463 .end_cons();
464 }
465 };
466
467 }
468
469 /*
470 * Encode the extension
471 */
472 MemoryVector<byte> Certificate_Policies::encode_inner() const
473 {
474 std::vector<Policy_Information> policies;
475
476 for(size_t i = 0; i != oids.size(); ++i)
477 policies.push_back(oids[i]);
478
479 return DER_Encoder()
480 .start_cons(SEQUENCE)
481 .encode_list(policies)
482 .end_cons()
483 .get_contents();
484 }
485
486 /*
487 * Decode the extension
488 */
489 void Certificate_Policies::decode_inner(const MemoryRegion<byte>& in)
490 {
491 std::vector<Policy_Information> policies;
492
493 BER_Decoder(in)
494 .start_cons(SEQUENCE)
495 .decode_list(policies)
496 .end_cons();
497
498 oids.clear();
499 for(size_t i = 0; i != policies.size(); ++i)
500 oids.push_back(policies[i].oid);
501 }
502
503 /*
504 * Return a textual representation
505 */
506 void Certificate_Policies::contents_to(Data_Store& info, Data_Store&) const
507 {
508 for(size_t i = 0; i != oids.size(); ++i)
509 info.add("X509v3.ExtendedKeyUsage", oids[i].as_string());
510 }
511
512 /*
513 * Checked accessor for the crl_number member
514 */
515 size_t CRL_Number::get_crl_number() const
516 {
517 if(!has_value)
518 throw Invalid_State("CRL_Number::get_crl_number: Not set");
519 return crl_number;
520 }
521
522 /*
523 * Copy a CRL_Number extension
524 */
525 CRL_Number* CRL_Number::copy() const
526 {
527 if(!has_value)
528 throw Invalid_State("CRL_Number::copy: Not set");
529 return new CRL_Number(crl_number);
530 }
531
532 /*
533 * Encode the extension
534 */
535 MemoryVector<byte> CRL_Number::encode_inner() const
536 {
537 return DER_Encoder().encode(crl_number).get_contents();
538 }
539
540 /*
541 * Decode the extension
542 */
543 void CRL_Number::decode_inner(const MemoryRegion<byte>& in)
544 {
545 BER_Decoder(in).decode(crl_number);
546 }
547
548 /*
549 * Return a textual representation
550 */
551 void CRL_Number::contents_to(Data_Store& info, Data_Store&) const
552 {
553 info.add("X509v3.CRLNumber", crl_number);
554 }
555
556 /*
557 * Encode the extension
558 */
559 MemoryVector<byte> CRL_ReasonCode::encode_inner() const
560 {
561 return DER_Encoder()
562 .encode(static_cast<size_t>(reason), ENUMERATED, UNIVERSAL)
563 .get_contents();
564 }
565
566 /*
567 * Decode the extension
568 */
569 void CRL_ReasonCode::decode_inner(const MemoryRegion<byte>& in)
570 {
571 size_t reason_code = 0;
572 BER_Decoder(in).decode(reason_code, ENUMERATED, UNIVERSAL);
573 reason = static_cast<CRL_Code>(reason_code);
574 }
575
576 /*
577 * Return a textual representation
578 */
579 void CRL_ReasonCode::contents_to(Data_Store& info, Data_Store&) const
580 {
581 info.add("X509v3.CRLReasonCode", reason);
582 }
583
584 }
585
586 }
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